Vitrectomy for Epiretinal Membranes: Ganglion Cell Features Correlate with Visual Function Outcomes

Functional and anatomic changes between early postoperative recovery and long-term follow-up after combined epiretinal and internal limiting membrane peeling

OBJECTIVE

To evaluate short- and long-term changes in best-corrected visual acuity (BCVA) and retinal layer thicknesses after combined epiretinal membrane (ERM) and internal limiting membrane (ILM) peeling for macular holes and symptomatic ERMs.

DESIGN

Retrospective observational case series.

PARTICIPANTS

Patients with ERMs or with macular holes and ERMs treated with combined ERM and ILM peeling.

METHODS

Study eyes (n = 36) and healthy fellow eyes (n = 17) were evaluated using the automated segmentation of retinal layers performed by SPECTRALIS software that automatically calculated the average central retinal thickness and the average thickness in each of the individual retinal layers. The analysis was performed at 6-18 months after surgery and after 60 months.

MAIN OUTCOME MEASURES

Changes in BCVA and retinal layer thicknesses determined by automated segmentation at the first and last follow-up visits.

RESULTS

BCVA improved from a baseline 0.48 ± 0.25 logMAR (20/60 Snellen) to 0.18 ± 0.18 logMAR (20/30 Snellen) at the short-term postoperative examination (p < 0.0001). Between first and last follow-up visit, 5 eyes (14%) were classified as better, 28 (78%) as stable, and 3 (8%) as worse. BCVA of the control fellow eyes remained stable during the follow-up. The thicknesses of retinal layers decreased significantly (p < 0.009). At the last follow-up, the ganglion cell layer was thinner and the inner nuclear layer was thicker in the operated eyes compared with the healthy fellow eyes.

CONCLUSION

Combined ERM and ILM peeling may improve BCVA in some patients. However, over a long follow-up period, it can be associated with progressive ganglion cell layer thinning that could affect BCVA stability.

A Comparison of Peel-Induced Maculopathy Following ILM Peeling Using a Microvacuum Pick Versus Forceps

OBJECTIVE

To compare peel-induced maculopathy (PIM) using surgical forceps versus the microvacuum pick (MVP).

METHODS

Consecutive eyes undergoing internal limiting membrane (ILM) peeling using either the MVP or forceps were assessed. En face optical coherence tomography (OCT) images at the level of the nerve fiber layer were generated for 6-month postoperative visit. The percentage of the imaged area showing PIM was termed the PIM index. PIM severity was additionally measured using a qualitative PIM severity scale.

RESULTS

Seventy-four consecutive eyes underwent ILM peeling with either the MVP (36/74; 49%) or forceps (38/74; 51%). At month-6 postoperatively, the mean PIM index for forceps was 7.7% vs 4.7% for the MVP (P < 0.001, R² = 0.15). At 6 months, 26/38 eyes (68.5%) in the forceps group had either moderate or severe PIM compared to 12/36 eyes (33.3%) in the MVP group (P = 0.001).

CONCLUSIONS

ILM peeling with the MVP resulted in lower PIM severity compared to forceps. [Ophthalmic Surg Lasers Imaging Retina 2023;54:37-42.].

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.

FACTORS RELATED TO UNFAVORABLE VISUAL OUTCOME AFTER IDIOPATHIC EPIRETINAL MEMBRANE SURGERY IN PATIENTS WITH GLAUCOMA

PURPOSE

To evaluate the visual outcomes after idiopathic epiretinal membrane surgery in glaucomatous and nonglaucomatous eyes and factors related to unfavorable outcomes in glaucomatous eyes.

METHODS

This was a retrospective cohort study including patients undergoing idiopathic epiretinal membrane surgery with ≥12-month follow-up. Final visual acuity at pseudophakic status was compared among groups of glaucoma, glaucoma suspect, and nonglaucoma and correlated with optical coherence tomography and visual field characteristics in patients with glaucoma.

