Time Course of Changes in Aniseikonia and Foveal Microstructure after Vitrectomy for Epiretinal Membrane

Impact of retinal traction induced by epiretinal membrane on aniseikonia

We investigated the effect of retinal traction caused by epiretinal membranes (ERMs) on aniseikonia and retinal microstructures in 81 unilateral ERMs. Retinal traction was quantified by measuring the maximum depth of the retinal fold (MDRF) using en face optical coherence tomography (OCT) images. Measurements included the mean inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), central retinal thickness (CRT), and interocular ratios of the foveal avascular zone (FAZ) area (FAZ ratio). Significant correlations were found between the preoperative MDRF and preoperative aniseikonia (P < 0.001), INL thickness (P < 0.001), CRT (P < 0.001), and FAZ ratio (P = 0.003). Preoperative aniseikonia was significantly correlated with preoperative INL and OPL-ONL thicknesses (P < 0.001 and P = 0.020, respectively) and CRT (P = 0.003). Multiple regression analysis revealed that preoperative aniseikonia was significantly associated with preoperative MDRF, INL, and OPL-ONL thicknesses (P = 0.029, 0.006, and 0.006, respectively). Twenty-nine eyes underwent membrane peeling, resolving all retinal folds 6 months postoperatively. A significant correlation was observed between preoperative MDRF and postoperative aniseikonia (P = 0.011). Our findings suggest that retinal traction by ERM is significantly associated with aniseikonia both pre- and postoperatively, alongside other OCT parameters.

Relationship between binocular vision and Govetto's stage in monocular idiopathic epiretinal membrane

Govetto's staging system (stages 1-4) for epiretinal membrane (ERM) based on optical coherence tomography images is a useful predictor of monocular visual function; however, an association between Govetto's stage and binocular vision has not been reported. This study aimed to investigate the factors associated with Govetto's stage among the monocular and binocular parameters. This retrospective study included consecutive patients with treatment-naïve eyes with unilateral ERM without pseudo-hole. We investigated Govetto's stage, degrees of aniseikonia and metamorphopsia, foveal avascular zone area, central retinal and choroidal thickness, vertical ocular deviation, stereopsis, and binocular single vision (BSV). We compared the parameters between the BSV-present and BSV-absent groups and investigated correlations between Govetto's stage and the monocular and binocular parameters. Twenty-eight eyes of 28 patients were examined (age, 66.6 ± 10.2 years). In multivariate correlation analyses, Govetto's stage correlated with BSV (P = 0.04, β = - 0.36) and central retinal thickness (P < 0.001, β = 0.74). Of the eyes, 18 were assigned to the BSV-present group and 10 to the BSV-absent group. Govetto's stage was significantly more advanced in the BSV-absent group than in the BSV-present group (3.2 ± 0.8 vs 2.5 ± 0.7, P = 0.03). Of the 28 patients, 11 (39%) showed small-angle vertical deviations (1-12Δ). In conclusion, our findings showed that Govetto's stage correlated with binocular vision in patients with monocular ERM. Govetto's staging is a useful parameter for predicting not only monocular but also binocular vision.

Cellular Determinants of Visual Outcomes in Eyes with Epiretinal Membrane: Insights from Adaptive Optics OCT

Objective

In this study, we aimed to evaluate cellular alterations in the foveal neuroglia of eyes with idiopathic epiretinal membrane (ERM) and examine their correlation with visual function. We also aimed to identify prognostic markers for visual outcomes postvitrectomy.

Design

A prospective longitudinal study.

Subjects

The study comprised 84 subjects, including 50 eyes diagnosed with idiopathic ERM and 34 healthy eyes serving as controls.

Methods

The foveal neuroglial changes in eyes with idiopathic ERM were determined using adaptive optics OCT (AO-OCT) by comparing them with healthy eyes. For patients with ERM, the ERM and inner limiting membrane were removed during vitrectomy in all eyes.

Main Outcome Measures

Foveal microstructures on AO-OCT images, best-corrected visual acuity (BCVA) and M-CHARTS scores, evaluated preoperatively and at 1, 3, and 6 months postoperatively, and associations between foveal neuroglial changes and these parameters.

Results

Adaptive optics OCT revealed discernible differences in the foveal cones of the eyes with ERM and their healthy counterparts. The thickness of the ellipsoid zone (EZ) band was augmented in eyes with ERM. The alignment of the Müller cells was more vertical and the density of the foveal cone cell nuclei was higher in eyes with ERM than in healthy eyes. Within the AO-OCT parameters, the higher cone nuclei count correlated with worse M-CHARTS scores, both preoperatively and 6 months postoperatively (P = 0.004, 0.010, respectively). Greater EZ thickness was significantly associated with poorer 6-month postoperative BCVA (P = 0.005).

Conclusions

Adaptive optics OCT can be used to precisely identify cellular alterations in eyes with ERM that are closely related to visual function impairments. These cellular insights enhance our understanding of ERM pathology and offer promising prognostic indicators of visual outcome after vitrectomy.

THE IMPACT OF EARLY SURGICAL INTERVENTION ON ANISEIKONIA IN PATIENTS WITH EPIRETINAL MEMBRANE: A Prospective Cohort Study

PURPOSE

To investigate the efficacy of early surgical intervention in ameliorating aniseikonia among patients with epiretinal membrane.

METHODS

This prospective cohort study enrolled patients who underwent surgery for epiretinal membrane. Patients were divided into early (symptom onset within 1 year) and late (symptom onset ≥1 year) treatment groups. Changes in aniseikonia, best-corrected visual acuity, and tangential retinal displacement were assessed and compared at 6 and 12 months postoperatively.

RESULTS

Of the 56 patients, 30 (53.6%) belonged to the early treatment group and 26 (46.4%) to the late treatment group. The early treatment group demonstrated a significant reduction in aniseikonia score at 6- and 12-month follow-up visits (-1.10 ± 1.50 [P = 0.002] and -1.18 ± 1.79 [P = 0.003], respectively); however, no improvement was observed in the late treatment group (0.98 ± 4.62 [P = 0.310] and 1.52 ± 4.35 [P = 0.124], respectively). The early treatment group showed larger tangential retinal displacement at the 12-month postoperative follow-up visit. In addition, the amount of tangential retinal displacement was associated with postoperative changes in aniseikonia.

CONCLUSION

Early surgical intervention is helpful in improving aniseikonia in patients with epiretinal membrane. The degree of recovery in inner retinal displacement was associated with the improvement of aniseikonia.

