Dysfunctional lens syndrome: a prospective review / Síndrome do cristalino disfuncional: uma revisão prospectiva

ABSTRACT The term dysfunctional lens syndrome has gained acceptance in the field and encompasses natural changes due to aging of crystalline lens. The evolution of diagnostic devices has been a key factor in better staging, understanding and characterizing of these degenerative changes. Even with these technological advances and the use of subjective classifications, such as the classic Lens Opacities Classification System, an objective staging of early dysfunctional lens syndrome has yet to be established. Ocular wavefront aberrometry and objective scatter index, associated with Scheimpflug backscatter densitometry, have proven instrumental in detecting early dysfunctional lens syndrome. Staging of early dysfunctional lens syndrome has been proposed in the literature, but no classification has been recognized worldwide. The purpose of this literature review is to assess the current state of dysfunctional lens syndrome from a technological perspective and propose a new staging system to assist surgeons in making surgical decisions.

RESUMO O termo "síndrome disfuncional do cristalino" tem sido mais aceito na área e engloba mudanças naturais devido ao envelhecimento do cristalino. A evolução dos dispositivos diagnósticos tem sido fator fundamental para melhor estadiamento, compreensão e caracterização dessas alterações. Mesmo com esses avanços tecnológicos e o uso de classificações subjetivas, como o Lens Opacities Classification System , um estadiamento objetivo da síndrome disfuncional do cristalino precoce ainda não foi estabelecido. A aberrometria ocular total e o índice de superfície ocular, associado à densitometria de Scheimpflug, mostraram-se instrumentais na detecção da síndrome disfuncional do cristalino precoce. Embora estadiamentos precoces de síndrome disfuncional do cristalino tenham sido propostos na literatura, nenhum foi reconhecido mundialmente até o momento. O objetivo desta revisão de literatura é avaliar o estado atual da síndrome disfuncional do cristalino a partir de uma perspectiva tecnológica, e propor um novo sistema de estadiamento para auxiliar os cirurgiões na tomada de decisões cirúrgicas.

Clinical Outcomes of Small Incision Lenticule Extraction in Myopia: Study of Vector Parameters and Corneal Aberrations

Comparison of Corneal Astigmatism and Higher-order Aberrations between Color Light-emitting Diode Topographer and Scheimpflug Imager

PURPOSE: To compare corneal astigmatism, keratometry and corneal higher order aberrations between the light emitting diode corneal topography analyzer and Scheimpflug Imager. METHODS: This prospective study involved 45 patients (45 eyes) who visited Seoul St. Mary's hospital before cataract surgery from June 7, 2017, to August 2, 2017. For each eye, keratometry, astigmatism and its axis of cornea, higher-order aberrations were evaluated with a Scheimpflug Imager (Pentacam HR®, Oculus, Wetzlar, Germany) and a color-LED corneal topographer (Cassini®, i-Optics, Den Haag, The Netherlands). RESULTS: Astigmatism magnitude measured using Cassini® and Pentacam® showed no statistically differences but anterior and total astigmatic axes were significantly different, as measured by the two devices (p < 0.05). Anterior and total mean keratometry were statistically significantly different, as measured by the two devices (p < 0.05). J0 and J45 vectors of anterior and total cornea were statistically different (p < 0.05). In addition, Cassini® and Pentacam® showed discrepancies between total corneal astigmatism, total J0 and J45 vectors. Corneal anterior spherical aberration, vertical and horizontal coma, and oblique and horizontal trefoil aberrations were not statistically different between the two devices. CONCLUSIONS: Astigmatic axes obtained from the two devices based on different principles showed statistically significant differences. Astigmatism magnitude was not statistically different but showed a discrepancy between the two devices.

Astigmatismo y aberraciones corneales en ojos con Iridociclitis Heterocrómica de Fuchs / Corneal astigmatism and aberrations in patients with Fuchs heterochromic iridocyclitis

Introducción: La Iridociclitis Heterocrómica de Fuchs (IHF) es la causa del 2 a 7% de las uveítis anteriores, el astigmatismo corneal como condición de la IHF y como posible causa de la disminución de la visión, ha sido una entidad muy poco estudiada hasta el momento, tiene una gran importancia debido a que por la anisometropía que podría generar, puede llevar a alteraciones de la agudeza visual. Objetivo: Evaluar la existencia de astigmatismo corneal y/o aberraciones corneales inherentes a los ojos con Iridociclitis Heterocrómica de Fuchs. Diseño del estudio: Estudio transversal, analítico, de fuentes primarias. Método: Se realizó muestreo por conveniencia, en el cual se incluyeron 44 ojos de 22 pacientes con diagnóstico de IHF unilateral o bilateral. Para cada caso, se realizó tomografía corneal (Pentacam® AXL - OCULUS) y aberrometria (OPD-Scan III® - NIDEK) y se compararon ojos enfermos con los ojos sanos. Resultados: Se encontró una mediana de 1.35 (RIC: 0.50 ­ 1.70) para el astigmatismo de la cara anterior de los ojos enfermos .vs. 0.8 (RIC: 0.7 ­ 1.1) para el astigmatismo de la cara anterior de los ojos sanos (p= 0.135). Se identificó un astigmatismo en cara anterior >1.00 D en el 61.5% de los ojos enfermos .vs. 27.8% de los ojos sanos (p= 0.027) con un RR de 2.15. No se encontró una diferencia estadísticamente significativa entre los ojos enfermos y los ojos sanos para las aberraciones analizadas. Conclusión: El presente estudio no demuestra la existencia de astigmatismo o aberraciones inherentes a la IHF, pero evidencia una tendencia de mayor astigmatismo en los ojos con IHF, que posiblemente podría lograr significancia estadística con una muestra mayor.