RESULTS

Of the 314 patients enrolled, 31 had glaucoma and 22 were glaucoma suspect. Baseline visual acuity and central foveal thickness were similar across the groups. Most patients had improved/stable visual acuity postoperatively, with a lower proportion of 83.9% with glaucoma than 96.9% and 100% without glaucoma and glaucoma suspect, respectively (P = 0.002). The mean visual acuity did not change in the glaucoma group (from 6/29 to 6/23), but it improved from 6/25 to 6/12 (a gain of 16.7 approxETDRS letters) in nonglaucoma and 6/26 to 6/14 in glaucoma suspect (a gain of 14.0 approxETDRS letters) (both P < 0.001). The change of visual acuity was correlated with preoperative visual field defects (P < 0.001, r2 = 0.554). Patients with glaucoma with more advanced, fixation-threatening defects or temporally located inner nuclear layer microcysts were more likely to have worsened visual acuity.

CONCLUSION

Visual field testing is imperative for patients with glaucoma before idiopathic epiretinal membrane surgery for outcome assessment.

Unsuspected Central Vision Decrease from Macular Ganglion Cell Loss after Posterior Segment Surgery

PURPOSE

To describe a novel post-surgical complication of circumscribed macula ganglion cell loss as an apparent cause of unsuspected vision loss following posterior segment surgery.

METHODS

Patients were seen in referral and were evaluated with comprehensive examination to include optical coherence tomography (OCT) and microperimetry.

RESULTS

All 8 patients had a sudden central vision loss following vitrectomy and many patients suspected the central loss was present even before the eye patch was removed on the first postoperative day. Of the 8, 1 had a vitrectomy with no membrane peeling while the remaining 7 had membrane peeling. The mean post-operative visual acuity was 20/200. The mean ganglion cell layer (GCL) volume was 0.69 µm3 in the involved eye and 1.035 µm3 in the fellow eye (P<.001). The global retinal nerve fiber layer (RNFL) thicknesses in the involved and fellow eyes were 81.3 and 90 µm respectively (P = .08). The outer retinal architecture was unremarkable in the involved eyes and did not appear to explain the poor acuity. The GCL volume loss was not necessarily associated with RNFL thicknesses that were in the abnormal range or in optic nerve pallor. Microperimetry showed severe depression of the threshold sensitivities.

CONCLUSION

Severe loss of the macular ganglion cells may occur after vitrectomy and is associated with central vision loss. The diagnosis is made by having a high index of suspicion when examining OCT B-scan images and by evaluating GCL volumes. The frequency of this occurrence is currently unknown.

Vitrectomized versus non-vitrectomized eyes in diabetic macular edema response to ranibizumab-retinal layers thickness as prognostic biomarkers

To evaluate the role of the vitreous in the management of diabetic macular edema with ranibizumab intravitreal injections in a pro re nata regimen. Prospective study of 50 consecutive eyes with diabetic macular edema treated with ranibizumab and 12 months of follow-up. Primary endpoint: to assess differences between non-vitrectomized and vitrectomized eyes in the number injections needed to control the edema. Secondary endpoints: comparison of groups regarding best corrected visual acuity, central foveal thickness and thickness of seven retinal layers. 46 eyes from 38 patients, 10 vitrectomized and 36 non-vitrectomized, completed the follow-up. At month 12, the two groups achieved an equivalent anatomical outcome and needed a similar number of ranibizumab intravitreal injections. In vitrectomized eyes final visual acuity was worse when baseline retinal nerve fiber layers in the central foveal subfield were thicker, showing a strong correlation (r = − 0.942, p < 0.001). A similar, albeit moderate correlation was observed in non-vitrectomized eyes (r = − 0.504, p = 0.002). A decrease of retinal nerve fiber layers inner ring thickness was correlated with a better final visual acuity only in vitrectomized eyes (r = 0.734, p = 0.016). The effect of diabetic macular edema seems to be worse in vitrectomized eyes, with a thinner inner retina reservoir.

Clinicaltrials.govNCT04387604.

Structure-function analysis for macular surgery in patients with coexisting glaucoma

PURPOSE

To develop methods to assess the effects of epiretinal membranes (ERM) and macular holes (MH) coexisting with glaucoma on pre-operative retinal structure and function and evaluate post-operative outcomes.

