Evaluation of the safety of sclerotomy incision in patients with choroidal colobomas with/without associated microcornea.

PURPOSE:Whether the position of the ora serrata is normal in patients with choroidal colobomas remains unknown. The aim of this study was to measure the distance between the ora serrata and limbus in these patients and define safe sclerotomy sites for standard three-port pars plana vitrectomy. METHODS:Twelve patients with choroidal colobomas with normal corneas (Group 1) and 11 patients with choroidal colobomas with microcornea (Group 2) were included in the study. Twelve patients with simple retinal detachment served as control subjects. All participants underwent vitrectomy. The distance between the limbus and ora serrata, corneal diameter, and ocular axial length were measured. RESULTS:The average corneal diameter was 10.9 mm in Group 1, 7.9 mm in Group 2, and 11.4 mm in the control group. The average distance between the limbus and ora serrata was 6.3 mm in Group 1, 7.6 mm in Group 2, and 6.2 mm in the control group. There were significant differences in the distance between the limbus and ora serrata among the 3 groups (analysis of variance test, P < 0.05). CONCLUSION:Our study confirmed that it is safe to perform a sclerotic puncture 4 mm posterior to the limbus for vitrectomy in patients with choroidal colobomas with or without microcornea.