Ester Sakae Yamazaki

Phototherapeutic Keratectomy for the Treatment of Corneal Opacities After Epidemic Keratoconjunctivitis

PURPOSE To assess visual results and compare methods of measuring central corneal thickness (CCT) and corneal opacity thickness (COT) in patients with corneal opacities induced by epidemic keratoconjunctivitis (EKC) and treated with phototherapeutic keratectomy (PTK) using low-dose mitomycin C (MMC). DESIGN Prospective consecutive case series. METHODS Patients with chronic adenoviral corneal opacity underwent transepithelial PTK with MMC 0.002% for 1 minute. The presence of photophobia, the best spectacle-corrected visual acuity (BSCVA), and the contrast sensitivity were evaluated. CCT measurements were obtained with ultrasound pachymeter (US), ultrasound biomicroscopy (UBM), Scheimpflug tomography (Pentacam Oculus), and optical coherence tomography (OCT Visante). COT measurements were obtained with UBM, Pentacam, and OCT. RESULTS Thirty-one eyes of 23 patients, comprising 15 women (65.2%) and 8 men (34.8%), mean age 41.8 years, were enrolled in the study. Duration of visual disturbance was 19.1 ± 14 months. The number of patients with photophobia was reduced from 100% to 29% after surgery. BSCVA improved 2 or more lines in 78% of the patients at 12 months. A hyperopic shift of 1.52 ± 0.91 diopters was achieved. Contrast sensitivity improved in both photopic and mesopic conditions. For each of the instruments, the CCT postoperative mean was significantly smaller than the preoperative measurement (P < .0001) and COT values were significantly reduced in comparison to the preoperative values (P < .001). CONCLUSION Improvements in photophobia, BSCVA, and contrast sensitivity were observed in patients treated using excimer laser PTK with low-dose MMC for subepithelial infiltrates.

Pentacam Scheimpflug Evaluation of Corneal Volume After LASIK

PURPOSE To assess the change in corneal volume and laser ablation volume over time after LASIK using a rotating Scheimpflug camera. METHODS Twenty-six patients (49 eyes) underwent LASIK. Pentacam Scheimpflug measurements were performed pre- and postoperatively at 1, 3, 7, 15, and 30 days. Central corneal thickness, total corneal volume (10-mm diameter), and partial corneal volumes (3, 5, and 7 mm) based on the apex of the cornea, were measured. Main outcome measures were differences between pre- and postoperative volume measurements of total and partial corneal regions, volume changes over time postoperatively, and comparison between laser ablation volume and corneal volume. RESULTS A strong linear relationship was noted between spherical equivalent refraction and laser ablation volume (r = -0.931, P < .0001). Furthermore, 30 days after LASIK, a strong linear relationship was noted between planned thickness and achieved thickness (r = 0.9457, P < .001). Corneal volumes for 3-, 5-, and 7-mm diameter regions significantly decreased over time postoperatively (one-way analysis of variance, P < .05). CONCLUSIONS Alterations in corneal volume correlated with laser ablation volume when the diameter of the region considered was 3, 5, or 7 mm from the corneal apex.

Adaptação de lente de contato gelatinosa especial para ceratocone

PURPOSE: To evaluate the fitting and use of a soft contact lens in keratoconic patients. METHODS: Retrospective study on 80 eyes of 66 patients, fitted with a special soft contact lens for keratoconus, at the Contact Lens Section of UNIFESP and private clinics. Keratoconus was classified according to degrees of disease severity by keratometric pattern. Age, gender, diagnosis, keratometry, visual acuity, spherical equivalent (SE), base curve and clinical indication were recorded. RESULTS: Of 66 patients (80 eyes) with keratoconus the mean age was 29 years, 51.5% were men and 48.5% women. According to the groups: 15.0% were incipient, 53.7% moderate, 26.3% advanced and 5.0% were severe. The majority of the eyes of patients using contact lenses (91.25%) achieved visual acuity better than 20/40. To 88 eyes 58% were tihed with lens with spherical power (mean -5.45 diopters) and 41% with spherocylinder power (from -0.5 to -5.00 cylindrical diopters). The most frequent base curve was 7.6 in 61% of the eyes. The main reasons for this special lens fitting were due to reduced tolerance and poor fitting pattern achieved with other lenses. CONCLUSION: The special soft contact lens is useful in fitting difficult keratoconic patients by offering comfort and improving visual rehabilitation that may allow more patients to postpone the need for corneal transplant.

Wavefront-guided refractive surgery results of training-surgeons

PURPOSE To assess clinical outcomes and changes on higher-order aberrations (HOA) after wavefront-guided laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) for correction of myopia and myopic astigmatism performed by training-surgeons. METHODS One hundred and seventy patients had customized LASIK (207 eyes) and PRK (103 eyes) performed by surgeons in-training using the LADARVision 4000 (Alcon, Fort Worth, TX). Preoperative and 1, 3, 6 and 12 months postoperative data of spherical equivalent (SE), best spectacle-corrected visual acuity (BSCVA) and uncorrected visual acuity (UCVA) were analysed. Wavefront changes were determined using the LADARWave Hartmann-Shack wavefront aberrometer and the pupil size was scaled for 6.5 mm. RESULTS The mean SE in the LASIK group was -3.04 ±1.07 D and in the PRK group was -1.60 ± 0.59 D. At 1-year follow-up, (80.6%) (LASIK) and (66.7%) (PRK) were within ± 0.50 D of the intended refraction. The UCVA was 20/20 or better in (58.1%) (LASIK) and (66.7%) (PRK) of the operated eyes. A statistically significant positive correlation was found between achieved versus attempted refractive correction in both groups: LASIK (r=0.975, P<0.0005) and PRK (r=0.943, P<0.005). The higher-order aberrations (HO) RMS and coma did not changed significantly in the PRK group between preoperative and 1-year follow-up. In the LASIK group the HO RMS and coma changed between preoperative and 1-month postoperative but remained statistically unchanged during 1-year follow-up. The spherical aberration showed statistically significant changes in both groups. CONCLUSIONS Wavefront-guided LASIK and photorefractive keratectomy performed by training-surgeons were found to be similarly effective, predictable and stable.

