Spectrum of variants associated with inherited retinal dystrophies in Northeast Mexico.

BACKGROUND: Inherited retinal dystrophies are hereditary diseases which have in common the progressive degeneration of photoreceptors. They are a group of diseases with clinical, genetic, and allelic heterogeneity. There is limited information regarding the genetic landscape of inherited retinal diseases in Mexico, therefore, the present study was conducted in the northeast region of the country. METHODS: Patients with inherited retinal dystrophies were included. A complete history, full ophthalmological and medical genetics evaluations, and genetic analysis through a targeted NGS panel for inherited retinal dystrophies comprising at least 293 genes were undertaken. RESULTS: A total of 126 patients were included. Cases were solved in 74.6% of the study's population. Retinitis pigmentosa accounted for the most found inherited retinal disease. Ninety-nine causal variants were found, being USH2A and ABCA4 the most affected genes (26 and 15 cases, respectively). CONCLUSIONS: The present study documents the most prevalent causative genes in IRDs, as USH2A, in northeastern Mexico. This contrasts with previous reports of IRDs in other zones of the country. Further studies, targeting previously unstudied populations in Mexico are important to document the genetic background of inherited retinal dystrophies in the country.

SILICONE OIL VERSUS PERFLUOROPROPANE GAS TAMPONADE DURING VITRECTOMY FOR TRACTIONAL RETINAL DETACHMENT OR FIBROUS PROLIFERATION: A Randomized Clinical Trial.

PURPOSE: To compare vitreous substitution with silicone oil to perfluoropropane gas in proliferative diabetic retinopathy subjects undergoing pars plana vitrectomy (PPV) for the treatment of tractional retinal detachment or extensive fibrous proliferation. DESIGN: Randomized clinical trial. METHODS: Three hundred and two proliferative diabetic retinopathy subjects with tractional retinal detachment or extensive fibrous proliferation requiring PPV were enrolled into the trial. Subjects were prospectively randomized into one of two vitreous substitution groups during PPV: Group A subjects underwent 1,000 centistoke silicone oil tamponade, whereas Group B subjects underwent 14% to 16% silicone oil to perfluoropropane gas tamponade. The principal outcome was the best-corrected visual acuity at 6-month follow-up. Secondary outcomes were postoperative complications and unplanned PPV during the 6-month trial interval. RESULTS: Two hundred and fifty-eight subjects were randomized to receive a vitreous substitute and completed 6-month follow-up. Group B had better best-corrected visual acuity, more subjects ending up with 0.4 logarithm of the minimum angle of resolution (20/50) or better visual acuity, and more subjects ending up with 1 logarithm of the minimum angle of resolution (20/200) or better visual acuity at 6 months compared with Group A (P < 0.001, P = 0.02, P < 0.001, respectively). There were no significant differences in baseline characteristics, intraoperative or postoperative complications, or incidence of unplanned PPV between groups. CONCLUSION: This trial demonstrated that vitreous substitution with silicone oil to perfluoropropane gas resulted in better visual acuity at 6 months compared with silicone oil tamponade in proliferative diabetic retinopathy patients undergoing PPV for tractional retinal detachment or extensive fibrous proliferation. Surgeons should consider silicone oil to perfluoropropane gas tamponade as the first-line vitreous substitute in this patient population.

INTERNAL LIMITING MEMBRANE PEELING DURING VITRECTOMY FOR DIABETIC VITREOUS HEMORRHAGE: A Randomized Clinical Trial.

PURPOSE: To evaluate the benefits of internal limiting membrane peeling in proliferative diabetic retinopathy subjects undergoing pars plana vitrectomy for the treatment of vitreous hemorrhage. METHODS: Two hundred and fifty-eight proliferative diabetic retinopathy subjects undergoing pars plana vitrectomy for vitreous hemorrhage were enrolled into the trial. Patients were randomized into one of two cohorts: Group A patients underwent internal limiting membrane peeling, whereas Group B patients did not undergo internal limiting membrane peeling. The main outcome was best-corrected visual acuity at 6 months. Secondary outcomes were optical coherence tomography central macular thickness at 6 months, incidence of diabetic macular edema treatment during the postoperative trial period, and incidence of epiretinal membrane at 6 months. RESULTS: Two hundred and seven patients were randomized and completed 6 months follow-up. Group A had better best-corrected visual acuity at 6 months than Group B (P < 0.01). Group A had a lower incidence of diabetic macular edema treatment during the postoperative trial period and a lower incidence of epiretinal membrane at 6 months than Group B (P = 0.02 and P < 0.001, respectively). There was a trend toward lower central macular thickness on optical coherence tomography in Group A than Group B (P = 0.09). There were no significant differences in baseline details or complications intraoperatively or postoperatively between cohorts. CONCLUSION: This trial demonstrated better vision, fewer postoperative diabetic macular edema treatments, and a lower incidence of epiretinal membrane at 6 months when internal limiting membrane peeling was performed. Internal limiting membrane peeling may be considered a vital maneuver to perform in proliferative diabetic retinopathy subjects undergoing pars plana vitrectomy for vitreous hemorrhage.