METHODS

Seven eyes of 7 patients with glaucoma, 6 with ERMs and 1 with MH, were enrolled; 4 underwent vitrectomy for ERM and one for MH. Visual fields (VFs) and optical coherence tomography (OCT) scans were obtained pre- and post-operatively. The 10-2VF deviation map was overlayed on ganglion cell and inner plexiform layer (GCL + IPL) and retinal nerve fiber layer (RNFL) deviation maps derived from OCT macula and disc cube scans. Optic nerve circle scans were obtained to assess RNFL thickness, and OCT b-scans associated with VF defects were compared pre- and post-operatively.

RESULTS

Examination of pre-operative VFs and OCT scans showed the importance of determining the extent to which glaucomatous damage contributed to VF loss; verifying automated segmentation of the GCL + IPL and RNFL; and assessing foveal anatomy. Evaluation of post-operative structure-function outcomes required correction of magnification changes in OCT scans and repeated follow-up visits to clarify the origin of VF changes.

CONCLUSIONS

Pre-operative comparisons of VFs and OCT scans may be beneficial in guiding surgical planning, and evaluating outcomes, in eyes with glaucoma undergoing macular surgery.

Inner retinal structure and visual function after idiopathic epiretinal membrane surgery with and without brilliant blue G

PURPOSE

Vital dyes are frequently used to visualize the internal limiting membrane (ILM) of the neuroretina. This study evaluated and compared the microstructure of the inner retina and visual function with and without brilliant blue G (BBG) staining for ILM peeling during idiopathic epiretinal membrane (ERM) surgery.

STUDY DESIGN

Retrospective, consecutive, interventional case series.

METHODS

Fifty-five patients (55 eyes) with ERM underwent ILM peeling without dyes (non-dye group) and 55 patients (55 eyes) underwent ILM peeling with BBG staining (BBG group). The logMAR visual acuity (VA) and ganglion cell complex (GCC) thickness were measured using optical coherence tomography at baseline and 12 months after surgery.

RESULTS

LogMAR VA improved significantly in both groups at 12 months and the BBG group tended to be better than the non-dye group but with no significant difference between the groups (unpaired t-test, P = 0.490). The average GCC thickness significantly decreased in both groups; however, there was no difference in the rates of change in GCC thickness between the groups. The ratio of GCC thickness to total retinal thickness (%) was significantly higher in the BBG group in the superior quadrant at 12 months postoperatively (P = 0.010).

CONCLUSION

BBG-assisted ERM surgery resulted in better visual improvement and fewer structural changes in the inner retinal layers. BBG-assisted ILM peeling is safe both functionally and anatomically.

Evaluation of postoperative visual function based on the preoperative inner layer structure in the epiretinal membrane

PURPOSE

To evaluate the postoperative visual function using a preoperative epiretinal membrane (ERM) classification based on the status of the inner layer structure.

METHODS

We assessed 62 eyes, one from each patient undergoing vitrectomy with internal limiting membrane (ILM) peeling for unilateral ERM. The inclusion criteria were as follows: (1) the presence of idiopathic ERM based on optical coherence tomography and a healthy contralateral eye, (2) successful surgery after 25- or 27-gauge transconjunctival 3-port pars plana vitrectomy with ILM peeling, and (3) a minimum follow-up period of 12 months. We included patients with preoperative ERM morphology with no disruption of the inner retinal layer in group A (37 eyes) and those with disruption in group B (25 eyes) and compared the visual acuity, central visual-field sensitivity (CVFS) measured using the Humphrey field analyzer 10-2 program, and detection rate of micro-scotoma (< 10 dB) at baseline and 12 months postoperatively between the groups.

RESULTS

Visual acuity at 12 months showed greater improvement in group A than in group B (P = .03). There was no significant difference in CVFS at baseline; however, that of the nasal area was substantially lower after surgery in group B than in group A (P = .02). The 12-month postoperative detection rate of micro-scotoma was significantly higher in group B than in group A (P = .002).

CONCLUSION

ERM that has preoperatively disrupted the inner layer poses the risks of CVFS reduction and micro-scotoma formation after vitrectomy. Evaluating the inner layer could be an important prognostic factor in determining retinal function in ERM.

