Duration of face down positioning following full-thickness macular hole repair: A protocol for a randomized pilot study.

OBJECTIVE: Full-thickness macular holes (FTMH) are defects in the fovea involving all neural retinal layers. They reduce patients' visual acuity (VA) and impact their quality of life. FTMHs are repaired with pars plana vitrectomy (PPV) with intraocular gas tamponade and post-operative face-down positioning (FDP). There is no consensus regarding the ideal positioning requirements following FTMH repair and there lacks clear guidelines on the topic. While analysis of global practice patterns indicates that between 5-7 days is the most common duration suggested by surgeons, there is significant heterogeneity in surgeon preferences. There is, however, biological plausibility to support minimal or even no FDP following surgery and given the disabling nature of FDP for patients, there is a need to better assess key patient outcomes with different FDP durations. As such, this prospective randomized controlled pilot trial will compare 3-days of FDP to 7-days of FDP following PPV for FTMH. METHODS: This single-centered, parallel-group randomized controlled pilot trial will randomize patients 1:1 following PPV to 3 days or 7 days of FDP. This investigation has been approved by the local ethics board (HiREB # 16100) and has been registered on clinicaltrials.gov (NCT06000111). The primary objective will be focused on assessing the feasibility of a larger trial; this will be determined through an assessment of the recruitment rate, retention rate, completion rate and recruitment time. The secondary outcomes involve assessment of the following patient-important outcomes a) macular hole closure rate, b) best-recorded VA, c) a general quality of life measure and vision-specific quality of life measure, d) patient compliance and e) complication rates. Outcomes will be evaluated at 3 months following surgery. DISCUSSION: The results of this pilot study will determine the feasibility of a larger-scale trial that will answer a patient important question with clinical equipoise.

Impact of Baseline Morphologic Stage of Rhegmatogenous Retinal Detachment on Postoperative Visual Acuity.

PURPOSE: To evaluate the association of baseline morphologic stage of rhegmatogenous retinal detachment (RRD) using OCT with postoperative anatomic and visual acuity (VA) outcomes. DESIGN: Retrospective cohort study. SUBJECTS: Consecutive primary fovea-involving RRDs referred from January 2012 to September 2022. METHODS: Patients with primary RRD and no prior macular pathology with gradable baseline OCT were assessed. Best-corrected VA (BCVA) was assessed at presentation and at 3, 6, and 12 months postoperatively. OCT scans were graded for parafoveal morphologic stage of RRD and foveal photoreceptor integrity. MAIN OUTCOME MEASURES: Association of morphologic stage of RRD with 12-month BCVA. RESULTS: Three hundred fifty-one patients were included. Sixty-eight percent (238/351) were male, the mean (standard deviation) age was 61.2 (± 12.8) years, and 59% (206/351) were phakic. Thirteen percent (47/351) presented in stages 1 and 2, 15% (54/351) in stage 3a, 36% (126/351) in stage 3b, 24% (83/351) in stage 4, and 12% (41/351) in stage 5. Increasing stage was associated with worse foveal photoreceptor integrity, reduced baseline BCVA and longer duration of central vision loss (P < 0.001). Mean (standard deviation) 12-month BCVA by stage was 0.77 (± 0.64) for stages 1 and 2, 1.00 (± 0.53) for stage 3a, 1.36 (± 0.55) for stage 3b, 1.33 (± 0.66) for stage 4 and 1.55 (± 0.47) for stage 5. Increasing stage was associated with reduced postoperative BCVA (P < 0.001) at all time points after adjusting for covariates. A subgroup analysis of acute detachments with retinal pigment epithelium-photoreceptor dysregulation demonstrated no difference in postoperative BCVA between stages 1, 2, and 3a. However, 12-month BCVA was significantly better in stages 1, 2, and 3a vs. stage 3b (P = 0.002) and stage 3a vs. 3b (P = 0.008). CONCLUSIONS: This study validates the clinical relevance of a recently proposed OCT-based staging system for outer retinal morphologic changes over time in RRD. Postoperative BCVA was significantly reduced in patients with worse presenting stage at all time points. In acute RRDs, 12-month BCVA was significantly better in stages 1, 2, and 3a vs. stage 3b, which suggests early stages may have better retinal recovery compared with stage 3b or worse. Stage 3b may represent a critical point where substantial structural changes occur, leading to worse outcomes in acute RRDs. Patients presenting with fovea-involving RRDs in stages 1, 2, or 3a may benefit from more urgent intervention. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this article.

Pathophysiology of outer retinal corrugations: Imaging dataset and mechanical models.

