Functional and Morphological Correlations before and after Video-Documented 23-Gauge Pars Plana Vitrectomy with Membrane and ILM Peeling in Patients with Macular Pucker

Clinical utilization of microperimetry in ophthalmic surgery: A narrative review

Microperimetry is an emerging technology that provides concurrent analysis of retinal structure and function by combining retinal sensitivity and fixation analysis with fundus imaging. We summarize the substantial evidence validating the evolving role of microperimetry as an adjunctive assessment of visual function in the perioperative setting. We show that microperimetry provides useful complementary information to other established imaging and functional modalities in the perioperative setting for a wide range of vitreoretinal surgical procedures, as well as in cataract and refractive surgeries. This includes preoperative uses such as prognostication of visual and anatomical outcomes, timing of surgical intervention, and assessment of patient suitability for surgery-as well as postoperative uses including quantification of visual recovery, investigation of unexplained postoperative vision loss, and informing expected long term functional outcomes.

[Disorders of the visual system following vitreoretinal and macular surgery]

The visual system is highly complex. Monocular or binocular disorders can develop, for example during tractive alterations of the macula, such as in epimacular membranes, and result in symptoms, such as double vision, aniseikonia or metamorphopsia. These symptoms are also observed following vitreomacular or vitreoretinal surgery, especially after treatment of large retinal detachment involving the macular area using pars plana vitrectomy or scleral buckle surgery but also as a result of vitreomacular interventions, such as membrane peeling in epimacular gliosis. Some patients have preoperatively existing latent conditions, which are not explicitly addressed during routine preoperative diagnostics. For patients and surgeons it is worth noting that these troublesome symptoms are often manifested in patients with good restoration of best corrected visual acuity following vitreomacular surgery. In such cases, patients tend to be dissatisfied with the surgical result despite good visual acuity. Treatment of postoperative metamorphopsia, aniseikonia and double vision is often difficult. In clinical studies, the maximum depth of tractive retinal folds has been described as a reliable morphological biomarker for the occurrence of metamorphopsia in epimacular gliosis. As metamorphopsia tends to postoperatively resolve slowly and even persist in ca. 30% of cases, this biomarker can have an impact on preoperative consulting and postoperative monitoring. Persistent binocular discomfort is often treatable by exact refraction correction and by applying a vertical and, if necessary, a horizontal prism. This often requires patience on the part of both the patient and the physician but is mostly successful due to fusion and adaptability.

MACULAR SENSITIVITY IN THE AREA OF INTERNAL LIMITING MEMBRANE PEELING IN EYES AFTER PARS PLANA VITRECTOMY WITH THE TEMPORAL INVERTED INTERNAL LIMITING MEMBRANE FLAP TECHNIQUE FOR A FULL-THICKNESS MACULAR HOLE

PURPOSE

To examine the relationship between retinal sensitivity and the area of internal limiting membrane (ILM) peeling during pars plana vitrectomy for a full-thickness macular hole.

METHODS

Twenty-four eyes a minimum of 6 months after temporal inverted flap pars plana vitrectomy for a full-thickness macular hole were included in the study. En face spectral-domain optical coherence tomography images were used to assess margins of the peeled ILM area. Microperimetry was performed to examine retinal sensitivity within the central 10°. Areas of peeled ILM in en face optical coherence tomography images were correlated with the average sensitivity threshold. Retinal sensitivities at the location of each measurement point were compared with structural abnormalities observed in en face spectral-domain optical coherence tomography images.

RESULTS

The mean retinal sensitivity in the area of ILM removal was significantly lower compared with the area of preserved ILM (24.29 ± 3.96 dB vs. 26.19 ± 2.10 dB, P < 0.0001, respectively). The peeled ILM area showed a negative correlation with the average sensitivity threshold (r = -0.56, P < 0.01).

CONCLUSION

A larger area of ILM peeling during temporal inverted flap pars plana vitrectomy for a full-thickness macular hole is related to lower retinal sensitivity in the central macula.

Novel Optical Coherence Tomography Parameters as Prognostic Factors for Stage 3 Epiretinal Membranes

Purpose

We aimed to describe the visual prognosis of eyes with ectopic inner foveal layers (EIFLs) after epiretinal membrane (ERM) surgery.

Methods

This retrospective study enrolled patients diagnosed with stage 3 ERM based on the EIFL staging scheme who underwent ERM surgery with a minimum follow-up period of 12 months. Central foveal thickness (CFT), EIFL thickness, and the length of the ellipsoid zone defect were evaluated at baseline and at 1 month, 6 months, and 12 months after surgery based on pre- and postoperative swept-source optical coherence tomography (OCT) images. The association of EIFL thickness and other OCT parameters with pre- and postoperative best-corrected visual acuity (BCVA) was analyzed.