Background: Fuchs heterochromic iridocyclitis (FHI) represents 2 to 7% of cases of anterior uveitis. To date, few studies have addressed corneal astigmatism as an inherent condition and as possible cause of decreased visual acuity in FHI patients. This may be relevant since the generated anisometropia may lead to alterations in visual acuity. Objective: To evaluate the presence of corneal astigmatism and/or corneal aberrations in patients with FHI. Study design: Analytic cross sectional study. Method: A convenient sampling was performed. The sample included 44 eyes of 22 patients with unilateral or bilateral FHI. All participants were studied by corneal tomography (Pentacam® AXL ­ OCULUS) and aberrometry (OPDScan III® - NIDEK); measurements of diseased and healthy eyes were compared. Results: Twenty-two patients were enrolled in this study. The mean age at diagnosis was 46.9 +/- 12 years, and 40.9% were men. FHI eyes exhibited a median astigmatism of the anterior surface of 1.35D (IQR: 0.50 ­ 1.70), compared to 0.8D (IQR: 0.7 ­ 1.1) observed in healthy eyes (p= 0.135). Anterior surface astigmatism >1.00 diopters (D) was found in 61.5% of diseased eyes compared to 27.8% of healthy eyes, with a risk ratio of 2.15. Regarding corneal aberrations, no statistically significant differences were identified between diseased and healthy eyes for the analyzed aberrations. Conclusion: While our current data does not show statistically signifi cant differences between groups that support that corneal astigmatism or aberrations are inherent to FHI-aff ected eyes, our study does show a trend that suggests increased presence of clinically relevant astigmatism in eyes with FHI. Statistical significance may be achieved with a larger sample size.

Corneoscleral contact lenses fitting on irregular corneas after laser-assisted in situ keratomileusis / Lentes de contato corneoesclerais adaptadas em córneas irregulares após cirurgia LASIK

ABSTRACT Purpose: We aimed to describe the outcomes of corneoscleral contact lens fitting with multi-aspherical geometry designs in patients with irregular corneas after laser-assisted in situ keratomileusis (LASIK). Methods: This was a retrospective series of 18 patients (age, 26-38 years) selected from an eye clinic database. Participants were required to have unsatisfactory visual acuity with their current contact lenses or spectacles after LASIK for myopia correction. All patients were fitted with corneoscleral contact lenses designed to correct corneal surface irregularities. A diagnostic trial set was used for fitting, and assessments were performed according to a standardized methodology. Subjective comfort, visual acuity, central corneal thickness, endothelial cell count, and corneal-compensated intraocular pressure were evaluated. The follow-up period was one year. Results: Contact lens use was discontinued in 3 patients, thus leaving 24 eyes from 8 females and 7 males for analysis. The fitting characteristics were optimal in terms of lens position and movement. Statistically significant improvements were found in the best spectacle-corrected vision from before fitting to the visual acuity after fitting (p<0.001). Moreover, the patients reported high subjective comfort ratings and usage times (12.98 ± 2.3 hours/day). After one year of wear, visual acuity, subjective comfort, and usage time were maintained. No statistically significant adverse changes developed in the corneas over this period. Conclusion: Corneoscleral contact lenses with a multi-aspherical geometry design provide optimal visual acuity, improved comfort, and prolonged usage times in patients with irregular corneas after LASIK.

RESUMO Objetivo: Descrever os resultados do ajuste de lentes de contato corneoesclerais com geometria multiasférica em pacientes com córneas irregulares após cirurgia de ceratomileuse in situ assistida por laser (LASIK). Métodos: Esta foi uma série retrospectiva de 18 pacientes (idade, 26-38 anos) selecionados a partir de um banco de dados de uma clínica oftalmológica. Os participantes foram escolhidos ao manifestaram acuidade visual insatisfatória com suas lentes de contato ou óculos atuais depois de terem sido submetidos à LASIK para correção de miopia. Todos os pacientes receberam lentes de contato corneoesclerais projetadas para corrigir irregularidades na superficie da córnea. Um conjunto diagnóstico de prova foi usado para a adaptação e as avaliações foram feitas de acordo com uma metodologia padronizada. O conforto subjetivo, a acuidade visual, a espessura central da córnea, a contagem de células endoteliais e a pressão intraocular compensada da córnea foram avaliados. O período de acompanhamento foi de um ano. Resultados: O uso de lentes de contato foi descontinuado em 3 pacientes, deixando 24 olhos de 8 mulheres e 7 homens para análise. As características de adaptação foram ótimas em termos de posição e movimento da lente. Melhorias estatisticamente significativas foram encontradas na melhoria da visão corrigida por óculos antes de se ajustar a acuidade visual após a adaptação (p<0,001). Além disso, os pacientes relataram altos índices subjetivos de conforto e tempo de uso (12,98 ± 2,3 horas/dia). Após um ano de uso, a acuidade visual, o conforto subjetivo e o tempo de uso foram mantidos. Não houve alterações adversas estatisti­camente significativas nas córneas ao longo deste período. Conclusão: As lentes de contato corneoesclerais com projeto geométrico multiasférico proporcionam acuidade visual ideal, maior conforto e tempo de uso prolongado em pacientes com córneas irregulares após o LASIK.

Assessing the accommodation response after near visual tasks using different handheld electronic devices / Avaliação da resposta de acomodação após tarefas visuais próximas usando diferentes dispositivos eletrônicos portáteis

ABSTRACT Purpose: To assess the accommodation response after short reading periods using a tablet and a smartphone as well as determine potential differences in the accommodation response at various stimulus vergences using a Hartmann- Shack aberrometer. Methods: Eighteen healthy subjects with astigmatism of less than 1 D, corrected visual acuity of 20/20 or better, and normal findings in an ophthalmic examination were enrolled. Accommodation responses were obtained under three different conditions: accommodation system of the eye relaxed and visually stressed with a tablet and an smartphone for 10 min, at a distance of 0.25 m from the subject's eyes. Three measurements of accommodation response were monocularly acquired at stimulus vergences ranging from 0 to 4 D (1-D step). Results: No statistically significant differences were found in the accommodation responses among the conditions. A moderate but gradually increasing root mean square, coma-like aberration was found for every condition. Conversely, the spherical aberration decreased as stimulus vergences increased. These outcomes were identified in comparison to the one-to-one ideal accommodation response, implying that a certain lag value was present in all stimulus vergences different from 0 D. Conclusions: The results support the hypothesis that the difference between the ideal and real accommodation responses is mainly attributed to parameters associated with the accommodation process, such as the near visual acuity, depth of focus, pupil diameter, and wavefront aberrations. The wavefront aberrations were dependent on the 3-mm pupil size selected in this study. The accommoda tion response was not dependent on the electronic device employed in each condition, and it was mainly associated with young age and level of amplitude of accommodation of the subjects.

