PERIPAPILLARY RETINAL NERVE FIBER THICKNESS CHANGES AFTER VITRECTOMY FOR EPIRETINAL MEMBRANE IN EYES WITH AND WITHOUT VITREOUS DETACHMENT

Long-Term Changes in Retinal Nerve Fiber Layer Thickness after Vitrectomy for Epiretinal Membrane Using Optical Coherence Tomography Images

This study investigated the long-term effects of epiretinal membrane (ERM) surgery on peripapillary retinal nerve fiber layer (RNFL) thickness using optical coherence tomography (OCT) images. We included 30 patients with idiopathic ERM who underwent a vitrectomy for ERM removal with internal limiting membrane peeling. The patients were followed up for 5 years after surgery, and their medical records were reviewed for best-corrected visual acuity (BCVA) and OCT parameters. The study population comprised 24 females (80.0%), and the mean age was 65.4 ± 7.2 years. The baseline BCVA significantly improved from 0.28 ± 0.24 to 0.12 ± 0.09 logMAR (p < 0.001) 1 year after surgery and continued to improve for 5 years after surgery. The peripapillary RNFL thickness initially increased after surgery and then gradually decreased. The peripapillary RNFL thicknesses of the global and temporal sectors showed significant reductions 2 years after surgery, whereas those of the nasal sectors did not significantly change. The peripapillary RNFL thickness was thinner in the global and temporal areas of the operated eyes than in those of the fellow eyes 4 and 5 years after surgery. In conclusion, peripapillary RNFL thicknesses decreased in the global and temporal areas after ERM surgery, whereas peripapillary RNFL thicknesses in the nasal sectors did not change significantly during the long-term follow-up.

Peripapillary microvasculature changes after vitrectomy in epiretinal membrane via swept-source OCT angiography

PURPOSE

To evaluate the peripapillary microvasculature changes in patients with epiretinal membrane (ERM) following pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling using swept-source optical coherence tomography angiography (SS-OCTA).

METHOD

Medical records and multimodal imaging data of 33 eyes after PPV for ERM were retrospectively reviewed. Peripapillary SS-OCTA images of 6×6 mm² were recorded at at pre- and post-operatively every 6 months for 1 year. A semi-automated method was used to analyzed SS-OCTA images, excluding the optic disc area, using the MATLAB software. The peripapillary vessel density (pVD) of superficial capillary plexus (SCP) and deep capillary plexus (DCP) was quantified in four quadrants (superior, inferior, nasal and temporal).

RESULT

The mean pVD in SCP and DCP decreased at 6- and 12-months follow-up. In sectoral analysis, superior, inferior, and temporal quadrants pVD in SCP and DCP were significantly reduced at 1 year after vitrectomy (all p < 0.05). Meanwhile, inferior quadrants pVD in SCP and DCP showed the earliest significant reduction at 6-months (p = 0.022 and 0.048, respectively). A reduction of post-operative mean pVD in DCP was significantly greater in patients with diabetic retinopathy (p = 0.043).

CONCLUSION

Peripapillary capillary density significantly decreased after surgical removal of ERM. Vitrectomy with ILM peeling can cause peripapillary microvascular damage starting in inferior sector.

Longitudinal Change in Retinal Nerve Fiber Layer Thickness and Its Association With Central Retinal Sensitivity After Epiretinal Membrane Surgery

PURPOSE

To investigate the longitudinal changes in the peripapillary retinal nerve fiber layer (pRNFL) thickness after epiretinal membrane (ERM) vitrectomy with internal limiting membrane (ILM) peeling, examine associations between pRNFL thickness and central retinal sensitivity, and identify predictors of postoperative pRNFL thickness.

DESIGN

Prospective, observational, cohort study.

METHODS

This study enrolled 82 eyes of 82 Japanese patients that underwent surgery for unilateral idiopathic ERM, with their fellow eyes as controls. pRNFL thickness was measured in 4 (superior, temporal, inferior, and nasal) quadrants preoperatively and at 1, 3, 6, and 12 months postoperatively. Microperimetry was performed at 12 months postoperatively to evaluate central retinal sensitivity. Regression tree analysis was performed to predict pRNFL thickness at 12 months postoperatively.

RESULTS

The temporal quadrant showed continuous pRNFL thinning after surgery, reaching statistical significance at 3, 6, and 12 months postoperatively (all P < 0.001). The pRNFL thicknesses in the fellow eyes significantly increased at all postoperative time points (all P < 0.001). At 12 months postoperatively, the average central retinal sensitivity was significantly correlated with the temporal pRNFL thickness in the eyes with ERM (r = 0.372, P < 0.001); no significant correlation was found in the fellow eyes. Regression tree analysis showed that the preoperative pRNFL thickness in the temporal quadrant and patient age were the main determinants of the temporal pRNFL thickness at 12 months postoperatively.

CONCLUSIONS

The risk of deterioration of central retinal sensitivity after ERM vitrectomy with internal limiting membrane peeling should be considered for patients with thin temporal pRNFLs and older adults.

