Contractility of temporal inverted internal limiting membrane flap after vitrectomy for macular hole

Visualizing spatiotemporal pattern of vascularization by SWIR fluorescence imaging in a mouse model of perforator flap transplantation

Vascularization as a spatiotemporally interlaced process involving angiogenesis and vascular remodeling, has seldom been investigated comprehensively regarding the interrelationship of the two intertwining but sequential processes. Here, a shortwave infrared (SWIR) fluorescence imaging strategy based on quantum dots (QDs) was designed to dynamically visualize vascularization in vivo and in situ in a perforator transplantation mouse model. The vascularization process could be directly perceived from the established flap model with an optimal observation window at 10 min post-injection. Anchored in SWIR technology and image processing, it was revealed that temporally, angiogenesis lasted throughout 21 days after surgery while vascular remodeling took a dominant role after 14 days both in vivo and in situ. Moreover, four perforasomes of the flap in situ displayed spatially that Zone IV shortened the vascularization process with sufficient blood supply from the LDCIA, while Zone II recovered slowly from ischemia with a lack of blood supply. This study serves as a pioneer in adding novel cognition to spatiotemporal pattern of vascularization through visualizing angiogenesis and vascular remodeling simultaneously and dynamically, thus facilitating further investigation into the mechanisms behind.

COMPLEX MACULAR HOLE CLOSURE BY TEMPORAL INTERNAL LIMITING MEMBRANE FLAP WITHOUT ENDOTAMPONADE

PURPOSE

To evaluate the safety, efficacy, and imaging features of a novel surgical technique without endotamponade in repairing complex macular hole (MH).

METHODS

Retrospective review of consecutive cases with complex MH underwent pars plana vitrectomy with temporal internal limiting membrane flap, which was stabilized using perfluorocarbon liquid and viscoelastics. At the conclusion of surgery, perfluorocarbon liquid was removed, and no endotamponade agent would be used. Complex MH was defined as a basal linear diameter of ≥400 µm and/or associated with high myopia. Visual acuity, pattern of MH closure on optical coherence tomography, formation of epiretinal membrane, and operative complications were reported.

RESULTS

Twenty-four eyes were included, and the mean basal linear diameter was 988.3 µm. MH closure was achieved in 24 (100%), of which, 8 (33%) achieved type 1A closure. The mean postoperative logarithm of the minimum angle of resolution visual acuity improved from 0.93 at baseline to 0.74, 0.51, 0.55, and 0.52 at 1-month, 3-month, 6-month, and last follow-up, respectively. Foveal gliosis was observed in 3 eyes (12.5%), and 10 (41.7%) developed nasal epiretinal membrane. One eye developed vitreous hemorrhage, which resolved spontaneously.

CONCLUSION

This novel surgical technique that requires no endotamponade is effective in achieving complex MH closure. A substantial proportion of patients developed epiretinal membrane, and its clinical significance requires further investigation.

Changes in vascular density in the macula after pars plana vitrectomy for idiopathic macular hole with macular peeling and one type of flap

BACKGROUND AND AIMS

The aim of this study was to evaluate changes in vascular density in the macula after pars plana vitrectomy for idiopathic macular hole (IMD) with macular peeling and flap.

METHODS

A prospective study of 35 eyes in 34 patients who had undergone standard surgery. Evaluated parameters were best-corrected visual acuity (BCVA), intraocular pressure (IOP), central macular thickness (CRT), macular volume (TMV) and vascular density of the superficial and deep capillary plexus. The follow-up period was one year.

RESULTS

We divided the total group into two: temporal and circular flap and total group. We compared the values after surgery with the preoperative values. In the total group, BCVA increased from 48.38 to 71.44 letters (P≤0.05). IOP changed from 15.24 to 14.76 mmHg (P>0.05). CRT decreased from 432.27 to 323.64 µm (P≤0.05). TMV changed from 0.26 to 0.25 mm3 (P>0.05). The vascular density of the superficial plexus decreased from 32 to 28% (P≤0.05). The intercapillary space of the superficial plexus increased from 68 to 72% (P≤0.05). The vascular density of the deep plexus increased from 17 to 23%. The intercapillary space of the deep vascular plexus decreased from 83 to 77%. Changes in vascular density and intercapillary space of the deep plexus were statistically significant for certain months after operations (P≤0.05). There were no significant differences between subgroups.