RESUMO Objetivo: Avaliar a resposta de acomodação após períodos de leitura curtos usando um tablet e um smartphone, bem como para determinar potenciais diferenças na resposta de acomodação em estímulos de várias vergências com uma aberrômetro Hartmann-Shack. Método: Dezoito indivíduos saudáveis com astigmatismo inferior a 1 D, apresentando acuidade visual corrigida de 20/20 ou melhor com exame oftalmológico normal foram avaliados. As respostas acomodativas foram obtidas em três condições diferentes: sistema de acomodação com o olho relaxado, e visualmente estressado com um tablet e um smartphone por 10 min, a uma distância de 0,25 m dos olhos dos sujeitos. Três medidas de resposta acomodativa foram obtidas monocularmente com estímulos cujas vergências variaram de 0 a 4 D (intervalos de 1 D). Resultados: Não houve diferença estatisticamente significativa entre as respostas acomodativas em todas as condições. Foi observada moderada aberração do tipo coma com aumento progressivo para cada condição, enquanto houve diminuição da aberração esférica com o aumento das vergências do estímulo. Estes resultados foram identificados em comparação com a resposta acomodativa de um-para-um ideal, o que implica que um certo valor de desfasagem estava presente em todos os estímulos com vergências diferentes de 0 D. Conclusões: Os resultados apoiam a hipótese de que a diferença entre as respostas acomodativas ideal e real é atribuída principalmente a parâmetros tais como a acuidade visual para perto, profundidade de foco, diâmetro pupilar e aberrações de frente de onda, associados ao processo acomodativo. As aberrações de frente de onda foram dependentes do tamanho da pupila de 3 mm, selecionado neste estudo. A resposta acomodativa não foi dependente do dispositivo eletrônico empregue em cada condição e foi associada principalmente à idade jovem e ao nível da amplitude de acomodação dos sujeitos avaliados.

Effect of corneal biomechanical properties on surgically-induced astigmatism and higher-order aberrations after cataract surgery / Efeito das propriedades biomecânicas da córnea no astigmatismo induzido cirurgicamente e nas aberrações de alta ordem após a cirurgia de catarata

ABSTRACT Purpose: To investigate the relationship between biomechanical properties of the cornea and postoperative refractive changes in patients with low-level astigmatism after cataract surgery. Methods: This prospective study recruited patients undergoing cataract surgery involving 2.8-mm superior incisions. Biomechanical properties of the cornea were evaluated preoperatively using the Ocular Response Analyzer, and corneal profiles were evaluated using a Scheimpflug system (Pentacam HR). Topographic astigmatism, total corneal aberrations (TCA) and higher-order corneal aberrations (HOCA) analyses were performed preoperatively and during 1- and 3-month postoperative exams. The incidences of surgically-induced astigmatism (SIA) and HOCAs were calculated using vector analyses. Associations of the preoperative biomechanical properties of the cornea with SIA and HOCAs were evaluated. Results: This study included 28 eyes of 28 patients. The preoperative corneal hysteresis (CH) was 8.68 ± 1.86 mmHg, and the corneal resistance factor (CRF) was 8.66 ± 1.61 mmHg. At the 1-month postoperative evaluation, significant changes were observed in HOCAs (p=0.023), TCAs (p=0.05), astigmatism (p=0.02), and trefoil (p=0.033); in contrast, differences in coma (p=0.386) and spherical aberration (SA) were not significant (p=0.947). At the 3-month visit, significant changes were only observed in TCAs (p=0.02) and HOCAs (p=0.012). No relationships between the preoperative corneal hysteresis and corneal resistance factor and postoperative SIA and HOCA were identified, other than a positive correlation between the 3-month postoperative incidence of corneal hysteresis and spherical aberration. Conclusions: Despite the observed lack of relationships of preoperative biomechanical properties of the cornea with SIA and postoperative aberrations (except for SA), further studies involving larger patient groups are needed to explore the unexpected refractive deviations after cataract surgery.

RESUMO Objetivo: Investigar a relação entre as propriedades biomecânicas da córnea e as mudanças refrativas pós-operatórias em pacientes com baixa astigmatismo após a cirurgia de catarata. Método: Neste estudo prospectivo, recrutamos os pacientes submetidos a cirurgia de catarata com incisões superiores de 2,8 mm. As propriedades biomecânicas da córnea foram avaliadas no pré-operatório pelo Ocular Response Analyzer (ORA, Reichert, EUA) e o perfil corneano foi avaliado por um sistema Scheimpflug (Pentacam HR, Oculus Optikgeräte, GmbH). As avaliações do astigmatismo topográfico e das aberrações corneanas de alta ordem (HOCA) foram feitas no pré-operatório e no 1º e 3º mês pós-operatório. O astigmatismo induzido cirurgicamente (SIA) e aberrações corneanas de alta ordem foram calculados pela análise vetorial. Associações das propriedades biomecânicas da córnea no pré-operatório com astigmatismo induzido cirurgicamente e aberrações corneanas de alta ordem foram avaliadas. Resultados: O estudo foi realizado em 28 olhos de 28 pacientes. A histerese corneana (CH) pré-operatória foi 8,68 ± 1,86 mmHg, e o fator de resistência da córnea (CRF) foi de 8,66 ± 1,61 mmHg. No pós-operatório de 1 mês houve mudanças significativas aberrações corneanas de alta ordem (p=0,023), aberração total (p=0,05), astigmatismo (p=0,02) e trifóglio (p=0,033), mas as diferenças em coma (p=0,386) e aberração esférica (SA) foram insignificantes (p=0,947). No terceiro mês, a única mudança significativa foi em RMS total (p=0,02) e aberração total (p=0,012). Não houve relação entre histerese corneana e o fator de resistência da córnea pré-operatórios e astigmatismo induzido cirurgicamente e aberrações corneanas de alta ordem pós-operatórios, além de uma correlação positiva entre o histerese corneana e o aberração esférica do 3º mês pós-operatório. Conclusões: Apesar de não haver relação entre as propriedades biomecânicas pré-operatórias da córnea e astigmatismo induzido cirurgicamente e aberrações (exceto SA) após a cirurgia em nosso estudo, são necessários mais estudos com grupos de pacientes maiores de explicar os erros refrativos inesperados após a cirurgia de catarata.