[Epiretinal membrane: diagnostics, indications and surgical treatment]

An epiretinal membrane (ERM) is a frequently occurring disease affecting the macula, which can be associated with visual impairment and metamorphopsia, depending on the severity and location. A distinction is made between an idiopathic form caused by age-related changes of the vitreous body and a secondary form associated with diseases of the posterior segment. The development of fibrocellular epiretinal membranes formed by dedifferentiation of intraretinal and extraretinal cells at the level of the vitreomacular interface plays a major role in the pathogenesis. The diagnostics and indications for surgical treatment of ERM are based on the visual acuity, evidence of metamorphopsia, ophthalmoscopic findings and optical coherence tomography (OCT) of the macula. In addition to the possibility of observation of the course where benign spontaneous courses are not uncommon, pars plana vitrectomy (PPV) with peeling of the ERM and internal limiting membrane (ILM) to prevent recurrences is the treatment of choice in symptomatic patients. The prognosis after surgical treatment is very good. In approximately two thirds of the cases, an improvement in visual acuity and/or a reduction of metamorphopsia can be achieved, with a number of predictive, primarily OCT-based factors enabling a prediction of the functional prognosis. Comprehensive patient education regarding the generally long duration of postoperative rehabilitation and the possibility of persistent symptoms or visual deterioration despite successful membrane removal is essential.

Optical coherence tomography parameters as prognostic factors for stereopsis after vitrectomy for unilateral epiretinal membrane: a cohort study

This retrospective cohort study explored the relationship between monocular and interocular optical coherence tomography (OCT) parameters and stereopsis in 56 patients undergoing pars plana vitrectomy (PPV) for unilateral idiopathic epiretinal membrane (IERM). IERM impairs visual functions, with symptoms ranging from asymptomatic to severe impairment. Despite established surgical interventions, including PPV with membrane peeling, the impact on advanced three-dimensional visual functions such as stereopsis remains inadequately investigated. All subjects were assessed for stereopsis, visual acuity, and metamorphopsia, alongside spectral domain OCT parameters. These visual functions significantly improved 3-month postoperatively. Central retinal thickness at the fovea, parafovea, and perifovea (CFT, CRT-3 mm, and CRT-6 mm), ectopic inner foveal layer thickness, and retinal layer thickness notably decreased 1 week to 3 months after surgery. The interocular difference in OCT parameters between bilateral eyes was included as a parameter. Baseline CRT-3 mm difference and inner nuclear layer (INL) thickness were independently correlated with postoperative stereopsis on the Titmus Stereo Test, while baseline CRT-6 mm difference and INL thickness were independently related to stereopsis on the TNO stereotest. This study highlights the substantial enhancement in stereopsis post-IERM surgery, with both interocular and monocular OCT parameters independently influencing postoperative stereopsis. These findings underscore the importance of retinal microstructures in assessing and predicting stereopsis in IERM patients after vitrectomy.

Aniseikonia and retinal morphological changes in eyes undergoing macular hole surgery

Even after idiopathic macular hole (MH) surgery and with successful closure of MH, aniseikonia is a common postoperative symptom. We investigated the correlation of MH diameter, retinal displacement and retinal layer thicknesses with aniseikonia in 41 eyes of 41 patients undergoing MH surgery with internal limiting membrane peeling. Aniseikonia was measured with the New Aniseikonia Test. Retinal displacement (RD%) was defined as change of retinal distance between the temporal margin of the optic papilla and the intersection of the retinal vessels. Changes of thicknesses of the inner nuclear layer (INL%) and the outer retinal layer (OR%) were calculated. Aniseikonia improved postoperatively. Preoperative aniseikonia and their improvement at 6 months correlated with MH diameters (P = 0.004-0.046). Improvement of aniseikonia correlated with temporal RD% (P = 0.002-0.012). Improvement of vertical aniseikonia correlated with INL% at 2 weeks and with the nasal OR% at 1, 3, and 6 months (P = < 0.001-0.028). MH diameter and age were significant predictors for improvement of aniseikonia. The greater the temporal retina displacement, and the thinner the postoperative INL and OR, the greater the improvement of aniseikonia. MH diameter and age are strong predictors for improvement of aniseikonia after MH surgery.

Evaluation of Aniseikonia in Patients with Successfully Treated Anisometropic Amblyopia Using Spatial Aniseikonia Test

Anisometropic amblyopia is decreased visual acuity in one eye, and treatment consists of wearing complete corrective spectacles. Aniseikonia occurs with complete correction of anisometropia using spectacles. Aniseikonia has been ignored when treating pediatric anisometropic amblyopia because of the prevailing belief that anisometropic symptoms are suppressed by adaptation. However, the conventional direct comparison method for evaluating aniseikonia significantly underestimates the degree of aniseikonia. This study investigated whether the adaptation occurs due to long-term anisometropic amblyopia treatment in patients who have had successful amblyopia treatment using a spatial aniseikonia test with high accuracy and repeatability compared with the conventional direct comparison method. The amount of aniseikonia was not significantly different between the patients with successful amblyopia treatment and individuals with anisometropia without a history of amblyopia. In both groups, the aniseikonia per 1.00 D of anisometropia and the aniseikonia per 1.00 mm of aniso-axial length were comparable. The repeatability of the amount of aniseikonia using the spatial aniseikonia test did not differ significantly between the two groups, indicating a high degree of agreement. These findings suggest that aniseikonia is not adapted to amblyopia treatment and that aniseikonia increases as the difference between spherical equivalent and axial length increases.

Short-term postoperative changes in the choroidal vascularity index in patients with a unilateral epiretinal membrane

BACKGROUND

To investigate short-term choroidal structural and vascular changes after epiretinal membrane (ERM) surgery.

METHODS

In this retrospective study, 65 patients with unilateral ERM underwent pars plana vitrectomy combined with cataract surgery and were examined one day before surgery and one week, one month, and three months after surgery. Choroidal thickness (CT) and choroidal vascular index (CVI) were evaluated using horizontal enhanced depth imaging optical coherence tomography (EDI-OCT) scans and were further calculated using semi-automatic algorithms using MATLAB R2017a.

RESULTS

Preoperatively, CVI was higher in eyes with ERM (61.70 ± 5.17%) than in fellow eyes (59.99 ± 5.26%). CVI increased significantly at one week after surgery (62.14 ± 5.02%) and decreased at 1 and 3 months after surgery (60.76 ± 4.97% and 60.4 ± 4.83%, respectively). The change was pronounced in the nasal region (p < 0.001) and central region (p < 0.05). CT in the temporal macula increased at 1 week (239.65 ± 72.98 μm) after surgery and decreased at 1 and 3 months after surgery (222.15 ± 71.91 μm and 222.33 ± 65.72 μm, respectively; p < 0.01).

CONCLUSIONS

Short-term postoperative variations in the choroid have been demonstrated in eyes with ERM. This may be related to the release of macular traction. CVI assessment using EDI-OCT may be a useful tool for investigating choroidal structural changes accompanying ERM and postoperative period.

Visual Functions Affecting Vision-Related Quality of Life Following Intravitreal Ranibizumab Therapy for Central Retinal Vein Occlusion

Visual functions that affect vision-related quality of life (VR-QoL) before and after intravitreal injection of ranibizumab in patients with cystoid macular edema secondary to central retinal vein occlusion (CRVO-CME) are poorly understood. This multicenter, open-label, single-arm prospective study included 23 treatment-naïve patients with CRVO-CME. The best-corrected visual acuity (BCVA), letter contrast sensitivity (LCS), severity of metamorphopsia (M-CHARTS), amount of aniseikonia (New Aniseikonia Test), and stereopsis (Titmus Stereo Test and TNO stereotest) were examined every month from before treatment to 12 months after treatment. For VR-QoL assessment, the 25-item National Eye Institute Visual Function Questionnaire (VFQ-25) was provided to the patients before treatment and at 3, 6, and 12 months after treatment. Stepwise multiple regression analysis revealed that the BCVA of the fellow eye was related to the VFQ-25 composite score before treatment, and that the BCVA of the fellow eye and TNO values were related to the VFQ-25 composite score 12 months after treatment. Changes in LCS were significantly correlated with changes in the VFQ-25 composite score. In patients with CRVO-CME, visual acuity of the fellow eye had the strongest impact on VR-QoL. The contrast sensitivity of the affected eye and stereopsis were also associated with VR-QoL.

