Biocompatibility with the Ocular Surface and Antimicrobial Activity of a New Multi-Purpose Contact Lens Solution / Biocompatibilidad con la superficie ocular y actividad antimicrobiana de una nueva solución multipropósito para lentes de contacto / Biocompatibilidade com a superfície ocular e atividade antimicrobiana de uma nova solução de lentes de contato multipropósito

Abstract Introduction: Multipurpose solutions (MPS) for soft contact lenses (SCL) play an essential role in inhibiting potentially pathogenic agents. Their antimicrobial effectiveness is assessed in vitro and their safety in vivo, with clinical trials that include a combination of different solutions and lens materials. The objective is to assess the biocompatibility of a new SCL MPS produced in Colombia that contains polyhexamethylene biguanide (PHMB) and to determine its antimicrobial activity. Materials and Methods: This was a crossover study with 25 subjects who did not wear lens and who were fitted with different combinations of five SCL materials with either MPS or control physiological saline solution (CS). Corneal thickness, conjunctival hyperemia, corneal staining, and comfort were assessed after two hours of wearing SCL. Antimicrobial effectiveness was measured using ISO 14729 standard assays. Results: When considering SCL material, there was a statistically significant difference between the new MPS and the CS for Comfilcon A (p < 0.05). There was no statistical or clinically significant difference for corneal thickness or corneal staining between the combination of lens material and new MPS with the CS (p > 0.05). After two hours of lens insertion, comfort scores were higher than 7.8. The MPS reduced bacteria colony forming units (CFU) in over 3 log, and fungal CFU in over 1.0 log. Conclusions: The new MPS met the antimicrobial standards of ISO 14729, is considered safe and biocompatible with the ocular surface and retains high comfort levels.

Resumen Introducción: las soluciones multipropósito (SMP) para lentes de contacto blandos (LCB) desempeñan un papel esencial en la inhibición de agentes potencialmente patógenos. Su efectividad antimicrobiana se evalúa in vitro, y su seguridad, in vivo, con ensayos clínicos que incluyen una combinación de diferentes soluciones y materiales para lentes. El objetivo es evaluar la biocompatibilidad de una nueva SMP producida en Colombia que contiene polihexametileno biguanida (PHMB) y determinar su actividad antimicrobiana. Materiales y métodos: estudio cruzado con 25 sujetos no usuarios de lentes, que fueron adaptados con cinco combinaciones diferentes de materiales de LCB con una nueva SMP o solución salina fisiológica de control (CS). El grosor corneal, la hiperemia conjuntival, la tinción corneal y la comodidad se evaluaron después de dos horas de uso del LC. La efectividad antimicrobiana se midió utilizando ensayos estándar ISO 14729. Resultados: considerando el material del LCB, solo hubo una diferencia estadísticamente significativa entre la nueva SMP y el CS para el Comfilcon A (p < 0.05). Tampoco hubo diferencias estadísticamente o clínicamente significativas para el grosor corneal o la tinción corneal, entre la combinación del material del lente y la nueva SMP con el CS (p > 0.05). Después de dos horas de uso del lente, las puntuaciones de confort fueron superiores a 7.8. La SMP redujo las unidades formadoras de colonias (UFC) de bacterias en más de 3 log, y las UFC fúngicas en más de 1.0 log. Conclusiones: la nueva SMP cumplió con los estándares antimicrobianos de ISO 14729, y se considera segura y biocompatible con la superficie ocular, con altos niveles de confort.

Resumo Introdução: as soluções multipropósito (SMP) para lentes de contato macias (LCM) apresentam um papel essencial na inibição de agentes potencialmente patógenos. Sua eficácia como agente antimicrobiano se valia in vitro, e sua segurança, in vivo, como ensaios clínicos que incluem uma combinação de diferentes soluções e materiais para lentes. O objetivo é avaliar a biocompatibilidade de uma nova SMP produzida na Colômbia a base de polihexametileno biguanida (PHMB) e determinar seu potencial antimicrobiano. Materiais e métodos: estudo cruzado com 25 indivíduos não usuários de lentes, que foram adaptados com cinco combinações diferentes de LCM como uma nova SMP ou solução salina fisiológica como controle (CS). A espessura da córnea, a hiperemia conjuntival, a coloração da córnea e a comodidade, foram avaliadas após duas horas de uso da LCB. A eficácia antimicrobiana foi medida com ensaios padrão ISO 14729. Resultados: considerando o material da LCB, houve apenas uma diferença estatisticamente significativa entre a nova SMP e o CS, paro o Comfilcon A (p <0.05). Não houve diferença estatisticamente ou clinicamente significativa para a espessura da córnea ou a coloração da córnea, entre a combinação do material da lente e a nova SMP com o controle CS (p > 0.05). Após duas horas de uso, as pontuações de conforto foram superiores a 7,8. A SMP reduziu as unidades formadoras de colônias (UFC) de bactérias em mais de 3 log, e as UFC fúngicas em mais de 1.0 log. Conclusões: a nova SMP cumpriu com os padrões antimicrobianos ISO 14729, é considerada segura e biocompatível com a superfície ocular, com altos níveis de conforto.