Intraocular straylight before and after low myopic photorefractive keratectomy with and without mitomycin C / Dispersão de luz intraocular antes e depois da ceratectomia fotorrefrativa para baixa miopia com e sem mitomicina C

ABSTRACT Purpose: To evaluate ocular straylight before and after photorefractive keratectomy (PRK) for low myopia with and without topical mitomycin (MMC) treatment. Methods: Patients who underwent PRK for low myopia were enrolled into the study. PRK without MMC was performed in 21 eyes (12 patients), whereas PRK with topical 0.02% MMC was performed in 25 eyes (14 patients). Both groups were treated using the NIDEK EC5000 excimer laser. Measurements were performed using the C-Quant straylight meter preoperatively and at two and four months postoperatively. Results: The mean patient age was 30 ± 4 years, and the mean spherical equivalent refractive error was -2.2 ± 0.75 D. The mean preoperative intraocular straylight values were 1.07 ± 0.10 in the PRK without MMC group and 1.07 ± 0.11 log(s) in the PRK with topical MMC group. At two months after surgery, there was a decrease in mean intraocular straylight values in both groups. However, a significant difference was only reached in the PRK with MMC group [0.98 ± 0.09 log(s), p=0.002] compared with preoperative values, which was likely due to a greater scatter of measurements in the PRK without MMC group [1.03 ± 0.13 log(s), p=0.082]. At four months postoperatively, ocular straylight values were not significantly different compared with those at baseline in either the PRK without MMC group [1.02 ± 0.14 log(s), p=0.26] or in the PRK with topical MMC group [1.02 ± 0.11 log(s), p=0.13]. Conclusion: PRK for low myopia decreases ocular straylight, and MMC application further reduces straylight in the early postoperative period. However, ocular straylight values do not significantly differ at four months after surgery compared with those at baseline.

RESUMO Objetivo: Avaliar a dispersão de luz intraocular antes e depois da ceratectomia fotorrefrativa (PRK) para baixa miopia com e sem a aplicação tópica de mitomicina C. Métodos: Pacientes submetidos à PRK para baixa miopia foram selecionados para o estudo. PRK sem MMC foi realizado em 21 olhos (12 pacientes) e PRK com MMC tópica a 0,02% foi realizado em 25 olhos (25 pacientes). Ambos os grupos foram tratados com o excimer laser da Nidek EC5000. Avaliações foram realizadas usando o medidor de dispersão de luz C-Quant no pré-operatório e com 2 e 4 meses de pós-operatório. Resultados: A média de idade dos pacientes foi 30 ± 4 anos e a média do equivalente esférico foi -2,2 ± 0,75 D. As médias da dispersão de luz intraocular no pré-operatório foram 1,07 ± 0,10 no grupo PRK sem MMC e 1,07 ± 0,11 log(s) no grupo PRK com MMC tópica. Após 2 meses da cirurgia houve uma diminuição na média da dispersão de luz intraocular em ambos os grupos. Entretanto uma diferença estatisticamente significante, comparado com os valores pré-operatórios, foi observada apenas no grupo PRK com MMC (0,98 ± 0,09 log(s), p=0,002), provavelmente devido as medidas com maior espalhamento de luz no grupo sem MMC (1,03 ± 0,13 log(s), p=0,082). Após 4 meses de pós-operatório, os valores de dispersão de luz não apresentavam diferença estatisticamente significantes quando comparados com os valores iniciais, tanto no grupo sem MMC (1,02 ± 0,14 log(s), p=0,26) quanto no grupo com MMC tópica (1,02 ± 0,11 log(s), p=0,13). Conclusão: PRK para baixa miopia diminui a dispersão de luz ocular e a aplicação de MMC contribui para uma ainda menor dispersão de luz no período pós-operatório inicial. Entretanto, quatro meses após a cirurgia a dispersão de luz intraocular não é significantemente diferente das medidas pré-operatórias.

Higher Order Aberration and Astigmatism in Children with Hyperopic Amblyopia

PURPOSE: To investigate the changes in corneal higher-order aberration (HOA) during amblyopia treatment and the correlation between HOA and astigmatism in hyperopic amblyopia children. METHODS: In this retrospective study, a total of 72 eyes from 72 patients ranging in age from 38 to 161 months were included. Patients were divided into two groups based on the degree of astigmatism. Corneal HOA was measured using a KR-1W aberrometer at the initial visit and at 3-, 6-, and 12-month follow-ups. Correlation analysis was performed to assess the association between HOA and astigmatism. RESULTS: A total of 72 patients were enrolled in this study, 37 of which were classified as belonging to the higher astigmatism group, while 35 were assigned to the lower astigmatism group. There was a statistically significant difference in success rate between the higher and lower astigmatism groups. In both groups, all corneal HOAs were significantly reduced during amblyopia treatment. When comparing the two groups, a significant difference in coma HOA at the 12-month follow-up was detected (p = 0.043). In the Pearson correlation test, coma HOA at the 12-month follow-up demonstrated a statistically significant correlation with astigmatism and a stronger correlation with astigmatism in the higher astigmatism group than in the lower astigmatism group (coefficient values, 0.383 and 0.284 as well as p = 0.021 and p = 0.038, respectively). CONCLUSIONS: HOA, particularly coma HOA, correlated with astigmatism and could exert effects in cases involving hyperopic amblyopia.

