Proliferative vitreoretinopathy may be a risk factor in combined macular hole retinal detachment cases

Clinical characteristics and optical coherence tomography of concomitant macular hole and rhgematogenous retinal detachment

To study the clinical characteristics of macula off rhegmatogenous retinal detachment (RRD) with peripheral causative breaks and concomitant macular hole (RRD+MH). This is a bi-center study. Consecutive eyes of macula off RRD with or without macular hole (MH) were collected. Eyes in these two groups were compared with best corrected visual acuity in logarithm of minimal angle of resolution (logMAR BCVA), the presence of choroidal detachment (CD), proliferative vitreoretinopathy (PVR) and the extent of RRD. In the group of RRD+MH, regression analysis was used to evaluate the correlation of clinical factors and final logMar BCVA. In addition, optical coherence tomography was performed both pre-and post-operatively if possible. There were 40 eyes in the RRD+MH group and 80 eyes in the control group. Eyes with RRD+MH had worse initial and final logMar BCVA (p < 0.001), higher incidence of CD (p < 0.001), PVR and extensive RRD at baseline (p < 0.001). Among the eyes with RRD+MH, final BCVA was correlated with initial BCVA (p < 0.001, CI 0.637 to 0.837), recurrent RRD (p = 0.004, CI - 0.661 to - 0.126), duration of RRD (p = 0.021, CI - 0.576 to - 0.048) and presence of PVR (p = 0.001, CI - 0.131 to - 0.035). The hole closure rate at final follow up is 87.5%.11 of the 17 eyes had preoperative optical coherence tomography (OCT) obtained had ellipsoid zone lining the bottom of MH. CD, PVR and extensive RRD were more commonly observed in RRD+MH. The morphology of MH may suggest the pathogenesis of MH in RRD+MH include mechanism different from that of idiopathic MH.

Unveiling the gut-eye axis: how microbial metabolites influence ocular health and disease

The intricate interplay between the gut microbiota and ocular health has surpassed conventional medical beliefs, fundamentally reshaping our understanding of organ interconnectivity. This review investigates into the intricate relationship between gut microbiota-derived metabolites and their consequential impact on ocular health and disease pathogenesis. By examining the role of specific metabolites, such as short-chain fatty acids (SCFAs) like butyrate and bile acids (BAs), herein we elucidate their significant contributions to ocular pathologies, thought-provoking the traditional belief of organ sterility, particularly in the field of ophthalmology. Highlighting the dynamic nature of the gut microbiota and its profound influence on ocular health, this review underlines the necessity of comprehending the complex workings of the gut-eye axis, an emerging field of science ready for further exploration and scrutiny. While acknowledging the therapeutic promise in manipulating the gut microbiome and its metabolites, the available literature advocates for a targeted, precise approach. Instead of broad interventions, it emphasizes the potential of exploiting specific microbiome-related metabolites as a focused strategy. This targeted approach compared to a precision tool rather than a broad-spectrum solution, aims to explore the therapeutic applications of microbiome-related metabolites in the context of various retinal diseases. By proposing a nuanced strategy targeted at specific microbial metabolites, this review suggests that addressing specific deficiencies or imbalances through microbiome-related metabolites might yield expedited and pronounced outcomes in systemic health, extending to the eye. This focused strategy holds the potential in bypassing the irregularity associated with manipulating microbes themselves, paving a more efficient pathway toward desired outcomes in optimizing gut health and its implications for retinal diseases.

Role of myeloid cells in ischemic retinopathies: recent advances and unanswered questions

Myeloid cells including microglia and macrophages play crucial roles in retinal homeostasis by clearing cellular debris and regulating inflammation. These cells are activated in several blinding ischemic retinal diseases including diabetic retinopathy, where they may exert both beneficial and detrimental effects on neurovascular function and angiogenesis. Myeloid cells impact the progression of retinal pathologies and recent studies suggest that targeting myeloid cells is a promising therapeutic strategy to mitigate diabetic retinopathy and other ischemic retinal diseases. This review summarizes the recent advances in our understanding of the role of microglia and macrophages in retinal diseases and focuses on the effects of myeloid cells on neurovascular injury and angiogenesis in ischemic retinopathies. We highlight gaps in knowledge and advocate for a more detailed understanding of the role of myeloid cells in retinal ischemic injury to fully unlock the potential of targeting myeloid cells as a therapeutic strategy for retinal ischemia.

Interleukin-17-mediated protective cytokine signaling against degeneration of the retinal pigment epithelium

Injuries to the retinal pigment epithelium (RPE) and outer retina often result in the accumulation of retinal microglia within the subretinal space. These subretinal microglia play crucial roles in inflammation and resolution, but the mechanisms governing their functions are still largely unknown. Our previous research highlighted the protective functions of choroidal γδ T cells in response to RPE injury. In the current study, we employed single-cell RNA sequencing approach to characterize the profiles of immune cells in mouse choroid. We found that γδ T cells were the primary producer of interleukin-17 (IL-17) in the choroid. IL-17 signaled through its receptor on the RPE, subsequently triggering the production of interleukin-6. This cascade of cytokines initiated a metabolic reprogramming of subretinal microglia, enhancing their capacity for lipid metabolism. RPE-specific knockout of IL-17 receptor A led to the dysfunction of subretinal microglia and RPE pathology. Collectively, our findings suggest that responding to RPE injury, the choroidal γδ T cells can initiate a protective signaling cascade that ensures the proper functioning of subretinal microglia.

