RESUMO
PURPOSE: To present the prospective application of the Orbscan II central 2-mm total-mean corneal power obtained by quantitative area topography in intraocular lens (IOL) calculation after refractive surgery. METHODS: Calculated and achieved refraction and the difference between them were studied in 77 eyes of 61 patients with previous radial keratotomy (RK), RK and additional surgeries, myopic LASIK, myopic photorefractive keratectomy (PRK), or hyperopic LASIK who underwent phacoemulsification without complications in 3 eye centers. All IOL calculations used the average from the central 2-mm Orbscan II total-mean power of maps centered on the pupil without the use of previous refractive data. Six IOL styles implanted within the bag were used. RESULTS: Using the SRK-T formula, the overall calculated refraction was -0.64+/-0.93 diopters (D). The overall achieved spherical equivalent refraction (-0.52+/-0.79 D; range: -3.12 to 1.25 D; 95% confidence interval [CI]: -0.70/-0.34 D) was +/-0.50 D in 53% of eyes, +/-1.00 D in 78% of eyes, and +/-2.00 D in 99% of eyes. The overall difference between the calculated and achieved refraction (0.12+/-0.93 D, P=.27; range: -2.18 to 2.62 D; 95% CI: 0.09/0.33 D) was +/-0.50 D in 39% of eyes, +/-1.00 D in 77% of eyes, and +/-2.00 D in 96% of eyes. This difference was +/-1.00 D in 77% of eyes with RK (P=.70), 82% of eyes with myopic LASIK (P=.34), and 90% of eyes with myopic PRK (P=.96). In eyes with RK followed by LASIK, a trend toward undercorrection was noted (P=.03). In eyes with hyperopic LASIK, a trend toward overcorrection was noted (P=.005). CONCLUSIONS: In eyes with previous corneal refractive surgery, IOL power calculation can be performed with reasonable accuracy using the Orbscan II central 2-mm total-mean power. This method had better outcomes in eyes with previous RK, myopic LASIK, and myopic PRK than in eyes with hyperopic LASIK or RK with LASIK.
Assuntos
Cirurgia da Córnea a Laser , Topografia da Córnea/métodos , Lentes Intraoculares , Óptica e Fotônica , Humanos , Hiperopia/cirurgia , Implante de Lente Intraocular , Miopia/cirurgia , Facoemulsificação , Estudos ProspectivosRESUMO
PURPOSE: To describe ultrasonographic findings of stages 4 and 5 retinopathy of prematurity. PATIENTS AND METHODS: Ocular ultrasonography was performed using a 10-MHz transducer. Forty-four patients (88 eyes) with stages 4 and 5 retinopathy of prematurity were evaluated. Twenty-five patients were female. The mean age was 8.4 months (standard deviation, +/- 4.9). RESULTS: Retinal detachment configurations were as follows: 31% closed posterior and open anterior, 19% closed posterior and anterior, 14% open posterior and anterior, and 14% open posterior and closed anterior. Additional findings included vitreous opacities (14%), proliferative vitreoretinopathy (22%), subretinal opacities (24%), choroidal thickening (18%), and reduced axial diameter (75%). CONCLUSIONS: Ultrasonographic evaluation in eyes with advanced retinopathy of prematurity guides surgical indication, management, and visual prognosis.