Reabilitação visual com lentes de contato após transplante de córnea / Visual reabilitation with contact lenses after corneal keratoplasty

Resumo A adaptação de lentes de contato após o transplante de córnea tem sido considerada um desafio na reabilitação visual. Atualmente existe a possibilidade de adaptação de lentes de contato de vários tamanhos, diversos desenhos e com diferentes espessuras e materiais, como por exemplo lentes gelatinosas, lentes corneanas rígidas gás-permeáveis, lentes córneo-esclerais, mini esclerais e esclerais. O objetivo deste estudo foi apresentar uma revisão da literatura atual que possa exemplificar a utilização de alguns dos diferentes tipos de lentes de contato que possam ser usadas após o transplante de córnea. Foi realizada uma revisão integrativa da literatura médica na língua inglesa, utilizando como base de dados para a pesquisa, Pubmed e Mendeley. Como critério de inclusão, foi estabelecido a relevância do artigo de acordo com a experiência da equipe. Foram selecionados 26 artigos, com ano de publicação entre 2001 e 2018. Dentre os artigos selecionados, cinco possuem como principal assunto o transplante de córnea, nove artigos sobre lentes de contato em geral, e 12 artigos sobre lentes de contato esclerais ou mini esclerais. Devido a maior transmissibilidade de oxigênio para a córnea, o uso das lentes corneanas rígidas gás-permeáveis mostrou-se mais seguro e com probabilidade de uso por um período maior de tempo.

Abstract Contact lens fitting after corneal transplantation has been considered a challenge in visual rehabilitation. There is currently the possibility of adapting contact lenses of various sizes, various designs and with different thicknesses and materials, such as gelatinous lenses, gas-permeable rigid corneal lenses, corneal-scleral lenses, mini-scleral and scleral lenses. The objective of this study was to present a review of current literature that may exemplify the use of some of the different types of contact lenses that can be used after corneal transplantation. An integrative review of the medical literature in the English language, using as a database for the research, Pubmed and Mendeley. Twenty six articles were selected, with year of publication between 2001 and 2018, as inclusion criterion, the relevance of articles according to the authors' experience was used. Five articles were selected that have as main subject corneal transplantation, nine articles on contact lenses in general, and 12 articles on scleral or mini scleral contact lenses. Due to the greater transmissibility of oxygen to the cornea, the use of rigid gas-permeable corneal lenses was shown to be safer and more likely to be used for a longer period of time.

Effects of two different contact lenses on ocular physiological parameters and tear function tests / Efeitos de duas lentes de contacto diferentes nos parâmetros fisiológicos oculares e nos testes de função lacrimal

Abstract Objective: To investigate the effects of two types of contact lenses made of two different types of silicone hydrogel material on ocular physiological parameters and tear function tests. Methods: The contact lenses with the appropriate diopters were supplied to the volunteering patients. The patients were evaluated before wearing the contact lenses (visit0:V0), at the first month(visit1:V1) and at the thirth month(visit2:V2) following their wear. At all visits a detailed biomicroscopic examination was done, ocular physiological variables were collected, the tear function tests were performed and the tear meniscus area (TMA) was visualized and measured with anterior segment optical coherence tomography (AS-OCT). Results: The results of Schirmer 1 test were 12.07 ± 1.51 [9-16] mm for the right eyes (samfilcon A group) and 12.09 ± 1.5 [9-16] mm for the left eyes (senofilcon A group) at V0. (p=0.950) At V2, the mean Schirmer 1 test results were 11.92±1.34 [9-15] mm in the samfilcon A group and 12.2±1.41 [9-16] mm in the senofilcon A group (p=0.239). The mean TMA dimensions in the AS-OCT images were 338.42±47.1 [241-401] microns in the samfilcon A group and 338.42±47.1 [241-401]microns in the senofilcon A group at V0. (p>0.05). At V2, the mean TMA dimensions were 337.2±45.53 [241-402] microns in thesamfilcon A group and 340.31±48.22 [240-411] microns in the senofilcon A group (p=0.728). Conclusions: Our study has demonstrated that contact lenses containing samfilcon A and senofilcon A silicone hydrogel material do not cause meaningful ocular surface problems.

Resumo Objetivo: Investigar os efeitos de dois tipos de lentes de contacto feitas de dois tipos diferentes de material de hidrogel de silicone nos parâmetros fisiológicos oculares e testes de função lacrimal. Métodos: As lentes de contacto com as dioptrias apropriadas foram fornecidas aos pacientes voluntários. Os pacientes foram avaliados antes do uso das lentes de contacto (visita0: V0), no primeiro mês (visita1: V1) e no terceiro mês (visita2: V2), após o uso destas. Em todas as visitas, foi realizado um exame biomicroscópico detalhado, as variáveis fisiológicas oculares foram recolhidas, os testes de função lacrimal foram realizados e a área do menisco lacrimal (TMA) foi visualizada e medida com tomografia de coerência óptica do segmento anterior (AS-OCT). Resultados: Os resultados do teste de Schirmer 1 foram 12,07 ± 1,51 [9-16] mm para os olhos direitos (grupo samfilcon A) e 12,09 ± 1,5 [9-16] mm para os olhos esquerdos (grupo senofilcon A) em V0. (p = 0,950) Em V2, os resultados médios do teste de Schirmer 1 foram 11,92 ± 1,34 [9-15] mm no grupo samfilcon A e 12,2 ± 1,41 [9-16] mm no grupo senofilcon A (p = 0,239). As dimensões médias do TMA nas imagens AS-OCT foram 338,42 ± 47,1 [241-401] mícrons no grupo samfilcon A e 338,42 ± 47,1 [241-401] mícrons no grupo senofilcon A em V0. (p> 0,05).> Em V2, as dimensões médias do TMA foram 337,2 ± 45,53 [241-402] mícrons no grupo samfilcon A e 340,31 ± 48,22 [240-411] mícrons no grupo senofilcon A (p = 0,728). Conclusões: O nosso estudo demonstrou que as lentes de contacto que contêm material de hidrogel de silicone de samfilcon A e senofilcon A não causam problemas significativos na superfície ocular.

