Automated Capsular Decompression to Avoid Argentinian Flag Sign in Intumescent Cataract.

Purpose: We describe an alternative automated technique that consists of simultaneous anterior capsule puncture and decompression of the capsular bag by using an insulin needle attached to the aspiration tubing of the phacoemulsification device to prevent the occurrence of the "Argentinian Flag sign" during capsulorhexis in intumescent cataract. Setting: Instituto de Olhos de Assis and Center of Specialties Hoftalmed, located in the state of São Paulo, Brazil. Design: Prospective interventional study. Methods: Eighty-eight eyes of 88 patients with white or intumescent cataracts were included in this study. Routine clear cornea incision, capsule staining with trypan blue, intracameral anesthesia, and ophthalmic viscoelastic device were used before the procedure. A 26-gauge needle was connected to the phacoemulsification aspiration tubing using a double male Luer connector for irrigation, and aspiration was inserted into the anterior chamber through a new paracentesis incision with the bevel facing down. Immediately after insertion, automated aspiration of the liquefied cortex was performed to remove anterior intralenticular material and achieve capsular decompression. Compression of the nucleus with the needle tip was performed to remove any liquefied material trapped between the posterior surface of the nucleus and the posterior capsule. All surgeries were performed using the same phacoemulsification and parameters. The rate of complete continuous capsulorhexis was observed and noted. Results: No complications were observed in any of the cases. A single-stage, continuous, and well-centered capsulorhexis was achieved in 100% of cases. Conclusion: We conclude that a simultaneous puncture and decompression of the capsular bag using an insulin needle attached to the aspiration tubing of the phacoemulsification machine effectively avoided the "Argentinian Flag sign" in intumescent cataract surgery.

New Device for the Correction of Aphakia Without Capsular Support.

PURPOSE: This study describes a prototype developed for aphakia without capsular support (AWCS) and its proof of concept. METHODS: This descriptive study used a 3D software to create and analyze virtual prototypes before manufacturing. A nylon-6/nylon-6.6 copolymer filament and a 3D printer were used for prototyping. A device implantation technique was developed using a 23-gauge hypodermic needle. Two opposing markings, 2 mm posterior to the limbus, were made to determine the location of the scleral punctures and the final position of the device. After adequate centralization and positioning of the device, its haptics were cut and cauterized to generate thermal modeling of the extremity and allow the thickening of the tips (flange), serving as an anchoring mechanism to the sclera. The efficacy and adequacy of the technique and device were then evaluated. RESULTS: Vitreous tissue extrusion was not observed during the sclerotomy. The device was well fixed to the sclera; however, adequate IOL stability and centralization still needed to be achieved. The surgeon evaluated the adequacy of all the other devices' characteristics. CONCLUSIONS: The development of a technology prototype for correcting AWCS was possible. Although the proposed prototype met most of the established concept guidelines, the stability of the IOL position remains challenging.

Visual rehabilitation after LASIK complication: flap amputation, topo-guided surgery, and phacoemulsification.

We present a case of a patient complaining of monocular diplopia due to a decentered ablation after LASIK. The patient underwent a wavefront-guided retreatment, which resulted in an epithelial ingrowth complication. Additionally, the patient developed cataract, with cataract surgery requiring reliable biometric measurements. Therefore, we opted for corneal treatment and corneal surface regularization. Although we attempted to lift the flap and wash the interface initially, the procedure proved unsuccessful, thereby necessitating immediate flap amputation. Once the corneal surface was regularized in the seventh postoperative month, transepithelial photorefractive keratectomy was successfully performed to homogenize the ocular surface, thereby significantly improving the patient's corrected visual acuity and resolving monocular diplopia. The surface and corneal curvature stabilized by the fifth month after the procedure. Phacoemulsification was then performed along with the implantation of a toric monofocal lens, which was selected using an appropriate formula, resulting in an excellent uncorrected visual acuity.

Ultraviolet-A absorbance analysis in thin porcine corneas pre-and post-crosslinking.

