Comparison of eye-rubbing effect in keratoconic eyes and healthy eyes using Scheimpflug analysis and a dynamic bidirectional applanation device.

PURPOSE: To compare the effect of eye rubbing on Scheimpflug imaging parameters and corneal biomechanics in eyes with keratoconus and healthy eyes. SETTING: Oftalmosalud Instituto de Ojos, Lima, Peru. DESIGN: Prospective cohort study. METHODS: The study included healthy and keratoconus patients who attended the institution between January 2017 and July 2017. Eye rubbing was performed for 1 minute followed by a 5-second break, followed by further rubbing for 1 minute. Baseline tests were performed before rubbing; post-rubbing tests were performed immediately after (0 minutes), and then again at 7 minutes and 14 minutes. Parameters related to anterior and posterior curvature and elevation, pachymetry, and corneal biomechanics obtained from tomography with a rotating Scheimpflug camera (Pentacam HR) and a dynamic bidirectional applanation device (Ocular Response Analyzer) were measured and compared between healthy and keratoconic eyes. RESULTS: The study included 30 healthy eyes and 31 keratoconic eyes. In the healthy group, the immediate mean changes in steeper anterior keratometry, posterior astigmatism, anterior chamber volume (ACV), flattest posterior keratometry, and Goldmann-correlated intraocular pressure (IOPg) after eye rubbing were 0.07 diopters (D) ± 0.15 (SD), -0.01 ± 0.08 D, 0.03 ± 7.06 mm3, -0.001 ± 0.04 mm, and -1.21 ± 1.99 mm Hg, respectively, whereas the mean changes in the keratoconus group were -0.03 ± 0.32 D, 0.14 ± 0.50 D, -5.09 ± 8.45 mm3, 0.03 ± 0.06 mm, and -1.61 ± 1.41 mm Hg, respectively. There were statistically significant differences between the preoperative and postoperative eye-rubbing values of posterior astigmatism, ACV, and IOPg in the keratoconus group (P = .03, P = .0003, and P = .001, respectively) but not in the healthy group (P = .65, P = .85, and P = .23, respectively). CONCLUSIONS: Unlike the healthy eyes group, the keratoconus group experienced significant changes in ACV, IOP, and corneal posterior astigmatism after eye rubbing.

Hemorrhagic Descemet Membrane Detachment during Ab Interno Canaloplasty.

PURPOSE: To describe a Descemet membrane detachment in peripheral cornea after canaloplasty with ab interno approach in glaucoma. CASE REPORT: A 60-year-old male with uncontrolled primary open-angle glaucoma (POAG) underwent ab interno canaloplasty in the left eye. The previous corrected visual acuity was 20/400 and intraocular pressure 26 mmHg with maximum medical therapy. There was evidence of minor intrastromal bleeding and limited Descemet membrane detachment during the introduction of intracanalicular viscoelastic. Speculate that the Descemet detachment occurred owing to the excessive pressure while injecting the viscoelastic. A conservative management was decided due to the size of the detachment outside the visual axis. On the first postsurgical day, the slit lamp biomicroscopy confirmed that the paralimbal extension of the pre-Descemet hemorrhage was 3mm and the radial extension was 2mm. Moreover the initial thickness of the pre-Descemet hemorrhage measurement with anterior segment OCT was 0.6mm. The follow-up was done weekly. At 3 months postoperatively, cornea recovered its transparency and morphology and intraocular pressure was 18mmHg with maximum medical therapy. CONCLUSION: Descemet membrane detachment by viscoelastic with partial intrastromal hematoma is a rare complication of the ab interno canaloplasty, which can be managed conservatively if it has not compromised the visual axis and has a limited extension.