Pathophysiology of Secondary Macular Hole in Rhegmatogenous Retinal Detachment

Purpose

To describe the pathophysiology of secondary macular hole (MH) in rhegmatogenous retinal detachment (RRD).

Methods

A retrospective cohort of 360 consecutive primary fovea-off RRDs presenting to St. Michael's Hospital, Toronto, from January 2012 to September 2022 were included. Preoperative OCT was assessed for bacillary layer detachment (BALAD) abnormalities. Histological sections of normal eyes were assessed to inform OCT interpretations. Primary outcome measure was the progression of BALAD to full-thickness MH (FTMH).

Results

Of the 360 patients, 22.5% (n = 81) had BALAD abnormalities at presentation. Eight percent (29/360) had associated MH, of which 79.3% (23/29) were a BALAD-lamellar hole and 20.7% (6/29) were FTMH. After reattachment, 62% of MHs persisted (18/29), of which 83% (15/18) had BALAD-lamellar holes that subsequently progressed to FTMH in a mean of 8.1 ± 3.2 days. BALAD-lamellar holes had significantly worse postoperative visual acuity (P < 0.001) when compared with other BALAD abnormalities (58/81) or with the rest of the cohort (279/360). OCT spectrum from BALAD to FTMH includes (1) cleavage planes extending from Henle fiber layer into the BALAD; (2) central outer nuclear layer thinning; (3) Müller cell cone loss with tissue remnants at the foveal walls; (4) retinal tissue operculum close to BALAD-MH; and (5) progressive thinning or degradation of the posterior band of BALAD-lamellar hole leading to FTMH. Histological specimens identified foveal regions of low mechanical stability.

Conclusions

BALAD plays a crucial role in the pathophysiology of MH in RRDs, which forms owing to sequential changes in four critical areas: RPE-photoreceptor interface, myoid zone, Henle fiber layer, and Müller cell cone with surrounding tissue. Timely management of fovea-off RRD with BALAD may be prudent to avoid the progression to BALAD-lamellar hole, subsequent FTMH, and worse functional outcomes.

Tinnitus as a Potential Risk Factor for Uveitis: A 14-Year Nationwide Population-Based Cohort Study in Taiwan

BACKGROUND

Tinnitus and uveitis have shared commonality in pathophysiology in terms of autoimmunity. However, no studies that have linked any association between the conditions of tinnitus and uveitis.

METHODS

This is a retrospective study conducted from the Taiwan National Health Insurance database in order to investigate whether tinnitus patients are at increased risk of uveitis. Patients newly diagnosed with tinnitus between 2001 and 2014 were recruited and followed up until 2018. The endpoint of interest was a diagnosis of uveitis.

RESULTS

A total of 31,034 tinnitus patients and 124,136 matched comparisons were analyzed. Tinnitus patients were found to have a significantly higher cumulative incidence for uveitis than those without the diagnosis of tinnitus with incidence rate of 1.68 (95% CI 1.55-1.82) per 10 000 person-months for tinnitus group and 1.48 (95% CI 1.42-1.54) per 10 000 person-months for non-tinnitus group.

CONCLUSION

Tinnitus patients were found to have increased risk of developing uveitis.

Comparison of Intraocular Tamponade in Patients with Peripheral Tear-Induced Retinal Detachment and Coexisting Macular Hole without High Myopia

INTRODUCTION

To introduce the surgical results and examine the effect of intraocular tamponades on surgical outcomes in patients with coexisting macular hole (MH) and rhegmatogenous retinal detachment (RRD) without high myopia.

METHODS

This retrospective, cross-sectional, two-center study was carried out with 29 eyes of 29 patients. The patients were divided into two groups according to the intraocular tamponade used in surgery: silicone oil (Group 1) and C₃F₈ gas (Group 2). In all patients, the internal limiting membrane was peeled during surgery. Exclusion criteria were determined as RRD with MH due to high myopia (≥ 6 D) without peripheral retinal tears and traumatic MH.