Contact Lens Induced Limbal Stem Cell Deficiency: Clinical Features in Korean Patients

PURPOSE: To describe the clinical features of Korean patients with contact lens-induced limbal stem cell deficiency (CL-LSCD).METHODS: Medical records of 22 patients who were diagnosed with CL-LSCD between 2014 and 2019 were reviewed retrospectively. Outcome measures included demographics, clinical presentation, treatment, clinical course, and pattern of contact lens (CL) wear.RESULTS: Forty-two eyes of 22 patients were found to have typical changes associated with CL-LSCD. Twenty (91%) patients were women and mean age was 36 ± 12 years. All patients had myopia with mean spherical equivalent of −7.52 ± 3.2 diopter. Twenty (91%) patients had bilateral disease and the location of limbal involvement was diffuse in 20 eyes (47.6%) and partial in 22 eyes (52.4%, superior in 20 eyes and inferior in 2 eyes). Fourteen (63.6%) patients complained of decreased visual acuity. Average period of CL wear was 14 ± 9 years. Four patients used cosmetic colored CLs and four patients had a history of overnight CL wear. All 12 patients who completed follow-up (28 ± 42 weeks) showed improvement in visual acuity and ocular surface condition after cessation of CL wear and medical treatment. Of them, five (42%) patients showed full recovery while seven (58%) showed partial recovery.CONCLUSIONS: If a patient with a history of CL wear for an extended period of time presents with decreased visual acuity, practitioners should perform detailed examinations with suspicion of CL-LSCD, including fluorescein staining. CL-LSCD is usually reversible and close follow-up with conservative treatment is recommended as the initial treatment option.

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.

The Effect of Refractive Power on Retinal Volume Measurement Using Spectral Domain Optical Coherence Tomography

PURPOSE: To investigate the change of retinal volume according to anterior segment refractive power using contact lens by spectral domain optical coherence tomography (SD-OCT). METHODS: The retinal volume was measured using a SD-OCT (Heidelberg retinal angiography Spectralis + OCT, Heidelberg Engineering, Heidelberg, Germany) in 60 subjects without any underlying disease. The same examiner performed a 31-section macular volume-scan at 240 µm intervals, re-measured the same area by changing the refractive power of the anterior segment by wearing soft contact lenses of +6.0 diopters and −6.0 diopters. By using the ImageJ software to calculate the cross-sectional area and of the cross-sectional area and the volume was measured. RESULTS: The mean age of the participants was 25.6 ± 1.5 years and the mean axial length was 25.7 ± 1.57 mm. The volume of the posterior pole retina measured without the contact lens was 13.48 ± 0.05 and the mean volume of the retina measured with +6.0 diopter and −6.0 diopter contact lens in the same patient was 13.47 ± 0.07 mm³ and 13.48 ± 0.05 respectively. The mean volume was significantly lower(p = 0.036) in the measurement with the +6.0 diopter lens than in the measurement without the lens, and the mean volume was significantly higher in the measurement with the +6.0 diopter lens (p = 0.042). The change in retinal thickness was increased with longer axial length (r = 0.32, p < 0.05), but the central foveal thickness did not correlate with anterior corneal power (p = 0.463). CONCLUSIONS: The volume of the retina measured using the SD-OCT is affected by the refractive power of the anterior segment and the axial length. Therefore, it is necessary to consider the change of refractive index because it can change the retinal volume measured by SD-OCT.

Influence of Sodium Hyaluronate Concentration on Corneal Aberrations in Soft Contact Lens Wearers

PURPOSE: This study aimed to evaluate the influence of varying concentrations of sodium hyaluronate (SH) eye drops on corneal aberrations in normal individuals wearing silicone hydrogel contact lenses. METHODS: Normal individuals wearing silicone hydrogel contact lenses were enrolled in this study. Subjects were classified into two groups depending on the concentration of the preservative-free SH used (group 1, 0.1% SH; group 2, 0.3% SH). All subjects were asked to blink five times after instillation of the SH eye drop and before the Galilei measurements. Corneal aberrations were measured over the contact lenses before and after SH eye drop instillation. Visual acuity (VA) over the contact lenses was also measured both before instillation of the SH eye drop and after the subjects completed the five blinks. RESULTS: There was no change in VA after SH instillation in group 1; however, group 2′s VA significantly deteriorated after SH instillation. Changes in VA after SH instillation compared to baseline were significantly higher in group 2 than in group 1. Similarly, the increase in corneal aberrations after SH instillation was significant in group 2 but not significant in group 1. Among the significantly increased corneal aberration parameters, defocus was the main type in group 2. Changes in corneal aberrations after SH instillation compared to baseline were significantly higher in group 2 than in group 1. CONCLUSIONS: A 0.3%-concentration of SH increases corneal aberration and decreases VA in soft contact lens wearers. Defocus is the main type of aberration that increased in the 0.3% SH instillation group.

