Retinal Contraction and Metamorphopsia Scores in Eyes with Idiopathic Epiretinal Membrane

TANGENTIAL RETINAL DISPLACEMENT INCREASES AFTER MACULAR PUCKER SURGERY: An Apparent Nonsense

PURPOSE

To measure the tangential retinal displacement and vision before and after macular pucker surgery and study if pars plana vitrectomy with epiretinal membrane peeling allows the reconstitution of previous anatomy or else it results in a different configuration.

METHODS

Retrospective series of patients undergoing pars plana vitrectomy for epiretinal membrane, with >6-month follow-up before and after surgery, complete with best-corrected visual acuity, optical coherence tomography, M-Charts, and infrared retinography. Tangential retinal displacement between earliest visit (T E ), time of surgery (T 0 ), and latest available visit (T L ) of the examined retina, concentric circles at 0.5, 1.5, and 4.5 mm radii, and the central horizontal and vertical meridians were measured. Tangential displacement was calculated as the optical flow of consecutive infrared photographs.

RESULTS

The study comprised 32 patients: 15 men and 17 women. Average preoperative and postoperative follow-up were 23.4 ± 27.9 months and 19.2 ± 11.8 months, respectively. Best-corrected visual acuity reduced before surgery (0.69 ± 0.16 Snellen to 0.46 ± 0.17; P < 0.001) and increased after (0.866 ± 0.16 Snellen; P < 0.001). Horizontal and vertical metamorphopsia increased between before surgery but only horizontal metamorphopsia significantly reduced after. Average tangential displacement before surgery was 35.6 ± 29.9 µ m versus 56.6 ± 41.3 µ m after ( P = 0.023). Preoperative and postoperative displacement within the fovea was less than over the entire area ( P < 0.001).

CONCLUSION

Retinal tangential displacement between diagnosis and surgery (T E - T 0 ) is less than the displacement occurring after surgery (T 0 - T L ). Postoperative displacement does not represent the restoration of the anatomy existing before the disease ensued but rather the resulting equilibrium of newly deployed forces.

Quantification of Metamorphopsia in Resolved Idiopathic Central Serous Chorioretinopathy: An Analysis Using M-CHARTS, Amsler Grid, and Optical Coherence Tomography

Purpose

To quantify metamorphopsia in patients with resolved idiopathic Central Serous Chorioretinopathy (CSCR) using M-CHARTS and compare the results with the traditional Amsler grid and optical coherence tomography (OCT).

Patients and Methods

For the purpose of this study, all consecutive cases of patients with resolved CSCR were evaluated for metamorphopsia (using the standard Amsler grid and M-CHARTS) and spectral domain OCT. The OCT images were analyzed for the following five parameters: central macular thickness, pigment epithelial detachment, retinal pigment epithelial bumps, discontinuation in the inner segment/outer segment junction or the external limiting membrane, fibrinous exudates in the subretinal space, and hyperreflective dots in the intraretinal and/or subretinal layer. Binary logistic regression was used to find the association between metamorphopsia and foveal morphology. Cohen's Kappa was used to determine the agreement between the M-CHARTS and Amsler grid for diagnosing metamorphopsia. The sensitivity, specificity, and accuracy in the diagnosis of metamorphopsia were calculated against the Amsler grid.

Results

Of 41 eyes, Amsler Grid detected metamorphopsia in 39.02%, and M-CHARTS detected metamorphopsia in 53.66%. The agreement rate of detection between the two tests was moderate (Kappa=0.52). M-CHARTS had a sensitivity of 87.50%, a specificity of 68.00%, a positive predictive value of 63.64%; and a negative predictive value of 89.47% for the diagnosis of metamorphopsia compared to the Amsler grid. The presence of PED in OCT was significantly associated with metamorphopsia.

Conclusion

M-CHARTS can be a useful ancillary test to detect and quantify metamorphopsia even after fluid resolution in CSCR. Structural changes in macular morphology as observed with OCT can predict the likelihood of metamorphopsia.

Changes in Metamorphopsia in Patients Undergoing Treatment for Vitreoretinal Disorders

PURPOSE

To quantify and compare the severity of metamorphopsia in patients undergoing vitrectomy for vitreoretinal disorders.

METHODS

Data were collected evaluated from 319 patients with vitreoretinal disorders, including epiretinal membrane (ERM), macular hole (MH), cystoid macular edema with branch retinal vein occlusion (BRVO-CME), CME with central retinal vein occlusion (CRVO), diabetic macular edema (DME), macula-off rhegmatogenous retinal detachment (M-off RD), and macula-on RD (M-on RD). Metamorphopsia was recorded with the M-CHARTS preoperatively and at 3 and 6 months postoperatively.

RESULTS

Preoperative and 6-month postoperative metamorphopsia scores were 0.69 ± 0.50 and 0.50 ± 0.52, respectively. Before surgery, 94% of patients presented with metamorphopsia (score ≥0.2). Preoperative metamorphopsia scores were significantly correlated with postoperative metamorphopsia scores (r = 0.378, p < 0.0001). Preoperative metamorphopsia score was significantly higher for ERM (0.89) than for DME (0.51). Vitrectomy significantly improved metamorphopsia in ERM and MH but not in the other disorders. In contrast, treatment improved visual acuity for all disorders except CRVO-CME and M-on RD.

CONCLUSION

This quantitative study indicated that metamorphopsia is present in most patients undergoing surgery for vitreoretinal diseases and is most severe in ERM. In these patients, vitrectomy improved visual acuity but not metamorphopsia.

Japan-epiretinal membrane (J-ERM) registry: A prospective cohort study protocol investigating the surgical outcome of epiretinal membrane

BACKGROUND

Epiretinal membrane (ERM) causes visual impairment such as reduction in visual acuity and metamorphopsia due to retinal traction. With the improvement of optical coherence tomography (OCT) and microincision vitrectomy surgery (MIVS), the surgery of ERM has significantly advanced. However, there have been no large-scale studies on the following: (1) how to evaluate visual impairment in ERM, (2) the relationship between OCT findings and visual function, (3) when is the optimal timing of surgery, and (4) the relationship between the surgical instruments as well as techniques and prognosis. The purpose of this study was to obtain evidence regarding these ERM surgeries.