Idiopathic Epiretinal Membranes: Visual Outcomes and Prognostic Factors

Objectives

To evaluate the associations between anatomical changes and visual outcomes in patients with idiopathic epiretinal membrane (ERM).

Materials and Methods

We performed a prospective study of 130 consecutive idiopathic ERM patients and report their visual outcomes and the factors associated with visual outcome and anatomical changes.

Results

Of 130 eyes of 130 patients, 87 eyes underwent surgery, while the remaining 43 eyes were observed. At 6-month follow-up, the best-corrected visual acuity (BCVA) increased in the whole population. Mean Early Treatment Diabetic Retinopathy Study letter score changed from 51 to 65 in the surgical group and from 67 to 68 in the non-surgical group. The surgical group had improvement in BCVA at all ERM stages and grades of disorganization of the retinal inner layers (DRIL) (p<0.01). In multivariable analysis of the surgical group, factors associated with BCVA of ETDRS 60 letters or more were no or mild DRIL and the absence of ellipsoid zone disruption at baseline (p=0.002 and p=0.034, respectively) and this statistically significant positive correlation was still maintained at 12-month follow-up.

Conclusion

Baseline DRIL grade and presence of ellipsoid zone disruption were the most informative prognostic factors in patients with idiopathic ERMs. Patients with severe DRIL and/or advanced ERMs had improved vision after ERM removal.

Idiopathic epiretinal membrane: progression and timing of surgery

Primary idiopathic epiretinal membrane (iERM) is a common finding, particularly so in the era of high street spectral-domain optical coherence tomography. Clinicians often face the dilemma of early versus delayed surgical intervention in the management of iERM with macular pucker, especially in those patients with good vision. The aim of this review is to assist clinicians in their understanding of the natural history of iERM to enable decision-making and optimally advising patients. We systematically searched the Medline and EMBASE databases for relevant publications from 2001 onwards using defined search terms with pre-planned inclusion and exclusion criteria. In this article, we review the epidemiology of iERM, classifications, their effect on visual function, the natural history and factors predicting progression and finally, factors which might predict the visual outcome with surgery.

Long-term functional outcomes and vision-related quality of life after vitrectomy for epiretinal membrane: a prospective cohort study

To investigate the long-term effect of unilateral idiopathic epiretinal membrane (uiERM) removal on monocular and binocular visual function, and on vision-related quality of life (VR-QoL). Prospective, single-center study. The following data were collected before and after surgery: distance monocular and binocular best-corrected visual acuity (BCVA), horizontal and vertical metamorphopsia, horizontal and vertical aniseikonia, stereoacuity and National Eye Institute Visual Function Questionnaire-25 item (NEI VFQ-25). Forty-two patients (mean age: 72.7 ± 7.4 years; 24 men) were included. At 6 months postoperatively, distance monocular BCVA (p < 0.001), horizontal metamorphopsia (p = 0.001) and the composite score of NEI VFQ-25 (p < 0.001) significantly improved, in comparison to baseline. At 2 years postoperatively, distance monocular (p < 0.001) and binocular (p = 0.01) BCVA, horizontal (p < 0.001) and vertical (p = 0.02) metamorphopsia, vertical aniseikonia (p = 0.01), stereoacuity (p < 0.001) and 3 subscales scores of the NEI VFQ-25 (p < 0.05) (“general vision”, “mental health”, “driving”) significantly improved in comparison to baseline. Removal of uiERM improves VR-QoL and achieves good visual outcomes on both monocular and binocular visual parameters over long-term. Visual symptoms induced by macular contraction have different improvement kinetics after surgery. Stereopsis, the highest level of binocular vision, can be improved in some cases.

Influence of postoperative ectopic inner foveal layer on visual function after removal of idiopathic epiretinal membrane

Purpose

To investigate the functional and anatomical parameters and their postoperative changes according to the ectopic inner foveal layer (EIFL) staging scheme for idiopathic epiretinal membrane (ERM).

Methods

In this prospective study, patients with idiopathic ERM underwent pars plana vitrectomy and ERM removal, and were followed-up for 6 months. The associations of EIFL with pre- and postoperative functional and anatomical parameters were analyzed.

Results

A total of 84 eyes (84 patients) were included: 39 (46.4%), 33 (39.3%), and 12 (14.3%) as EIFL stages 2, 3, and 4, respectively. At 6 months after surgery, the mean best-corrected visual acuity (BCVA) significantly improved in all EIFL stages (P ≤ 0.003); however, metamorphopsia improved only in eyes with EIFL stage 2 (P = 0.039) and 3 (P = 0.011). The aniseikonia and foveal avascular zone (FAZ) area showed no significant postoperative changes in any of the EIFL stages. Both preoperatively and during 6 months after surgery, the EIFL stage showed a significant correlation with BCVA (P ≤ 0.033), metamorphopsia (P ≤ 0.008), central macular thickness (P < 0.001), and FAZ parameters (P ≤ 0.016) at each time point, but not with aniseikonia. Significant correlations of EIFL thickness with BCVA (P = 0.028) and metamorphopsia (P = 0.006) before surgery were not persistent after surgery.

Conclusion

Both pre- and postoperatively, the staging of EIFL, rather than its thickness, is a simple and adequate surrogate marker for visual acuity and metamorphopsia in eyes with idiopathic ERM.

TEMPORAL CHANGES OF PARAFOVEAL MICROVASCULATURE AFTER EPIRETINAL MEMBRANE SURGERY: An Optical Coherence Tomography Angiography Study

PURPOSE

To investigate whether the parafoveal capillary architecture predicts clinical course and visual outcomes after epiretinal membrane (ERM) surgery.

METHODS

A total of 71 eyes of 71 patients treated with vitrectomy for idiopathic ERM were enrolled. The parafoveal capillary displacement and fractal geometries were compared according to the stage of ERM. Correlations between the parafoveal capillary displacement in the superficial capillary plexus, the fractal dimension and lacunarity in the deep capillary plexus (DCP), foveal thickness, and visual outcomes were evaluated.

RESULTS

Compared with eyes with mild ERM, eyes with severe ERM exhibited higher parafoveal capillary displacement in the superficial capillary plexus, lower fractal dimension and higher lacunarity in the DCP, and greater foveal thickness (P < 0.05). The parafoveal capillary displacement in the superficial capillary plexus and fractal dimension and lacunarity in the DCP improved significantly, particularly at 1 month postoperatively (P < 0.05) and reached a plateau thereafter. The preoperative fractal dimension in the DCP showed a significant correlation with the best-corrected visual acuity at all follow-up time points (P < 0.05).