PURPOSE: To determine the absorbance coefficient of the thin porcine cornea to ultraviolet-A radiation (365 nm) submitted for crosslinking. METHODS: This in vitro, benchtop experiment using cadaver tissue study analyzed 12 porcine corneal lamellas, which were obtained using a microkeratome after mechanical de-epithelization and separated into three thickness groups: 180, 300, and 360 µm. The corneal thickness values were measured by anterior-segment optical coherence tomography. All lamellas had ultraviolet-A (365 nm) absorbance measured with a 96-well plate spectrophotometer using an ultraviolet transparent microplate before riboflavin instillation and preand post-crosslinking according to the Dresden protocol. RESULTS: The ultraviolet absorbance profiles of the 180, 300, and 360 µm groups were obtained as α-coefficients of 12.85, 76.55, and 120.27, respectively. A theoretical formula was calculated though a statistical analysis that demonstrated the correlation between stromal lamellar thickness and ultraviolet absorbance. CONCLUSIONS: Corneal thickness and ultraviolet-A spectral absorbance of corneal lamellas showed linear correlation. These findings can potentially contribute to the optimization of ultraviolet-A application during crosslinking, making the treatment of corneas with thickness <400 µm safe and personalized energy delivery for each corneal thickness.

Radial keratotomy: background and how to manage these patients nowadays.

In this review, we presented the principles of radial keratotomy (RK), its evolution, enhancement, and complications, and strategies to manage the consequences of RK in the present day. It is essential to understand the RK procedure f, the theoretical background that supported this surgery, the current effect on the cornea, and how to approach patients needing vision improvement. These patients are developing cataracts that need to be handled well, from the IOL calculation to the surgical procedure. Guided keratorefractive surgery is the most accurate procedure to improve these patient's vision and life. Nevertheless, some patients may need other approaches, such as sutures, penetrating keratoplasty, corneal rings, and pinhole implants, depending on the degree of irregularity of the cornea, ablation depth for guided surgery or if the sutures are open.

Vision-Related Quality of Life in Patients With Keratoconus With Enantiomorphic Topography After Bilateral Intrastromal Corneal Ring Implantation.

PURPOSE: The aim of this study was to evaluate the quality of life (QOL) after intrastromal ring implantation in patients with keratoconus. METHODS: This was a prospective, randomized, interventional study. We analyzed 60 eyes of 30 patients aged 16 to 35 years who were treated at the Department of Ophthalmology and Visual Sciences, Federal University of São Paulo, Brazil. The Visual Function Questionnaire (VFQ-25) and Short-Form 36 Questionnaire (SF-36) were used before intracorneal ring segment (ICRS) implantation and at 3, 6, and 12 months after surgical intervention. RESULTS: The mean corrected visual acuity improved from a mean of 0.32 ± 0.2 logMAR (20/40) preoperatively to 0.14 ± 0.11 logMAR (20/25) 1 year postoperatively ( P = 0.001). The mean spherical equivalent varied from -7.24 ± 3.47 preoperatively to -4.13 ± 2.41 postoperatively ( P = 0.001). The overall composite score for the VFQ-25 improved from 55.1 preoperatively to 80.4 1 postoperatively ( P = 0.001). SF-36 showed statistically significant improvement in all scores. When analyzing the correlation between visual acuity and VFQ composite score, a significant correlation was found between both variables (Pearson correlation coefficient of -0.40, P = 0.001). CONCLUSIONS: Patients with keratoconus had increased psychological symptoms and lower QOL and improved psychosocial criteria associated with corneal remodeling and decreased visual dependence on others after surgery. Extrapolation of these data to the whole keratoconus population suggests that ICRS implantation could improve QOL in these patients.

Comparison of visual outcomes of bilateral dual-technology diffractive intraocular lens vs blended enhanced monofocal with dual-technology intraocular lens.