Retrospective study of ocular complication following phacoemulsification with intraocular acrylic lens implantation in dogs / Estudo retrospectivo das complicações oculares em cães submetidos à facoemulsificação com implantação de lente acrílica

The aim of this study was to analyze for 120 days, post-operative complications following bimanual phacoemulsification with implantation of hydrophilic or hydrophobic intraocular acrylic lens. The hospital records of 15 dogs were analyzed, and distributed in two groups, being Gfi and Gfo the hydrophilic intraocular lens and hydrophobic intraocular lens group, respectively. On the first day, both groups presented blepharospasm, conjunctival hyperemia and flare. On day 1, fibrin was slightly apparent in two and three eyes of Gfi and Gfo, and on day 7, present in one and two patients from Gfi and Gfo. Synechia was observed on day 1 in one eye from Gfi and Gfo. Two eyes from Gfi developed from 7 to 120 days, and in Gfo, one eye developed from 7 to 90 days, on day 120, two eyes formed them. The presence of posterior capsule opacity of the lens in all periods, there was no statistical significant between the groups. Only one eye, in Gfo, that had no opacity formation. The intraocular pressure of both groups remained within normal range. There was no statistical significance between hydrophilic and hydrophobic intraocular lens, the use of intraocular lens has led to satisfactory results in visual ability.(AU)

Objetivou-se com o presente estudo avaliar por 120 dias as complicações após a facoemulsificação bimanual com implantação de lentes acrílicas hidrofílicas ou hidrofóbicas. Os prontuários de 15 cães foram avaliados, sendo distribuídos em dois grupos, Gfi e Gfo, grupos com lentes intraoculares hidrofílicas e com lentes hidrofóbicas, respectivamente. No primeiro dia, ambos os grupos apresentaram blefarospasmo, hiperemia conjuntiva e flare. No dia 1, fibrina foi discretamente observada em dois e três olhos do Gfi e Gfo; no dia 7, observou-se em um e três olhos nos pacientes do Gfi e Gfo. Foi observada sinéquia no dia 1 em um olho do Gfi e do Gfo; em dois olhos do Gfi ocorreu do dia 7 ao dia 120. No Gfo apenas um olho teve sinéquia do dia 7 ao dia 90, contudo aos 120 dias, dois olhos formaram-na. A opacidade de cápsula posterior da lente esteve presente em todos os períodos, não havendo diferença estatística entre os grupos. Somente um olho, do Gfo, não teve formação de opacidade. A pressão intraocular foi normal em ambos os grupos. Não houve diferença estatística entre as lentes hidrofílicas e hidrofóbicas. O uso de lentes intraoculares apresentaram resultados satisfatórios na acuidade visual.(AU)

Differentiation of mild keratoconus from corneal warpage according to topographic inferior steepening based on corneal tomography data / Diferenciação de ceratocone leve e deformação corneana por lente de contato com encurvamento inferior baseado em dados da tomografia de córnea

ABSTRACT We report two cases of suspicious asymmetric bow tie and inferior steepening on topographic evaluations with reflection (Placido) and projection (Scheimpflug). Rotating Scheimpflug corneal and anterior segment tomography (Oculus Pentacam HR, Wetzlar, Germany)® was performed in the first case, with a maximal keratometric value (Kmax) of 43.2 D and an overall deviation value from the Belin/Ambrósio Enhanced Ectasia Display (BAD-D) of 1.76, which was observed in the study eye (OD). BAD-D was 6.59 in the fellow eye, which had clinical findings that were consistent with keratoconus stage 2. The second case presented with a Kmax of 45.3 D and BAD-D of 0.76 in OD and 1.01 in OS. This patient had discontinued wearing soft contact lens less than 1 day prior to examination. Corneal tomographic data enabled us to distinguish mild or forme fruste keratoconus from contact lens-induced corneal warpage, and similar findings were observed on curvature maps.

RESUMO O presente estudo tem por objetivo relatar dois casos suspeitos que apresentam bow tie assimétrico e encurvamento inferior nas avaliações topográficas de reflexão (Placido) e projeção (Scheimpflug). A tomografia de córnea e segmento anterior com o sistema Scheimpflug (Oculus Pentacam HR, Wetzlar, Alemanha)® mostrou no primeiro caso, a ceratometria máxima (Kmax) de 43,2 D e o valor D no Belin/Ambrósio Enhanced Ectasia Display (BAD-D) de 1,76 no olho estudado (OD). O olho contralateral apresentava BAD-D de 6,59 e achados clínicos compatíveis com ceratocone (KC) grau 2. O segundo caso apresentava Kmax de 45,3 D e BAD-D de 0,76 em OD e 1,01 em OS. Este paciente havia interrompido o uso de lentes de contato gelatinosas 1 dia antes do exame. A avaliação tomográfica avançada nos permitiu distinguir ceratocone leve ou subclínico de warpage induzido por lentes de contato, enquanto resultados semelhantes foram observados em mapas de curvatura anterior.