Evaluation of possible factors affecting contrast sensitivity function in patients with primary Sjögren’s syndrome / A avaliação dos possíveis fatores que afetam a função de sensibilidade ao contraste em pacientes com síndrome de Sjögren primária

ABSTRACT Purpose: The contrast sensitivity (CS) function in patients with primary Sjögren’s syndrome (pSS) may be impaired either frequently as a result of dry eye diseases or rarely as a result of optic neuropathy. In this study, we aimed to evaluate the CS function in pSS patients as well as to assess corneal aberrations and thickness of the peripapillary retinal nerve fiber layer (pRNFL). Methods: Fourteen eyes of 14 pSS patients (pSS group) and 14 eyes of 14 healthy participants (control group) were subjected to assessment of CS at the spatial frequencies of 1.5, 3.0, 6.0, 12, and 18 cycles/degree (cpd) using a functional visual acuity contrast test (FACT); measurement of corneal high-order aberrations (HOAs) in terms of coma-like, spherical-like, and total HOAs using Scheimpflug corneal topography; and measurement of the thickness of both the macular ganglion cell-inner plexiform layer (mGCIPL) and pRNFL in all quadrants using optical coherence tomography. None of the participants were under treatment with artificial tears. Results: The results of the CS test did not differ between the 2 groups at all spatial frequencies (p>0.05). In addition, there were no statistically significant differences between the 2 groups in terms of corneal HOAs (p>0.05) and thickness of mGCIPL (p>0.05). However, among all quadrants, only the inferior quadrant of pRNFL in pSS patients was statistically significantly thinner than that in the healthy participants (p=0.04). Conclusions: The CS function in pSS patients can be maintained with normal thickness of both pRNFL and mGCIPL and with lack of increased corneal HOAs, which may be present even in the absence of artificial tear usage. .

RESUMO Objetivo: A função de sensibilidade ao contraste em pacientes com síndrome de Sjögren primário (pSS) pode ser prejudicada, quer frequentemente como resultado de doenças do olho seco, ou mais raramente como um resultado de neuropatia óptica. Neste estudo, objetivamos avaliar a função de sensibilidade ao contraste de pacientes com pSS, além da avaliação das aberrações da córnea e a espessura da camada de fibras nervosas da retina (pRNFL). Métodos: Catorze olhos de 14 pacientes com pSS e 14 olhos de 14 participantes saudáveis foram submetidos, respectivamente, à avaliação do teste de sensibilidade aos contrastes (CS) nas frequências espaciais de 1,5, 3,0, 6,0, 12 e 18 ciclos/grau (cpd), utilizando teste de contraste acuidade visual funcional (FACT); a medida das aberrações de alta ordem da córnea (HOAs) em termos de coma, aberrações esféricas e aberrações totais, utilizando topografia corneana por Scheimpflug; e medida de espessura da camada de macular de células ganglionares plexiforme interna (mGCIPL) e a espessura de pRNFL em todos os quadrantes usando tomografia de coerência óptica. Nenhum dos participantes estava sob tratamento com lágrimas artificiais. Resultados: O teste CS em pacientes pSS não diferiu do que o teste CS em participantes saudáveis em todas as frequências espaciais (p>0,05). Não houve também nenhuma diferença estatisticamente significativa entre os dois grupos em termos de HOAs da córnea (p>0,05), e espessura de mGCIPL (p>0,05). No entanto, entre todos os quadrantes, apenas o quadrante inferior da pRNFL em pacientes pSS foi significativamente mais fino que o quadrante inferior da pRNFL em participantes saudáveis (p=0,04). Conclusões: A função de CS em doentes com pSS pode ser mantida em condições de ambas as espessuras normais de pRNFL e mGCIPL, assim como nas condições de falta de aumento HOAs da córnea, que pode ser mantida, mesmo na ausência do uso de lágrimas artificiais. .

Four-year follow-up of corneal aberrations and visual functionsof myopic patients after laser in situ keratomileusis

Objective: To report on 4-year follow-up of corneal higher-order aberrations and daily visual functions of myopic patients after laser in situ keratomileusis [LASIK]

Methods: One hundred thirty four eyes of 67 patients who underwent LASIK guided by aspherical ablation were included in this study. The vision, corneal spherical aberration [SphA] and Coma were recorded before LASIK and at 6 month and 4 year after LASIK. The evaluation of the questionnaire about daily visual functions was performed by the same physician after LASIK

Results: No eye decreased the BCVA during 4 year follow-up. The effect index and safety index were 1.08 +/- 0.16, 1.11 +/- 0.17 and 1.12 +/- 0.16, 1.13 +/- 0.14 respectively at 6 month and 4 year post-LASIK. After LASIK the corneal SphA and Coma were significantly increased, however the difference between 6 month and 4 year post-LASIK was no statistical significance. Most patients [94.3%-92.4%] felt satisfaction or high satisfaction about the ability to perform each daily visual function after LASIK. Meanwhile there was still about 7.4%-9.2% patients who complained that they could not drive at night. Further analysis showed that the score of driving at night was negative correlation with corneal SphA [r=-0.645, p=0.040; r=-0.688, p=0.040 at 6 month and 4 year post-LASIK respectively]

Conclusions: Our four-year follow-up outcomes indicated that the myopic patients after LASIK had the long-term stable corneal aberration and satisfaction of daily visual functions

Higher order aberrations in amblyopic children and their role in refractory amblyopia / Aberrações de alta ordem em crianças com ambliopia e seu papel na ambliopia refratária