PURPOSE: To compare clinical outcomes after implantation of TECNIS Synergy (ZFR00V) intraocular lenses (IOLs) in both eyes and implantation of the TECNIS Synergy and TECNIS Eyhance (ICB00) combination in patients undergoing cataract surgery. SETTING: Department of Cataract, Hospital Oftalmológico de Brasilia (HOB), Brasília, Brazil. DESIGN: Prospective, interventional, randomized, parallel-group study. METHODS: Patients were categorized into 2 groups: Group 1: ZFR00V IOL was implanted in both eyes. Group 2: An ICB00 IOL was implanted in the dominant eye, and a ZFR00V IOL was implanted in the nondominant eye. RESULTS: Visual acuity was similar between the 2 groups (95% CI <0.1 logMAR). A superior visual acuity of ≥ 20/25 (at -2.00 to -2.50 diopters [D]) was achieved in Group 1 (bilateral ZFR00V) than in Group 2 (combination of ZFR00V/ICB00). The binocular defocus curve demonstrated better visual acuity at 40 cm (-2.00 D) and 50 cm (-2.50 D) in Group 1 than in Group 2 ( P < .05). Similar contrast sensitivity values were observed between the 2 groups. Patients in Group 1 reported higher satisfaction (completely satisfied) than those in Group 2 ( P < .05). However, halos and glare were more pronounced in Group 1 than in Group 2 ( P < .05). CONCLUSIONS: Both presbyopia-correcting IOL combinations showed similar binocular visual acuity results. Group 1 demonstrated enhanced visual acuity in the defocus curve at 40 cm (-2.00 D) and 50 cm (-2.50 D). Comparable contrast sensitivity outcomes were observed in both groups. Patients were more completely satisfied in Group 1 than in Group 2, despite the higher frequency of postoperative nighttime halos and glare.

Ultraviolet-A absorbance analysis in thin porcine corneas pre-and post-crosslinking

ABSTRACT Purpose: To determine the absorbance coefficient of the thin porcine cornea to ultraviolet-A radiation (365 nm) submitted for crosslinking. Methods: This in vitro, benchtop experiment using cadaver tissue study analyzed 12 porcine corneal lamellas, which were obtained using a microkeratome after mechanical de-epithelization and separated into three thickness groups: 180, 300, and 360 μm. The corneal thickness values were measured by anterior-segment optical coherence tomography. All lamellas had ultraviolet-A (365 nm) absorbance measured with a 96-well plate spectrophotometer using an ultraviolet transparent microplate before riboflavin instillation and preand post-crosslinking according to the Dresden protocol. Results: The ultraviolet absorbance profiles of the 180, 300, and 360 μm groups were obtained as α-coefficients of 12.85, 76.55, and 120.27, respectively. A theoretical formula was calculated though a statistical analysis that demonstrated the correlation between stromal lamellar thickness and ultraviolet absorbance. Conclusions: Corneal thickness and ultraviolet-A spectral absorbance of corneal lamellas showed linear correlation. These findings can potentially contribute to the optimization of ultraviolet-A application during crosslinking, making the treatment of corneas with thickness <400 μm safe and personalized energy delivery for each corneal thickness.

Measurement of the visual axis through two different methods: quantification and differences for measuring chord μ / Medição do eixo visual através de dois métodos diferentes: quantificação e diferenças para medição da corda μ

ABSTRACT Purpose: To compare the differences between the apparent and actual chord μ. Methods: In this prospective, comparative, non-randomized, and non-interventional study, imaging examinations using Pentacam and the HD Analyzer were performed in the same room under the same scotopic conditions. The inclusion criteria were patients aged 21-71 years, able to provide informed consent, myopia up to 4D, and anterior topographic astigmatism up to 1D. Patients using contact lenses, those with previous eye diseases or surgeries, corneal opacities, corneal tomographic changes, or suspected keratoconus were excluded. Results: Altogether, 116 eyes of 58 patients were analyzed. The patients' mean age was 30.69 (±7.85) years. In the correlation analyses, Pearson's correlation coefficient of 0.647 indicates a moderate positive linear relationship between apparent and actual chord μ. The mean actual and apparent chord μ were 226.21 ± 128.53 and 278.66 ± 123.90 μm, respectively, with a mean difference of 52.45 μm (p=0.01). The analysis of mean pupillary diameter resulted in 5.76 mm using the HD Analyzer and 3.31 mm using the Pentacam. Conclusions: We found a correlation between the two measurement devices, and even though we found considerable differences, both can be used in daily practice. Given their differences, we should respect their peculiarities as well.