Short-term visual performance of soft multifocal contact lenses for presbyopia / Desempenho visual de curto prazo de présbitas usando diferentes lentes de contato multifocais hidrofílicas

ABSTRACT Purpose: To compare visual acuity (VA), contrast sensitivity, stereopsis, and subjective visual performance of Acuvue® Oasys® for Presbyopia (AOP), Air Optix® Aqua Multifocal (AOMF), and Air Optix® Aqua Single Vision (AOSV) lenses in patients with presbyopia. Methods: A single-blinded crossover trial was conducted. Twenty patients with mild presbyopia (add ≤+1.25 D) and 22 with moderate/severe presbyopia (add ≥+1.50 D) who wore lenses bilaterally for 1 h, with a minimum overnight washout period between the use of each lens. Measurements included high- and low-contrast visual acuity (HCVA and LCVA, respectively) at a distance, contrast sensitivity (CS) at a distance, HCVA at intermediate (70 cm) and near (50 cm & 40 cm) distances, stereopsis, and subjective questionnaires regarding vision clarity, ghosting, overall vision satisfaction, and comfort. The test variables were compared among the lens types using repeated-measures ANOVA. Results: Distance variables (HCVA, LCVA, and CS) were significantly worse with multifocal lens than with AOSV lens (p≤0.008), except for AOMF lens in the mild presbyopia group in which no significant difference was observed (p>0.05). Multifocal lenses had significantly greater HCVA at 40 cm than AOSV lens (p≤0.026). AOMF lens had greater intermediate HCVA than AOP lens (p<0.03). AOP lens demonstrated greater improvements in stereopsis than AOMF and AOSV lens in the moderate/severe presbyopia group (p≤0.03). Few significant differences in subjective variables were observed, with no significant difference in the overall vision satisfaction observed between lens types (p>0.05). The proportions of patients willing to buy AOSV, AOMF, and AOP lenses were 20%, 40%, and 50%, respectively, in the mild presbyopia group and 14%, 32%, and 23%, respectively, in the moderate/severe presbyopia group; however, these differences were not statistically significant (p≥0.159). Conclusions: Further development of multifocal lenses is required before significant advantages of multifocal lenses over single vision lens are observed in patients with presbyopia.

RESUMO Objetivo: Comparar a acuidade visual, sensibilidade ao contraste, estereopsia e desempenho visual subjetivo de présbitas usando lentes de contato Acuvue Oasys para presbiopia (AOP), Air Optix Aqua Multifocal (AOMF) e Air Optix Aqua Single Vision (AOSV). Método: Foi realizado estudo mascarado simples, cruzado. Vinte pacientes com presbiopia baixa (adição ≤+1,25 D) e 22 com presbiopia média/alta (adição ≥+1,50 D) usaram cada lente bilateralmente durante 1 hora, com descanso mínimo de uma noite entre as diferentes lentes. As medições incluíram acuidade visual para distância em alto e baixo contraste (HCVA, LCVA), sensibilidade ao contraste para distância (CS), HCVA para distância intermediária (70 cm) e para perto (50 cm e 40 cm), estereopsia e questionários subjetivos sobre nitidez visual, fantasmas, satisfação visão geral e conforto. As variáveis foram comparadas entre os tipos de lentes, utilizando medidas repetidas ANOVA. Resultados: As variáveis para distância (HCVA, LCVA, CS) foram significativamente piores com as multifocais em relação a AOSV (p≤0,008), exceto para AOMF no grupo de baixa adição, que não foi significativamente diferente (p>0,05). As multifocais foram significativamente melhores do que a AOSV para HCVA em 40 cm (p≤0,026). AOMF superou AOP para HCVA intermediária (p<0,03). AOP superou AOMF e AOSV em relação à estereopsia no grupo de presbiopia médio/alto (p≤0,03). Houve poucas diferenças significativas nas variáveis subjetivas, mas a satisfação visual global não foi significativamente diferente entre as lentes (p>0,05). A disposição para comprar lentes AOSV, AOMF e AOP foi: 20%, 40%, 50%, respectivamente, no grupo de presbiopia baixa; 14%, 32%, 23% no grupo de presbiopia média/alto, mas essas diferenças não foram estatisticamente significativas (p≥0,159). Conclusões: Melhorias futuras parecem ser necessárias para produção de uma lente multifocal que forneça aos présbitas uma vantagem significativa sobre a lente de visão única.

Descriptive analysis of the type and design of contact lenses fitted according to keratoconus severity and morphology / Análise descritiva dos tipos e parâmetros das lentes de contato adaptadas de acordo com o grau evolutivo e a morfologia do ceratocone

ABSTRACT Purpose: Keratoconus is characterized by bilateral asymmetrical corneal ectasia that leads to inferior stromal thinning and corneal protrusion. There is currently a lack of consensus regarding the most efficacious method for fitting contact lenses in patients with keratoconus, given the various topographical patterns and evolution grades observed in affected populations. The purpose of the present study was to evaluate the association between keratoconus evolution grade and topography pattern and the type and design of fitted contact lens. Methods: We performed a retrospective analysis of contact lenses fitted in a total of 185 patients with keratoconus (325 eyes). Keratoconus was classified as either grade I, II, III, or IV based on keratometry and cone morphology (nipple, oval, globus, or indeterminate) results. Results: A total of 325 eyes were evaluated in the present study. Of the 62 eyes classified as grade I, 66.1% were fitted with monocurve contact lenses. Of the 162 eyes classified as grade I and II, 51%, 30%, and 19% were fitted with adapted monocurve rigid gas-permeable contact lenses (RGPCL), bicurve lenses, and others lens types, respectively. Bicurve lenses were fitted in 52.1% and 62.2% of eyes classified as grade III and IV, respectively. Of the eyes classified as grade III and IV, monocurve and bicurve RGPCL were fitted in 26% and 55%, respectively. In eyes with oval keratoconus, 45%, 35%, and 20% were fitted with monocurve lenses, bicurve lenses, and other lens types, respectively. In eyes with round cones (nipple morphology), 55%, 30%, and 15% were fitted with bicurve lenses, monocurve lenses, and other lens types, respectively. Conclusion: Monocurve RGPCL were most frequently fitted in patients with mild to moderate keratoconus and oval cones morphology, while bicurve lenses were more frequently fitted in patients with severe and advanced keratoconus. This was probably because bicurve lenses are more appropriate for round cones due to increased corneal asphericity.

