Peripapillary changes after vitrectomy and silicone oil tamponade for rhegmatogenous retinal detachment.

PURPOSE: To evaluate the peripapillary changes after vitrectomy and silicone oil (SO) tamponade in eyes with rhegmatogenous retinal detachment (RRD). METHODS: In this study, 25-gauge vitrectomy with SO tamponade was performed in 22 eyes with RRD. The radial peripapillary capillary (RPC) vessel density (VD) and retinal nerve fiber layer thickness (RNFLT) were assessed by optical coherence tomography angiography at 2, 4, 8, and 12 weeks postoperatively. The values of healthy fellow eyes were used as controls. RESULTS: The global RPC VDs were significantly lower in the eyes with RRD than in fellow healthy eyes at 2 weeks (P < 0.001), and increased at 4 weeks, then decreased over time after surgery (F = 1.046, P = 0.377). The RPC VDs in the superior-hemifield were lower than those in the inferior-hemifield at 12 weeks postoperatively (t = -2.844, P = 0.010). The global RNFLTs decreased gradually after vitrectomy in the eyes with RRD (F = 1.312, P = 0.276). The RNFLTs in the superior-hemifield were thinner than those in the inferior-hemifield at 12 weeks postoperatively (t = -2.222, P = 0.037). The global, superior, and inferior RNFLTs were correlated with corresponding RPC VDs in the eyes with RRD at all time-points postoperatively (P < 0.05). CONCLUSION: RRD resulted in the decrease of RPC VDs. The RPC VDs recovered in the early postoperative period but were still lower than the normal level. Long-term application of SO tamponade resulted in the reduction of peripapillary VDs secondary to loss of RNFLTs.

Evaluation of macular vessel density changes after vitrectomy with silicone oil tamponade in patients with rhegmatogenous retinal detachment.

AIM: To evaluate macular microvasculature changes in eyes after pars plana vitrectomy (PPV) and intraocular silicone oil (SO) tamponade for macula-off rhegmatogenous retinal detachment (RRD) using optical coherence tomography angiography (OCTA). METHODS: Totally 19 eyes (19 patients) with macula-off RRD who underwent PPV and intraocular SO tamponade were retrospectively reviewed. The parafoveal superficial capillary plexus (SCP) vessel density (VD), deep capillary plexus (DCP) VD, choriocapillaris plexus (CCP) VD, and foveal macular thickness were evaluated using OCTA throughout 16wk postoperatively. The values of healthy fellow eyes were used as control. RESULTS: The parafoveal SCP, DCP, and CCP VDs were significant increased over time in RRD eyes during the 12wk postoperatively, then decreased at 16wk postoperatively (all P<0.01). The ratios of RRD eyes and fellow healthy eyes (r/f ratios) of the SCP and DCP VDs were lower than those of the CCP VD postoperatively (all P<0.05). There were not significant differences in the r/f ratios between SCP and DCP VDs postoperatively (all P>0.05). CONCLUSION: The parafoveal SCP, DCP, and CCP VDs gradually recover over time after PPV surgery with SO tamponade. Long-time SO tamponade might decrease postoperative macular VDs. Compared to parafoveal CCP VD, the parafoveal SCP and DCP VDs were more vulnerable in RRD eyes postoperatively.

Interchangeability and reliability of macular perfusion parameter measurements using optical coherence tomography angiography.

AIM: The aim of the study was to investigate the interchangeability and reliability of macular perfusion measurements using optical coherence tomography angiography. METHODS: A prospective cross-sectional observational study. Healthy adult Chinese subjects were recruited. Macular perfusion parameters were automatically analysed by software included in a spectral-domain optical coherence tomography system. The vessel density (VD) of the whole, parafovea, superior-hemi, inferior-hemi, fovea, temporal, superior, nasal and inferior quadrants as well as the foveal avascular zone (FAZ) and choroidal capillary VD (CCVD) were quantified. RESULTS: A total of 51 eyes in 27 subjects were included (8 men and 19 women, mean age 24±4 years). Significant differences in VD of all quadrants (all p<0.001) was detected between the 3×3 mm and 6×6 mm macular scan size. The biggest difference of VD between the two scan size was 5.14±4.03, which was not clinically meaningful. No statistically significant differences were found in FAZ or CCVD between the two different scan sizes. The mean intraclass correlation coefficient (ICC) between two measurements from the inter-rater of 20 eyes was from 0.560 to 0.893 for VD and 0.845 for FAZ. The mean ICC between two measurements from the intrarater of 20 eyes was from 0.497 to 0.870 for VD and 0.780 for FAZ. CONCLUSIONS: FAZ and CCVD are interchangeable between the 3×3 mm and 6×6 mm macular scan sizes. The VD differences between the two different scan sizes are not clinically meaningful. The macular perfusion parameters presented good but not perfect reliability, which should be acknowledged in clinical practice.

Corneal biomechanical properties changes after coaxial 2.2-mm microincision and standard 3.0-mm phacoemulsification.

AIM: To compare the changes in corneal biomechanics measured by ocular response analyzer (ORA) after 2.2-mm microincision cataract surgery and 3.0-mm standard coaxial phacoemulsification. METHODS: The prospective nonrandomized study comprised eyes with cataract that had 2.2-mm coaxial microincision or 3.0-mm standard incision phacoemulsification. The corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPcc) and Goldmann-correlated intraocular pressure (IOPg) were measured by ORA preoperatively and at 1d, 1-, 2-, 3- and 4-week postoperatively. Results were analyzed and compared between groups. RESULTS: In both groups, CH decreased in the immediate postoperative period (P<0.05), returned to the preoperative level at one week (P=0.249) in the 2.2-mm group, and at two weeks in the 3.0-mm group (P=0.264); there was no significant change in CRF values. In 2.2-mm group, mean IOPcc and IOPg increased at 1d postoperatively (both P<0.05), and returned to preoperative level at one week (P=0.491 and P=0.923, respectively). In 3.0-mm group, mean IOPcc and IOPg increased at 1d and 1wk postoperatively (P=0.005 and P=0.029, respectively), and returned to preoperative level at 2wk (P=0.347 and P=0.887, respectively). CONCLUSION: Significant differences between preoperative and postoperative corneal biomechanical values were found for CH, IOPcc and IOPg. But the recovery time courses were different between the two groups. The 2.2-mm coaxial microincision cataract surgery group seemed recovery faster compared to the 3.0-mm standard coaxial phacoemulsification group.