METHODS AND DESIGN

This is a prospective, multicenter cohort study of ERM surgery in Japan from March 1, 2023, to March 31, 2027 (UMIN000048472, R-3468-2). Patients who underwent ERM surgery during the study period and agreed to participate in this study will be included. The goal is to have a total of 5,000 eyes surgically treated for ERM. The following data will be collected: age, gender, medical history, subjective symptoms, visual function before and 6 and 12 months after surgery, clinical findings, OCT data, surgical technique, instruments used in surgery, and complications.

DISCUSSION

The results of this study will support the surgical decisions and procedures in ERM practices.

Epiretinal Membrane Impairs the Inner Retinal Layer in a Traction Force-Dependent Manner

Purpose

To investigate the relationship between retinal traction force and impairment of the inner retinal layer in patients with epiretinal membrane (ERM).

Design

Nonrandomized, retrospective consecutive case series.

Participants

Two hundred nine eyes of 201 patients with idiopathic ERM who underwent vitrectomy for idiopathic ERM were enrolled.

Methods

Retinal folds caused by ERM were visualized using en face OCT, and the maximum depth of retinal folds within the parafovea (MDRF) was measured. Focal macular electroretinogram (ERG) was used to measure the amplitude and implicit time of each component for the ERM eyes and the normal fellow eyes. B-scan OCT images were used to measure the thicknesses of the inner nuclear layer (INL) and outer nuclear layer (ONL) + outer plexiform layer (OPL). Expression of α-smooth muscle actin (α-SMA) in surgically removed ERM specimens was quantified by reverse-transcription polymerase chain reaction.

Main Outcome Measures

We analyzed the relationship between MDRF and the relative amplitudes of focal macular ERG (affected eye/fellow eye), the relationships between MDRF and the mean INL thickness and ONL+OPL thickness, comparison of INL thickness and ONL+OPL thickness for each area when cases were classified according to MDRF localization in the ETDRS chart, and the relationship between MDRF and the relative expression of α-SMA in the ERM specimens.

Results

The MDRF significantly correlated with the relative amplitudes (affected eye/fellow eye) of b-waves and oscillatory potentials (r = -0.657, P = 0.015; r = -0.569, P = 0.042, respectively) and the mean INL thickness and ONL+OPL thickness (r = 0.604, P < 0.001; r = 0.210, P = 0.007, respectively). However, only the INL thickness progression rate was significantly correlated with the MDRF progression rate (r = 0.770, P < 0.001). On case stratification by localization of MDRF based on the ETDRS chart, in regions other than temporal regions, the INL thickness was significantly greater in regions with MDRF than in other regions. The MDRF significantly correlated with α-SMA expression in the ERM specimens (r = 0.555, P = 0.009).

Conclusions

The findings suggest that ERM impairs the inner retinal layer in a traction force-dependent manner.

Financial Disclosures

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

RHOMBUS DEFORMATION OF RETINAL LATERAL DISPLACEMENT AFTER EPIRETINAL MEMBRANE REMOVAL REVEALED BY DIFFEOMORPHIC IMAGE REGISTRATION

PURPOSE

To establish an analysis method using diffeomorphic image registration and evaluate microvascular displacement through epiretinal membrane (ERM) removal.

METHODS

Medical records of eyes that underwent vitreous surgery for ERM were reviewed. Postoperative optical coherence tomography angiography (OCTA) images were converted to the corresponding preoperative images according to a configured algorithm using diffeomorphism.

RESULTS

Thirty-seven eyes with ERM were examined. Measured changes in the foveal avascular zone (FAZ) area showed a significant negative correlation with central foveal thickness (CFT). The average amplitude of microvascular displacement calculated for each pixel was 69 ± 27 µ m in the nasal area, which was relatively smaller than that in other areas. The vector map, which included both the amplitude and the vector of microvasculature displacement, showed a unique vector flow pattern called the rhombus deformation sign in 17 eyes. Eyes with this deformation sign showed less surgery-induced changes in the FAZ area and CFT and a milder ERM stage than those without this sign.

CONCLUSION

The authors calculated and visualized microvascular displacement using diffeomorphism. The authors found a unique pattern (rhombus deformation) of retinal lateral displacement through ERM removal, which was significantly associated with the severity of ERM.

Binocular metamorphopsia in patients with branch retinal vein occlusion: a multi-center study

PURPOSE

The pathology of branch retinal vein occlusion (BRVO), a retinal circulatory disease, is related to monocular metamorphopsia-related vision impairment of the affected eyes, but the association of binocular metamorphopsia in such patients is unclear. This study aimed to examine the frequency of binocular metamorphopsia and its association with the clinical characteristics of patients with BRVO.

METHODS

A total of 87 patients who were treated for BRVO-associated macular edema (ME) were included in this study. At baseline and 1 and 3 months after the initiation of anti-vascular endothelial growth factor (VEGF) treatment, we quantified metamorphopsia in the affected eyes and binocular metamorphopsia using the M-CHARTS^® diagnostic tool.

RESULTS

At baseline, 53 and 7 patients had metamorphopsia in the affected eyes and binocular metamorphopsia, respectively. Although the visual acuity improved significantly after the initiation of anti-VEGF treatment, the mean M-CHARTS score in the affected eyes did not change from the baseline score. At 3 months, 9 patients showed binocular metamorphopsia; it was significantly associated with metamorphopsia in the affected eyes with a 95% confidence interval of 0.021-0.122 (β = 0.306, p = 0.006).

CONCLUSION

Metamorphopsia in the affected eyes can cause binocular metamorphopsia in patients with BRVO-ME.

Retinal Vascular Tortuosity Index Change after Idiopathic Epiretinal Membrane Surgery: Does Internal Limiting Membrane Peeling Affect Retinal Vascular Tortuosity?

BACKGROUND

Idiopathic epiretinal membrane (iERM) surgery is one of the most commonly performed vitreoretinal surgeries, and the issue of internal limiting membrane (ILM) peeling in ERM surgery is still controversial. The aims of this study are to evaluate the changes in retinal vascular tortuosity index (RVTI) after pars plana vitrectomy for the iERM using optical coherence tomography angiography (OCTA) and to assess whether ILM peeling has an additional effect on RVTI reduction.