RESUMO Objetivo: Comparar as diferenças entre a chord aparente μ e o chord real μ. Métodos: Estudo prospectivo, comparativo, não randomizado e não intervencionista. Os exames de imagem (Pentacam e HD Analyzer) foram realizados na mesma sala e nas mesmas condições escotópicas. Os critérios de inclusão foram idade de 21 a 71 anos; compreensão do termo de consentimento; miopia até 4D e astigmatismo topográfico anterior até 1D. Os critérios de exclusão foram usuários de lentes de contato; pacientes com doenças oculares prévias ou cirurgias; opacidades da córnea; a presença de alterações tomográficas da córnea ou suspeita de ceratocone. Resultados: Em nosso estudo foram analisados 116 olhos de 58 pacientes. A média de idade foi de 30,69 anos (± 7,85). Análises de correlação foram desenvolvidas e o coeficiente de correlação de Pearson (0,647) indica uma relação linear positiva moderada entre as variáveis. A média do chord μ real foi 226,21 ± 128,53 μm e a média do chord μ média foi 278,66 ± 123,90 μm, com diferença média de 52,45 μm (p=0,01). A análise do diâmetro pupilar médio apresentou: 5,76mm no HD Analyzer e 3,31mm no Pentacam. Conclusões: Entendemos a existência de uma diferença significativa entre os métodos e assim a medida de ambos os dispositivos com base em princípios diferentes devemos respeitar suas peculiaridades. Como encontramos correlação entre as duas medidas, acreditamos que ambas podem ser utilizadas na prática diária.

Visual rehabilitation after LASIK complication: flap amputation, topo-guided surgery, and phacoemulsification

ABSTRACT We present a case of a patient complaining of monocular diplopia due to a decentered ablation after LASIK. The patient underwent a wavefront-guided retreatment, which resulted in an epithelial ingrowth complication. Additionally, the patient developed cataract, with cataract surgery requiring reliable biometric measurements. Therefore, we opted for corneal treatment and corneal surface regularization. Although we attempted to lift the flap and wash the interface initially, the procedure proved unsuccessful, thereby necessitating immediate flap amputation. Once the corneal surface was regularized in the seventh postoperative month, transepithelial photorefractive keratectomy was successfully performed to homogenize the ocular surface, thereby significantly improving the patient's corrected visual acuity and resolving monocular diplopia. The surface and corneal curvature stabilized by the fifth month after the procedure. Phacoemulsification was then performed along with the implantation of a toric monofocal lens, which was selected using an appropriate formula, resulting in an excellent uncorrected visual acuity.

Ten-year follow-up of corneal cross-linking and refractive surface ablation in patients with asymmetric corneal topography.

Purpose: Compare the safety and efficacy of wavefront-guided photorefractive keratotomy (PRK) 6 months after cross-linking (CXL) to wavefront-guided PRK alone for refractive correction in patients with bilateral asymmetric corneal topography. Methods: Prospective randomized clinical trial with 16 patients (32 eyes). CXL with subsequent PRK after 6 months in one eye, and PRK alone was performed in contralateral eyes. The follow-up was 10 years. We analyzed visual outcomes, Scheimpflug topography, and corneal haze evaluation. Results: Eyes in the PRK group showed better results than in the CXL + PRK group. Mean postoperative CDVA was 0.044 logmar (SD, 0.073) in the PRK group and 0.1 logmar (SD, 0.21) in the CXL + PRK group, the mean sphere was + 0.21 (SD, 0.6) D in the PRK group and 0.87 (SD, 2.3) D in the CXL + PRK group, and mean SE was -0.35 (SD, 0.65) D in the PRK group and 0.62 (SD, 2.32) D in the CXL + PRK group. In one patient, a steepening of 2.5 D and a thinning of 17 µm occurred in PRK alone group. Two patients in the CXL + PRK group presented corneal haze. The overall complication rate was 18,75% (haze and ectasia). Conclusion: Non-simultaneous CXL and PRK procedures yielded good refractive results, but worse than those obtained with PRK alone. Although one patient in the PRK group developed corneal ectasia, the CXL + PRK group had a higher loss of vision lines, indicating less safety.