Results

Sixty-nine eyes with stage 3 ERMs were analyzed. Preoperative BCVA was correlated with preoperative CFT (r = 0.517, p < 0.001) and preoperative EIFL thickness (r = 0.652, p < 0.001). At 12 months, postoperative BCVA was correlated negatively with preoperative CFT (r = 0.470, p=0.016) and preoperative EIFL thickness (r = 0.582, p=0.004). The improvement in BCVA was not associated with postoperative reduction in CFT (p=0.06), although it was significantly associated with postoperative reduction in EIFL thickness (r = 0.635, p=0.007).

Conclusions

EIFL thickness should be considered a negative prognostic factor for postoperative anatomical and functional recovery in patients with stage 3 ERMs.

Vitrectomy for the removal of idiopathic epiretinal membrane with or without internal limiting membrane peeling: a meta-analysis

Purpose:

The aim of this study is to analyze the effect of internal limiting membrane peeling in removal of idiopathic epiretinal membranes through meta-analysis.

Methods:

We searched PubMed for studies published until 30 April 2018. Inclusion criteria included cases of idiopathic epiretinal membranes, treated with vitrectomy with or without internal limiting membrane peeling. Exclusion criteria consisted of coexisting retinal pathologies and use of indocyanine green to stain the internal limiting membrane. Sixteen studies were included in our meta-analysis. We compared the results of surgical removal of epiretinal membrane, with or without internal limiting membrane peeling, in terms of best-corrected visual acuity and anatomical restoration of the macula (central foveal thickness). Studies or subgroups of patients who had indocyanine green used as an internal limiting membrane stain were excluded from the study, due to evidence of its toxicity to the retina.

Results:

Regarding best-corrected visual acuity levels, the overall mean difference was –0.29 (95% confidence interval: –0.319 to –0.261), while for patients with internal limiting membrane peeling was –0.289 (95% confidence interval: –0.334 to –0.244) and for patients without internal limiting membrane peeling was –0.282 (95% confidence interval: –0.34 to –0.225). Regarding central foveal thickness levels, the overall mean difference was –117.22 (95% confidence interval: –136.70 to –97.74), while for patients with internal limiting membrane peeling was –121.08 (95% confidence interval: –151.12 to –91.03) and for patients without internal limiting membrane peeling was –105.34 (95% confidence interval: –119.47 to –96.21).

Conclusion:

Vitrectomy for the removal of epiretinal membrane combined with internal limiting membrane peeling is an effective method for the treatment of patients with idiopathic epiretinal membrane.

Changes in macular pigment optical density after membrane peeling

Introduction

To highlight the differences in macular pigment optical density (MPOD) between eyes with vitreoretinal interface syndrome and healthy control eyes, to assess the changes in MPOD in eyes treated with macular peeling, to investigate the relationships between MPOD changes and measures of retinal sensitivity such as best corrected visual acuity (BCVA) and microperimetry.

Methods

In this cross-sectional comparative study, 30 eyes affected by idiopathic epiretinal membrane (iERM, 15eyes) or full-thickness macular hole (FTMH, 15eyes) were compared with 60 eyes from 30 healthy age-matched patients. MPOD values (mean MPOD, maximum MPOD, MPOD area, and MPOD volume) were measured in a range of 4°–7° of eccentricity around the fovea, using the one-wavelength reflectometry method (Visucam 200, Carl-Zeiss Meditec). Patients affected by iERM and FTMH were treated with vitrectomy and epiretinal membrane-inner limiting membrane (ERM-ILM) peeling, with follow-up examinations performed preoperatively and 6 months postoperatively. The main outcome measures were the differences in MPOD between eyes with vitreoretinal interface syndrome and healthy eyes, changes in MPOD after ERM-ILM peeling, and relationships between MPOD and functional changes.

Results

Mean MPOD differed significantly between control eyes and those with iERM (P = .0001) or FTMH (P = .0006). The max MPOD and MPOD area increased, but not significantly. After peeling, the only significant change in MPOD was in MPOD volume (P = .01). In the ERM group, postoperative mean MPOD correlated significantly with best-corrected visual acuity (r = .739, P = .002).