METHODS

This study included25 eyes of 25 iERM patients who underwent ERM surgery. The ERM was removed without ILM peeling in 10 eyes (40.0%), and the ILM was peeled in addition to the ERM in 15 eyes (60.0%). The existence of the ILM after ERM peeling was checked with second staining in all eyes. Best corrected visual acuity (BCVA) and 6 × 6 mm en-face OCTA images were recorded before surgery and at the first month postoperatively. A skeleton model of the retinal vascular structure was created following Otsu binarization of en-face OCTA images using ImageJ software (1.52U). RVTI was calculated as the ratio of each vessel length to its Euclidean distance on the skeleton model using the Analyze Skeleton plug-in.

RESULTS

The mean RVTI declined from 1.220 ± 0.017 to 1.201 ± 0.020 (p = 0.036) in eyes with ILM peeling and from 1.230 ± 0.038 to 1.195 ± 0.024 in eyes without ILM peeling (p = 0.037). There was no difference between the groups in terms of postoperative RVTI (p = 0.494). A statistically significant correlation was found between postoperative RVTI and postoperative BCVA (rho = 0.408, p = 0.043).

CONCLUSIONS

The RVTI is an indirect indicator of the traction created by the iERM on retinal microvascular structures, and it was effectively reduced after iERM surgery. The postoperative RVTIs were similar in cases who underwent iERM surgery with or without ILM peeling. Therefore, ILM peeling may not have an additive effect on the loosening of microvascular traction and thus may be reserved for recurrent ERM surgeries.

Vision-Related Parameters Affecting Stereopsis after Retinal Detachment Surgery

Even after successful surgery, the stereopsis of retinal detachment (RD) patients is inferior to that of normal subjects. However, it is unclear which visual dysfunction in the affected eye is responsible for the postoperative stereopsis impairment. This study included 127 patients after successful surgery for unilateral RD. Stereopsis, best-corrected visual acuity (BCVA), severity of metamorphopsia, letter contrast sensitivity and amount of aniseikonia were examined at 6-month postoperatively. Stereopsis was assessed using the Titmus Stereo Test (TST) and TNO stereotest (TNO). Postoperative stereopsis (log) in patients with RD were 2.09 ± 0.46 in the TST and 2.56 ± 0.62 in the TNO. Multivariate analysis with stepwise regression revealed postoperative TST was associated with BCVA, and TNO was associated with BCVA, letter contrast sensitivity, metamorphopsia and absolute values of aniseikonia. In a subgroup analysis that selected those with more impaired stereopsis, postoperative TST was associated with BCVA (p < 0.001), and TNO was associated with letter contrast sensitivity (p < 0.005) and absolute values of aniseikonia (p < 0.05) by multivariate analysis. Deterioration of stereopsis after RD surgery was affected by a variety of visual dysfunctions. The TST was affected by visual acuity, while the TNO was affected by contrast sensitivity and aniseikonia.

Vascular tortuosity analysis in eyes with epiretinal membrane imaged by optical coherence tomography angiography

Background

This study aimed to evaluate macular vessel tortuosity using optical coherence tomography angiography (OCTA) and its association with visual outcomes in eyes undergoing surgery for epiretinal membrane (ERM).

Methods

The study included 22 consecutive patients who underwent vitrectomy for ERM between May 2019 and July 2020 and OCTA at Osaka University Hospital. All patients underwent ophthalmologic examinations, including swept-source OCTA. Standard vitrectomy was performed, and the patients were followed up for 6 months postoperatively. Distortion of retinal vessels was calculated using two parameters: the actual vessel length in the vessel section (VL) and the direct vessel branching point distance (BD) in the three quadrants (nasal, temporal, and superior-inferior) of the macula. We analyzed the correlation between these parameters and visual outcomes.

Results

Significantly longer VL was found at 1, 3, and 6 months postoperatively (p = 0.006, 0.008, and 0.022, respectively) in the temporal quadrant compared to baseline temporal VL. Significantly shorter VL was found in nasal quadrants at 1 and 3 months (p = 0.046 and p = 0.018) in the comparison of nasal baseline VL. VL/BDs were correlated with the same postoperative best-corrected visual acuity (BCVA) at 1, 3, and 6 months (p = 0.035, 0.035, and 0.042, respectively) in the superior-inferior quadrant. A significant association of changes in VL and BCVA was found at 3 and 6 months postoperatively in the nasal quadrant (p = 0.018 and 0.0455, respectively).

Conclusions

Changes in vascular distortion after ERM surgery can be measured using OCTA. The change in vessels around the macula became more linear; this was associated with visual outcomes after surgery.

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.

Finite Element Analysis of the Epiretinal Membrane Contraction

The epiretinal membrane is a thin sheet of fibrous tissue that can form over the macular area of the retina, and may result in the loss of visual acuity or metamorphopsia, due to superficial retinal folds. A vitrectomy surgery, the current treatment procedure for this pathology, is only performed after symptoms are present. However, sometimes the patients do not present any vision improvements after the surgery. The use of computational methods for a patient-specific biomechanical analysis can contribute to better understanding the mechanisms behind the success or failure of a vitrectomy. Using medical data from two patients who underwent a vitrectomy, one with substantial improvements and another with no improvements, an analysis of the retinal displacement due to the contraction of the epiretinal membrane was performed. Our results suggest a causal effect between the magnitude of the retinal displacements caused by the epiretinal membrane contraction and the outcome of the vitrectomy procedure.

Visual functions affecting stereopsis in patients with branch retinal vein occlusion

PURPOSE

To quantify stereopsis and other visual functions in patients with unilateral branch retinal vein occlusion (BRVO) and to investigate vision-related parameters that affect stereopsis.

DESIGN

Prospective observational study.

SUBJECTS

Forty-five patients undergoing intravitreal ranibizumab (IVR) treatment for unilateral BRVO.

METHODS

We examined stereopsis using the Titmus stereo test (TST) and TNO stereotest (TNO), best corrected visual acuity (BCVA), letter contrast sensitivity, severity of metamorphopsia and degree of aniseikonia before and 6 months after IVR.

MAIN OUTCOME MEASURES

Visual functions that affect stereopsis.