Results of Fibrin Glue Applied Over the Corneal Surface Immediately After Pterygium Surgery: A Novel Pain Relief Technique.

PURPOSE: The aim of this study was to compare the use of fibrin glue on the corneal epitheliectomy site at the end of pterygium surgery versus conventional eye patch regarding pain levels, need for oral analgesic medications, number of days feeling pain, and awakening due to pain after surgery. METHODS: Forty-eight eyes of 24 patients with bilateral primary pterygium were included in this prospective, randomized, double-masked controlled trial. Each eye of the same patient was randomized to the intervention or control group. The intervention group received 2 drops of fibrin glue in the epitheliectomy site at the end of surgery and an eye patch, whereas the control group was only received an eye patch. Patients returned on the first and seventh days after surgery. Pain intensity (measured using the visual pain analog scale), need for oral analgesics, the number of days the pain lasted, and quality of sleep were assessed during follow-up visits and compared between groups. Comparison analysis accounted for sex, age, pterygium grading, and comorbidities. RESULTS: Visual analog pain scale after surgery was significantly lower in eyes receiving fibrin glue (-1.58; 95% confidence interval: -2.84 to -0.32; P = 0.014). In addition, the intervention group presented a 73% lower chance of using oral analgesics (OR: 0.27; 95% confidence interval: 0.07-0.95; P = 0.041). No difference in the awakenings at night was noted ( P = 0.240) nor the mean days of ocular pain in the first week after surgery ( P = 0.474). CONCLUSIONS: Fibrin glue at the end of pterygium surgery effectively reduces pain and the need for oral analgesics compared with conventional eye patching. This study is the first to describe the results of this strategy.

Spectrophotometric Analysis of Different Polymethyl Methacrylate Filters and their Importance in the Implantation of Corneal Rings.

PURPOSE: This study evaluated the luminous behavior applied to materials used in intraocular surgeries. METHODS: Discs of the different products were delivered in 19.00 mm × 3.00 mm. Each sample was fixed on support keeping it perpendicular to the spectrophotometer beam. Later, their analyses were carried out in the air/PMMA ratio. The graphs of individual profiles of the measurements along the length were constructed according to each of the filters from the spectrophotometric analysis. In addition, descriptive statistics of transmittance and absorbance for each wavelength presented were correlated for each filter. RESULTS: It is possible to observe that the minimum absorption measure was found in the Red Filter, especially in the blue and green light spectrum. CONCLUSION: Using filters in PMMA materials appears to improve visual quality in corneal implants, especially the red filter, due to greater absorbance of light leading to fewer light scattering phenomena through corneal rings. However, further studies comparing the effects of different filters on Intracorneal rings should be carried out to elucidate this field of study.

Comparison of endothelial cell loss in diabetic patients after conventional phacoemulsification and femtosecond laser-assisted cataract surgery.

PURPOSE: This study aims to comparatively evaluate the morphological changes of the cornea after phacoemulsification (PHACO) and femtosecond laser-assisted cataract surgery (FLACS) without intercurrences in patients with type 2 diabetes mellitus. METHODS: A total of 95 diabetic patients with moderate cataracts (N2 + and N3+), 47 undergoing PHACO and 48 undergoing FLACS, were selected randomly for the study. Surgeries were performed by a single surgeon between July 2021 and December 2021. Cumulative dissipated energy (CDE) and total balanced saline solution (BSS) data were obtained at the end of each surgery. Changes in corneal endothelial cell density (ECD) and central corneal thickness (CCT) at three months postoperatively were investigated. RESULTS: After three months, evidence is lacking between groups in the CCT measures; the difference was neither statistically nor clinically relevant. However, for ECD, a significant and clinically significant difference was found; if all patients were treated with laser, the mean ECD would be 423.55 greater (RSE: 86.09; p-value < 0.001; 95% CI: 254.81-592.29) than the ECD potential means of 1656.423 among the conventional group (RSE: 74.90; p-value < 0.001; 95% CI: 1509.62-1803.23). CONCLUSIONS: Diabetic patients under treatment with moderate cataracts may predispose themselves to a more significant loss of endothelial cells after conventional phacoemulsification than femtosecond laser-assisted cataract surgery. TRIAL REGISTRATION: It was registered at The Brazilian Registry of Clinical Trials (ReBEC) with the code RBR-6d8whb5 (UTN code: U1111-1277-6020) on 17/05/2022.

