Macular vascularisation changes analysed using OCT angiography after successful rhegmatogenous retinal detachment repair.

AIM: To analyse the macular vascularisation changes analysed using optical coherence tomography angiography (OCTA) after successful rhegmatogenous retinal detachment (RRD) repair by comparing gas vs silicone oil and macula-on vs macula-off. METHODS: This retrospective data collection included 77 eyes with RRD that underwent pars plana vitrectomy (PPV) and gas or silicone oil tamponade. We performed an OCTA during the postoperative control between 6 and 24mo after the last surgery and evaluated the main parameters measured by OCTA: foveal avascular zone (FAZ) and parafoveolar vascular density (PVD) in the superficial capillary plexus. The patients were divided into four groups: RRD with macular involvement treated with gas tamponade, RRD without macular involvement treated with gas tamponade, RRD with macular involvement treated with silicone oil tamponade and RRD without macular involvement treated with silicone oil tamponade. A one-way ANOVA test combined with post hoc Bonferroni corrections compared FAZ sizes and PVD in all four groups. RESULTS: The FAZ size was statistically significantly larger in eyes with RRD involving the macula than in those not involving it (P=0.005). There was no statistically significant difference in the FAZ sizes of the eyes treated with silicone oil tamponade compared to those treated with gas tamponade (P=0.54). There was no statistically significant difference in the PVD comparing all four groups. CONCLUSION: Despite the known risks associated with silicone oil, our findings suggest that the type of tamponade used during PPV to treat an RRD has no significant effect on the future integrity of the PVD or the size of the FAZ in the superficial capillary plexus as measured by OCTA.

Impact of Hypothyroidism on Tomography and Biomechanics in Keratoconus - Cross-Sectional and Longitudinal Assessment within the Homburg Keratoconus Center at the Time of Inclusion and after 1 Year.

BACKGROUND AND PURPOSE: The etiology of keratoconus (KC) is probably multifactorial but remains essentially unknown. Previous scientific observations have suggested that hypothyroidism might play a role in the development and progression of KC. The purpose of this study was to analyze the tomographic and biomechanical parameters in KC patients with or without hypothyroidism. METHODS: Twenty-eight patients with KC and hypothyroidism (HT group) and fifty-six KC patients without thyroid dysfunction (WHT group) with matching gender and age were analyzed. Mean age was 40.3 years (range 14 - 57) in the HT group and 40.3 years (range 14 - 57) in the WHT group. Routine ophthalmic examinations consisted of corneal tomography and biomechanical parameters. We extracted the following KC parameters from the Pentacam (Pentacam HR, Oculus, Wetzlar, Germany): Keratoconus Index (KI), maximum keratometry (Kmax), astigmatism, and thinnest pachymetry (TP). From the ocular response analyzer (ORA, Reichert Ophthalmic Instruments, Depew, NY, USA), we extracted corneal hysteresis (CH), corneal resistance factor (CRF), and KC match index (KMI). RESULTS: The comparison of the tomographic and biomechanical values from cross-sectional and longitudinal analyses showed no significant differences between the HT and WHT groups. CONCLUSION: The severity of KC based on tomographical and biomechanical parameters does not seem to depend on the presence of hypothyroidism.