Estudo do segmento anterior com a câmera rotatória de Scheimpflug em pacientes candidatos à cirurgia refrativa

PURPOSE: To analyze the anterior segment of refractive surgery candidates and establish the variability pattern in this population regarding corneal volume, anterior chamber volume and depth and corneal thickness, using the noncontact three dimensional analyzer Pentacam®. METHODS: A retrospective study of 297 eyes of 149 patients was conducted using Pentacam®. According to the spherical equivalent value two groups were created, myopia (n=242 eyes) and hyperopia (n=55 eyes), to analyze the variables of corneal volume, anterior chamber volume and depth and corneal thickness. RESULTS: The mean values of the myopia group were: corneal total volume 59.37 ± 3.51mm3, corneal volume at 3 mm 3.87 ± 0.23 mm3, at 5 mm 11.31 ± 0.67 mm3, and at 7 mm 24.30 ± 1.43 mm3, anterior chamber volume 198.74 ± 32.40 mm3, anterior chamber depth 3.19 ± 0.28 mm and corneal thickness 533.33 ± 33.47 mm. In the hyperopia group, the mean total corneal volume was 60.77 ± 3.31 mm3, corneal volume at 3 mm from the apex was 4.01 ± 0.20 mm3, at 5 mm was 11.73 ± 0.58 mm3, and at 7 mm was 25.09 ± 1.21 mm3, the anterior chamber volume was 146.61 ± 32.86 mm3, the anterior chamber depth was 2.76 ± 0.38 mm and the corneal thickness was 550.52 ± 29.49 mm. The difference between the groups was significant for all variables (p<0.05). CONCLUSION: We observed in this study that patients with myopia had lesser mean corneal volume and pachymetry, and greater anterior chamber depth and volume compared with hyperopic patients.

Long-term results of photorefractive keratectomy for myopia and myopic astigmatism

PURPOSE To assess the long-term refractive outcomes of photorefractive keratectomy in myopia and myopic astigmatism. METHODS A retrospective study of 120 photorefractive keratectomy operated eyes with at least four-year follow-up (maximum of 96 months, mean follow-up 55 months). We divided patients into group 1 (G1) spherical equivalent (SE) up to -4.00 diopters (D) and group 2 (G2) SE >-4.00 D. The Summit Apex Plus excimer laser was used for ablation. All eyes were analyzed in terms of uncorrected and best spectacle corrected visual acuity (UCVA/BSCVA) and cycloplegic refraction. Data were analyzed using the Refractive Surgery Consultant Elite database software. RESULTS G1 with 85 eyes (49 patients) presented mean SE -2.42 D and G2 with 35 eyes (22 patients) and mean SE of -4.45 D. Ninety-four percent of eyes in G1 and 82.9% of G2 were within +/-1.00 D of emmetropia at 4 years. The UCVA was 20/30 or better in 82.0% of G1 eyes and 77.0% of G2 in the last postoperative follow-up. No patient lost more than one line in G2 compared to 13.0% in G1. Eyes that gained one or more lines after 4-year follow-up were 11.9% G1 and 2.9% in G2, respectively. A statistically significant positive correlation was found between achieved versus attempted refractive correction in both groups (r=0.925, p<0.0005). CONCLUSIONS Photorefractive keratectomy was a safe and stable surgical procedure to correct myopic refractive errors, with no significant change in mean postoperative spherical equivalent refraction in the long-term follow-up.

Comportamento e características de usuários de lentes de contato entre estudantes universitários da área de saúde

Objetivo: Estudar o comportamento e caracteristicas de usuarios de lentes de contato ligados a area de saude. Metodo: Realizou-se um levantamento entre universitarios da area de saude da Pontificia Universidade Catolica do Parana, em Curitiba, no periodo de 23 a 27 de novembro de 1998. Para a coleta de dados foi utilizado um questionario auto-aplicavel, previamente testado. Resultados e Discussao: Dentre 1.173 estudantes, 207 (17,2%) usavam lentes de contato, sendo 78,3% do sexo feminino e 21,7% do sexo masculino. Eram usuarios de lentes rigidas 12,1% e 87,9% utilizavam hidrofilicas, demonstrando um aumento progressivo das ultimas quando se compara a estudos nacionais anteriores. Dos usuarios de lentes de contato hidrofilicas, 57,6% utilizavam descartaveis e desses 88,5% nao as utilizavam de acordo com os padroes de uso e descartabilidade estabelecidos. Do numero total de usuarios, 37,7% relataram algum problema ocular durante o uso. Embora 97,1% tenham feito a adaptacao com o oftalmologista, 14,2% dos usuarios de descartaveis nao obtiveram novas lentes em clinicas oftalmologicas. Por outro lado, 81,1% procuraram o oftalmologista, semestral ou anualmente, para a revisao da adaptacao. Recomendacao: Para reduzir o numero de complicacoes e a desistencia do uso de lentes de contato, o usuario deve ser educado sobre a forma correta de utiliza-las, ser orientado sobre os sinais e sintomas de alerta para problemas oculares e receber as informacoes tambem por escrito.