SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY REVEALS INTERNAL LIMITING MEMBRANE PEELING ALTERS DEEP RETINAL VASCULATURE

Foveal microvascular features following inverted flap technique for closure of large macular holes

PURPOSE

To describe the anatomical and functional outcomes following use of the inverted flap technique (IFT) to close idiopathic macular holes (MH) of diameter greater than 400 μm. To compare the changes in the macular microvascularization following surgery in operated and healthy fellow eyes.

METHODS

Retrospective study of 24 patients who underwent vitrectomy and IFT for large MH closure. The main variables were closure pattern, best corrected visual acuity (BCVA) and recovery of the external limiting membrane (ELM) and ellipsoid zone (EZ). Foveal avascular zones (FAZ) and vessel and perfusion densities, obtained by OCT angiography scans, were compared with those in healthy fellow eyes.

RESULTS

Complete MH closure was achieved in 95.8% (23/24) of patients 6 months after surgery. There was a significant improvement in postoperative BCVA, from 1.0 to 0.4 logMAR (p < 0.001). The most frequent closure pattern was 1a (62.5%, 15/24), followed by 2c (12.5%, 3/24). The closure pattern was not correlated with height, minimum or maximum diameters or macular hole index (MHI) (p > 0.05). ELM and EZ recovery occurred in 87.5% and 83.3% of cases, respectively. FAZ were smaller in operated eyes than in the fellow eyes (p = 0.012). There were no differences in the vessel or perfusion densities between the operated and fellow eyes (p > 0.05).

CONCLUSIONS

Use of the inverted flap technique for large MH closure provides a high rate of functional and anatomical recovery. We observed a reduction in the FAZ following surgery, with no differences in the macular microvascularization parameters, suggesting that the technique is safe.

Perifoveal Microvascular Changes following Internal Limiting Membrane Peeling Surgery for Epiretinal Membrane and Macular Hole

INTRODUCTION

The aim of the study was to evaluate perifoveal microvasculature changes following pars plana vitrectomy with internal limiting membrane peeling for the epiretinal membrane (ERM) and macular hole (MH).

METHODS

This retrospective study included 59 eyes from 59 patients. Subjects were divided into two groups: an ERM group (n = 43) and an MH group (n = 16) based on the initial diagnosis. Swept-source optical coherence tomography angiography (SS-OCTA) was performed in the macular area, pre- and postoperatively. Perifoveal microvascular changes were calculated using MATLAB from the 6 × 6 mm SS-OCTA images, excluding the foveal avascular zone. Pre- and postoperative perifoveal vessel densities (pfVDs) were separately analyzed in six sectors (superior, superotemporal, inferotemporal, inferior, inferonasal, and superonasal) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). The baseline characteristics and other clinical factors were compared between the ERM and MH groups.

RESULTS

The postoperative best-corrected visual acuity significantly improved in both groups (p < 0.05). One year after surgery, the pfVD in the SCP of the ERM group significantly decreased in the inferotemporal sector (p = 0.049). The postoperative pfVD in the DCP of the MH group significantly decreased in temporal sectors (p < 0.05). The postoperative mean pfVD in the SCP in the MH group was significantly lower than that in the ERM group (p = 0.003). The presence of a dissociated optic nerve fiber layer (DONFL) was 75% in the MH group and 22% in the ERM group (p = 0.018). The correlation between the pfVD and DONFL was not statistically significant.

CONCLUSION

Postoperative pfVD reduction in the temporal sector, a corresponding area in which DONFL is present after MH surgery, was significantly observed. After vitreoretinal surgery in MH patients, OCTA may serve as a useful tool for monitoring perifoveal microvascular changes, especially in temporal sectors.

Non-Invasive Retinal Imaging Modalities for the Identification of Prognostic Factors in Vitreoretinal Surgery for Full-Thickness Macular Holes

In this review, we will focus on different non-invasive retinal imaging techniques that can be used to evaluate morphological and functional features in full-thickness macular holes with a prognostic purpose. Technological innovations and developments in recent years have increased the knowledge of vitreoretinal interface pathologies by identifying potential biomarkers useful for surgical outcomes prediction. Despite a successful surgery of full-thickness macular holes, the visual outcomes are often puzzling, so the study and the identification of prognostic factors is a current topic of interest. Our review aims to provide an overview of the current knowledge on prognostic biomarkers identified in full-thickness macular holes by means of different retinal imaging tools, such as optical coherence tomography, optical coherence tomography angiography, microperimetry, fundus autofluorescence, and adaptive optics.

