Artificial intelligence-based extraction of quantitative ultra-widefield fluorescein angiography parameters in retinal vein occlusion.

OBJECTIVE: To examine the association between quantitative vascular parameters extracted from intravenous fluorescein angiography (IVFA) and baseline clinical characteristics of patients with retinal vein occlusion (RVO). METHODS: Our prospective single-centre study in Toronto, Canada, recruited patients with a diagnosis of macular edema secondary to RVO presenting with a central macular thickness (CMT) ≥310 µm from 2017 to 2023. IVFA images were captured using an ultra-widefield scanning laser ophthalmoscope and processed using the artificial intelligence-based RETICAD system to extract quantitative measurements of blood flow, perfusion, and blood-retinal barrier (BRB) permeability. Univariable and multivariable regression models were used to investigate associations between quantitative IVFA parameters and baseline best-corrected visual acuity (BCVA), CMT, and macular volume. RESULTS: The study included 41 eyes from 41 RVO patients. In the multivariable analysis, BRB permeability was significantly associated with both CMT (p < 0.001) and macular volume (p = 0.005). Subgroup analyses revealed that in central RVO patients, central BRB permeability remained significantly associated with CMT (p = 0.022) and macular volume (p = 0.010); however, there was no association with BCVA (p = 0.921). In branch RVO patients, central BRB permeability was significantly associated with BCVA (p = 0.006) and CMT (p = 0.009), but not with macular volume (p = 0.723). Additionally, both central and peripheral BRB permeability were significantly higher in patients with RVO compared to healthy controls (p < 0.001). CONCLUSIONS: Our investigation reveals novel associations between baseline clinical characteristics and quantitative IVFA parameters in RVO patients, which may serve as clinically relevant biomarkers. Future studies should explore these associations in diverse RVO patient populations with extended follow-up.

The Mini-Steamroll: An Abbreviated Variation of the Steamroller Maneuver Following Pneumatic Retinopexy for Rhegmatogenous Retinal Detachment.

PURPOSE: To describe a novel positioning maneuver for patients with rhegmatogenous retinal detachment (RRD) following pneumatic retinopexy(PnR). METHODS: Single-center prospective case series of primary RRDs referred to St. Michael's Hospital, Toronto, Canada, between 2021 and 2023. All patients underwent PnR. Baseline ultra-widefield fundus imaging and repeat imaging 10 minutes after the gas injection was performed. After PnR, patients were instructed to perform the mini-steamroll maneuver which consists of a face-down position for ten minutes followed by positioning to the retinal break. The reduction of subretinal fluid (SRF) volume after the initial face-down position was evaluated with clinical examination and ultra-widefield imaging. RESULTS: Six patients who presented with primary bullous RRD and a sizable superior break were enrolled. The mini-steamroll maneuver resulted in a rapid and significant reduction of SRF in all patients with bullous RRD and large superior breaks, allowing subretinal fluid to be expressed into the vitreous cavity with 10 minutes of face-down positioning. One patient required a sequential PnR. Primary retinal reattachment was achieved in all cases .This approach was well-tolerated by patients. CONCLUSION: This case series demonstrates that the mini-steamroll maneuver may be a suitable alternative for patient positioning following PnR in certain cases. The mini-steamroll is a simpler positioning regimen with the potential benefits of direct-to-break and full steamroller maneuver.

ARTIFICIAL INTELLIGENCE-ENHANCED ANALYSIS OF RETINAL VASCULATURE IN AGE-RELATED MACULAR DEGENERATION.

PURPOSE: To investigate associations between quantitative vascular measurements derived from intravenous fluorescein angiography (IVFA) and baseline characteristics on optical coherence tomography (OCT) in neovascular age-related macular degeneration (nAMD) patients. METHODS: The authors prospectively recruited patients with active choroidal neovascularization secondary to AMD over 50 years old, presenting to a single center in Toronto, Canada from 2017 to 2023. Ultra-widefield IVFA images were processed using the artificial intelligence RETICAD FAassist system to extract quantitative information on blood flow, perfusion, and blood-retinal-barrier (BRB) permeability. Associations between IVFA parameters with functional and anatomical outcomes were examined using univariable and multivariable regression models. RESULTS: Eighty-one nAMD eyes and seven healthy control eyes were included. Compared with healthy controls, BRB permeability in the central and peripheral retina was significantly higher in nAMD patients (P < 0.001). On univariable analysis, BRB permeability measured centrally was significantly associated with central macular thickness (P = 0.035), whereas perfusion and blood flow measured centrally were significantly associated with macular volume (P = 0.043 and 0.037, respectively). On multivariable analysis, BRB permeability remained significantly associated with central macular thickness (P = 0.026). CONCLUSION: Central BRB permeability measured on IVFA was significantly associated with baseline central macular thickness in nAMD patients. Future work should longitudinally explore associations between IVFA parameters and clinical characteristics in diverse nAMD populations.