Objective: Some studies have hypothesized that an unfavourable higher order aberrometric profile could act as an amblyogenic mechanism and may be responsible for some amblyopic cases that are refractory to conventional treatment or cases of “idiopathic” amblyopia. This study compared the aberrometric profile in amblyopic children to that of children with normal visual development and compared the aberrometric profile in corrected amblyopic eyes and refractory amblyopic eyes with that of healthy eyes. Methods: Cross-sectional study with three groups of children – the CA group (22 eyes of 11 children with unilateral corrected amblyopia), the RA group (24 eyes of 13 children with unilateral refractory amblyopia) and the C group (28 eyes of 14 children with normal visual development). Higher order aberrations were evaluated using an OPD-Scan III (NIDEK). Comparisons of the aberrometric profile were made between these groups as well as between the amblyopic and healthy eyes within the CA and RA groups. Results: Higher order aberrations with greater impact in visual quality were not significantly higher in the CA and RA groups when compared with the C group. Moreover, there were no statistically significant differences in the higher order aberrometric profile between the amblyopic and healthy eyes within the CA and RA groups. Conclusions: Contrary to lower order aberrations (e.g., myopia, hyperopia, primary astigmatism), higher order aberrations do not seem to be involved in the etiopathogenesis of amblyopia. Therefore, these are likely not the cause of most cases of refractory amblyopia. .

Objetivo: Alguns estudos levantaram a hipótese de que um perfil aberrométrico de alta ordem desfavorável poderia ser um fator ambliogênico, responsável por certos casos de ambliopia “idiopática” ou refratária ao tratamento convencional. Este trabalho tem como objetivos: 1) comparar o perfil aberrométrico de crianças amblíopes com o de crianças com desenvolvimento visual normal; 2) comparar a aberrometria de olhos amblíopes tratados com sucesso/curados e olhos amblíopes refratários ao tratamento convencional com a aberrometria de olhos saudáveis. Métodos: Estudo transversal com três grupos de crianças: grupo CA (22 olhos de 11 crianças com ambliopia unilateral curada), grupo RA (24 olhos de 13 crianças com ambliopia unilateral refratária) e grupo C (28 olhos de 14 crianças com desenvolvimento visual normal). Avaliou-se a aberrometria ocular total utilizando o OPD Scan-III (NIDEK). Comparou-se o perfil aberrométrico dos três grupos de estudo bem como dentro dos grupos CA e RA, o olho amblíope com o saudável. Resultados: As aberrações de alta ordem com maior impacto na qualidade visual não foram significativamente superiores nos grupos CA e RA, comparativamente ao grupo C. Por outro lado, não se encontraram diferenças estatisticamente significativas entre o perfil aberrométrico de alta ordem dos olhos amblíopes e dos olhos sãos dentro dos grupos CA e RA. Conclusão: Contrariamente às aberrações de baixa ordem (miopia, hipermetropia, astigmatismo primário), as de alta ordem não parecem relacionar-se com a etiopatogênese da ambliopia. É também pouco provável que estas sejam a causa da maioria dos casos de ambliopia refratária. .

Intrastromal corneal ring segments: how successful is the surgical treatment of keratoconus?

This review evaluates the outcomes of intrastromal corneal ring segment [ICRS] implantation for the treatment of keratoconus considering a new grading system based on the preoperative visual impairment of the patient. Additionally, a five-year follow-up analysis of patients with stable and progressive keratoconus is performed in order to assess the long term stability of the surgical procedure. Corrected distance visual acuity decreased statistically significantly in patients with mild keratoconus [P < 0.01] but statistically significantly increased in all other grades [P< 0.05]. The improvement in visual acuity and the decrease of keratometric and aberrometric values were stable throughout a long period of time in patients with stable keratoconus. In patients with progressive form keratoconus, a significant improvement was found immediately after the procedure, however clinically relevant regression greater than 3 D was observed at the end of the follow up period

Higher Order Aberrations of the Corneal Surface after Laser Subepithelial Keratomileusis

PURPOSE: To evaluate the changes of higher order aberrations (HOAs) before and after laser subepithelial keratomileusis (LASEK) and to analyze the influence of tear film instability on HOAs of the corneal surface after LASEK. METHODS: In this cross-sectional study, 31 patients who underwent LASEK were divided into dry eye (16 patients, 32 eyes) and non-dry eye groups (15 patients, 30 eyes). Uncorrected distance visual acuity, spherical equivalent refraction, ablation depth, tear film parameters and Ocular Surface Disease Index (OSDI) questionnaire scores were evaluated in both groups. Total HOA root mean square (RMS), third-order coma, third-order trefoil and fourth-order spherical aberration (SA) of the corneal surface immediately and at 10 seconds after blinking were measured before and after surgery. RESULTS: The total HOA RMS, coma, trefoil and SA significantly increased after LASEK compared with preoperative values in both groups. In the dry eye group, total HOA RMS, coma and trefoil significantly increased except for SA at 10 seconds after blinking compared with those measured immediately after blinking. In addition, the changes of total HOA RMS, coma and trefoil were negatively correlated with tear film break-up time (R = -0.420, -0.473 and -0.439, respectively), but positively correlated with OSDI score (R = 0.433, 0.499 and 0.532, respectively). In the non-dry eye group, there were no significant differences between HOAs measured at 10 seconds after blinking and those measured immediately after blinking. CONCLUSIONS: The HOAs including coma, trefoil and SA significantly increased after LASEK. The tear film instability in the dry eye can be associated with more deterioration of the optical quality after LASEK, due to more significant increase of total HOA RMS, coma and trefoil.

