RESUMO
PURPOSE: To evaluate the safety and efficacy of corneal collagen cross-linking (CXL) by riboflavin/UV light for the treatment of keratoconus. METHODS: This randomized, prospective, and comparative study involved 10 eyes with keratoconus diagnosed between September 2006 and January 2008. Each patient underwent CXL in the keratoconus eye. Preoperative and postoperative (at 1, 3, 6, and 12 months) biomicroscopy examinations, distance uncorrected and best-corrected visual acuities, refractive error, endothelial cell counts, keratometry readings, ultrasound pachymetry, macular thickness, and Scheimpflug analyses were performed and compared. RESULTS: Mean uncorrected visual acuity was 1.18 logarithm of the minimum angle of resolution preoperatively and 0.46 logarithm of the minimum angle of resolution at 12 months postoperatively (P < 0.001). Statistically significant reductions in the mean maximum [2.66 diopter (D), P = 0.04] and minimum (1.61 D, P = 0.03) keratometry values were present at 12 months postoperatively, in addition there was a 2.25 D reduction in the mean spherical equivalent (P = 0.01). At the end of follow-up, 8 (80%) and 6 (60%) of the 10 eyes showed a decrease in the anterior and posterior elevation values, respectively, and the thinnest point of the cornea was statistically thinner by a mean of 13.4 µm (P = 0.03). No statistically significant differences were found between preoperative and postoperative endothelial cell counts and macular thicknesses. The improvements in visual acuity, keratometry readings, and spherical equivalent values occurred progressively during follow-up. CONCLUSIONS: CXL procedure is a safe treatment for keratoconus, yields good visual results, and reduces the progression of the disease, but long follow-up is necessary.
Assuntos
Colágeno/metabolismo , Córnea/metabolismo , Reagentes de Ligações Cruzadas , Ceratocone/tratamento farmacológico , Fotoquimioterapia , Riboflavina/uso terapêutico , Raios Ultravioleta , Adolescente , Adulto , Contagem de Células , Endotélio Corneano/patologia , Feminino , Humanos , Ceratocone/metabolismo , Ceratocone/fisiopatologia , Masculino , Fotografação , Fármacos Fotossensibilizantes/uso terapêutico , Estudos Prospectivos , Refração Ocular , Resultado do Tratamento , Acuidade Visual/fisiologia , Adulto JovemRESUMO
PURPOSE: To report a case of an abnormally thick flap that was detected with the use of anterior segment optical coherence tomography (OCT) prior to planned LASIK retreatment surgery. METHODS: A 43-year-old man presented 6 years after bilateral LASIK surgery with uncorrected visual acuity (UCVA) of 20/20 in the right eye and 20/100 in the left eye, and best spectacle-corrected visual acuity (BSCVA) of 20/20 in the right eye and 20/20 in the left eye (refraction -2.25 -1.25 x 131). Anterior segment OCT was performed before LASIK retreatment surgery in the left eye. RESULTS: The flap was found to be 394 microm and the residual stromal bed was too thin (152 microm) to allow for safe LASIK retreatment surgery. After waiting 4 months to ensure refractive stability, photorefractive keratectomy was performed. Postoperative UCVA was 20/20 plano. CONCLUSIONS: The use of anterior segment OCT in the preoperative examination for planned LASIK retreatment surgery provided more reliable data.