Optical coherence tomography angiography and Humphrey field analyser for macular capillary non-perfusion evaluation in branch retinal vein occlusion

We non-invasively evaluated macular non-perfused areas (m-NPAs) of branch retinal vein occlusion (BRVO) using optical coherence tomography (OCT) angiography and the Humphrey visual field analyser 10-2 programme (HFA 10-2). We enrolled 30 patients (30 eyes) with macular oedema secondary to BRVO. OCT angiography was used to photograph the macula at 6 × 6-mm; sizes of m-NPAs in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were measured in four areas. For HFA 10-2, we divided the actual measurement threshold of 68 points into four areas and calculated the mean central visual field sensitivity (CVFS). The correlation between the mean m-NPA and mean CVFS (dB) in each area was examined. There was a strong correlation between the m-NPA of each region detected in SCP and DCP, and the mean CVFS of each corresponding area (SCP: r = − 0.83, r = − 0.64, r = − 0.73, and r = − 0.79; DCP: r = − 0.82, r = − 0.71, r = − 0.71, and r = − 0.70), p values were < 0.001 for all. m-NPAs were associated with decreased visual field sensitivity in BRVO. Non-invasive m-NPA evaluation was possible using OCT angiography and HFA 10-2.

Effect of internal limiting membrane peeling on visual field sensitivity in eyes with epiretinal membrane accompanied by glaucoma with hemifield defect and myopia

PURPOSE

To investigate the effects of internal limiting membrane (ILM) peeling on visual field sensitivities in eyes with epiretinal membrane (ERM) accompanied by glaucoma with hemifield defect and myopia.

STUDY DESIGN

Retrospective clinical study METHODS: We reviewed clinical records of patients with ERM who underwent vitrectomy and ERM/ILM peeling. We first collected clinical data of eyes with ERM and glaucoma with hemifield defect. We recorded visual field sensitivities at 52 points and analyzed differences between before and after surgery. We then compared the changes in visual field sensitivity between glaucomatous and normal hemifields. Next, we collected ERM eyes without glaucoma and stratified them into two groups based on axial length (threshold = 26.0 mm). In these eyes, we also recorded visual field sensitivities at 52 points and analyzed differences between before and after surgery.

RESULTS

The study included 18 eyes with ERM and glaucoma with hemifield defect (11 men; mean age, 68.3 ± 7.2 years). These eyes showed significant sensitivity reductions at 5/26 points, mainly in the nasal area of the glaucomatous hemifield, whereas only 1/26 points exhibited significant sensitivity reduction in the normal hemifield. In eyes with axial length <26.0 mm and axial length ≥26.0 mm, 29 peripheral and seven superior peripheral points showed significant improvements in visual field sensitivities, respectively.

CONCLUSION

Visual field sensitivity reduction occurred mainly in the nasal region of the glaucomatous hemifield. Differences in axial length alone were not a prominent risk factor for reduced visual field sensitivity after ILM peeling in eyes with ERM.

Retinal applications of swept source optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA)

The advent of optical coherence tomography (OCT) revolutionized both clinical assessment and research of vitreoretinal conditions. Since then, extraordinary advances have been made in this imaging technology, including the relatively recent development of swept-source OCT (SS-OCT). SS-OCT enables a fast scan rate and utilizes a tunable swept laser, thus enabling the incorporation of longer wavelengths than conventional spectral-domain devices. These features enable imaging of larger areas with reduced motion artifact, and a better visualization of the choroidal vasculature, respectively. Building on the principles of OCT, swept-source OCT has also been applied to OCT angiography (SS-OCTA), thus enabling a non-invasive in depth-resolved imaging of the retinal and choroidal microvasculature. Despite their advantages, the widespread use of SS-OCT and SS-OCTA remains relatively limited. In this review, we summarize the technical details, advantages and limitations of SS-OCT and SS-OCTA, with a particular emphasis on their relevance for the study of retinal conditions. Additionally, we comprehensively review relevant studies performed to date to the study of retinal health and disease, and highlight current gaps in knowledge and opportunities to take advantage of swept source technology to improve our current understanding of many medical and surgical chorioretinal conditions. We anticipate that SS-OCT and SS-OCTA will continue to evolve rapidly, contributing to a paradigm shift to more widespread adoption of new imaging technology to clinical practice.