CONCLUSION

The parafoveal fractal dimension in the DCP was significantly correlated with the visual acuity before and after ERM surgery. The parafoveal fractal dimension may serve as a predictive marker for visual outcomes after ERM surgery.

MISALIGNMENT BETWEEN CENTER OF FOVEAL AVASCULAR ZONE AND CENTER OF FOVEAL PHOTORECEPTORS IN EYES WITH IDIOPATHIC EPIRETINAL MEMBRANE

PURPOSE

To determine the degree of misalignment between the center of foveal avascular zone and the center of foveal photoreceptors in eyes with an idiopathic epiretinal membrane (ERM).

METHODS

We reviewed the medical records of 61 eyes with an idiopathic ERM. A 3 × 3 mm area centered on the fovea was scanned with optical coherence tomography angiography before and at 6 months after surgery. The center of foveal avascular zone and the center of foveal photoreceptors were detected by en-face optical coherence tomography angiography images and sequential optical coherence tomography B-sections in the macular region. The presence or absence of ectopic inner foveal layers was also evaluated.

RESULTS

The mean distance from the center of foveal photoreceptors to the center of foveal avascular zone was 111.7 ± 106.8 µm in eyes with preoperative ERM. This distance was significantly correlated with the preoperative central foveal thickness (r = 0.33, P = 0.0104). Preoperatively, the ectopic inner foveal layers were present in 27 (44.3%) of 61 eyes. The foveal misalignment was greater in eyes with ectopic inner foveal layers than in those without ectopic inner foveal layers (158.6 ± 140.0 vs. 74.4 ± 45.4 µm, P < 0.0003). At 6 months after ERM surgery, the foveal misalignment was significantly reduced to 73.7 ± 48.0 µm (P = 0.0018).

CONCLUSION

Determining the degree of misalignment between the center of foveal avascular zone and the center of foveal photoreceptors might be a useful way to evaluate the degree of ERM traction.

Aniseikonia following intravitreal ranibizumab treatment for branch retinal vein occlusion

PURPOSE

To quantify aniseikonia following intravitreal ranibizumab (IVR) in patients with branch retinal vein occlusion (BRVO) and assess the relationship between aniseikonia and retinal microstructure.

STUDY DESIGN

Prospective observational study.

METHODS

This study included 50 patients undergoing IVR treatment for unilateral BRVO. The degree of aniseikonia and best-corrected visual acuity (BCVA) was examined, and retinal microstructure was assessed with optical coherence tomography (OCT) before and 1, 2, 3, 4, 5, and 6 months after treatment. Based on OCT images, we assessed central retinal thickness (CRT), presence of the epiretinal membrane, and serous retinal detachment (SRD), as well as status of the external limiting membrane and ellipsoid zone.

RESULTS

At baseline, mean aniseikonia was - 1.0 ± 2.5%, ranging from - 11.0 to + 6.0%. Nine out of 50 patients had micropsia (18%), one had macropsia (2%), and 40 had no aniseikonia (80%). After 6 months of treatment, mean aniseikonia was - 0.7 ± 1.5%, ranging from - 4.5 to + 3.5%. BCVA significantly improved after treatment (P < 0.001), but aniseikonia did not change (P = 0.73). In patients with BRVO who had micropsia (≤ - 2.0%) at baseline, mean aniseikonia significantly improved from - 4.8 ± 3.3% to - 0.9 ± 1.4% (P < 0.05). Aniseikonia after treatment significantly correlated with BCVA (P < 0.05) and the presence of SRD at baseline (P < 0.05).

CONCLUSION

Majority of eyes with aniseikonia in BRVO had micropsia. The BCVA as well as the micropsia improved following treatment with IVR for BRVO. BCVA and the presence of SRD were predictors of post-treatment aniseikonia.

CORRELATION BETWEEN MACULAR MICROSTRUCTURES AND ANISEIKONIA AFTER IDIOPATHIC EPIRETINAL MEMBRANE REMOVAL

PURPOSE

To analyze the correlation between preoperative measurements of macular microstructures and aniseikonia after epiretinal membrane removal.

METHODS

This retrospective study included 32 eyes of 32 patients who underwent epiretinal membrane surgery and were followed up for 12 months. Spectral-domain optical coherence tomography was used to measure the thicknesses of the ganglion cell layer-inner plexiform layer, inner nuclear layer (INL), and outer retinal layer in macular microstructures. The new aniseikonia test was used to measure vertical and horizontal aniseikonia scores.

RESULTS

There was a significant decrease in central macular thickness and ganglion cell layer-inner plexiform layer thickness at 6 and 12 months postoperatively (all P < 0.001). Vertical aniseikonia scores, horizontal aniseikonia scores, and INL and outer retinal layer thicknesses did not show significant changes. Vertical aniseikonia scores and horizontal aniseikonia scores were significantly associated with INL thicknesses of each meridian at each follow-up time point (all P < 0.05). Preoperative vertical and horizontal INL thicknesses were correlated with vertical aniseikonia scores and horizontal aniseikonia scores at 12 months postoperatively (P = 0.014 and P = 0.002, respectively).

CONCLUSION

Aniseikonia values did not change after epiretinal membrane removal and were associated with INL thickness before and after surgery. Thus, preoperative INL thickness could be used as a predictor of surgical prognosis in epiretinal membrane patients.

Foveal configurations with disappearance of the foveal pit in eyes with macular pucker: Presumed role of Müller cells in the formation of foveal herniation

Many eyes with macular pucker are characterized by a centripetal displacement of the inner foveal layers which may result in a disappearance of the foveal pit. In this retrospective case series of 90 eyes with macular pucker of 90 patients, we describe using spectral-domain optical coherence tomography different foveal configurations with ectopic inner foveal layers, document the relationship between posterior vitreous detachment (PVD) and idiopathic epiretinal membrane (ERM) formation and spontaneous and postoperative morphological alterations of the fovea, and propose an active role of Müller cells in the development of foveal herniation. We found that ERM were formed during or after partial perifoveal PVD, or after foveal deformations caused by tissue edema. The ERM-mediated centripetal displacement of the inner foveal layers and in various eyes anterior hyaloidal traction caused a disappearance of the foveal pit and an anterior stretching of the foveola with a thickening of the central outer nuclear layer (ONL). After the edges of the thickened inner layers of the foveal walls moved together, continuous centripetal displacement of the inner foveal layers generated a bulge of the fovea towards the vitreous (foveal herniation). Macular pseudoholes with a herniation of the inner foveal layers show that the outer layer of the protruding foveal walls is the outer plexiform layer (OPL). If the ERM covered the foveal walls and parafova, but not the foveola, the inner layers of the foveal walls were not fully centripetally displaced and the foveal pit was present. The visual acuity of eyes with ectopic inner foveal layers was inversely correlated with the thickness of the foveal center. Spontaneous morphological alterations after disappearance of the foveal pit may include the development of cystoid macular edema or additional thickening of the foveal tissue and foveal herniation. The foveal configuration with ectopic inner layers of the foveal walls and a thick central ONL persisted over longer postoperative time periods. The data show that the centripetal displacement of the inner foveal layers in eyes with macular pucker, which results in a disappearance of the foveal pit, may also generate foveal herniation which is suggested to be caused by contraction of Müller cell processes in the OPL. The centripetal displacement of the inner foveal layers and the formation of foveal herniation are suggested to reverse the foveal pit formation during development.