This article presents high-resolution swept-source optical coherence tomography (SS-OCT) imaging data used to elaborate a mechanical model that elucidates the formation of outer retinal corrugations (ORCs) in rhegmatogenous retinal detachments (RRD). The imaging data shared in the repository and presented in this article is related to the research paper entitled "Outer Retinal Corrugations in Rhegmatogenous Retinal Detachment: The Retinal Pigment Epithelium-Photoreceptor Dysregulation Theory" (Muni et al., AJO, 2022). The dataset consists of 69 baseline cross-sectional SS-OCT scans from 66 patients that were assessed for the presence of ORCs and analyzed considering the clinical features of each case. From the 66 cases, we selected SS-OCT images of 4 RRD patients with visible ORCs and no cystoid macular edema (CME) to validate the mechanical model. We modelled the retina as a composite material consisting of the outer retinal layer (photoreceptor layer) and the inner retinal layer (the part of the retina that excludes the photoreceptor layer) with thicknesses T o and T i and elastic modulus E o and E i , respectively. The thickness of the outer and inner retinal layers and the relative increase in the length of the outer retinal layer (γ) were measured from the SS-OCT images. Measurements from the SS-OCT images of patients with RRD demonstrated a 30% increase (γ=0.3) in the length of the outer retinal layer and a 400% increase in the thickness of the outer retinal layer (To). Using the mathematical model, Eo/Ei ranged between 0.05 to 0.5 to result in ORCs with a similar frequency to those observed in the SS-OCT scans.

Outer Retinal Corrugations in Rhegmatogenous Retinal Detachment: The Retinal Pigment Epithelium-Photoreceptor Dysregulation Theory.

PURPOSE: Outer retinal folds occur when outer retinal corrugations (ORCs) persist after retinal reattachment with worse functional outcomes. We investigate the pathophysiology of ORCs in vivo. DESIGN: Prospective cohort study. METHODS: Patients with rhegmatogenous retinal detachment (RRD) presenting to St. Michael's Hospital, Toronto, Ontario, Canada, between August 2020 and February 2022 were assessed with swept-source optical coherence tomography (SS-OCT) and ultra-widefield SS-OCT for ORCs. Clinical characteristics of eyes with/without ORCs were compared. Mathematical models were used to deduce mechanical properties leading to ORCs. RESULTS: Sixty-six patients were included. More than half (60.6%, 40/66) were fovea-off and 48.4% (32/66) had ORCs at presentation. All eyes (32/32) with ORCs had retinal pigment epithelium (RPE)-photoreceptor dysregulation for at least 2 days, defined as loss of RPE control with acute, progressive, and extensive RRDs. In all (34/34) eyes without ORCs the RPE was in relative control of the subretinal space with nonprogressive subclinical or small localized or resolving RRDs, or with RPE-photoreceptor dysregulation for fewer than 2 days. Mathematical models indicate that a modulus of elasticity of the outer retina relative to the inner retina of 0.05 to 0.5 leads to ORCs. CONCLUSIONS: ORCs develop with (1) acute exposure of subretinal space to liquified vitreous, (2) for >2 days, that (3) overwhelms RPE capacity, leading to progressive and extensive RRD. Mathematical models suggest that a reduction in the modulus of elasticity of the outer retina occurs such that intrinsic compressive forces, likely related to progressive outer retinal hydration and lateral expansion, lead to ORCs. Understanding the pathophysiology of ORCs has implications for management.

BACILLARY LAYER DETACHMENT AND ASSOCIATED ABNORMALITIES IN RHEGMATOGENOUS RETINAL DETACHMENT.

PURPOSE: To describe bacillary layer detachment and related abnormalities of the foveal bouquet in rhegmatogenous retinal detachment and assess their impact on photoreceptor recovery and full-thickness macular hole formation, using optical coherence tomography. METHODS: Prospective cohort of 93 consecutive patients with fovea-off rhegmatogenous retinal detachment presenting to St. Michael's Hospital from January 2020 to April 2022, with gradable preoperative foveal optical coherence tomography. RESULTS: 23.7% (22/93) of patients had evidence of bacillary layer detachment and associated abnormalities. The mean fovea-off duration was 6.4 days (±5.6 SD). 86.4% (19/22) had foveal bacillary layer detachment, 15.8% (3/19) of which had cleavage planes extending from the outer nuclear layer into the myoid zone, and 14% (3/22) had an inner lamellar hole with a residual bridge of photoreceptor remnants (all of which progressed to full-thickness macular hole). Among patients with gradable optical coherence tomography at 3 months post-operatively, 80% (12/15) had ellipsoid zone discontinuity, which persisted in 41% (5/12) at 1 year. CONCLUSION: Bacillary layer detachment was described for the first time in the setting of rhegmatogenous retinal detachment. This is hypothesized to occur from horizontal traction secondary to hydration/lateral expansion of the outer retina in the presence of the Müller cell cone scaffold. Bacillary layer detachment may render the fovea susceptible to further injury, possibly representing a pathophysiological basis for full-thickness macular hole formation in rhegmatogenous retinal detachment.