Ricardo Menon Nosé

Toric Intraocular Lens Misalignment Inducing Astigmatism After Refractive Surgery

PURPOSE To report the unexpected induction of astigmatism after phacoemulsification and toric intraocular lens (IOL) implantation in an eye with previous corneal refractive surgery. METHODS Case report of a 46-year-old man with bilateral nuclear cataract and previous photorefractive keratectomy. Because corneal topography identified regular corneal astigmatism at the central optical zone, phacoemulsification and implantation of a one-piece hydrophobic acrylic toric IOL were performed. RESULTS Unexpected induction of astigmatism occurred in the first operated eye despite proper alignment of the IOL according to the preoperative calculations using simulated K values to determine toric IOL power and alignment. A retrospective qualitative analysis of corneal topography showed mismatching of the steepest meridian, leading to an off-axis IOL. Secondary IOL rotation improved both uncorrected and corrected distance visual acuity. CONCLUSIONS Qualitative analysis of the corneal topography is mandatory during the assessment of toric IOL alignment in eyes with previous corneal refractive surgery to identify the actual location of the steepest meridian.

Optical coherence tomography analysis of hydrofluoric acid decontamination of human cornea by mannitol solution

PURPOSE To evaluate the efficacy of mannitol solution as a decontamination agent on the chemical burn of the human corneas. METHODS Eight donor corneas from an eye bank were exposed to 25μl of 2.5% hydrofluoric acid (HF) solution on a filter paper for 20s. Three eyes were rinsed with 1000ml of mannitol 20% for 15min immediately after removal of the filter paper, 3 other were rinsed with sodium chloride (NaCl) 0.9% (1000ml for 15min) and two eyes were not rinsed. Microstructural changes were monitored in the time domain by optical coherence tomography (OCT) imaging for 75min. RESULTS NaCl reduced the penetration depth to approximately half the thickness of the cornea at 15min; scattering within the anterior cornea was higher than that for the unrinsed eye. With mannitol, no increased scattering was observed in the posterior part of the corneal stroma within a time period of 1h after rinsing. OCT images revealed low-scattering intensity within the anterior stroma at the end of the rinsing period. CONCLUSION In eye bank human corneas, mannitol proved to be an efficient agent to decontaminate HF burn.

Difference between bevel-up and bevel-down 23-gauge one-step incisions: analysis of anterior chamber optical coherence tomography and IOP.

Difference Between Bevel-Up and Bevel-Down 23-Gauge One-Step Incisions: Analysis of Anterior Chamber Optical Coherence Tomography and IOP Sutureless 23-gauge pars plana vitrectomy can reduce the postoperative inflammation at the sclerotomy sites, resulting in decreased patient discomfort postoperatively and faster postoperative recovery.1,2 However, the rates of incision-related complications (hypotony and leakage) are unknown using different tunnel techniques, which theoretically can cause several postoperative and intraoperative complications. A better understanding of the 23-gauge incision will lead to safer surgical procedures. The purpose of this research was to evaluate the wound length, wound area, leakage, and Day 1 intraocular pressure (IOP) in human eyes that underwent pars plana vitrectomy with creation of a 23-gauge 1-step incision with the bevel facing-up or the bevel facing-down.

Persistence of granular corneal dystrophy type-1 deposits in the predescemetic layer after big-bubble deep anterior lamellar keratoplasty

We report intraoperative finding of Granular Corneal Dystrophy Type-1 (GCD1) deposits after stromal pneumodissection in deep anterior lamellar keratoplasty (DALK) in a 61-year-old female. Pneumodissection was performed from the center to the periphery of the cornea, characterizing a big bubble type 1 technique which dissects the deep stroma from the predescemetic layer. After stromal removal, persistence of whitish deposits inside the predescemetic layer was noted. During post-operative evaluation, anterior biomicroscopy and anterior segment optical coherence tomography showed granular opacities between the patients Descemets membrane and the donor cornea, suggesting possible involvement of the predescemetic layer in GCD1. This may require the surgeons attention to choose between DALK keratoplasty or penetrating keratoplasty.

Refractive and Visual Outcomes of Different Intraocular Lenses with Femtosecond Laser Cataract Surgery: The Expectation of Independence from Spectacles

Purpose: To evaluate the visual performance of different types of intraocular lens (IOL) in eyes submitted to femtosecond laser (FSL) cataract surgery and to analyze whether this technology could result in spectacles independence. Design: Retrospective comparative case series. Methods: Consecutive eyes that were scheduled for FSL cataract surgery were included in this study. After one month postoperative, patients were divided into two groups: cases that required prescription for eyeglasses and cases that did not require prescription. In addition, the patients were analyzed according to the type of IOL that was implanted (monofocal, monofocal toric, multifocal and multifocal toric). Results: Thirty-five cataract surgeries were analyzed. Twenty-three eyes had a monofocal IOL implanted, and 12 had a multifocal IOL implanted. After 1 month, 12 cases required prescription (Group 1), and 23 did not require prescription (Group 2). The proportion of eyes that did not require corrective lenses was significantly greater (P = 0.02) in eyes that received multifocal IOL (91.67%) compared with those that received monofocal IOL (47.83%). Additionally, 100% of eyes that received multifocal toric IOL did not require eyeglasses at one month postoperatively. Conclusion: The FSL surgical precision associated with modern IOL technology may be an important factor related to vision satisfaction after cataract surgery.