[Optical coherence tomography biomarkers in epimacular membranes and vitreomacular traction syndrome]

Using high-resolution imaging, such as optical coherence tomography (OCT), the different layers of the retina as well as the vitreoretinal interface and its alterations can be very clearly differentiated. This includes the morphological characteristics of tractive maculopathies, such as epiretinal gliosis and vitreomacular traction syndrome. Additionally, structural alterations of the various layers of the neurosensory retina as a result of traction due to these pathologies can be demarcated. The latter have been investigated in clinical trials and evaluated as OCT biomarkers with respect to their prognostic and predictive value. In this review we would like to present and discuss various OCT biomarkers in the context of epimacular membranes and vitreomacular traction syndrome.

Acute unilateral inner retinal dysfunction with photophobia: importance of electrodiagnosis

PURPOSE

To establish with negative electroretinogram (ERG) the clinical entity of eight patients with unilateral severe photophobia, essentially normal fundus, good visual acuity, and severe cone and rod dysfunction.

STUDY DESIGN

Multicenter retrospective observation case series.

METHODS

Comprehensive ophthalmologic examinations were performed, including best-corrected visual acuity (BCVA), full-field ERGs and multifocal ERGs (mfERGs), fundus photographs, and OCT. Systemic and genetic examinations were performed.

RESULTS

The mean (± SD) age at the onset was 60.0 ± 8.4 years, and the six patients noticed severe photophobia in the affected eye in spite of almost normal fundus appearance and good BCVA. The dark-adapted bright flash ERGs in the affected eye had relatively well-preserved a-waves and depressed b-waves, i.e., a negative ERG. Cone ERGs and both b- and d-waves of the photopic long-duration ERGs were almost undetectable. Rod ERGs were severely reduced; however, only two patients complained of night blindness. In five patients, the mfERGs were extinguished in the periphery but preserved in the central retina, resulting in good BCVA. Electrophysiological findings indicated a severe diffuse dysfunction of the inner retina affecting bipolar cells of both ON- and OFF-pathways, and in five patients there was a reduction in the thickness of the inner nuclear layer. In seven patients the retinal arteries were attenuated. Anti-retinal antibodies were detected in the serum of two patients. No genetic causes were found.

CONCLUSIONS

The common features in the eight patients with unilateral negative ERGs suggest a new disease entity of unilateral acute inner retinal layer dysfunction. In most patients, the only subjective complain was photophobia.

Monocular and binocular end-points after epiretinal membrane surgery and their correlation to patient-reported outcomes

PURPOSE

This study evaluates current available endpoints for epiretinal membrane (ERM) surgery and examine their correlation to patient reported outcomes (PRO).

METHODS

Retrospective study including 38 eyes of 38 patients who underwent cataract extraction and subsequent vitrectomy for idiopathic ERM. The fellow eye was phakic with good visual acuity. The registered outcomes were monocular and binocular visual acuity, stereoacuity, M-chart metamorphopsia score, aniseikonia and aniseikonia tolerance range (ATR). Two questionnaires were completed: the convergence insufficiency symptom survey and Visual Function Questionnaire (VFQ-39).

RESULTS

Median total aniseikonia was 11% (range 0-35). There was a statistically significant correlation between the mean total M-chart score of the study eye and VFQ-Near (Spearman rho: VFQ-Near: -0.54, p < 0.01). There was no correlation between the best corrected visual acuity (BCVA) of the project eye, binocular BCVA, stereoacuity, ATR or mean total aniseikonia and PRO (Spearman p-values > 0.05). There was no correlation between mean total aniseikonia and mean total M-chart score (Spearman rho: 0.21 p = 0.26). There was a large variation between the mean total M-chart scores and questionnaire results.

CONCLUSION

The mean total M-chart score is currently the best end-points to predict PRO of ERM surgery; however, it is possible to have high M-chart values and have no visual complaints.

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.

Comparative analysis of metamorphopsia and aniseikonia after vitrectomy for epiretinal membrane, macular hole, or rhegmatogenous retinal detachment

This study investigated postoperative changes in metamorphopsia and aniseikonia in eyes that underwent vitrectomy for epiretinal membrane (ERM), macular hole (MH), or rhegmatogenous retinal detachment (RRD). In total, 166 eyes were included from 166 patients with ERM, MH, or RRD who underwent primary vitrectomy. Metamorphopsia and aniseikonia were quantified by M-CHARTS and the New Aniseikonia Test (NAT). Best-corrected visual acuity (BCVA), M-CHARTS, NAT assessments, and OCT examination were performed at 1, 3, and 6 months postoperatively. Of the 166 eyes, 65 had ERM, 21 had MH, 42 had macula-off RRD, and 38 had macula-on RRD. BCVA improved significantly between 1 and 6 months postoperatively in eyes with ERM, MH, and macula-off RRD (P = 0.0057, P = 0.0065, and P = 0.0021, respectively). M-CHARTS scores at 1 month postoperatively significantly decreased in eyes with ERM (P = 0.0034) and tended to decrease in eyes with MH (P = 0.068). NAT scores did not change between baseline and 1 month postoperatively in eyes with ERM or MH. Between 1 and 6 months postoperatively, M-CHARTS and NAT scores significantly decreased in eyes with macula-off RRD (P = 0.0064 and P = 0.0009, respectively), but not in eyes with ERM, MH, or macula-on RRD. At 6 months postoperatively, significant metamorphopsia was evident in 33.3% of eyes with ERM, 29.2% of eyes with MH, and 35.7% of eyes with macula-off RRD; 61.5% of eyes with ERM showed macropsia and 52.3% of eyes with macula-off RRD showed micropsia. In eyes with ERM, more central retinal thickness (CRT) correlated with postoperative BCVA, and deep retinal folds on enface OCT image correlated with postoperative metamorphopsia. In eyes with macula-off RRD, less CRT correlated with postoperative BCVA, and tended to correlate with postoperative micropsia. Macular morphologies could contribute to differences in postoperative visual acuity, metamorphopsia, and aniseikonia.

FOVEAL AVASCULAR ZONE AREA ANALYSIS USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY BEFORE AND AFTER IDIOPATHIC EPIRETINAL MEMBRANE SURGERY

PURPOSE

To determine the size of the foveal avascular zone (FAZ) by optical coherence tomography angiography before and after idiopathic epiretinal membrane surgery.

METHODS

Thirteen consecutive patients (13 eyes) with unilateral epiretinal membrane were studied retrospectively. Optical coherence tomography angiography was used to measure the FAZ area within 3 mm × 3 mm scans of the superficial (superficial FAZ) and deep plexus layers (deep FAZ) before and 6 months after vitrectomy. The unaffected fellow eyes were used as controls.