RESUMO Objetivo: O ceratocone é uma ectasia corneana bilateral e assimétrica que leva a afinamento corneano inferior e protrusão da córnea, não existe consenso sobre qual é o melhor caminho para adaptar lentes de contato em pacientes com ceratocone, considerando seus diferentes padrões topográficos e graus de evolução. O objetivo desse estudo é associar o grau de evolução e padrão topográfico com o tipo/desenho da lente adaptada. Métodos: Análise retrospectiva das lentes de contato adaptadas em 185 pacientes com ceratocone (325 olhos) no Departamento de Lentes de Contato. O ceratocone foi classificado de acordo com a ceratometria em graus I, II, III e IV e de acordo com a morfologia em cone redondo, oval, globoso e indeterminado. Resultados: Foram avaliados 325 olhos. Em 66,1% dos olhos com grau I foi adaptada lente monocurva. Dos 162 olhos classificados como graus I e II foram adaptadas lentes monocurva em 51%, bicurva em 30% e outros em 19%. Em relação aos olhos grau III, em 52,1% foram adaptadas lentes bicurvas e o mesmo aconteceu em 62,2% dos olhos com grau IV. Apenas 26% dos olhos grau III ou IV receberam lentes monocurva, com necessidade de bicurvas em 55%. 45% dos cones ovais foram adaptados com lentes monocurva, 35% com bicurvas e 20% com outros tipos, enquanto 55% dos cones redondos foram adaptados com lentes bicurvas, apenas 30% com monocurvas e 15% com outros desenhos. Conclusão: Lentes de contato rígida gás-permeável (LCRGP) monocurvas são mais frequentemente utilizadas em ceratocones leves e moderados e em ovais, enquanto bicurvas são mais usadas para casos graves e avançados e em cones redondos.

Intraocular Pressure Sensor Based on a Contact Lens / 生物医学工程学杂志

Intraocular pressure detection has a great significance for understanding the status of eye health, prevention and treatment of diseases such as glaucoma. Traditional intraocular pressure detection needs to be held in the hospital. It is not only time-consuming to doctors and patients, but also difficult to achieve 24 hour-continuous detection. Microminiaturization of the intraocular pressure sensor and wearing it as a contact lens, which is convenient, comfortable and noninvasive, can solve this problem because the soft contact lens with an embedded micro fabricated strain gauge allows the measurement of changes in corneal curvature to correlate to variations of intraocular pressure. We fabricated a strain gauge using micro-electron mechanical systems, and integrated with the contact lens made of polydimethylsiloxane (PDMS) using injection molding. The experimental results showed that the sensitivity was 100. 7 µV/µm. When attached to the corneal surface, the average sensitivity of sensor response of intraocular pressure can be 125.8 µV/mm Hg under the ideal condition.

Paecilomyces Keratitis: Cases in Korea and Literature Review

PURPOSE: To analyze the Paecilomyces keratitis cases in Korea and compare cases from foreign literature. METHODS: The records of 3 patients diagnosed with Paecilomyces keratitis at our hospital and other reported cases in Korea were evaluated to examine the predisposing factors, clinical aspects, antifungal therapy, therapeutic surgery, and visual outcome and compared with previously reported foreign cases. RESULTS: In Korea, 1 patient was female, 4 patients were male and had predisposing factors including prior corneal trauma or surgery, except 1 spontaneous occurrence. All 5 eyes of 5 patients had poor initial visual acuity, less than finger count, and deep corneal infiltration. The patients were treated with multiple topical and systemic antifungal treatments such as intracameral or intrastromal voriconazole injections and required evisceration and penetrating keratoplasty. However, the final outcomes were unsatisfactory. Previously reported cases from foreign literature also had predisposing factors such as corneal surgery, trauma, and soft contact lens use. They were resistant to antifungal therapy and eventually led to surgeries such as penetrating keratoplasty and the final outcomes were poor. CONCLUSIONS: Frequently, Paecilomyces keratitis has direct risk factors and is resistant to many topical and systemic antifungal agents. In the majority of cases, therapeutic surgery was required and the final visual outcomes were poor. When Paecilomyces keratitis is suspected, we suggest aggressive therapy including intracameral and intravitreal injections of voriconazole in the initial treatment.