Glaucoma-related central visual field deterioration after vitrectomy for epiretinal membrane: topographic characteristics and risk factors

BACKGROUND/OBJECTIVES

To identify risk factors for glaucoma-related central visual field (VF) deterioration after vitrectomy with internal limiting membrane (ILM) peeling for epiretinal membrane (ERM).

SUBJECTS/METHODS

A prospective cohort study consisting of cases with or without glaucoma (33 eyes of 33 patients in each group) who underwent vitrectomy with ILM peeling for ERM. Humphrey 10-2 VFs and ganglion cell complex (GCC) thickness were measured at baseline and about 3, 6, and 12 months postoperatively. Longitudinal changes in VF indices and factors associated with their postoperative changes were investigated using mixed-effects models, as was sectorwise total deviation (TD) analysis using six sectors consisting of outer/inner arcuate and cecocentral sectors in each hemifield.

RESULTS

VF mean deviation significantly deteriorated postoperatively only in the glaucoma group (P < 0.001). Older age, longer axial length, preoperative worse mean deviation, and thinner GCC were significant risk factors for postoperative deterioration (coefficient ± standard errors: -0.139 ± 0.067, -0.740 ± 0.241, 0.16 ± 0.07, 0.050 ± 0.020; P = 0.038, P = 0.002, P = 0.024, P = 0.012, respectively). Sectorwise analysis revealed that TD in the superior/inferior outer arcuate sectors significantly deteriorated only in the glaucoma group. Preoperative worse TD and thinner GCC were significant risk factors for deterioration in the superior outer arcuate sector (0.65 ± 0.11, 0.08 ± 0.03; P < 0.001, P = 0.042, respectively).

CONCLUSIONS

Central VF deterioration, especially in the outer arcuate sectors, found to be glaucoma-related changes after vitrectomy with ILM peeling for ERM. Preoperative worse VF and thinner GCC were identified as risk factors for postoperative VF deterioration.

Early retinal flow changes after vitreoretinal surgery in idiopathic epiretinal membrane using swept source optical coherence tomography angiography

(1) Background: The aim of this observational cross-sectional work was to investigate early retinal vascular changes in patients undergoing idiopathic epiretinal membrane (iERM) surgery using swept source optical coherence tomography angiography (SS-OCTA); (2) Methods: 24 eyes of 24 patients who underwent vitrectomy with internal limiting membrane (ILM) peeling were evaluated pre- and postoperatively using SS-OCTA system (PLEX Elite 9000, Carl Zeiss Meditec Inc., Dublin, CA, USA). For each eye, five 6x6-mm OCTA volume scans were acquired by two observers independently. The en face images of superficial capillary plexus (SCP) were then exported to imageJ and a semi-automated algorithm was used for subsequent quantitative analysis. Perfusion density (PD), vessel length density (VLD), vessel diameter index (VDI) and vessel tortuosity (VT) of SCP were evaluated in both the parafoveal (2.5 mm diameter) and perifoveal areas (5.5 mm diameter); (3) Results: At OCTA analysis statistically significant differences were found between controls and diseased eyes for all parameters in parafoveal and perifoveal regions (p < 0.001; p < 0.05) except for perifoveal VLD. During 6-month follow up, both anatomical/perfusion and functional parameters showed a statistically significant improvement if compared to preoperative values. In detail, at one-month post vitrectomy, VLD and VT significantly changed in parafoveal region (p = 0.043; p = 0.045), while PD and VDI showed a trend of increase in both parafoveal and perifoveal region. At 6 months after surgery, PD, VLD and VT of parafoveal region significantly improved (p = 0.021, p = 0.018, p = 0.047 respectively). (4) Conclusions: SS-OCTA provides a quantitative and qualitative analysis of the superficial capillary plexus allowing for early vascular changes assessment after vitrectomy with iERM and ILM peeling.