Changes in Spherical Aberration after Various Corneal Surface Ablation Techniques

PURPOSE: The corneal change induced by refractive procedures influence both the postoperative refractive status and the ocular spherical aberration (SA). We evaluated changes in corneal SA after three types of surface ablation: phototherapeutic keratectomy (PTK), myopic photorefractive keratectomy (PRK), and myopic wavefront-guided laser epithelial keratomileusis (LASEK). METHODS: Twenty-six eyes (25 patients) were subjected to PTK 26 eyes (14 patients) to PRK, and 34 eyes (17 patients) to wavefront-guided LASEK. Corneal SA was measured with the iTrace in all patients both preoperatively and 6 months postoperatively. RESULTS: Six months after surgery, mean corneal SA was -0.173 +/- 0.171 micrometer in the PTK group, 0.672 +/- 0.200 micrometer in the PRK group, and 0.143 +/- 0.136 micrometer in the wavefront-guided LASEK group. The mean difference between the preoperative and postoperative corneal SA (DeltaSA) was -0.475 micrometer in the PTK group, 0.402 micrometer in the PRK group, and -0.143 micrometer in the wavefront-guided LASEK group. CONCLUSIONS: Surgically induced changes in corneal SA vary with procedure. The prediction of the pattern of SA change induced by various surface ablation procedures may be helpful for developing future surgical procedures.

Changes in Spherical Aberration after Various Corneal Surface Ablation Techniques

PURPOSE: The corneal change induced by refractive procedures influence both the postoperative refractive status and the ocular spherical aberration (SA). We evaluated changes in corneal SA after three types of surface ablation: phototherapeutic keratectomy (PTK), myopic photorefractive keratectomy (PRK), and myopic wavefront-guided laser epithelial keratomileusis (LASEK). METHODS: Twenty-six eyes (25 patients) were subjected to PTK 26 eyes (14 patients) to PRK, and 34 eyes (17 patients) to wavefront-guided LASEK. Corneal SA was measured with the iTrace in all patients both preoperatively and 6 months postoperatively. RESULTS: Six months after surgery, mean corneal SA was -0.173 +/- 0.171 micrometer in the PTK group, 0.672 +/- 0.200 micrometer in the PRK group, and 0.143 +/- 0.136 micrometer in the wavefront-guided LASEK group. The mean difference between the preoperative and postoperative corneal SA (DeltaSA) was -0.475 micrometer in the PTK group, 0.402 micrometer in the PRK group, and -0.143 micrometer in the wavefront-guided LASEK group. CONCLUSIONS: Surgically induced changes in corneal SA vary with procedure. The prediction of the pattern of SA change induced by various surface ablation procedures may be helpful for developing future surgical procedures.

Comparison of wavefront aberrations under cycloplegic, scotopic and photopic conditions using WaveScan / Comparação de aberrações de frente de onda sob cicloplegia, condições escotópica e fotópica usando WaveScan

PURPOSE: To evaluate the differences of wavefront aberrations under cycloplegic, scotopic and photopic conditions. METHODS: A total of 174 eyes of 105 patients were measured using the wavefront sensor (WaveScan® 3.62) under different pupil conditions: cycloplegic 8.58 ± 0.54 mm (6.4 mm - 9.5 mm), scotopic 7.53 ± 0.69 mm (5.7 mm - 9.1 mm) and photopic 6.08 ± 1.14 mm (4.1 mm - 8.8 mm). The pupil diameter, standard Zernike coefficients, root mean square of higher-order aberrations and dominant aberrations were compared between cycloplegic and scotopic conditions, and between scotopic and photopic conditions. RESULTS: The pupil diameter was 7.53 ± 0.69 mm under the scotopic condition, which reached the requirement of about 6.5 mm optical zone design in the wavefront-guided surgery and prevented measurement error due to the pupil centroid shift caused by mydriatics. Pharmacological pupil dilation induced increase of standard Zernike coefficients Z3-3, Z4(0) and Z5-5. The higher-order aberrations, third-order aberration, fourth-order aberration, fifth-order aberration, sixth-order aberration, and spherical aberration increased statistically significantly, compared to the scotopic condition (P<0.010). When the scotopic condition shifted to the photopic condition, the standard Zernike coefficients Z4(0), Z4², Z6-4, Z6-2, Z6² decreased and all the higher-order aberrations decreased statistically significantly (P<0.010), demonstrating that accommodative miosis can significantly improve vision under the photopic condition. Under the three conditions, the vertical coma aberration appears the most frequently within the dominant aberrations without significant effect by pupil size variance, and the proportion of spherical aberrations decreased with the decrease of the pupil size. CONCLUSIONS: The wavefront aberrations are significantly different under cycloplegic, scotopic and photopic conditions. Using the wavefront sensor (VISX WaveScan) to measure scotopic wavefront aberrations is feasible for the wavefront-guided refractive surgery.

OBJETIVO: Avaliar as diferenças de aberrações de frente de onda, em diferentes condições pupilares: sob cicloplegia, escotópica e fotópica. MÉTODOS: Um total de 174 olhos de 105 pacientes foram avaliados utilizando o sensor de frente de onda (WaveScan® 3.62) em diferentes condições pupilares: sob cicloplegia 8,58 ± 0,54 mm (6.4 mm-9.5 mm), escotópica 7,53 ± 0,69 mm (5,7 mm - 9,1 mm) e fotópica 6,08 ± 1,14 mm (4,1 mm - 8,8 mm). Diâmetro da pupila, coeficientes de Zernike, RMS ("Root Mean Square") das aberrações de alta ordem e as aberrações dominantes foram comparados entre as condições sob cicloplegia e escotópica, e entre as condições escotópica e fotópica. RESULTADOS: O diâmetro da pupila foi 7,53 ± 0.69 mm sob a condição escotópica e atingiu a exigência de cerca de 6,5 mm de zona óptica na cirurgia baseada em análise de frentes de ondas, evitando erros de medição consequentes à mudança de centroide pupilar provocada por midriáticos. A dilatação farmacológica da pupila induziu aumento dos coeficientes de Zernike Z3-3, Z4(0) e Z5-5. As aberrações de mais alta ordem (terceira, quarta, quinta e sexta ordem) e a aberração esférica aumentaram de forma estatisticamente significativa, em comparação com a condição escotópica (P<0,010). Quando a condição escotópica se mudou para a condição fotópica, os coeficientes de Zernike Z4(0), Z4², Z6-4, Z6-2, Z6² e todas as aberrações de alta ordem diminuíram de forma estatisticamente significativa (P<0,010), demonstrando que a miose acomodativa pode significativamente melhorar a visão sob a condição fotópica. Sob as três condições, a aberração coma vertical apareceu mais frequentemente dentro das aberrações dominantes, sem influência significativa da variação do tamanho da pupila, e a proporção de aberração esférica diminuiu com a diminuição do tamanho da pupila. CONCLUSÕES: As aberrações de frente de onda são significativamente diferentes sob cicloplegia, condições escotópica e fotópica. O uso do sensor de frentes de onda (VISX WaveScan) para medir as aberrações de frente de onda escotópicas é uma opção viável para a cirurgia refrativa baseada em análise de frentes de onda.