The Effect of the Idiopathic Epiretinal Membrane and Surgically Induced Posterior Vitreous Detachment on the Retinal Nerve Fiber Layer

Aim

To investigate the changes in the retinal nerve fiber layer (RNFL) following pars plana vitrectomy (PPV) with surgically induced posterior vitreous detachment (PVD) and idiopathic epiretinal membrane (ERM) and internal limiting membrane (ILM) peeling.

Methods

Patients with unilateral ERM with vitreomacular traction were included in this prospective, randomized, and controlled clinical trial. The control group (Group 1) was formed with the nonoperated fellow eyes of the patients, and the study group (Group 2) was formed with the eyes that underwent PPV including idiopathic ERM and ILM peeling. In the preoperative and postoperative periods (1^st, 2^nd, 3^rd, 6^th, and 12^th months), complete ophthalmological examination of the eyes was performed and RNFL measurements were examined in 4 different quadrants (superior, temporal, inferior, and nasal) with the help of spectral domain optical coherence tomography (OCT).

Results

There was no statistically significant change in Group 1 during the follow-up period in all quadrants (p > 0.05). The mean RNFL thickness in Group 2 was statistically significantly higher than in Group 1 in superior, inferior, and temporal quadrants (p < 0.01), preoperatively. The mean RNFL in Group 2 was higher in the 1^st, 2^nd, 3^rd, and 6^th months and lower in the 12^th month in superior, inferior, and temporal quadrants (p < 0.01) when compared to the preoperative period. The mean RNFL thickness in the nasal quadrant in Group 2 was higher in the 1^st, 2^nd, and 3^rd (p < 0.01) months, same in the 6^th month (p > 0.05), and lower in the 12^th (p < 0.01) month when compared to the preoperative period.

Conclusion

Idiopathic ERM may cause an increase in RNFL thickness in superior, inferior, and temporal quadrants with possible tractional effect. PPV with PVD induction and ERM and ILM peeling may cause these RNFL changes.

Dynamics of structural reversal in Bruch's membrane opening-based morphometrics after glaucoma drainage device surgery

PURPOSE

Structural reversal of disc cupping is a known phenomenon after trabeculectomy. The aim of this retrospective, longitudinal, cross-sectional analysis was to evaluate the postoperative dynamics of Bruch's membrane opening-based morphometrics of the optic nerve head following glaucoma drainage device surgery.

METHODS

Forty-three eyes, treated by glaucoma drainage device surgery, were included in the study. Individual changes in the spectral domain optic coherence tomography (SD-OCT) parameters Bruch's membrane opening minimum rim width (BMO-MRW), Bruch's membrane opening minimum rim area (BMO-MRA) and peripapillary retinal nerve fiber layer (RNFL) thickness as well as mean defect in 30-2 perimetry were analyzed. Changes were correlated to postoperative intraocular pressure levels over time. Available follow-up visits were aggregated and grouped into a short-term follow-up (20 to 180 days after surgery), a midterm follow-up (181 to 360 days after surgery) and a long-term follow-up (more than 360 days after surgery).

RESULTS

In short-term follow-up, BMO-MRW and BMO-MRA increased significantly (p <= 0.034). This increase correlated negatively with the intraocular pressure at the time of the follow-up (Pearson's rho = - 0.49; p = 0.039). From 6 months after surgery on, there was no statistically significant change in BMO-MRW and BMO-MRA (p >= 0.207). RNFL thickness and mean defect of 30-2 perimetry showed no significant changes after GDD implantation (p >= 0.189).

CONCLUSIONS

Lowering of intraocular pressure by glaucoma drainage device surgery leads to an increase of Bruch's membrane opening based parameters in the first 6 months after surgery. These changes have to be taken into account when evaluating patients' longitudinal follow-up after glaucoma drainage device implantation.

Effect of partial posterior vitreous detachment on spectral-domain optical coherence tomography retinal nerve fibre layer thickness measurements

Background/aims

To assess the effect of partial posterior vitreous detachment (pPVD) on spectral-domain optical coherence tomography (OCT) peripapillary retinal nerve fibre layer thickness (RNFL) measurements.

Methods

Spectral-domain OCT RNFL thickness measurements were obtained from 684 consecutive patients who were seen in the Massachusetts Eye and Ear Glaucoma Service. Of these patients, we compared RNFL thickness measurements between 101 eyes of 101 glaucoma suspects who met inclusion criteria (55 eyes with and 46 eyes without pPVD).

Results

Among all 684 patients, 253 (37%) had pPVD in at least one eye. Among a subset of 101 eyes of 101 glaucoma suspects, average RNFL thickness was greater in eyes with compared to eyes without pPVD (p=0.02). Measurements were significantly greater in the inferior (p=0.004) and superior quadrants (p=0.008), but not in the nasal (p=0.10) and temporal quadrants (p=0.25). The difference in average RNFL thickness remained significant (p=0.05) even when corrected for expected age-related decline in RNFL thickness.

Conclusion

Over a third of patients were found on peripapillary spectral-domain OCT to have a pPVD, which was associated with greater RNFL thickness measurements. Judicious clinical interpretation of this finding on spectral-domain OCT RNFL thickness scans should be factored into the assessment of glaucoma suspects.