Conclusions

MPOD was reduced in patients with iERM or FTMH compared with healthy eyes. We found a significant correlation between the mean postoperative MPOD and postoperative BCVA, hypothesizing that the postoperative increase in mean MPOD could be due to a change in distribution for unfolding and expansion of the fovea after the peeling. MOPD may be considered as a prognostic factor associated with a good visual prognosis in patients with iERM.

Current Clinical Application of Microperimetry: A Review

Microperimetry (MP) is a technology that allows the study of retinal sensitivity at different foveal and parafoveal areas as well as eye fixation. It is a technique of functional evaluation, providing a direct correlation between anatomical and functional outcomes. There are a great variety of studies which evaluate the repeatability or reliability of measurements obtained with this technology and also describe and explore different clinical applications. MP has been shown to be useful in the characterization of sensory and motor conditions, such as amblyopia or nystagmus. Concerning ocular pathology, several studies have confirmed the usefulness of MP for evaluating and analyzing different retinal pathological conditions, such as age-related macular degeneration or glaucoma, and for analyzing the effect of different medical or surgical treatments for these conditions. MP has also been shown to be useful for visual training or rehabilitation in some specific cases.

Anatomical and Functional Changes in the Coexistence of Vitreomacular Traction and Epiretinal Membrane: A Spectral-Domain Optical Coherence Tomography Study

PURPOSE

The purpose of this study was to evaluate the anatomical and functional findings in patients with vitreomacular traction (VMT) combined with epiretinal membrane (ERM) in the same eye.

METHODS

In this retrospective, cross-sectional study, we studied 65 patients with VMT and ERM. In 36 of them, ERM/VMT had a 'unified' appearance (group Ι) but in 29, VMT and ERM coexisted without an interrelationship (group ΙΙ). All patients were examined with spectral-domain optical coherence tomography (SD-OCT). We recorded the macular thickness, the presence, type and location of macular edema, the horizontal diameter of VMT, ellipsoid zone/external limiting membrane (EZ/ELM) status, the vitreofoveal angle of VMT nasally and temporally and the best corrected visual acuity (BCVA).

RESULTS

Group Ι presented with increased macular thickness, a broader adhesion diameter, extensive EZ/ELM defect and decreased BCVA compared to those where VMT and ERM were not intercorrelated. In group I ('unified' VMT and ERM), cystoid macular edema was found at a greater percentage (41.7%), while in patients where the 2 entities were not intercorrelated, diffuse macular edema was more evident (69%). There was no statistically significant difference between the 2 groups in the vitreofoveal angle temporally and nasally.

CONCLUSIONS

Macular thickness, type of macular edema, adhesion diameter, the extent of the EZ/ELM defect and BCVA appeared different in cases where VMT and ERM were unified compared to cases where ERM and VMT coexisted but were not intercorrelated.

Comparison of Macular Findings due to Vitreomacular Traction Alone or in Association with Epiretinal Membrane

Purpose

To evaluate the anatomical and functional findings in patients with vitreomacular traction (VMT) alone or in combination with epiretinal membrane (ERM).

Methods

In this retrospective, cross-sectional study, we studied 102 patients with VMT, either alone (n = 37) or combined with ERM (n = 65). All patients were examined with spectral-domain optical coherence tomography (SD-OCT). We recorded the vitreofoveal angle of VMT nasally and temporally, the horizontal diameter of VMT, macular thickness, the presence, type, and location of macular edema, the ellipsoid zone (ΕΖ)/external limiting membrane (ELM) status, and the visual acuity.

Results

Patients with VMT combined with ERM presented smaller vitreofoveal angle nasally and temporally, broader adhesion diameter, and a greater extent of EZ defect compared to patients with VMT alone, although there was no statistically significant difference in EZ and ELM condition regarding the number of affected cases. There is also no statistically significant difference between the 2 groups concerning the visual acuity. In the majority of patients with VMT alone, cystoid macular edema was present mainly at the foveal area. In cases where VMT coexisted with ERM, macular edema was mostly found to be diffuse, while cystoid or mixed type, extending to the whole macular area, was also present.

Conclusions

Patients with VMT in association with ERM have different characteristics in SD-OCT compared to those with VMT alone regarding the type and location of macular edema, the extent of EZ defect, as well as the vitreofoveal angle and the VMT diameter. Moreover, they presented worse visual acuity compared to those with VMT alone, although the difference did not reach statistical significance.

[Structural and functional characteristics of vitrectomized eyes]

The article describes the potential effects of vitrectomy on clinical refraction, refraction of the cornea and its biomechanical parameters, the state of the lens, intraocular pressure, and biometric parameters of the anterior eye segment.