Comparison and Investigation of the National Standards for Tinted Contact Lenses between Various Countries

PURPOSE: In this study we investigated the safety level of the national standard for tinted soft contact lenses by comparing the standards in various countries. METHODS: To evaluate the current guidelines for tinted soft contact lenses such as form and appearance, diameter, curvature radius, vertex power, cylindrical refractivity and cylindrical axis, luminous/ultraviolet ray (UV) transmittance, moisture content, oxygen permeability coefficient, extractables, elution test, cytotoxicity, sensitization, eye irritation test, acute systemic/subchronic/subacute toxicity, genotoxicity and biocompatibility safety test using rabbit eyes and sterility test. We compared the standards of International Organization for Standardization (ISO), Food and Drug Administration (FDA) of the United States, Ministry of Health, Labor and Welfare (MHLW) of Japan and Ministry of Food and Drug Safety (MFDS) of Korea. RESULTS: The guidelines for tinted soft contact lenses of ISO, FDA and MFDS are similar to soft contact lenses but MHLW of Japan classifies these lenses and sets specific guidelines. First, the oxygen permeability coefficient measured at 6mm from the center should be maintained over 80%. Also, coloring should not affect the oxygen permeability coefficient significantly. Regarding the physical (form and appearance, diameter, curvature radius, moisture content) and optical (vertex power, cylindrical refractivity and cylindrical axis, luminous/UV transmittance, oxygen permeability coefficient) characteristics, no differences were found between ISO and MFDS. However, several differences were found in chemical characteristics (extractables, elution test) and biological stability (cytotoxicity, sensitization, eye irritation test, acute systemic/subchronic/subacute toxicity test, genotoxicity, biocompatibility safety test using rabbit eyes, sterility test). For example, the elution test is required only by MFDS. CONCLUSIONS: The reinvestigation into the effectiveness of the elution test is needed and new evaluation measures including scanning electron microscopy and atomic force microscopy designed for tinted soft contact lenses to evaluate the size of the optical area, the location and roughness of the pigmented layer are required.

Feasibility Research of Determined Oxygen Permeability of Finished Soft Contact Lens / 中国医疗器械杂志

<p><b>OBJECTIVE</b>A method for determined oxygen permeability (Dk) of finished soft contact lens.</p><p><b>METHODS</b>Oxygen permeability(Dk) of 10 group finished soft contact lens was determined by polarographic method, and the values were linearly calibrated using the measured and established Dk values of the specified reference materials.</p><p><b>RESULTS</b>Only one Dk value fell outside of the requirement of GB 11417.3-2012 tolerance for Dk (± 20%).</p><p><b>CONCLUSION</b>It is great practicability when determined the oxygen permeability (Dk) of finished soft contact lens by polarographic method which were linearly calibrated using the measured and established Dk values of the specified equal thickness reference materials without the measured lens customized 4 different thickness.</p>

Artificial pupil versus contralateral balanced contact lens fit for presbyopia correction / Pupila artificial vs adaptação contralateral equilibrada de lentes de contato para correção da presbiopia

Purpose: To assess and compare the effects of contact lens-based artificial pupil design and contralateral balanced multifocal contact lens combination (CBMCLC) on visual performance. Methods: This randomized crossover study conducted at the University of Valencia, Spain included 38 presbyopic patients using an artificial pupil contact lens in the nondominant eye and a CBMCLC. After a month of lens wear, the binocular distance visual acuity (BDVA), binocular near visual acuity (BNVA), defocus curve, binocular distance, and near contrast sensitivity and near stereoacuity (NSA) were measured under photopic conditions (85 cd/m2). Moreover, BDVA and binocular distance contrast sensitivity were examined under mesopic conditions (5 cd/m2). Results: Visual acuity at an intermediate distance and near vision was better with the CBMCLC than with the artificial pupil (p<0.05). Statistically significant differences were found in contrast sensitivity between the two types of correction for distance (under mesopic conditions) and for near vision, with the CBMCLC exhibiting better results in both cases (p<0.05). The mean NSA values obtained for the artificial pupil contact lens were significantly worse than those for the CBMCLC (p=0.001). Conclusion: The CBMCLC provided greater visual performance in terms of intermediate and near vision compared with the artificial pupil contact lens. .

Objetivo: Avaliar e comparar os efeitos da pupila artificial baseada em lentes de contato e a combinação equilibrada de lente de contato multifocal contralateral (CBMCLC) sobre o desempenho visual. Métodos: Estudo realizado na Universidade de Valência, Espanha. Em um projeto de estudo do tipo "cross-over", 38 pacientes présbitas foram avaliados utilizando uma lente de contato com pupila artificial no olho não-dominante e CBMCLC. Após 1 mês, foram avaliadas, em condições fotópicas (85 cd/m2), a acuidade visual binocular para distância (BDVA), a acuidade visual binocular para perto (BNVA), a curva de desfocagem, a sensibilidade ao contraste binocular para distância e para perto, assim como a acuidade estereoscópica para perto (NSA). Além disso, a BDVA e a sensibilidade ao contraste binocular para distância foram avaliadas em condições mesópicas (5 cd/m2). Resultados: A acuidade visual em distâncias intermediárias e para perto foram melhores com CBMCLC do que com pupila artificial (p<0,05). Foram encontradas diferenças estatisticamente significativas entre a sensibilidade ao contraste com os dois tipos de correção para distância (em condições mesópicas) e para perto, com CBMCLC ser melhor em ambos os casos (p<0,05). Os valores médios da NSA obtidos com as lentes de contato das pupilas artificiais foram significativamente piores do que com CBMCLC (p=0,001). Conclusão: CBMCLC proporciona melhor desempenho visual para visão intermediária e para perto do que a lente de contato com pupila artificial. .