RESULTS

The mean superficial and deep FAZ areas at 6 months after vitrectomy (0.080 ± 0.038 and 0.113 ± 0.045 mm, respectively) were significantly (P < 0.0001, P = 0.0035) larger than the corresponding mean preoperative FAZ areas (0.056 ± 0.030 and 0.082 ± 0.035 mm). However, the areas of FAZ expansion were small (0.024 ± 0.013 and 0.031 ± 0.031 mm). The mean postoperative superficial and deep FAZ areas were significantly (P < 0.0001, P < 0.0001) smaller than those of fellow eyes (0.295 ± 0.108 and 0.410 ± 0.142 mm). Multiple regression analysis showed that preoperative FAZ area had the highest correlation with postoperative FAZ area (P < 0.05).

CONCLUSION

This study showed horizontal contraction of the FAZ area in eyes with epiretinal membrane. Because preoperative FAZ area correlates with postoperative FAZ area, FAZ area may be a useful parameter for determining timing of surgery for epiretinal membrane.

Preoperative aniseikonia is a prognostic factor for postoperative stereopsis in patients with unilateral epiretinal membrane

PURPOSE

To investigate stereopsis and other visual functions in patients with unilateral epiretinal membrane (ERM) and to identify vision-related parameters affecting stereopsis.

METHODS

This prospective study included 63 consecutive patients who were scheduled to undergo vitrectomy for unilateral idiopathic ERM. We examined stereopsis (Titmus Stereo Test, TST; TNO stereotest, TNO), best-corrected visual acuity (BCVA), letter contrast sensitivity, severity of metamorphopsia, and degree of aniseikonia preoperatively and 6 months postoperatively.

RESULTS

Preoperatively, we observed significant correlation between TST scores and other vision-related parameters except severity of metamorphopsia and between TNO score and all the vision-related parameters. Multiple regression analysis showed that preoperative TST and TNO scores were significantly associated with the degree of aniseikonia (both P < 0.01). ERM surgery significantly improved stereopsis, BCVA, contrast sensitivity, and metamorphopsia, but not aniseikonia. Postoperatively, TST was significantly associated with BCVA, and TNO showed association with BCVA and aniseikonia. Postoperative TST and TNO scores showed significant correlation with preoperative aniseikonia (P < 0.005 and P < 0.001, respectively).

CONCLUSIONS

Impairment of stereopsis in patients with unilateral ERM was considered to be due to retinally induced aniseikonia. Aniseikonia did not improve by surgery, and preoperative aniseikonia can be a prognostic factor for postoperative stereopsis.

Prospective study of vitrectomy for epiretinal membranes in patients with good best-corrected visual acuity

Background

To evaluate the efficacy of epiretinal membrane removal in patients with good best-corrected visual acuity (BCVA) for improving visual function and quality of life (QOL).

Methods

This prospective case study compared 37 subjects with preoperative BCVA ≦ 0.046 logMAR (Good group) to 35 patients with 0.10–0.52 logMAR (Moderate group) at 3 and 6 months. Linear mixed-effect models were used for statistical analysis. The primary outcome was the horizontal metamorphopsia score (MH) at 6 months postoperatively (post-6 M), while secondary outcomes were postoperative BCVA, vertical metamorphopsia score (MV), aniseikonia, stereopsis and central foveal thickness. In the Good group, QOL was assessed using the National Eye Institute Visual Functioning Questionnaire-25 (NEI VFQ-25) at 6 and 12 months.

Results

MH was significantly improved at post-3 M and post-6 M in the both groups but there were no significant differences between the two groups. MV showed no improvement at the final observation in either group. LogMAR BCVA was significantly improved at post-6 M in the Good group, which had significantly better vision than the Moderate group. Preoperative vertical and horizontal aniseikonia scores remained unchanged in the Good group at post-6 M but worsened in the Moderate group. The NEI VFQ-25 score improved in the Good group, reflecting improved general health, general vision, and mental health.

Conclusions

Early epiretinal surgery for patients with BCVA ≦ 0.046 logMAR was effective for improvement of HM, BCVA, and QOL and prevented worsening of aniseikonia.

Trial registration

UMIN000021220. Registered 10 September 2015.

UMIN Clinical Trials Registry.

POSTOPERATIVE CHANGES AND PROGNOSTIC FACTORS OF VISUAL ACUITY, METAMORPHOPSIA, AND ANISEIKONIA AFTER VITRECTOMY FOR EPIRETINAL MEMBRANE

PURPOSE

To investigate postoperative changes and prognostic factors of visual impairment after vitrectomy for unilateral epiretinal membrane.

METHODS

A prospective observational study on 45 eyes from 45 patients with unilateral idiopathic epiretinal membrane who underwent vitrectomy. Visual parameters (best-corrected visual acuity, metamorphopsia using M-CHARTS, and aniseikonia using the New Aniseikonia Test) and spectral domain optical coherence tomography parameters (macular retinal layer thickness and microstructure of the outer retina) were measured preoperatively and 6 and 12 months postoperatively. Statistical analyses included linear mixed-effects models for the longitudinal changes and prognostic factors of visual parameters.

RESULTS

Best-corrected visual acuity and horizontal metamorphopsia improved significantly from 6 months after surgery (P < 0.001), whereas aniseikonia decreased significantly only at 12 months (P = 0.015). Vertical metamorphopsia remained unchanged. Preoperative inner nuclear layer thickness was significantly correlated with preoperative metamorphopsia. Besides baseline values, best-corrected visual acuity had no significant prognostic factors, but preoperative ellipsoid zone disruption had a negative direction of association with postoperative metamorphopsia (coefficients: -0.37 and -0.62, P = 0.015 and 0.006 for horizontal and vertical metamorphopsia, respectively), and preoperative horizontal metamorphopsia had a positive direction of association with postoperative aniseikonia (coefficient: 1.77, P = 0.002).

CONCLUSION

After vitrectomy, postoperative changes and prognostic factors for unilateral epiretinal membrane differed for best-corrected visual acuity, metamorphopsia, and aniseikonia.

Changes in aniseikonia and influencing-factors following successful macula-off retinal detachment surgery

This study investigated the changes in the severity of aniseikonia after surgery for macula-off retinal detachment (RD), and the relationship between aniseikonia and retinal microstructures. The study included 26 eyes of 26 patients undergoing RD surgery. Visual acuity was measured preoperatively, and at 3, 6, and 12 months postoperatively. Degree of aniseikonia and OCT images were obtained at 3, 6, and 12 months postoperatively. The aniseikonia values (mean ± standard deviation) at 3, 6, and 12 months postoperatively were −5.3 ± 4.2%, −4.4 ± 4.4%, and −3.1 ± 3.2%, respectively. Significant improvement was observed from 3 to 12 months postoperatively (P = 0.001). Twelve months postoperatively, 14 eyes had micropsia, 1 eye had macropsia, and 11 eyes were free of aniseikonia. Stepwise multiple regression analyses revealed that the severity of aniseikonia at 12 months postoperatively was significantly associated with postoperative development of cystoid macular edema (CME) and epiretinal membrane (ERM), as well as area of preoperative RD. In conclusion, although aniseikonia was gradually relieved after RD surgery during a 1-year follow-up period, approximately half of patients had aniseikonia and almost all of them had micropsia. Aniseikonia was associated with presence of postoperative CME, ERM, and area of preoperative RD.