RESULTS

Baseline stereopsis in patients with BRVO was 2.7 ± 0.6 (range, 1.6-3.5) in the TST and 2.8 ± 0.5 (range, 1.8-3.3) in TNO. TST and TNO scores were significantly correlated with BCVA and letter contrast sensitivity at baseline (P < 0.001) but not with other visual functions. IVR treatment significantly improved stereopsis, BCVA, and letter contrast sensitivity. After treatment, TST scores were significantly correlated with BCVA (P < 0.001), letter contrast sensitivity (P < 0.001), and aniseikonia (P < 0.01). TNO scores were significantly correlated with BCVA (P < 0.01) and letter contrast sensitivity (P < 0.01). TST and TNO scores after treatment were significantly correlated with BCVA at baseline (P < 0.01 for both).

CONCLUSIONS

Deterioration of stereopsis in patients with BRVO was associated with changes in visual acuity and contrast sensitivity after treatment. Initial visual acuity is a prognostic factor for posttreatment stereopsis.

Ectopic inner foveal layer as a factor associated with metamorphopsia after vitrectomy for epiretinal membrane

PURPOSE

To analyse the relationship between the extent of metamorphopsia and optical coherence tomography (OCT) parameters including the ectopic inner foveal layer (EIFL) in patients with epiretinal membrane (ERM) who underwent pars plana vitrectomy (PPV).

METHODS

This study included 63 eyes of 62 patients who underwent PPV for ERM. Metamorphopsia was assessed by measuring the metamorphopsia score for vertical lines (MV) and metamorphopsia score for horizontal lines (MH) using M-CHARTS. Central retinal thickness (CRT), EIFL thickness and disruption of outer retinal layers were measured before and after surgery, and the relationship of these parameters with metamorphopsia scores at 3 months after vitrectomy was analysed.

RESULTS

Preoperative MV correlated with preoperative CRT and EIFL (p = 0.005 and 0.045 respectively). Postoperative MH correlated with preoperative CRT (p = 0.048), while postoperative MV correlated with preoperative CRT and EIFL (p = 0.002 and 0.0006 respectively). Postoperative MH correlated with postoperative CRT and EIFL (p = 0.001 and 0.002 respectively), and postoperative MV also correlated with postoperative CRT and EIFL (p = 0.0008 and < 0.0001 respectively). MH and MV did not correlate with outer retinal layer disruptions, both before and after vitrectomy. When multiple regression analysis was performed on preoperative and postoperative OCT parameters that correlated with postoperative metamorphopsia scores, only postoperative EIFL was identified as an independent factor associated with postoperative MV (p = 0.042).

CONCLUSION

When PPV was conducted for ERM, postoperative EIFL was found to be a significant factor associated with postoperative metamorphopsia score.

Long-Term Follow-Up of Outer Retinal Layers in Patients with Epiretinal Membranes

PURPOSE

This study aimed to investigate the long-term effect of observed epiretinal membranes on the outer retinal layers and visual acuity.

METHODS

It is a retrospective observational study. Subjects with an epiretinal membrane and consecutive optical coherence tomography scans were followed for changes in visual acuity, central macular thickness, ellipsoid zone loss, and outer foveal thickness (OFT).

RESULTS

The study consisted of 24 eyes of 22 patients, with a mean follow-up of 5 ± 1.6 years. The mean visual acuity was slightly worse at the last follow-up (0.22 ± 0.36 LogMAR [20/33] vs. 0.27 ± 0.36 LogMAR [20/36], p = 0.05). Ellipsoid zone loss was found in 37.5% of eyes. Vision loss was associated with initial size of ellipsoid disruption (p = 0.048) and age (p = 0.027). A decrease in OFT was associated with an initially larger zone of ellipsoid disruption (p = 0.006) and an initially thicker OFT (p = 0.011). An epiretinal membrane associated with vitreomacular adhesion within 1,000 μm of the foveal center at baseline was associated with ellipsoid zone loss (p = 0.012) but not with a change in visual acuity.

CONCLUSIONS

Ellipsoid zone changes were common in this study and tended to enlarge over time. Epiretinal membranes associated with vitreomacular adhesion within 1,000 μm of the foveal center may be a risk factor for ellipsoid zone loss.

Association Between Retinal Artery Angle and Visual Function in Eyes With Idiopathic Epiretinal Membrane

Purpose

This study investigated the relationship between retinal artery angle and visual function in eyes with idiopathic epiretinal membrane (ERM).

Methods

Ultra-wide field fundus imaging was conducted to analyze ERM and normal contralateral eyes. In addition to the logMAR visual acuity (VA) measurement, the average of the vertical and horizontal metamorphopsia scores (Mave) was measured using m-Charts for each eye. We calculated the retinal artery angle (Yugami correlated angle [YCA]) in all the examined eyes using ImageJ software. The YCAs were then compared between the ERM and normal contralateral eyes. Additionally, the relationship between YCA and visual function was investigated in the ERM eyes.

Results

Data from 40 patients with ERM were analyzed. The mean age of the participants was 67.1 ± 8.1 years. The YCA was significantly smaller in the ERM eyes, compared with the contralateral eyes (P < 0.001, respectively; Wilcoxon signed rank test). Among age, axial length, YCAs, central retinal thickness (CRT), and central choroidal thickness (CCT), the optimal model for logMAR VA included age, YCA, and CRT. On the other hand, the optimal model for Mave included YCA and CCT.

Conclusions

The retinal artery angle may be useful for predicting visual function in eyes with ERM.

Translational Relevance

Our established quantitative measurements in fundus photography have potential clinical use in predicting visual function in ERM.

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.

Relationship Between Optical Coherence Tomography Parameter and Visual Function in Eyes With Epiretinal Membrane

Purpose

To investigate the associations between visual function and the optical coherence tomography (OCT) parameters in eyes with idiopathic epiretinal membrane (ERM).

Methods

Thirty-nine consecutive eyes with ERM were enrolled. In addition to OCT parameters, such as central retinal thickness (CRT), the area of gap between the ERM and the retinal surface (SUKIMA) was newly defined and calculated from the vertical and horizontal OCT images (SUKIMAv and SUKIMAh). The average of SUKIMAv and SUKIMAh (SUKIMAave) was used for the statistical analysis. The vertical and horizontal metamorphopsia scores (MV, MH) and the average of MV and MH (Mave) were also used for the analysis.