Reattachment rate with pneumatic retinopexy versus pars plana vitrectomy for single break rhegmatogenous retinal detachment.

AIM: To assess the primary reattachment rate (PARR) in pneumatic retinopexy (PnR) versus pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD) meeting the Pneumatic Retinopexy versus Vitrectomy for the Management of Primary Rhegmatogenous Retinal Detachment Outcomes Randomised Trial (PIVOT) criteria with a single break in detached retina. METHODS: A post hoc analysis of two clinical trials. To be included, patients with primary RRD had to meet PIVOT criteria but could have only one break in the detached retina. Patients with additional pathology in the attached retina were included in a secondary analysis. The primary outcome was PARR following PnR versus PPV at 1-year postoperatively. RESULTS: 162 patients were included. 53% (86/162) underwent PnR and 47% (76/162) had a PPV. 99% (85/86) and 86.8% (66/76) completed the 1-year follow-up visits in the PnR and PPV groups, respectively. PARR was 88.2% (75/85) in the PnR group and 90.9% (60/66) in the PPV group (p=0.6) with a mean postoperative logMAR best-corrected visual acuity of 0.19±0.25 versus 0.34±0.37 (Snellen 20/30 vs 20/44) (p=0.01) each in the PnR and PPV groups, respectively.In an additional analysis of patients who were also allowed to have any pathology in the attached retina, the PARR was 85% (91/107) and 91.6% (66/72) in the PnR and PPV groups, respectively (p=0.18). CONCLUSIONS: PnR and PPV provide similar long-term PARR in a substantial proportion of patients meeting PIVOT criteria with only a single break in the detached retina. Therefore, in patients meeting these specific criteria, PnR is an appropriate first-line therapy as it offers superior functional outcomes without compromising PARR.

Morphologic Features of Regulated vs. Dysregulated Rhegmatogenous Retinal Detachment Using Swept-Source Optical Coherence Tomography.

OBJECTIVE: To describe varying morphological features of patients with RRD based on the extent of regulation of the subretinal space by the retinal pigment epithelium (RPE) pump using swept-source optical coherence tomography (SS-OCT). DESIGN: Prospective clinical cohort study. METHODS:  Setting: St. Michael's Hospital, Toronto, Canada, from August 2020-August 2023. PARTICIPANTS: 120 consecutive eyes with primary RRD. Cohorts: Subclinical, non-progressive, localized RRD defined as regulated vs. acute, progressive, and extensive defined as dysregulated, assessed with SS-OCT. MAIN OUTCOME: Morphological features of regulated vs. dysregulated RRDs with SS-OCT. RESULTS: 19.2% (23/120) of RRDs were classified as regulated and 80.8% (97/120) were dysregulated. The mean age of patients with regulated RRDs was 37.1 years (±13.7 SD) vs. 62.6 years (±11.6SD) for patients with dysregulated RRDs (P < .001). The presence of outer retinal corrugations (ORCs) on OCT was observed in 4.3% (1/23) of regulated vs. 81.4% (79/97) of dysregulated RRDs (P < .001). CME was found in 41.6% (5/12) of regulated RRDs compared to 87.3% (83/95) of dysregulated RRDs (P < .001). ORC presence was an independent predictor of having a dysregulated RRD (P = .02, ß = 6.6, 95% CI [1.3-33.2]) when controlling for age, sex, baseline VA, lens status, and RD extent. Among patients with regulated RRDs, 25.0% (3/12) were in Stage 2, 0% (0/16) in Stage 3A, 8.3% (1/12) in Stage 3B, 0% (0/16) in Stage 4, and 66.7% (8/12) in Stage 5. In patients with dysregulated RRDs, 14.7% (14/95) were in Stage 2, 15.7% (15/95) were in Stage 3A, 37.9% (36/95) in Stage 3B, 22.1% (21/95) in Stage 4, and 9.5% (9/95) in Stage 5 (P < .001). CONCLUSIONS: There are significant morphologic differences between regulated and dysregulated RRDs using SS-OCT. ORCs are present in almost all dysregulated cases but in a minority of regulated cases and they are an independent predictor of RPE-photoreceptor regulation status. Demographic and clinical features differentiate regulated and dysregulated RRD and understanding these differences has significant implications for optimal management and postoperative outcomes.

Optical Coherence Tomography Features in Fovea-Off Exudative vs Rhegmatogenous Retinal Detachment.