Cross-Sectional Imaging Analysis of Epiretinal Membrane Involvement in Unilateral Open-Angle Glaucoma Severity

Purpose

To determine the relevance of epiretinal membranes (ERMs) in primary open-angle glaucoma (POAG) and potential risk for glaucoma severity.

Methods

Sixty eyes of 30 patients with POAG who had a unilateral ERM were analyzed; 60 nonglaucomatous eyes of 30 patients with a unilateral ERM also were recruited in this institutional cross-sectional study. Patients underwent swept-source (SS) optical coherence tomography (OCT) imaging and visual field testing. Intraindividual differences in the SS-OCT retinal nerve fiber layer (RNFL) disc cupping area measurements and visual field outcomes were analyzed in the two groups.

Results

In patients with POAG, the mean circumpapillary RNFL thickness in the eyes with an ERM was 75.6 ± 16.5 μm superiorly and 71.8 ± 26.0 inferiorly compared with the fellow eyes without an ERM (87.2 ± 23.6 μm, P = 0.0061 and 81.3 ± 27.7 μm, P = 0.034, respectively). The areas of disc cupping and cup-to-disc ratio seen on OCT horizontal and vertical B-scans were larger in eyes with an ERM than in the fellow eyes without ERM (P = 0.0004 and P = 0.0011, respectively). The average mean deviations were -11.6 ± 7.5 dB in the ERM group and -8.19 ± 6.4 dB in the group with no ERM (P = 0.029). Eyes with an ERM received more antiglaucoma eye drops (P = 0.018). Those differences were not seen between eyes with an ERM or fellow eyes in patients without glaucoma.

Conclusions

The presence of an ERM can be a potential risk factor for unilateral severity in eyes with POAG.

Aniseikonia and anisometropia: implications for suppression and amblyopia

Aniseikonia is a difference in the perceived size or shape of images between eyes, and can arise from a variety of physiological, neurological, retinal, and optical causes. Aniseikonia is associated with anisometropia, as both anisometropia itself and the optical correction for anisometropia can cause aniseikonia. Image size differences above one to three per cent can be clinically symptomatic. Common symptoms include asthenopia, headache and diplopia in vertical gaze. Size differences of three and more impair binocular visual functions such as binocular summation and stereopsis. Above five per cent of aniseikonia, binocular inhibition or suppression tend to occur to prevent diplopia and confusion. Aniseikonia can be measured using a range of techniques and can be corrected or reduced by prescribing contact lenses or specially designed spectacle lenses. Subjective testing of aniseikonia is the only way to accurately measure the overall perceived amount of aniseikonia. However, currently it is not routinely assessed in most clinical settings. At least two-thirds of patients with amblyopia have anisometropia, thus we may expect aniseikonia to be common in patients with anisometropic amblyopia. However, aniseikonia may not be experienced by the patient under normal binocular viewing conditions if the image from the amblyopic eye is of poor quality or is too strongly suppressed for image size differences to be recognised. This lack of binocular simultaneous perception in amblyopia may also prevent the measurement of aniseikonia, as most common techniques require direct comparisons of images seen by each eye. Current guidelines for the treatment of amblyopia advocate full correction of anisometropia to equalise image clarity, but do not address aniseikonia. Significant image size differences between eyes may lead to suppression and abnormal binocular adaptations. It is possible that correcting anisometropia and aniseikonia simultaneously, particularly at the initial diagnosis of anisometropia, would reduce the need to develop suppression and improve treatment outcomes for anisometropic amblyopia.

Clinical significance of ectopic inner foveal layers in patients with idiopathic epiretinal membranes

BACKGROUND/OBJECTIVES

To evaluate the relationship between the presence of ectopic inner foveal layers (EIFL), choroidal thickness, and visual acuity (VA) in patients with epiretinal membranes (ERM) staged by spectral-domain optical coherence tomography (SD-OCT).

SUBJECTS/METHODS

A total of 242 eyes of 121 patients with unilateral idiopathic ERM were prospectively evaluated. ERM stages were defined based on the SD-OCT staging system as stage 1: negligible morphological or anatomical disruption, retinal layers, and foveal pit are identified; stage 2: characteristic stretching of the outer nuclear layer, absence of foveal depression, retinal layers are identified; stage 3: continuous EIFL crossing the central foveal area, absence of foveal depression, retinal layers are identified; and stage 4: anatomical disruption of the fovea, continuous EIFL crossing the entire foveal area, retinal layers are distorted.

RESULTS

Of 121 eyes with ERM, 23.1% had stage 1, 26.5% had stage 2, 39.7% had stage 3, and 10.7% had stage 4 disease. VA was better in eyes with stage 1 or 2 ERM than stage 3 or 4 ERM (p < 0.001). VA in logMAR was positively correlated with central foveal thickness (r = 0.557, p < 0.001) and EIFL thickness (r = 0.526, p < 0.001), but not with an outer nuclear layer thickness (r = 0.233, p = 0.123). In multivariate analysis, the presence of EIFL was an independent predictor of VA in eyes with ERM (p < 0.001). The presence and stage of ERM did not have a significant effect on choroidal thickness (p > 0.05).

CONCLUSIONS

The SD-OCT staging system according to the presence of EIFL is effective for grading retinal damage and visual loss in eyes with ERM.

Potential role of Müller cells in the pathogenesis of macropsia associated with epiretinal membrane: a hypothesis revisited

Pathophysiological explanations for metamorphopsia associated with retinal pathologies generally focus on photoreceptor organization disruption. However, the retinal microarchitecture is complicated, and we hypothesize that other retinal cells may also be involved. Metamorphopsia has been widely studied in eyes with epiretinal membranes and we revisit the idea that Müller cell displacement causes retinal macropsia. A PubMed query and related article search for the macula ultrastructure under normal and pathological conditions revealed an enormous amount of information, particularly ultrahigh definition optical coherence tomography and other retinal imaging modality studies. Findings of these imaging studies support our hypothesis that Müller cells, and not cone photoreceptors, are primarily responsible for macropsia in eyes with epiretinal membranes. More specifically, we conclude that displacement of Müller cell endfeet, and not photoreceptor cones, is a more likely the explanation for retinal macropsia associated with epiretinal membranes.

Associations of aniseikonia with metamorphopsia and retinal displacements after epiretinal membrane surgery

PurposeTo determine the correlation of the degree of aniseikonia with the retinal displacements and metamorphopsia in patients that have undergone successful epiretinal membrane (ERM) surgery.MethodsSubjects were 28 eyes with an ERM in 28 patients. The New Aniseikonia Test (NAT) and M-CHARTS were used to quantify the degree of preoperative and postoperative aniseikonia and metamorphopsia. We also evaluated the distance between the intersections of 2 sets of retinal vessels situated vertically or horizontally by using spectral-domain optical coherence tomography (SD-OCT) images in 28 patients.ResultsThe vertical score of M-CHARTS (MV) was not significantly improved, but the horizontal score of M-CHARTS (MH) was significantly improved at 1 week, 1 month, and 3 months postoperatively. The preoperative NAT score was significantly correlated with the preoperative MH. The NAT score at 3 months was significantly correlated with the MH at 3 months and the MV at 3 months. The preoperative NAT score was significantly correlated with the ratio of the vertical retinal displacement at 1 month and at 3 months after surgery. However, the NAT scores did not improve significantly at any postoperative times.ConclusionsThe degree of aniseikonia was significantly correlated with the degree of metamorphopsia and the tangential displacement of the retina after ERM surgery. Aniseikonia is difficult to improve and metamorphopsia may be a more sensitive parameter to detect the functional recovery after successful ERM surgery.