Results

The Mave was not significantly associated with logMAR visual acuity (VA) (P = 0.57, linear regression analysis). Analysis using second-order bias-corrected Akaike information criterion model selection identified the age, CRT, and SUKIMAave as being associated with logMAR VA. On the other hand, among the OCT parameters, SUKIMAave and CRT were associated with the Mave. In addition, there was a significant relationship between SUKIMAh and MV (P = 0.011) and between SUKIMAv and MH (P = 0.0014).

Conclusions

We identified SUKIMA as a novel OCT parameter that is useful to predict both VA and metamorphopsia in patients with ERM.

Relationship between metamorphopsia and inner retinal microstructure following intravitreal ranibizumab injection for branch retinal vein occlusion

To evaluate the effects of intravitreal ranibizumab injection (IVR) on metamorphopsia in patients with branch retinal vein occlusion (BRVO), and to assess the relationship between metamorphopsia and inner retinal microstructure and other factors. Thirty-three treatment-naïve eyes of 33 patients with macular edema caused by BRVO with at least 12 months of follow-up were included. The degree of metamorphopsia was quantified using the M-CHARTS. Retinal microstructure was assessed with spectral-domain optical coherence tomography. Disorganization of the retinal inner layers (DRIL) at the first month after resolution of the macular edema (early DRIL) and at 12 months after treatment (after DRIL) was studied. Central retinal thickness (CRT), and status of the external limiting membrane as well as ellipsoid zone were also evaluated. IVR treatment significantly improved best-corrected visual acuity (BCVA) and CRT, but the mean metamorphopsia score did not improve even after 12 months. Post-treatment metamorphopsia scores showed a significant correlation with pre-treatment metamorphopsia scores (P < 0.005), the extent of early DRIL (P < 0.05) and after DRIL (P < 0.05), and the number of injections (P < 0.05). Multivariate analysis revealed that the post-treatment mean metamorphopsia score was significantly correlated with the pre-treatment mean metamorphopsia score (P < 0.05). IVR treatment significantly improved BCVA and CRT, but not metamorphopsia. Post-treatment metamorphopsia scores were significantly associated with pre-treatment metamorphopsia scores, the extent of DRIL, and the number of injections. Prognostic factor of metamorphopsia was the degree of pre-treatment metamorphopsia.

Correlation between tangential distortion of the outer retinal layer and metamorphopsia in patients with epiretinal membrane

PURPOSE

To evaluate tangential morphological changes in the outer retina and assess their correlation with the degree of metamorphopsia in patients with idiopathic epiretinal membrane (ERM).

METHODS

This retrospective study included patients with idiopathic ERM who underwent vitrectomy between January 2018 and December 2019. We evaluated the preoperative examination results. Using cross-sectional spectral-domain optical coherence tomography (OCT) images along the horizontal/vertical meridian through the fovea, we defined a new parameter, tangential displacement (TD), as the tangential component of the position vector of the distorted outer nuclear layer caused by ERM. Visual function measurements included M-CHARTS results (vertical/horizontal metamorphopsia score [MV/MH]) and best-corrected visual acuity (BCVA). The correlations among the OCT parameters including TD and central foveal thickness (CFT) with visual function measurements were determined.

RESULTS

Overall, 78 eyes of 76 patients (49 females; mean age, 67.9 [± standard deviation, 7.5 years]) were included. The mean horizontal TD was 24.0 ± 73.9 μm, which was significantly different from 0 (p = 0.005). The mean vertical TD was 6.0 ± 76.2 μm, which was not significantly different from 0. The absolute value of horizontal TD was significantly correlated with MV (r = 0.513, p < 0.01) and MH (r = 0.423, p < 0.01). The absolute value of vertical TD was also significantly correlated with MV (r = 0.274, p = 0.02) and MH (r = 0.413, p < 0.01). However, neither value was significantly correlated with BCVA. Multiple regression analysis showed that the horizontal absolute TD was an independent factor associated with both MV (β = 0.635, p < 0.001) and MH (β = 0.259, p = 0.048).

CONCLUSION

We found that ERM tended to distort the outer retinal layer toward the temporal side of the fovea. The tangential distortion of this layer was associated with the degree of metamorphopsia, suggesting that misalignment of parafoveal photoreceptors causes metamorphopsia in patients with ERM.

Correlation between new OCT parameters and metamorphopsia in advanced stages of epiretinal membranes

PURPOSE

To correlate metamorphopsia provided by M-CHARTS and ectopic inner foveal layers (EIFL) or 'central bouquet' abnormality (CBA) in patients with advanced stages of epiretinal membrane (ERM) following the novel Optical Coherence Tomography (OCT)-based grading scheme.

METHODS

In 60 eyes of 57 patients affected by ERM (stages 3 and 4), the degree of metamorphopsia using the M-CHARTS was evaluated (M-SCORE) and correlated with EIFL, CBA and central foveal thickness (CFT) as measured on OCT scans.

RESULTS

A total of 37 and 23 eyes were diagnosed having ERM stages 3 and 4, respectively. Mean vertical and horizontal M-SCORE (M-V and M-H) were 0.64 ± 0.43 and 0.58 ± 0.37 standard deviations, respectively. Mean M-SCORE exhibited a statistically significant correlation with EIFL and CFT (both p < 0.0001), but not with CBA (p = 0.84). Analysing the direction of metamorphopsia separately, M-H and M-V were significantly correlated with EIFL (both p < 0.0001), but not with CBA thickness (p = 0.70 and 0.33 respectively). Ectopic inner foveal layers (EIFL) was significantly influenced by the presence of CBA (CBA present, 158.29 ± 63.53 micron; CBA absent, 107.05 ± 94.13 micron, p = 0.04). No significant differences were found for both M-V and M-H with respect to the presence of CBA.

CONCLUSIONS

Based on the novel OCT-based grading scheme for ERMs, our results demonstrate that EIFL, but not CBA, might be considered a good indicator for metamorphopsia in patients with advanced ERMs.