Measurement of the visual axis through two different methods: quantification and differences for measuring chord µ.

PURPOSE: To compare the differences between the apparent and actual chord µ. METHODS: In this prospective, comparative, non-randomized, and non-interventional study, imaging examinations using Pentacam and the HD Analyzer were performed in the same room under the same scotopic conditions. The inclusion criteria were patients aged 21-71 years, able to provide informed consent, myopia up to 4D, and anterior topographic astigmatism up to 1D. Patients using contact lenses, those with previous eye diseases or surgeries, corneal opacities, corneal tomographic changes, or suspected keratoconus were excluded. RESULTS: Altogether, 116 eyes of 58 patients were analyzed. The patients' mean age was 30.69 (±7.85) years. In the correlation analyses, Pearson's correlation coefficient of 0.647 indicates a moderate positive linear relationship between apparent and actual chord µ. The mean actual and apparent chord µ were 226.21 ± 128.53 and 278.66 ± 123.90 µm, respectively, with a mean difference of 52.45 µm (p=0.01). The analysis of mean pupillary diameter resulted in 5.76 mm using the HD Analyzer and 3.31 mm using the Pentacam. CONCLUSIONS: We found a correlation between the two measurement devices, and even though we found considerable differences, both can be used in daily practice. Given their differences, we should respect their peculiarities as well.

Deslocamento espontâneo do núcleo do cristalino para câmara anterior / Spontaneous displacement of the lens nucleus into the anterior chamber

RESUMO Ao longo da vida, o cristalino produz novas fibras dispostas de forma concêntrica, que aumentam seu diâmetro anteroposterior e peso, tornando seu núcleo mais compacto e endurecido. A catarata hipermadura é uma forma de progressão avançada dessa proliferação de fibras, que pode desencadear uma variedade de complicações. A ruptura espontânea da cápsula anterior do cristalino, evoluindo com deslocamento anterior do núcleo, é uma complicação rara e com poucos casos publicados na literatura. Descrevemos o caso de uma paciente do sexo feminino, 68 anos, que apresentou ruptura espontânea da cápsula anterior do cristalino com deslocamento anterior do núcleo em olho esquerdo sem histórico de trauma ocular. A paciente foi submetida à facoemulsificação do cristalino e ao controle da pressão intraocular, evoluindo com melhora do quadro clínico.

ABSTRACT Throughout life, the lens produces new fibers arranged concentrically, which increase its anteroposterior diameter and weight, making its nucleus more compact and hardened. Hypermature cataract is an advanced stage of this fiber proliferation, which can trigger a variety of complications. Spontaneous rupture of the anterior lens capsule evolving with anterior displacement of the nucleus is a rare complication, with few cases published in the literature. We describe the case of a 68-year-old female patient, who presented spontaneous rupture of the anterior lens capsule with anterior displacement of the nucleus in the left eye, without a history of ocular trauma. The patient underwent phacoemulsification and clinical control of intraocular pressure, improving her condition.

Manifestações clínicas de ceratite ulcerativa periférica com ceratite neurotrófica: desafio terapêutico / Clinical manifestations of peripheral ulcerative keratitis together with neurotrophic keratitis: therapeutic challenge

RESUMO A ceratite ulcerativa periférica é uma infiltração corneana imunomediana associada a doenças autoimunes e inflamatórias sistêmicas. Comumente associada à artrite reumatoide, ela também pode estar associada a outras doenças reumatológicas, inflamatórias e doenças infecciosas. A ceratite ulcerativa periférica é geralmente unilateral e periférica, devido à proximidade com a vasculatura conjuntival. Há tipicamente um defeito epitelial sobrejacente ao infiltrado e afinamento do estromal associado. O objetivo deste relato de caso foi abordar uma das possíveis etiologias de ceratite ulcerativa periférica associada a quadro de ceratite neurotrófica por herpes simplex, apresentar sua apresentação clínica aguda e alertar sobre as implicações do tratamento.