The natural evolution of idiophatic epimacular membrane

BACKGROUND AND AIMS

Epiretinal membrane (ERM) refers to a semi-translucent tissue layer found on the inner surface of the retina especially in older people. Surgical treatment remains controversial, optimal timing for such treatment is difficult to determine and data on the natural evolution of this disorder are limited. In this study we evaluated the natural course of idiopathic epimacular membrane in 49 patients (53 eyes).

MATERIALS AND METHODS

Retrospective evaluation of a group of 49 patients (53 eyes) with idiopathic epimacular membrane confirmed by biomicroscopy, photography and optical coherence tomography (OCT).

RESULTS

Patient age ranged from 51-85 years (median 72). The average follow-up was 21.3 months (± 14). Between the initial and final best corrected visual acuity (BCVA) there was no statistically significant difference although there was a significant tendency to decrease in BCVA (Spearman P=0.05) during the follow-up. Initial BCVA correlated with initial central retinal thickness (CRT), final CRT, final volume, and age. The final BCVA significantly correlated with all parameters measured.

CONCLUSION

BCVA during follow-up tended to decrease: difference of starting BCVA and final BCVA values depending on the time of monitoring is significant. This we attribute to a slow gradual progression of macular changes. But, initial and final BCVA measurements were not substantially different at the end. Thus, in the absence of any clear signs of ERM progression, we can safely postpone the decision whether to perform PPV.

Prognostic factors of epiretinal membranes: A systematic review

INTRODUCTION

Epiretinal membranes (ERM) have been increasingly characterized with the advent of new optical coherence tomographies (OCTs). We intended to perform a systematic review regarding prognostic factors (PF) of ERM after surgery.

MATERIALS AND METHODS

Systematic review of electronic databases was performed (last date of search was 10 August 2015): Medline, Scopus, Google Scholar, clinicaltrials.gov and current controlled trials. Search queries included: "membrane", "pucker", "prognosis", "prognostic", "epiretinal", "épirétinienne". Inclusion criteria were: (1) primary purpose was to identify a PF of ERM; (2) prospective or retrospective study, case series (more than 10 patients), or clinical trials; (3) follow-up of at least 3 months; (4) complete ophthalmological evaluation in each patient with visual acuity and OCT, preoperative and≥3months after surgery; (5) vitrectomy with ERM peeling performed in each patient. Eligibility criteria verification, data extraction and evaluation of risk of bias were performed according to Cochrane's recommendations.

RESULTS

From 817 studies found, 21 were included (9 prospective, 12 retrospective, 0 trials). In all studies, there was significant visual acuity improvement after surgery. The majority of the studies included pars plana vitrectomy (PPV) combined with phacoemulsification.

DISCUSSION AND CONCLUSION

PF for visual acuity (VA) improvement after ERM surgery included: shorter duration of symptoms before surgery, lesser central foveal thickness at baseline identified by the OCT, good integrity of the inter segment/outer segment photoreceptor junction at baseline, and thinner ganglion cell inner plexiform layer at baseline. To avoid bias, studies should analyze VA separately if phacoemulsification is also performed. The knowledge of these PF may assist in planning surgery.

Inner-Retinal Irregularity Index Predicts Postoperative Visual Prognosis in Idiopathic Epiretinal Membrane

PURPOSE

To investigate the correlation between the inner-retinal irregularity index and visual outcomes before and after idiopathic epiretinal membrane (ERM) surgery.

DESIGN

Retrospective cohort study.

METHODS

We analyzed 66 eyes of 66 patients with idiopathic ERM. Ophthalmic examinations included best-corrected visual acuity (BCVA) measurements, metamorphopsia assessment, and spectral-domain optical coherence tomography before surgery and 1, 3, and 6 months post-surgery. Correlations between the inner-retinal irregularity index, defined as the length ratio between the inner plexiform layer and retinal pigment epithelium, and visual outcomes before and after ERM surgery were evaluated and compared with the correlation between the central foveal thickness, ganglion cell-inner plexiform layer (GC-IPL) thickness, interdigitation zone defect, and visual outcomes.

RESULTS

Inner-retinal irregularity index and central foveal thickness were significantly correlated with BCVA and metamorphopsia at each follow-up examination (all P < .05). The interdigitation zone defect correlated with BCVA at 3 and 6 months post-surgery (P < .001 and P < .015, respectively). However, GC-IPL thickness was not correlated with visual outcomes at any follow-up examination. The preoperative interdigitation zone defect was correlated with 6-month BCVA (P = .035) and the preoperative inner-retinal irregularity index was significantly correlated with the 6-month BCVA and marginally correlated with the 6-month metamorphopsia (P = .018 and P = .097, respectively).

CONCLUSION

The inner-retinal irregularity index was significantly correlated with visual outcomes before and after ERM surgery. This index can be used as a new surrogate marker for inner-retinal damage and a predictive prognostic marker in ERM.

Preoperative Prognostic Factors and Predictive Score in Patients Operated On for Combined Cataract and Idiopathic Epiretinal Membrane

PURPOSE

To report preoperative prognostic factors associated with visual acuity recovery 1 year after combined cataract and idiopathic epiretinal membrane (ERM) surgery and to introduce a predictive score.

DESIGN

Interventional case series and estimation of a predictive score.

METHODS

One hundred forty-two patients (1 eye per patient) operated on for combined cataract and idiopathic ERM in the University Hospital of Dijon were followed for 12 months. Preoperative clinical features and spectral-domain optical coherence tomography (OCT) parameters were compared between eyes that recovered ≥20/20 final best-corrected visual acuity (BCVA) and those with <20/20 final BCVA. Multivariate analysis and predictive score were provided.

RESULTS

At 12 months, 60 eyes (42%) recovered ≥20/20 BCVA and 82 (58%) had lower visual results. Logistic regression analysis showed that final BCVA was associated with age (P = .040), duration of symptoms (P = .025), initial BCVA (P = .002), and inner and outer segment (IS/OS) junction disruption on spectral-domain OCT (P = .010). The preoperative 10-point predictive score including these parameters reached 82% sensitivity and 66% specificity. With a score >5, patients had a ≥56% chance of recovering 20/20 final BCVA instead of ≤27% when the score was ≤5.

CONCLUSIONS

Age, duration of symptoms, and initial BCVA appear to be reliable prognostic factors in patients undergoing combined cataract and idiopathic ERM surgery. Combining these factors with analysis of the IS/OS junction provides a predictive score to estimate individual chances of good visual outcome.