Characteristics of secondary epiretinal membrane due to peripheral break

This study aimed to investigate morphological differences between idiopathic epiretinal membrane (ERM) and secondary ERM due to peripheral break (SEPB) and to identify clinical characteristics in eyes with SEPB to facilitate peripheral retinal examination. The retrospective cross-sectional study involved 93 consecutive eyes in 91 patients who underwent ERM removal surgery. Eyes were divided into two groups: the macular pucker group and the idiopathic ERM group. En-face Optical Coherence Tomography (OCT) images, fundus photographs, severity of metamorphopsia (M-score) and clinical characteristics of each group were compared. ERM extent and eccentricity (ratio of the shortest and longest distances from the foveal center to the boundary) were obtained through en-face OCT imaging. Fundus photographs were used to judge whether the membrane was turbid or not. Patients with SEPB were younger than patients with idiopathic ERM (61.3 ± 7.5 vs. 66.6 ± 8.3 years; p < 0.05). Preoperative M-score and myopic refractive error, axial length were also significantly higher in the macular pucker group than in the idiopathic ERM group (all p < 0.05). There was no difference in ERM extent between the two groups. The incidence of ERM eccentricity was 23 of the 34 eyes (67.6%) in the SEPB group and 26 of the 59 eyes (44.1%) in the idiopathic ERM group (p < 0.05). The incidence of turbid ERM was 18 of the 34 eyes (52.9%) in the SEPB group and 10 of the 59 eyes (16.9%) in the idiopathic ERM group (p < 0.01). The SEPB group, compared with the idiopathic ERM group, tended to have eccentric, turbid ERM at a younger age and with more severe metamorphopsia and myopic refractive error.

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.

Association between displacement and thickness of macula after vitrectomy in eyes with epiretinal membrane

The purpose of this cross-sectional retrospective study was to determine the relationship between the retinal displacements and the retinal thickness in eyes with epiretinal membrane (ERM) after vitrectomy with internal limiting membrane (ILM) peeling. To accomplish this, we measured the retinal thickness using optical coherence tomography (OCT) and the retinal displacement using OCT angiography to obtain 3 mm × 3 mm en face images before, and 2, 4, and 8 weeks following the surgery from 20 eyes of 20 patients. The distance between the retinal vessel bifurcations and the fovea was significantly displaced centrifugally and asymmetrically in the 4 quadrants postoperatively (P < 0.001). The foveal avascular zone (FAZ) was significantly enlarged, and the central foveal thickness (CFT) and the inner nuclear layer (INL) thickness were significantly thinner postoperatively. The displacements were significantly correlated with the changes in the FAZ area (r = 0.717, P < 0.001), the CFT (r = − 0.702, P < 0.001), and the INL thickness (r = − 0.702, P < 0.001). In conclusion, the distance between the retinal bifurcations and the fovea was asymmetrically expanded after the surgery and was significantly correlated with the morphological changes. These results indicate that a horizontal macular contraction is correlated with vertical retinal contraction in the eyes with an ERM.

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.

Vision-related parameters that affect stereopsis in patients with macular hole

This study evaluated stereopsis and other visual functions in patients with idiopathic macular hole (MH), and sought to identify vision-related parameters that affect stereopsis. In this prospective, consecutive, comparative study, 39 eyes of 39 patients with unilateral idiopathic MH were included. At baseline and at 6 months after MH surgery, we evaluated stereopsis, with the Titmus stereo test (TST) and TNO stereotest (TNO), best-corrected visual acuity (BCVA), letter contrast sensitivity, severity of metamorphopsia, as assessed using M-CHARTS, and extent of aniseikonia, by the new aniseikonia test. Preoperative stereopsis (log) in patients with MH were 2.72 ± 0.53 (range 1.9–4.1) in the TST and 2.82 ± 0.65 (range 1.8–3.9) in the TNO. Preoperative TST was significantly correlated with letter contrast sensitivity (p < 0.05), but not with the other visual functions. TNO showed significant correlation with letter contrast sensitivity (p < 0.05) and aniseikonia (p < 0.005). Preoperative TNO was associated with aniseikonia by multivariate analysis (p < 0.005). MH surgery significantly improved stereopsis, BCVA, letter contrast sensitivity, metamorphopsia, and aniseikonia. Postoperative TST and TNO was significantly associated with BCVA by multivariate analysis. Deterioration of stereopsis in MH patients is associated with contrast sensitivity and the degree of aniseikonia.

Are There Funduscopic and Optical Coherence Tomography Preoperative Characteristics to Predict Surgical Difficulty of Epiretinal Membrane Removal?

PURPOSE

To identify the correlation between preoperative funduscopic and optical coherence tomography characteristics of epiretinal membranes and the difficulty of surgical removal.

METHODS

Fifty eyes of 50 patients with an idiopathic epiretinal membrane (ERM) scheduled for pars plana vitrectomy (PPV) and ERM peeling were included. Surgical videos were analyzed and the difficulty of ERM removal (easy or difficult) determined subjectively by an independent surgeon. Furthermore, the peeling time and amount of grasping were measured on the videos to provide an objective factor of surgery difficulty. Preoperative spectral-domain optical coherence tomography (OCT) images and color fundus photos were analyzed to identify predictive factors for membrane removal difficulty.

RESULTS

The subjective surgical difficulty of ERM removal was strongly associated with fibrillary changes between the ERM and retinal nerve fiber layer (RNFL), severe retinal vascular tortuosity and severe glinting fundus reflex. Higher fundus pigmentation was associated with fewer and cystoid spaces with more attempts of grasping ERM. No other preoperative signs were found to be associated with the duration of the peeling time.

CONCLUSION

The presence of fibrillary changes between the ERM and RNFL, severe retinal vascular tortuosity and severe glinting reflex are preoperative findings that have a strong association with the difficulty in ERM peeling.

Negative correlation between retinal displacement and ganglion cell layer thickness changes in eyes with epiretinal membrane

PURPOSE

To examine retinal displacement after vitrectomy with internal limiting membrane peeling for epiretinal membrane treatment, and to determine the correlation between the extent of displacement and the ganglion cell layer thickness changes.

METHODS

Thirty-nine consecutive patients were evaluated. Optical coherence tomography was performed preoperatively, and 2 and 6 months postoperatively. The distance between the fovea, the vessel intersection in the superior nasal, superior temporal, inferior nasal, and inferior temporal macular regions, and the optic disk were measured. Ganglion cell layer thickness was recorded.