CONCLUSION

The superficial plexus vascular density is almost the same in the temporal flap and in the foveal-sparing flap is decreased, and the deep plexus vascular density increased statistically significantly during the follow-up period after surgery.

Effect of internal limiting membrane surgical techniques on the idiopathic and refractory management of macular holes: a systematic review and meta-analysis

Macular holes (MHs), including atraumatic idiopathic and refractory MHs, affect central vision acuity due to full-thickness defects in the retinal tissue. The existing controversy regarding the pathophysiology and management of MHs has significantly improved with the implementation of internal limiting membrane (ILM) surgical techniques and improved MH closure rates. Thus, to determine the effect of ILM techniques on large idiopathic and refractory MH management, the present study systematically reviewed 5910 original research articles extracted from online literature databases, including PubMed, Cochrane, Google Scholar, and Embase, following the PRISMA guidelines. The primary outcome measures were MH closure rate and postoperative visual acuity. A total of 23 randomized controlled trials (RCTs) with adequate patient information and information on the effect of ILM peeling, inverted ILM flaps, autologous retinal transplantation (ART), and ILM insertion techniques on large idiopathic and refractory MH patients were retrieved and analyzed using RevMan software (version 5.3) provided by the Cochrane Collaboration. Statistical risk of bias analysis was also conducted on the selected sources using RoB2, which showed a low risk of bias in the included studies. A meta-analysis indicated that the inverted ILM flap technique had a significantly greater MH closure rate for primary MH than the other treatment methods (OR = 3. 22, 95% CI 1.34-7.43; p = 0.01). Furthermore, the findings showed that the inverted ILM flap group had significantly better postoperative visual acuity than did the other treatment options for patients with idiopathic MH (WMD = - 0.13; 95% CI = 0.22-0.09; p = 0.0002). The ILM peeling technique had the second highest statistical significance for MH closure rates in patients with idiopathic MH (OR = 2. 72, 95% CI: 1.26-6.32; p = 0.016). In refractory MHs, autologous retinal transplant (ART) and multilayer ILM plug (MIP) techniques improve the closure rate and visual function; human amniotic membrane grafting (hAMG) provides a high degree of anatomical outcomes but disappointing visual results. This study demonstrated the reliability and effectiveness of ILM techniques in improving the functional and anatomical outcomes of large idiopathic and refractory MH surgery. These findings will help clinicians choose the appropriate treatment technique for patients with idiopathic and refractory MH.

Comparison of stereopsis and foveal microstructure after internal limiting membrane peeling and inverted internal limiting membrane flap techniques in patients with macular hole

PURPOSE

To compare stereopsis and foveal microstructure after internal limiting membrane peeling and inverted internal limiting membrane flap technique in patients with macular hole.

DESIGN

Retrospective observational study.

METHODS

Sixty-six patients with macular hole were included, of whom 41 underwent 25-gauge pars-plana vitrectomy with complete internal limiting membrane peeling (Peeling group) and 25 with the inverted flap technique (Inverted group). We evaluated stereopsis using the Titmus Stereo Test and the TNO stereo test, best-corrected visual acuity, macular hole closure rate, and foveal microstructure with optical coherence tomography before and at 3, 6, and 12 months after surgery.

MAIN OUTCOME MEASURES

Stereopsis and foveal microstructure.

RESULTS

Preoperatively, no difference was observed in the base and minimum diameters of macular hole, Titmus Stereo Test score, TNO stereo test score, and best-corrected visual acuity between the Peeling and Inverted groups. The macular hole closure rate in the Peeling and Inverted groups were 97.6% and 100%, respectively, with no significant difference between groups. At 12 months postoperatively, Titmus Stereo Test score (2.1 ± 0.4 in the peeling and 2.2 ± 0.4 in the inverted groups), TNO stereo test score (2.3 ± 0.4 and 2.2± 0.5), and best-corrected visual acuity (0.20 ± 0.18 and 0.24 ± 0.25) were not significantly different between groups (p = 0.596, 0.332, respectively). The defect of the external limiting membrane was more common in the Inverted group than in the Peeling group at 6 months after surgery (5.4 vs. 28.0%; p < 0.05). No statistically significant inter-group differences were noted in the ellipsoid zone defect ratio throughout the follow-up period.