ABSTRACT Peripheral ulcerative keratitis (PUK) is an immune-mediated corneal infiltration associated with autoimmune diseases and systemic inflammation. Commonly associated with rheumatoid arthritis, it may also be associated with other rheumatologic, inflammatory, and infectious diseases. PUK is usually unilateral and peripheral, due to its proximity to the conjunctival vasculature. There is usually an epithelial defect overlying the infiltrate and the associated stromal thinning. The objective of this case report is to address one of the possible etiologies of PUK associated with a picture of neurotrophic keratitis due to Herpes Simplex and its acute clinical presentation, and to warn about possible suggestions for treatment.

Unexpectedly high corneal flap thickness and ectasia after mechanical LASIK / Espessura inesperadamente alta do flap corneano e ectasia após LASIK mecânico

ABSTRACT LASIK is a refractive surgical procedure in which a corneal flap is created to expose the corneal stromal bed. Preoperative estimation of corneal flap thickness is necessary to calculate the percentage tissue altered in LASIK, an important quantitative risk factor for ectasia. The objective of this study was to assess flap thickness and calculate percentage tissue altered to check if unexpectedly thicker flaps and higher percentage tissue altered could pose as risk factors of ectasia. Four subjects (eight eyes) were submitted to mechanical LASIK in 2009 and 2010. Pre and postoperative clinical and tomographic data were reviewed. Mean preoperative estimated percentage tissue altered was 39.18±1.31%, which was borderline for increased ectasia risk when considering the limit of 40%. However, when considering the postoperatively measured flap thickness, the actual mean percentage tissue altered turned out to be 45.17 ± 4.13%, which was significantly higher than predicted preoperatively (p=0.002). Unexpectedly higher postoperative percentage tissue altered may be responsible for corneal ectasia after mechanical LASIK.

RESUMO A LASIK é um procedimento cirúrgico refrativo, no qual um retalho corneano é criado para expor o leito estromal corneano. A estimativa pré-operatória da espessura do retalho corneano é necessária para calcular o percentual de tecido alterado no LASIK, um importante fator de risco quantitativo para ectasia. O objetivo deste estudo foi avaliar a espessura do retalho e calcular o percentual de tecido alterado para verificar se retalhos inesperadamente mais espessos e percentuais de tecido alterado mais altos poderiam representar fatores de risco de ectasia. Quatro indivíduos (oito olhos) foram submetidos à LASIK mecânica em 2009 e 2010. Dados clínicos e tomográficos pré e pós-operatórios foram revisados. A média de percentual de tecido alterado pré-operatória estimada foi de 39,18±1,31%, limítrofe para risco aumentado de ectasia quando considerado o limite de 40%. No entanto, ao considerar a espessura do retalho medida no pós-operatório, o percentual de tecido alterado médio real foi de 45,17±4,13%, ou seja, significativamente maior do que o previsto no pré-operatório (p=0,002). O percentual de tecido alterado pós-operatóriao inesperadamente mais alto pode ser responsável pela ectasia da córnea após LASIK mecânico.

Analysis of the thickness of conjunctival autograft in pterygium surgery with the Moscovici dissection technique compared with manual dissection / Análise da espessura do autoenxerto conjuntival na cirurgia de pterígio com a técnica de dissecção de Moscovici comparada com a dissecção manual