RESULTS

The distance from the optic disk to the fovea and the superior nasal and inferior nasal vessel intersections significantly reduced at 2 and 6 months. Ganglion cell layer thickness significantly decreased in all the subfields (except nasal) at 6 months. A significant negative correlation was found between the change in the ganglion cell layer thickness and the movement of the fovea toward the optic disk. The ganglion cell layer thickness changes significantly correlated with retinal displacement.

CONCLUSION

Retinal displacement toward the optic disk was detected after vitrectomy with internal limiting membrane peeling in eyes with epiretinal membrane. Ganglion cell layer thickness significantly reduced in all the subfields (except nasal). The extent of the displacement and the ganglion cell layer thickness changes showed significant negative correlation.

Digital Nullification of Visual Distortion to Quantify Metamorphopsia: A Pilot Study

BACKGROUND AND OBJECTIVE

To evaluate a novel digital method of metamorphopsia quantification in patients with symptomatic visual distortion as determined by M-CHARTS.

PATIENTS AND METHODS

In this institutional review board-approved, prospective, cross-sectional observational study, subjects were presented with an objectively straight dotted line that bisects a central fixation point. The subjects digitally altered the line's contour until it appeared straight. Calculation of the area between the original objectively straight line presented to the subject and their newly manipulated line was performed to determine the manipulated area under the curve (M-AUC).

RESULTS

Sixty-two percent of test targets were fully or significantly straightened by affected subjects. M-AUC was significantly correlated with M-CHARTS scores in both the horizontal (P < .001) and vertical (P = .05) orientations.

CONCLUSIONS

The deformation of an objectively straight line by a subject with metamorphopsia may be a viable way of both quantifying and spatially characterizing visual distortions. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:11-20.].

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.

Functional and morphological results of treatment of macula-on and macula-off rhegmatogenous retinal detachment with pars plana vitrectomy and sulfur hexafluoride gas tamponade

BACKGROUND

To examine morphological and functional results after pars plana vitrectomy (PPV) with sulfur hexafluoride (SF6) gas tamponade due to macula-on and macula-off rhegmatogenous retinal detachment (RRD) during 6 months of the follow-up.

METHODS

The study included 62 eyes that underwent successful PPV with SF6 tamponade with macula-on (34 eyes) and macula-off (28 eyes) RRD preoperatively. The best-corrected visual acuity (BCVA), Amsler test, M-charts, optical coherence tomography (OCT) and microperimetry were performed at 1, 3 and 6 months postoperatively.

RESULTS

Results of the Amsler test were abnormal postoperatively in 54% of the patients in the group with macula-off and in 32% of the patients with macula-on RRD. Horizontal M-charts improved significantly from 0.33 to 0.2, vertical M-charts- from 0.29 to 0.17 during 6 months of the follow-up. There was a significant increase in the central retinal thickness (CRT) and average thickness (AT) between follow-up examinations only in the macula-off group. 29 of 62 eyes (47%) after surgery (equally with macula-on and macula-off RRD) showed morphological changes in OCT in the macular region, as epiretinal membrane, macular edema, subretinal fluid or alterations of the outer layers of the retina. The average threshold in microperimetry increased significantly within both groups during the follow-up.

CONCLUSION

Both horizontal and vertical M-charts scores, as were as microperimetry sensitivity improved significantly during the 6 months of the follow-up both in macula-on and macula-off group. Although PPV with SF6 gas tamponade was successful, almost half of eyes revealed anatomical changes in the macular region in OCT both with macula-on and macula-off group.

TRIAL REGISTRATION

Current Controlled Trials NCT03902795 registered on 03/04/2019. Retrospectively registered.

Idiopathic Macular Hole: A Comprehensive Review of Its Pathogenesis and of Advanced Studies on Metamorphopsia

Vitreous anteroposterior traction is an important factor that affects macular hole (MH) formation at the early stage, and vitreous tangential traction can lead to further hole expansion after hole formation. Recent studies have highlighted the significance of Müller cells for the pathogenesis of MH. Since the advent of MH treatment, success rates for MH closure have significantly improved, as has postoperative visual acuity. However, metamorphopsia, an initial and common symptom of MH, still exists. Metamorphopsia is significantly related to the deterioration of visual quality of life and can be used as an independent index to evaluate visual function before and after surgery. In MH patients, metamorphopsia has different manifestations representing different clinical implications. M-CHARTS, as a new means of inspection, can quantify the degrees of metamorphopsia, and with the development of optical coherence tomography (OCT), layer-by-layer scanning of the retinal structure has become possible. These methods enable detailed analysis of the connections between the degree of metamorphopsia and relevant OCT parameters. Preoperative OCT parameters can be used to evaluate the prognosis of the postoperative visual function of MH patients and are therefore of great significance in guiding the treatment of MH patients.

Assessment of the deformation of the outer nuclear layer in the Epiretinal membrane using spectral-domain optical coherence tomography

Background

We aimed to investigate the deformation of the outer nuclear layer using optical coherence tomography in patients with epiretinal membrane (ERM) and its relationship with metamorphopsia.

Methods

Thirty-nine eyes from 39 patients with ERM were included in the study. Patients with the subtypes of pseudo macula hole and lamellar hole were excluded. Twenty-one fellow eyes without macular disease were included as normal controls. Forty-nine B-scan images were obtained in the range of 20 degrees around the macula using SD-OCT. The outer nuclear layer (ONL) was evaluated as a three-dimensional image (3D-ONL) reconstructed using the distance between the ONL and retinal pigment epithelium (RPE) line. The deformation of the ONL was figured at the reference plane and evaluation plane (ONL-B). The characteristic parameters of the ONL-B were defined as circularity, area ratio, and axis ratio. The correlations between these parameters and visual acuity and MCHART score ratio (MH/MV) were then evaluated.