CONCLUSIONS

There was no difference in postoperative stereopsis nor foveal microstructure between the internal limiting membrane peeling group and the inverted group in patients with macular hole.

En Face OCT Detects Preretinal Abnormal Tissues Before and After Internal Limiting Membrane Peeling in Eyes with Macular Hole

PURPOSE

To assess preretinal abnormal tissue (PAT) using en face OCT in eyes with idiopathic macular holes (MHs).

DESIGN

Retrospective, observational study.

PARTICIPANTS

Patients with MH who received 6 × 6-mm spectral-domain-OCT scans.

METHODS

Preretinal abnormal tissue was detected by en face OCT images with a custom slab, defined with an anterior boundary of 6 μm anterior to the internal limiting membrane (ILM) and a posterior boundary at 3 μm posterior to the ILM. The PAT was defined as any abnormal tissues observed in en face OCT.

MAIN OUTCOME MEASURES

Characteristics of preoperative and postoperative PAT.

RESULTS

Sixty eyes with MH from 60 patients were included. Fifty-one eyes underwent preoperative analysis, and 46 eyes underwent postoperative examination. Before surgery, 48 (94%) eyes had a mean (standard deviation [SD]) PAT of 6.6 (9.8) mm². The corresponding cross-sectional OCT showed PAT consisting of epiretinal proliferation, epivascular glia, and a preretinal hyperreflective band. Preretinal abnormal tissue was contiguous to the hole (peri-MH PAT) in 12 eyes (24%), whereas others (36 eyes, 76%) had a scattered distribution (extrafoveal PAT). The area of PAT was greater in eyes with a peri-MH PAT than in eyes with an extrafoveal PAT (P < 0.0001). Compared to the eyes with the extrafoveal PAT, the eyes with the peri-MH PAT were associated with men (P = 0.0059) and worse baseline visual acuity (VA) (P = 0.0002). In eyes with ILM peeling (42 eyes), postoperative PAT proliferation was observed from the edge of the ILM peeling toward the periphery over a 1-year follow-up. The mean (SD) area of PAT at 2 weeks after surgery was 3.4 (3.6) mm² and increased to 12.1 (6.4) mm² at 12 months (P < 0.0001). However, no PAT increase was observed in 4 eyes that underwent vitrectomy without ILM peeling. The postoperative PAT size was not associated with the postoperative VA.

CONCLUSIONS

En face OCT revealed PAT in most eyes with MHs. Peri-MH PAT was associated with worse VA and was seen more frequently in male patients. Postoperative PAT proliferation may be triggered by ILM peeling, but it is not associated with worse VA.

Update on surgical management of complex macular holes: a review

Modern surgical interventions effectively treat macular holes (MHs) more than 90%. Current surgical treatment for MHs is pars plana vitrectomy with epiretinal membrane, internal limiting membrane (ILM) peeling, gas endotamponade, and prone posturing postoperatively. However, a small subset of MHs imposes challenges to surgeons and frustrations on patients. A narrative review was performed on the surgical treatment of challenging MHs including large and extra-large MHs, myopic MHs with or without retinal detachment, and chronic and refractory MHs. There are robust data supporting inverted ILM flap as the first-line treatment for large idiopathic MHs and certain secondary MHs including myopic MHs. In addition, several studies had shown that ILM flap manipulations in combination with surgical adjuncts increase surgical success, especially in difficult MHs. Even in eyes with limited ILM, surgical options included autologous retinal graft, human amniotic membrane, and creation of a distal ILM flap that can assist in MH closure even though the functional outcome may be affected by the MH chronicity. Despite relative success anatomically and visually after each technique, most techniques require a long-term study to analyze their safety profile and to establish any morphological changes of the MH plug in the closed MHs.