A Survey on Contact Lens Care in Young Adolescent Student

PURPOSE: The present study was conducted to gather valid data for promoting public eye health among adolescent contact lens wearers by investigating the current practices of contact lenses wearers. METHODS: A questionnaire regarding use and care of contact lenses was distributed to middle and high school students. A total of 920 students (472 males, 448 females) were enrolled and the purpose of the study was explained to the students. RESULTS: Among all student, 49% had myopia (male 44%, female 54%) and 12% hyperopia (male 12%, female 13%). In addition, 70% of the subjects chose to wear glasses for vision correction, 27% (male 4%, female 50%) reported they have worn contact lenses and 64% of those were soft contact lenses. The age for starting contact lenses was between 14-16 years of age (63%). Most students (95%) purchased their contact lenses from an optical store. Many (89%) cleaned the contact lenses with cleaning solution on a daily basis, however, only 25% of the students received instructions on how to clean the lens properly. Common complaints associated with use in descending order were hyperemia (31%), foreign body sensation (19%), tearing (16%), pruritis (13%), and keratitis (9%). The subjects reported that the main cause of complications was due to the users' lens handling (93%). CONCLUSIONS: The present study findings showed many adolescents have misleading knowledge regarding use of contact lenses. There is a need for better education of young contact lens users regarding the contact lens care.

Changes in Central Corneal Thickness and Corneal Endothelial Morphology in Contact Lens-Wearing Diabetic Patients

PURPOSE: To evaluate the changes in central corneal thickness and corneal endothelium in contact lens-wearing diabetic patients. METHODS: This study included 113 patients who visited the Department of Ophthalmology, Konkuk University Medical Center from August 2006 to August 2007. Ultrasound pachymetry and noncontact specular microscopy were performed on the right eyes of 26 diabetic patients who regularly wore soft contact lenses (group 1), 27 diabetic patients who did not wear soft contact lenses (group 2), 30 soft contact lens-wearers without diabetes mellitus (DM) (group 3), and 30 normal subjects who did not wear soft contact lenses (group 4). Central corneal thickness, corneal endothelial cell density, endothelial cell coefficient of variation, and percentage of hexagonal endothelial cells were compared between the groups. RESULTS: Average duration of diabetes in groups 1 and 2 was 4.38 and 4.41 years, respectively, and average duration of soft contact lens wear in groups 1 and 3 was 5.27 and 3.65 years, respectively. The central cornea was significantly thicker and the endothelial cell density was significantly lower in group 1 than in groups 3 and 4. The cell size coefficient of variation was higher in group 1 than in groups 2 and 4 and higher in group 3 than in group 4. The percentage of hexagonal cells was significantly lower in group 3 than in group 4. CONCLUSIONS: Central corneal thickness and endothelial cell density are more affected by DM than contact lens use, and corneal endothelial cell morphology is influenced more by contact lens use than DM. Contact lens use in diabetic patients significantly influences all characteristics of the corneal endothelium compared with those in normal subjects. Patients with DM should be advised not to wear contact lenses.

Clinical Features and Compliance in Patients with Cosmetic Contact Lens-Related Complications

PURPOSE: To investigate the clinical features and compliance of cosmetic contact lens (CL)-related complications compared with soft CL-related complications. METHODS: We performed a retrospective chart review of 97 patients (194 eyes) regarded as having CL-related complications at the outpatient clinic. The portion of complications, gender, age, and chief complaints at the initial visit were analyzed, as was compliance to cosmetic and soft CL-related guidelines for use. RESULTS: A total of 97 patients (49 patients with cosmetic CL-related complications and 43 patients with soft CL-related complications) were evaluated. The mean age of the subjects using cosmetic CL was 19.8 years (14-31 years), and all the patients were female. The chief complaints at the initial visit included ocular pain, injection, blurred vision, dryness, itching and foreign body sensation. The main complications included corneal erosion, sterile corneal infiltrate, allergic disease, neovascularization, corneal ulcer and dry eye syndrome. No statistical difference was found regarding chief complaints or complications. The proportion of patients lost to follow-up was 47% in cosmetic CL-related and 20% in soft CL-related complications, a significant difference (p = 0.015). CONCLUSIONS: Because young females are the most common CL patients and do not always fully comply with the guidelines for use, ophthalmologists need to warn these patients about the risk of serious complications.

Biometric Risk Factors for Corneal Neovascularization Associated with Hydrogel Soft Contact Lens Wear in Korean Myopic Patients

PURPOSE: To investigate the biometric risk factors for corneal surface complications associated with hydrogel soft contact lens (SCL) fitting in myopic patients in Korea. METHODS: This is a retrospective case-control study. The records of 124 subjects (124 eyes) who wore SCLs on a daily basis were reviewed. Thirty-one patients (31 eyes) who were diagnosed with corneal neovascularization (NV) while wearing SCLs were included in the complication group. Ninety-three age- and sex-matched patients (93 eyes) who wore SCLs, who did not have corneal NV and who visited our clinic for correction of refractive errors were included in the control group. The degree of spherical equivalent, astigmatism and corneal base curve radius (BCR) were compared in both groups. RESULTS: Patients with NV exhibited poorer best corrected visual acuity and more myopia than controls (p = 0.008 and 0.006, respectively). In univariate analysis, highly myopic patients (-9 diopters [D] or higher) were more likely to experience NV (odds ratio [OR], 2.232; 95% confidence interval [CI], 1.602 to 3.105). High astigmatism (> or =2 D) increased the risk of complications (OR, 2.717; 95% CI, 1.141 to 6.451). Steep cornea, in which BCR was <7.5 mm, also raised the risk of complications (OR, 4.000; 95% CI, 1.661 to 9.804). Flat cornea was not a risk factor for the development of NV. CONCLUSIONS: High myopia, high astigmatism, and steep cornea seemed to be risk factors in the development of corneal NV in SCL wearers.