Aberrações ópticas de alta ordem em pacientes com distonias faciais tratados com toxina botulínica / Ocular wavefront aberrations in patients with facial dystonia treated with botulinum toxin

OBJETIVO: Avaliar as aberrações ópticas de alta ordem em pacientes com distonias faciais tratados com toxina botulínica tipo A. MÉTODOS: Pacientes com diagnóstico clínico de espasmo hemifacial ou blefaroespasmo essencial em atividade foram submetidos ao exame biomicroscópico e à análise de frente de ondas através do aberrômetro Alcon LADARvision®, sob midríase medicamentosa. A seguir, foram tratados com injeções de toxina botulínica tipo A. Após um mês, a análise de frente de ondas foi repetida da mesma forma e pelo mesmo oftalmologista. As aberrações de alta ordem foram comparadas antes e após o tratamento. O teste T pareado foi utilizado para comparar os valores numéricos antes e após o tratamento. RESULTADOS: Foram incluídos no estudo um total de 11 pacientes, 6 com blefaroespasmo essencial (54,5 por cento) e 5 com espasmo hemifacial (45,5 por cento). Nos pacientes com espasmo hemifacial foram analisados apenas o lado acometido, totalizando 17 olhos com espasmo. A idade variou de 50 a 72 anos, com média de 65,9 ± 8,2 anos. Oito pacientes eram do sexo feminino (72,7 por cento), sendo a relação masculino/feminino de 1:2,6. A média do "root mean square" (RMS) das aberrações de alta ordem foi 0,68 antes e 0,63 após um mês do tratamento (p=0,01). A média da aberração esférica foi de 0,23 e 0,17 antes e após o tratamento respectivamente (p=0,01). Não houve diferenças estatisticamente significantes nos demais tipos de aberrações de alta ordem após o tratamento (p>0,05). CONCLUSÃO: O tratamento com toxina botulínica A pode diminuir as aberrações esféricas em pacientes com distonias faciais.

PURPOSE: To analyze the ocular wavefront aberrations in patients with facial dystonia treated with botulinum toxin A. METHODS: Patients with benign essential blepharospasm and hemifacial spasm in activity underwent slit lamp examination and bilateral wavefront analysis under pharmacologic mydriasis using Alcon LADARvision® wavefront aberrometry system. After that, all patients were treated with botulinum toxin A injections performed by the same ophthalmologist. After one month, the wavefront analysis was performed in the same way and by the same examiner. The main outcome measure was the change in ocular wavefront aberrations. Paired T-test was used to compare pre and post-injection numeric wavefront values. RESULTS: From a total of 11 patients enrolled in this study, 6 (54.5 percent) had essential blepharospasm and 5 (45.5 percent) had hemifacial spasm. The fellow eyes of patients with hemifacial spasm were not included, totalizing 17 eyes with spasm. Eight patients were female (72.7 percent) and three were male (27.3 percent), the male:female ratio was 1:2.6. The age ranged from 50 to 72 years old with a mean of 65.9 ± 8.2 years. The mean of high order root mean square (RMS) wavefront aberrations was 0.68 before and 0.63 one month after the treatment (p=0.01). Before the treatment, the mean of spherical aberration was 0.23 and decreased to 0.17 one month after the treatment (p=0.01). There was no significant difference in the other higher-order aberrations before and after the treatment (p>0.05). CONCLUSION: The treatment with botulium toxin may decrease spherical aberrations in patients with facial dystonia.

Entendiendo e interpretando las aberraciones ópticas / Understanding and interpreting optical aberrations

Los avances tecnológicos recientes permiten evaluar de manera objetiva y subjetiva la calidad visual. Es por ello que el optómetra como profesional de la salud visual y ocular, en la aplicacióny la práctica clínica, debe tener en cuenta el papel tan importante que desempeña al prescribir una corrección óptica, según la cantidad y calidad en la imagen visual, puesto que determina un factor cuantitativo, como es la agudeza visual desde el punto de vista subjetivo del paciente,y otro cualitativo, como sería la calidad y nitidez con que se pueden ver las imágenes. La óptica física aplicada a la clínica del ojo humano crea la posibilidad de analizar los frentes de onda deluz refractados por los medios transparentes del ojo y con ello ver el comportamiento óptico del sistema dióptrico ocular. Las aberraciones ópticas generadas por la córnea o por el cristalino se definen como las imperfecciones del sistema visual y, por lo tanto, producen en el paciente una imagen retinal defectuosa, limitando su visión.

Recent technological advances make it possible to evaluate visual quality in both an objective and subjective way. It is for this reason that, as visual and ocular health professionals, optometrists must consider the importance of prescribing optical correction based on visual image quantityand quality during their clinical practice, as it determines a quantitative factor, such as visual acuity from the patient’s subjective point of view, and a qualitative factor, such as quality and clarity with which images are seen. Physical optics applied to the human eye creates the possibility of analyzing light wavefronts refracted through the ocular media, making it possible to see the optical behavior of the dioptric system of the eye. Optical aberrations generated by the cornea orthe lens are defined as visual system imperfections, therefore producing defective retinal images in the patient and limiting their vision.