PEELED INTERNAL LIMITING MEMBRANE REPOSITION FOR IDIOPATHIC MACULAR HOLES: A Pilot Randomized Controlled Trial

PURPOSE

To compare the functional and anatomical outcomes of peeled internal limiting membrane reposition and traditional internal limiting membrane peeling for the treatment of idiopathic macular hole.

METHODS

This is a randomized, single-center, and double-blinded, pilot, controlled trial.

RESULTS

Of the 30 patients enrolled, 27 (13 in Group 1 and 14 in Group 2) were included in the primary analysis (22 women [81.5%]; mean [SD] age, 61.7 [6.8] years). The BCVA was 0.23 ± 0.18 logMAR in the reposition group and 0.44 ± 0.24 logMAR in the peeling group at 6 months postoperatively (P = 0.02). The primary MH closure rate is 86.7% in the reposition group and 93.3% in the peeling group (P = 0.60). The range of the inner retinal dimpling was significantly lower in the reposition group at 6 months postoperatively (P < 0.0001). The thickness of the full parafovea (P = 0.0092), inner parafovea (P = 0.0007), inner perifovea (P = 0.0044), and outer fovea (P = 0.0392) was significantly greater in the reposition group than that in the peeling group at 6 months postoperatively. The sensitivity threshold and mfERG P1 wave amplitude density in rings one, four, and five were higher in the reposition group than in the peeling group at 6 months postoperatively.

CONCLUSION

Our findings suggest that the novel technique of peeled internal limiting membrane reposition has advantages over the traditional internal limiting membrane peeling in better microstructural outcomes of inner retina and functional recoveries. Furthermore, larger RCT studies are warranted.

Swept-Source Optical Coherence Tomography Angiography in Vitreomacular Traction Syndrome

Purpose:

A swept-source optical coherence tomography angiography (SS-OCTA) analysis of vasculature in vitreomacular traction (VMT) before and after surgery as well as 15 months’ “watchful waiting” follow-up data.

Methods:

A retrospective analysis of 38 eyes. Patients were divided into group 1: untreated (20 eyes); group 2: untreated, spontaneous release of traction (4 eyes); and group 3: vitrectomy (14 eyes).

Results:

In all cases, SS-OCTA of the choriocapillaris revealed a hyporeflective area, which disappeared after traction release. In group 1, none of the analyzed factors significantly changed. In group 2, visual acuity (VA) improved from 0.3 logMAR to 0.1 logMAR. None of the following parameters significantly changed: central choroidal thickness, superficial fovea avascular zone (sFAZ), deep fovea avascular zone (dFAZ), and vessel densities. In 1 eye a lamellar macular hole formed. Factors increasing the chances of spontaneous release of traction were width of traction and central retinal thickness ( P < .05). In group 3, VA improved from 0.27 Snellen (0.6 logMAR) to 0.44 Snellen (0.4 logMAR) ( P < .05). Postoperative OCTA revealed significant decreases in central retinal thickness ( P < .001), the parameters sFAZ, and dFAZ ( P < .05).

Conclusions:

sFAZ and dFAZ decreased after vitrectomy but not after spontaneous release of traction. VA was better in eyes with spontaneous release of traction. The degree of improvement in VA was greater in the vitrectomy group. In all cases a hyporeflective area is visible in the choriocapillaris layer in SS-OCTA. It disappears when traction is released. Early treatment, at least in patients with lower VA, might be beneficial.

Macular microvasculature differences in patients with macular hole after vitrectomy with internal limiting membrane removal or single-layered temporal inverted flap technique

PURPOSE

To compare the macular microvasculature differences in cases with idiopathic macular hole (MH) after vitrectomy when using internal limiting membrane (ILM) removal or temporal inverted ILM flap technique (IFT).

METHOD

A total of 34 patients were included, of whom 20 were treated vitrectomy with ILM removal (group 1), and 14 were treated with IFT (group 2). The OCTA (RTVue; Optovue, Fremont, CA) parameters, including foveal avascular zone (FAZ), vessel density (VD) ratios in superficial capillary plexus (SCP), and deep capillary plexus (DCP) were evaluated at baseline and 6 months follow-up. The VD measurements in DCP and inner retinal thickness (IRT) in temporal and nasal sectors were compared in subanalyses.