Clinical experience with the first 40 cases with femtosecond laser cataract surgery technology: safety of the learning curve

Objetivo: Avaliar a introducao do laser de femtossegundo (FSL) para realizar etapas fundamentais da cirurgia de catarata tradicional e as dificuldades e seguranca desta nova tecnologia na rotina de um centro cirurgico no Brasil. Metodos: Um estudo retrospectivo foi realizado com os primeiros casos operados em um unico centro usando a plataforma de laser LenSx/Alcon, sendo utilizado lentes de contato gelatinosa na interface do paciente. Todos os pacientes foram submetidos a uma avaliacao pre-operatoria detalhada. Capsulotomia anterior, fragmentacao nuclear e incisoes na cornea foram criados com a FSL, em seguida, a cirurgia foi concluida com procedimento de facoemulsificacao padrao. As principais medidas de desfecho foram dificuldades e complicacoes relacionadas a curva de aprendizado e analise da acuidade visual pos-operatoria nao corrigida a distância (UDVA). Resultados: Dos 31 pacientes (40 olhos), 9 realizaram cirurgia de catarata em ambos os olhos com FSL. A media de idade foi de 64 ± 12 anos (variando de 42 a 82), a media de classificacao da catarata atraves da esclerose nuclear foi 2 ± 0,6 (variando de 1 a 4) e UDVA pre-operatoria em logMAR foi de 0,4 ± 0,2 (variando de 0,1 a 1,3). A capsulotomia anterior foi completa em todos os pacientes e nao precisou usar da pinca para cortar qualquer porcao intacta. Incisoes corneanas pos-operatorias nao foram lineares, mostrando ainda algumas irregularidades. A facofragmentacao a laser foi eficaz, com a divisao do nucleo em segmentos menores facilmente realizados antes da facoemulsificacao. Apos 1 mes de pos-operatorio, UDVA em logMAR foi de 0,1 ± 0,1 (variando de 0,0 a 0,4) (P < 0,0001). Conclusao: Com o aumento do volume dos casos cirurgicos e ganho de experiencia, passos precisos da facoemulsificacao sao realizados com o pre-tratamento com o FSL, resultando em uma segura curva de aprendizagem.

Análise quantitativa e qualitativa do filme lacrimal nos pacientes submetidos a PRK e LASIK com femtossegundo

Objetivo: Analisar a secrecao lacrimal, coloracao da superficie ocular e estabilidade do filme lacrimal em individuos submetidos a cirurgia de PRK e LASIK com laser de femtossegundo (femto LASIK). Metodos: Vinte olhos de 10 pacientes submetidos a tecnica de Femto LASIK e 11 olhos de 6 pacientes submetidos a tecnica de PRK foram estudados de forma prospectiva, longitudinal e intervencionista. Tempo de rotura do filme lacrimal (TRFL), teste de Schirmer basal e coloracao da superficie ocular com lissamina verde foram analisados no pre-operatorio (pre), no 15o e no 30o dia pos-operatorio (15o pos e 30o pos, respectivamente). Resultados: Agrupando todos os olhos, observou-se que o TRFL reduziu-se de forma estatisticamente significante no 15o pos em relacao ao valor pre-operatorio (p=0,025), mantendo-se reduzido no 30o pos (p= 0,001); nao houve diferenca estatisticamente significativa entre o 15o pos e o 30o pos (p=0,219). No teste da lissamina verde, houve aumento significativo desse escore, no 15o pos em relacao ao periodo pre-operatorio (p=0,021), havendo, posteriormente, reducao no 30o pos (p=0,010). No teste de Schirmer basal, nao foi detectada mudanca estatisticamente significante ao longo dos tres momentos (p=0,107). Comparando-se os testes TRFL, lissamina verde ou Schirmer basal, nos dois grupos estudados (PRK e LASIK), nao houve diferenca estatisticamente significante em nenhum dos tres momentos (pre, 15o pos e 30o pos). Conclusao: Evidenciou-se alteracao do filme lacrimal nos pacientes submetidos a cirurgia refrativa, quando foram utilizados os testes de TRFL e lissamina verde. Nas duas tecnicas empregadas, nao houve diferenca estatisticamente significante de alteracao do filme lacrimal, quando comparadas entre si (PRK e LASIK).