RESULTS

In Group 1, the median preoperative best-corrected visual acuity (BCVA) was 3.0 (M ± SD: 2.85 ± 0.27) logMAR, while the median postoperative BCVA was 1.0 (M ± SD: 1.39 ± 0.83) logMAR (p < 0.001). In Group 2, the median preoperative BCVA was 3.0 (M ± SD: 2.37 ± 0.93) logMAR, while the median postoperative BCVA was 0.76 (M ± SD: 1.06 ± 0.86) logMAR (p = 0.008). The retinal attachment success rate was 15/17 (89.3%) in Group 1, and 11/12 (91.7%) in Group 2 (p = 0.64). The MH closure rate was 12/17 (71.6%) in Group 1, and 10/12 (78.1%) in Group 2 (p = 0.52). No difference was determined between the groups in terms of preoperative and postoperative BCVA, preoperative and postoperative intraocular pressure, and BCVA improvement.

CONCLUSIONS

The study results showed no significant difference between using silicone oil or C₃F₈ gas as an intraocular tamponade after internal limiting membrane peeling in patients with RRD due to peripheral tear with coexisting MH.

INVERTED INTERNAL LIMITING MEMBRANE FLAP TECHNIQUE FOR MACULAR HOLE COEXISTENT WITH RHEGMATOGENOUS RETINAL DETACHMENT

PURPOSE

To report the clinical features and treatment outcomes of patients with macular hole coexistent with rhegmatogenous retinal detachment surgically treated with pars plana vitrectomy and inverted internal limiting membrane flap technique.

METHODS

Eleven consecutive patients with rhegmatogenous retinal detachment and macular hole who underwent vitrectomy and internal limiting membrane peeling with the inverted flap technique between December 2017 and February 2021 were retrospectively evaluated. The main outcome measures were retinal reattachment rate, macular hole closure rate, and postoperative best-corrected visual acuity. A nonsystematic literature review was performed to compare the study outcomes with those previously reported.

RESULTS

The primary retinal reattachment rate was 90% (10/11) with one surgery and 100% with 2 surgical procedures. Macular hole closure was achieved in all patients (11/11). All patients showed an improvement in visual acuity at the final postoperative visit, and the mean postoperative best-corrected visual acuity was 0.60 ± 0.32 logarithm of the minimum angle of resolution (20/80 Snellen equivalent).

CONCLUSION

Vitrectomy with the inverted internal limiting membrane flap technique achieved not only favorable anatomical retinal reattachment rates but also an encouraging recovery of central macular anatomy and visual function in patients with macular hole coexistent with rhegmatogenous retinal detachment.

Human Amniotic Membrane Plug for Macular Holes Coexisting with Rhegmatogenous Retinal Detachment

Purpose

To evaluate the efficacy of human amniotic membrane in promoting closure of macular holes coexisting with rhegmatogenous retinal detachment.

Methods

This is a retrospective case series of 14 eyes (14 patients) with macula off retinal detachment. These patients had a macular hole coexistent with peripheral retinal breaks. A human amniotic membrane plug was used to close the macular hole during vitrectomy without ILM peeling.

Results

The mean preoperative BCVA (logMAR value) was 1.87 ± 0.31. At the 6-month follow-up visit, the mean LogMAR best-corrected visual acuity was 0.67 ± 0.17. At the 6-month follow-up, all patients showed complete retinal reattachment with macular hole closure.

Conclusion

The use of human amniotic membrane is a valid option in surgery for macular holes coexisting with rhegmatogenous retinal detachment.

Overexpression p21WAF1/CIP1 in suppressing retinal pigment epithelial cells and progression of proliferative vitreoretinopathy via inhibition CDK2 and cyclin E

Background

P21 is one kind of cyclin-dependent kinase inhibitor that can prevent cells from going through the G1/S phase checkpoint and inhibit cell proliferation. Proliferative vitreoretinopathy (PVR) is a proliferative response in the eye. The aim of this study was to determine whether p21^Waf1/Cip1 (p21) suppresses the proliferation and migration of retinal pigment epithelial (RPE) cells in vitro and controls PVR development in vivo.

Methods

Cell cycle analyses and transwell assays were conducted to assess cell proliferation characteristics and the migration ability of RPE cells after transfection with p21. Western blot and reverse-transcription polymerase chain reaction technologies were used to detect the expression of p21, CDK₂ and cyclinE in RPE cells and rabbit retinal tissues. The impact of increasing p21 expression on PVR development was conducted by implantation of an adenovirus vector containing rabbit p21 (rAd-p21) in a PVR rabbit model. The prevalence of PVR and retinal detachment was determined by indirect ophthalmoscopy on days 3, 7, 14, and 21 after the injection of rAd-p21 into the vitreous. B scans and hematoxylin-eosin staining were employed to check rabbit retinas on day 21.

Results

Cell cycle analyses and transwell assays showed that p21 inhibited the proliferation and migration of RPE cells. Increased expression of p21 was detected in cultured RPE cells and rabbit retinas after transfection with the p21 gene, whereas levels of CDK₂ and cyclinE were decreased. The increase in p21 expression effectively suppressed the development of PVR in a rabbit model.

Conclusions

The increase in p21 expression in RPE cells not only inhibits the proliferation and migration of RPE cells in vitro, but also suppresses the development of PVR in vivo, which indicates its therapeutic potential in treating PVR.