Results

ONL height was significantly higher in ERM patients than in normal controls (54.1 ± 5.3 μm and 84.1 ± 12.9 μm, respectively; P < 0.001). In ERM patients, the MV score was 0.53 ± 0.50, the MH score was 0.71 ± 0.61, and the distance from the RPE line to the ONL-B was 153.5 ± 13.5 μm. The axis of the ONL-B in normal controls and ERM patients was − 6.25 ± 21.8 and − 1.28 ± 29.1, respectively, which indicates that the ONL is horizontally long in both normal individuals and ERM patients. The circularity and area ratio were significantly smaller in ERM patients than in normal controls. In all ERM patients, MH/MV had a significant correlation with axis (r = − 0.29, p = 0.034), circularity (r = − 0.28, p = 0.044), and area ratio (r = − 0.47, p = 0.001). Moreover, we found that the correlation was more significant if the subjects had an axis of the ONL within ±10 degrees (n = 16); the correlations of MH/MV with axis (r = − 0.29, p = 0.034), circularity (r = − 0.53, p = 0.021), and area ratio were more significant (r = − 0.78, P < 0.0001).

Conclusion

The ONL is horizontally long in normal individuals and ERM patients. The direction of metamorphopsia is correlated with the direction of ONL deformation.

Vertical and Horizontal M-Charts and Microperimetry for Assessment of the Visual Function in Patients after Vitrectomy with ILM Peeling due to Stage 4 Macular Hole

Purpose

To examine the relationship between the morphological and functional results in eyes after pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling due to stage 4 full-thickness macular hole (FTMH).

Methods

The study included 22 eyes that underwent successful PPV due to FTMH. Both vertical metamorphopsia (VM) and horizontal metamorphopsia (HM) were determined using type 2 M-charts, as well as best-corrected visual acuity (BCVA), microperimetry, and optical coherence tomography (OCT) were performed before PPV and 1 and 6 months postoperatively.

Results

A significant improvement of BCVA and metamorphopsia scores measured by M-charts in particular periods before surgery, 1 and 6 months after PPV, was observed. The VM scores were consistently higher than the HM scores at all assessment times. There was a correlation found between VM and BCVA and microperimetry parameters before surgery. The macular sensitivity (MS) as well as macular integrity index increased from 1 month to 6 months after PPV and were correlated with postoperative visual acuity (VA). There was a correlation found between the hole diameter and MS and P2 parameter 6 months after PPV. There was a correlation found between mean duration of symptoms of FTMH and VA and VM score.

Conclusions

VM scores seem to correlate better than HM scores with preoperative BCVA, microperimetry parameters, and duration of symptoms of the FTMH. VM scores are higher after PPV than HM scores in patients with stage 4 of the FTMH. This trial is registered with NCT03701542.

Five-Year Outcomes of Surgically Treated Symptomatic Epiretinal Membranes With and Without Internal Limiting Membrane Peeling

BACKGROUND AND OBJECTIVE

The authors evaluated long-term postoperative visual outcomes and recurrence rates following surgery for symptomatic epiretinal membrane (ERM) ± internal limiting membrane (ILM) peeling.

PATIENTS AND METHODS

This was a retrospective, consecutive case series of 78 patients undergoing vitrectomy for symptomatic ERM between 1/2010 and 4/2012 with follow-up through at least postoperative year 5 (POY5). Outcomes included visual acuity (VA) (Snellen VA converted to logMAR), central retinal thickness (CRT; μm), and ERM recurrence. Subgroup analysis evaluated outcomes related to ILM peeling.

RESULTS

Subgroup analysis based on ILM peeling did not find VA (20/50 [0.430 logMAR ± 0.061 logMAR; mean ± SD] vs. 20/60 [0.518 logMAR ± 0.128 logMAR] for ILM vs. non-ILM peeling respectively; P = .513) nor macular thickness (355 μm ± 13 μm vs. 360 μm ± 42 μm; P = .410) to be significantly different at POY5. Recurrence requiring surgery with and without ILM peeling was not statistically significantly different at POY5 (1.6% and 11.8%; P = .118).

CONCLUSION

Vitrectomy for symptomatic ERM led to improved visual and anatomic outcomes with sustained benefit through 5 years. ILM peeling was was associated with reduced ERM recurrence, but this benefit was not statistically significant at POY5. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:296-302.].

Quantitative assessment of outer retinal folds on enface optical coherence tomography after vitrectomy for rhegmatogenous retinal detachment

We aimed to investigate the possible causes of metamorphopsia for rhegmatogenous retinal detachment (RRD) based on findings of enface optical coherence tomography (OCT). The study was a retrospective, consecutive case series of 33 eyes with macula-off RRD. Metamorphopsia was measured by M-CHARTS and enface OCT images covering a macular area of 6 × 6 mm square obtained at 1, 3, and 6 months postoperatively. Within the outer retinal slabs of enface OCT, multiple lines that looked like folds were delineated in all eyes at month 1, and we succeeded in extracting images of folds by subtracting retinal vessels. We calculated their density by an image-processing technique. The mean M-CHARTS scores were 0.62 ± 0.47 at month 1 and 0.30 ± 0.29 at month 6 (P < 0.001). The fold density was 8.3 ± 4.2 at month 1 and 6.1 ± 3.1 at month 6 (P = 0.0044). The M-CHARTS scores at 6 months were significantly associated with the fold density at 1 month (r = 0.515, P = 0.002). In conclusion, enface OCT visualized the outer retinal folds in eyes that had undergone successful RRD surgery, and a larger number of folds was related to the remaining metamorphopsia.

Metamorphopsia Score and Central Visual Field Outcomes in Diabetic Cystoid Macular Edema

Aim

To detect abnormality of the visual function in naïve patients with cystoid diabetic macular edema (DME) using M-charts, Amsler test, and white on white (W/W) and blue on yellow (B/Y) perimetry.

Methods

There were 64 eyes included in the study: 30 eyes with DME, 22 eyes with diabetes without DME, and 12 eyes of normal subjects. Conventional W/W perimetry and B/Y perimetry were performed within the central 10° of the visual field. To assess metamorphopsia, Amsler test and M-charts were used.

Results

The rate of detection of metamorphopsia was 37% with Amsler test examination and 50% with M-charts. Specificity of both tests was 100%. We found a significant difference between vertical scores of M-charts in all groups, but not in horizontal scores (p < 0.0001). Mean defect (MD) was 8.9 dB and 3.6 dB and loss variance (LV) 4.8 dB and 3.3 dB (p < 0.0001).

Conclusions

M-chart is more sensitive than Amsler test method for detection of metamorphopsia. The MD and LV are higher in b/y in comparison to W/W perimetry. B/Y perimetry and M-charts are more sensitive than conventional methods for detecting the visual function loss in cystoid DME.