ABSTRACT Objective Compare the thickness of conjunctival autografts in pterygium surgery using the Moscovici dissection technique with manual dissection and assess the difficulty of the techniques. Methods In this randomized clinical trial, 30 eyes of 30 patients undergoing pterygium surgery were divided into the Moscovici Dissection Technique Group and the Manual Dissection Group. The patients were treated at the Hospital Oftalmológico Visão Laser (Santos, São Paulo, Brazil). Optical coherence tomography was performed to measure graft thickness three months postoperatively. Three images were obtained from each eye, and three measurements were taken at a distance of 1.5mm perpendicular to the limbus in each capture. The surgeon graded the difficulty of obtaining the graft with the technique performed from one (lowest difficulty) to four (highest difficulty). Results We found statistically significant difference between the difficulty of the two techniques and the mean conjunctival autograft thickness in the two groups (p=0.01 e p=0.05, respectively). The average difficulty rating for the Moscovici Dissection Technique Group (Air Group) was 1.47, while that for the Manual Dissection Group (MD group) was 2.20. The mean thickness of the three measurements was 252µ in the Air Group and 298µ in the MD Group, with medians of 250µ and 278µ, respectively. Conclusion Our study showed that the Moscovici technique results in thinner grafts and can be performed with greater surgical ease.

RESUMO Objetivo Comparar a espessura de autoenxertos conjuntivais em cirurgia de pterígio utilizando a técnica de dissecção de Moscovici com a de dissecção manual e avaliar a dificuldade das técnicas. Métodos Neste ensaio clínico randomizado, 30 olhos de 30 pacientes submetidos à cirurgia de pterígio foram divididos em um Grupo de Técnica de Dissecção de Moscovici e um Grupo de Dissecção Manual. Os pacientes foram tratados e avaliados no Hospital Oftalmológico Visão Laser (Santos, São Paulo, Brasil). A tomografia de coerência óptica foi realizada para medir a espessura do enxerto 3 meses após a cirurgia. Três imagens foram obtidas de cada olho, e três medidas foram realizadas a uma distância de 1,5mm perpendicular ao limbo em cada captura. O cirurgião classificou a dificuldade de obtenção do enxerto com a técnica realizada de um (menor dificuldade) para quatro (maior dificuldade). Resultados Encontramos diferenças estatisticamente significantes entre a dificuldade das duas técnicas e a espessura média do autoenxerto conjuntival nos dois grupos (p=0,01 e p=0,05, respectivamente). A classificação média de dificuldade para o Grupo de Técnica de Dissecção de Moscovici foi de 1,47, enquanto a do Grupo de Dissecção Manual foi de 2,20. A espessura média das três medidas foi de 252μ no Grupo de Técnica de Dissecção de Moscovici e de 298μ no Grupo de Dissecção Manual, com medianas de 250μ e 278μ, respectivamente. Conclusão Nosso estudo mostrou que a técnica de Moscovici resulta em enxertos mais finos e pode ser realizada com maior facilidade cirúrgica.

Ablação personalizada guiada por frente de onda após complicação na dissecção lamelar de FemtoLasik / Personalized wavefront-guided ablation after complication in FemtoLasik lamella dissection

RESUMO O FemtoLasik é uma das técnicas mais empregadas em cirurgia refrativa, por seus bons resultados refracionais, sua previsibilidade, sua reprodutibilidade e sua segurança. Tem alto grau de satisfação, com rápida recuperação visual. Apesar de as taxas de complicações do FemtoLasik serem pequenas, intercorrências podem existir. O objetivo deste trabalho foi relatar um caso de uma complicação na dissecção da lamela por Lasik com laser de femtossegundo com consequente rasgadura da lamela, sendo aplicado Excimer Laser com mitomicina C 0,02%. O retratamento foi realizado com ablação de superfície (ceratectomia fotorrefrativa) guiada por frente de onda, evoluindo com boa qualidade visual final.

ABSTRACT Femtolasik is one of the most used techniques in refractive surgery due to good refractive results, predictability, reproducibility, and safety, achieving excellent results and a high degree of satisfaction. Although the complication rates are small, it is worth noting that there may be intercurrences. The objective of this work is to report a case of complication in the dissection of the lamella of laser in situ keratomileusis (Lasik) with Femtosecond laser, and subsequent lamella tear. Excimer Laser was applied with mitomycin 0.02% and re-approached with wavefront guided surgery, evolving with good final visual quality.