RESULTS

There was no significant difference in means of post-operative BCVA and FAZ between the two groups (p = 0.943, p = 0.760). The mean VDs of the DCP was significantly decreased at 6 months postoperatively in both groups (p < 0.001, p < 0.001). The mean post-operative temporal VDs of DCP were similar in the two groups, but the mean post-operative nasal VDs of the DCP was lower in group 1 than in group 2 (p = 0.005 and p = 0.03 for parafovea and perifovea, respectively). The mean temporal IRTs were similar in the two groups, but paranasal and perinasal IRTs were significantly thinner in group 1 than in group 2 (p < 0.001, p < 0.001). The mean post-operative VDs of parafoveal and perifoveal temporal and nasal quadrants in DCP significantly and positively correlated with the IRTs.

CONCLUSION

Single-layered temporal IFT causes fewer VD changes when compared to complete ILM removal, especially in the DCP.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY FINDINGS BEFORE AND AFTER VITRECTOMY FOR MACULAR HOLES: Useful or Useless?

PURPOSE

To investigate the vascular remodeling of optical coherence tomography angiography in full-thickness macular hole surgery.

METHODS

This retrospective, observational case series included 33 eyes of 33 patients with a full-thickness macular hole who underwent epiretinal membrane removal. Data were collected on best-corrected visual acuity, structural B-scan optical coherence tomography, and optical coherence tomography angiography preoperatively and at 1, 3, and 6 months postoperatively. Optical coherence tomography angiography was used to assess the retinal vascular density (VD) of the superficial vascular plexus and deep vascular plexus (DVP). Vascular density was assessed using the Early Treatment Diabetic Retinopathy Study grid for the whole, inner, and outer grids.

RESULTS

A statistically significant correlation was found between the VD (whole, inner, and outer grids) of the superficial vascular plexus alone from baseline to 1-month postoperatively (P < 0.001). Similarly, VD was correlated from baseline to 1, 3, and 6 months postoperatively to the whole (P < 0.0005, F = 23.22), inner (P < 0.0005, F = 28.23), and outer Early Treatment Diabetic Retinopathy Study grids of DVP (P = 0.033, F = 3.49). The best-corrected visual acuity and VD were significantly correlated with the superficial vascular plexus and DVP at baseline and 6 months (P < 0.05, all correlations). The most significant correlation was observed at 6 months between best-corrected visual acuity and DVP in the whole, inner, and outer Early Treatment Diabetic Retinopathy Study grids (P < 0.001).

CONCLUSION

Superficial vascular plexus and DVP are affected by full-thickness macular holes, with the most significant effects being on the DVP. Full-thickness macular hole surgery leads to an improvement in the best-corrected visual acuity in many eyes and the restoration of the VD, especially of the DVP.

Current management strategies for atypical macular holes

This review evaluates the current surgical management options for refractory and atypical macular holes (MH) and proposes a treatment paradigm for approaching complex cases. A review of literature was performed to deliver a thorough discussion of the epidemiology and pathophysiology of MH as well as the historic evolution of surgical management strategies. With this context established, an update on recent surgical advances for management of large, chronic, and highly myopic MH is provided. New small MH may be adequately treated with pars plana vitrectomy, while those ≥300 μm should undergo internal limiting membrane (ILM) peel. For MH ≥400 μm with risk factors for failure, primary intervention should involve creation of an ILM flap and various methods of flap creation are discussed. For very large MH ≥700 μm or in refractory cases, autologous retinal transplants and other recently proposed procedures should be considered. While typical MHs enjoy high initial surgical success rates, atypical and refractory MH require additional intraoperative and postoperative considerations to maximize surgical success and optimize vision. With many techniques at the surgeon's disposal, patient selection becomes critical to improving outcomes.

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

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

The Influence of Crescent-Shaped Selective Internal Limiting Membrane Staining on Vital Dye Toxicity in Temporal Inverted Flap Technique

Purpose: To investigate the macular function and morphology after temporal inverted internal limiting membrane (ILM) flap technique with and without staining of the ILM flap in contact with the retinal pigment epithelium (RPE).Materials and Methods: This retrospective study included 30 patients with idiopathic macular hole (MH), who underwent 27 G vitrectomy and temporal inverted ILM flap technique with brillant blue G (BBG) assisted ILM staining. In Group 1 (n = 16), a large bubble of perfluorocarbon liquid (PFCL) measuring approximately 6-disc diameters was used to cover the hole and central part of the ILM flap whereas in Group 2 (n = 14), only a small drop of PFCL to merely cover the MH was used. Complete ophthalmic examination including microperimetry (MP), optical coherence tomography (OCT) was performed preoperatively, 6 months after surgery.Results: MH closure was achieved in all the eyes in both groups. The sizes of ellipsoid zone (EZ) and external limiting membrane (ELM) defect significantly decreased after surgery relative to the baseline width in both groups (p < .05 for all). The mean improvement in visual acuity (p = .896) and retinal sensitivity was similiar between groups (p = .409). Accordingly, the postoperative mean lengths of the EZ (p = .254) and ELM disruption (p = .406) on OCT scans were similiar between groups. However, 3 of the eyes in Group 2 developed cystoid macular edema between postoperative month-1 and month-6.Conclusion: The crescent-shaped selective staining of the ILM flap could prevent prolonged retinal toxicity of vital dyes in inverted ILM flap technique. Further studies involving larger number of patients with longer follow up are needed to determine the impact of this technique in the management of vital dye toxicity.

OCT-A in the Management of Vitreoretinal Diseases and Surgery

ABSTRACT

Optical coherence tomography angiography is a relatively new noninvasive technique that is changing our approach in the management of several retinal diseases such as neovascular age-related macular degeneration, occlusive retinal diseases, or diabetic retinopathy, but it could also be useful in nonprimary vascular retinal pathologies such as vitreoretinal interface surgical disorders.In idiopathic vitreoretinal interface disorders and surgical retinal diseases, the study of vascular involvement, not commonly assessed by invasive methods, could be useful to reveal specific vascular abnormalities. Such information may be useful for a more detailed phenotyping of each clinical picture before and after surgical treatment, providing potential new prognostic biomarkers.The review discusses the current and potential utility of optical coherence tomography angiography to study vitreoretinal pathologies of surgical interest.

Conventional internal limiting membrane peeling versus temporal inverted internal limiting membrane flap for large macular holes

PURPOSE

To compare the functional, anatomical, and morphological results of conventional internal limiting membrane peeling versus temporal inverted internal limiting membrane flap technique for the treatment of macular holes larger than 400 μm.

DESIGN

Retrospective, comparative case series.

METHODS

A total of 33 patients were included, of whom 18 were treated with internal limiting membrane peeling (Group 1) and 15 were treated with temporal inverted internal limiting membrane flap technique (Group 2). Complete ophthalmic examination, such as microperimetry and optical coherence tomography, was performed preoperatively and at 12 months after surgery.

RESULTS

The closure rates accomplished in Groups 1 and 2 were 72.2% and 100%, respectively (p = 0.036). The mean improvement in best-corrected visual acuity was logMAR 0.49 ± 0.17 in Group 1 and logMAR 0.91 ± 0.15 in Group 2 (p = 0.037). U-shaped closure was achieved in one eye in Group 1 and 12 eyes in Group 2 (p < 0.001). Complete restoration of external limiting membrane and ellipsoid zone rates were significantly higher in Group 2 (p = 0.027 and p = 0.001, respectively).

CONCLUSION

The single-layered temporal inverted internal limiting membrane flap technique improves not only anatomical and morphological but also functional outcomes of surgery for large macular holes. Furthermore, this technique seems to minimize the risk of iatrogenic trauma to the nasal part of the fovea and the corresponding papillomacular bundle fibers.

An Internal Limiting Membrane Plug and Gas Endotamponade for Recurrent or Persistent Macular Hole

Introduction

Recurrent or persistent macular holes (MHs) are rare today due to the tendency to carefully peel the internal limiting membrane. Conversely, their treatment is still a challenge for a vitreoretinal surgeon.

Materials and Methods

This is a retrospective, consecutive, and nonrandomized study of patients affected by recurrent or persistent MHs treated using small-gauge pars plana vitrectomy (25- or 23-gauge) and an autologous ILM plug, at the Eye Clinic of Azienda Ospedaliera Universitaria Careggi (Florence, Italy) between January 2016 and May 2018. We included 8 eyes of 8 patients in the study. Five patients had a recurrent MH while 3 had a persistent MH. The case series includes patients with myopic eyes and with large macular holes (>400 μ). Patients were followed up with ophthalmoscopic examinations and swept-source optical coherence tomography (SS-OCT).

Results

The mean age of the patients was 74 years (±4.81 standard deviation (SD)), 3 patients were men and 5 women. The average axial length was 26.28 mm (±2.84 SD). Four patients had an AL ≧ 26 mm. The mean MH diameter was 436.5 (±49.82 SD). Average preoperative best-corrected visual acuity (BCVA) was 0.81 logMAR (±0.16 SD) and 20/125 Snellen. The ILM plug has been found integrated in the MH in all the follow-ups.

Conclusion

In our study, an ILM autologous macular transplant was used successfully in 5 cases of macular hole recurrence and 3 cases of macular hole persistence. The anatomical success was achieved in all the cases; 4 patients improved their BCVA, and 4 patients maintained it. No macular alterations such as RPE or retinal atrophy/dystrophy were observed after 6 months.