PURPOSE: To describe the optical coherence tomography (OCT) features that can differentiate eyes with fovea-off exudative retinal detachment (ERD) vs rhegmatogenous retinal detachment (RRD), with particular attention to outer retinal corrugations (ORCs). DESIGN: Multicenter, retrospective cross-sectional study. METHODS: Multicenter, retrospective cross-sectional study of patients diagnosed with unilateral or bilateral fovea-off ERD or primary, acute, fovea-off RRD between 2016 and 2021. This study was performed with the approval from the Research Ethics Board at the University of Toronto and was conducted in accordance with the Declaration of Helsinki. Patients with any ERD etiology and evidence of extensive, bullous fovea-off detachment and in the RRD group: consecutive patients with acute, primary fovea-off RRD with good quality baseline SD-OCT imaging were included. Patients with exudative choroidal neovascularization from any etiology, optic nerve pit, significant media opacity, or OCT images with poor quality or low signal strength were excluded. Primary outcome was to describe the morphological features of the macula using SD-OCT in patients diagnosed with ERD vs RRD, with specific interest in ORCs. RESULTS: One hundred sixty-one eyes (51 ERD and 110 RRD) of 154 patients were included. Fifty-one eyes with ERD presented with 1 of 15 etiologies. ERD were associated with a greater risk of having hyperreflective dots in the outer retina (92.2% vs 74.5%, P = .009), hyperreflective material and dots in the subretinal fluid (72.5% vs 34.5%, P < .001), internal limiting membrane and inner retinal undulations (70.6% vs 39.4%, P < .001), and retinal pigment epithelium undulations (44.9% vs 6.4%, P < .001) compared to RRD. RRD was associated with a greater risk of outer retinal corrugations (80% vs 0%, P < .001), intraretinal fluid (90.9% vs 41.2%, P < .001) and ellipsoid zone thickening (90% vs 66.7%, P < .001) compared to ERD. CONCLUSION: The presence of ORCs are highly specific for RRD and absent in ERD. This is likely related to differences in the pathophysiology of the diseases process, specifically the content of the subretinal fluid. Understanding the differences in OCT morphological features of ERD vs RRD may aid with diagnosis and management.

VALIDATION OF M-CHARTS FOR QUANTITATIVE ASSESSMENT OF METAMORPHOPSIA FOLLOWING RHEGMATOGENOUS RETINAL DETACHMENT REPAIR.

PURPOSE: To validate the quantitative assessment of metamorphopsia in rhegmatogenous retinal detachment (RRD) using M-CHARTS by determining its correlation with subjective reporting of metamorphopsia with a validated metamorphopsia questionnaire (modified MeMoQ). METHODS: The Research Ethics Board approved a prospective observational study carried out at St. Michael's Hospital, Toronto, Canada. Patients with primary, unilateral RRD and healthy controls were included. Metamorphopsia at 3 months was assessed with modified MeMoQ and M-CHARTS. RESULTS: One hundred patients (50 with RRD, 50 controls) were included. Seventy percent (35/50) of the RRD group had metamorphopsia with M-CHARTS and 80% (40/50) with MeMoQ. The modified MeMoQ and total M-CHARTS scores were significantly higher in patients with RRD compared with controls ( P < 0.0001). Cronbach's alpha reliability coefficient was 0.934 in the RRD group. Horizontal, vertical, and total M-CHARTS scores were significantly correlated with MeMoQ scores (r s  = 0.465, P = 0.0007; r s  = 0.405, P = 0.004; r s  = 0.475, P = 0.0005, respectively). M-CHARTS was 72.7% sensitive and 94.6% specific for detection of metamorphopsia (positive score ≥ 0.2), with an area under the receiver operating characteristic curve = 0.801. A stronger correlation was found in patients who scored ≥0.2 on the M-CHARTS and reported metamorphopsia with the MeMoQ (r s  = 0.454, P = 0.001). CONCLUSION: The authors have validated M-CHARTS as a tool to quantitatively assess metamorphopsia in patients with RRD, which is significantly correlated with patient-reported outcomes using the MeMoQ. A total score of ≥0.2 with M-CHARTS was more strongly correlated with MeMoQ.

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.

POSTOPERATIVE PHOTORECEPTOR INTEGRITY AND ANATOMICAL OUTCOMES BASED ON PRESENTING MORPHOLOGIC STAGE OF RHEGMATOGENOUS RETINAL DETACHMENT.

PURPOSE: To evaluate outer retinal recovery on postoperative optical coherence tomography (OCT) based on presenting morphologic stage of rhegmatogenous retinal detachment (RRD). METHODS: Retrospective cohort of consecutive primary fovea-involving RRDs, referred from January 2012 to September 2022. Baseline OCTs were assessed for morphologic stage of RRD. Postoperative OCT scans were graded at 3, 6, and 12 months for external limiting membrane, ellipsoid zone and interdigitation zone discontinuity, epiretinal membrane formation and severity, and residual subfoveal fluid. RESULTS: Three hundred and fifty-one patients were included. Increasing baseline morphologic stage of RRD was significantly associated with external limiting membrane, ellipsoid zone, and interdigitation zone discontinuity at all time points postoperatively ( P < 0.001) and was shown to be an independent predictor of foveal photoreceptor integrity after adjusting for height of detachment, time to surgery, and duration of fovea involvement ( P < 0.001). Earlier stages were associated with residual subfoveal fluid ( P < 0.001). There was no association between the stages of RRD and epiretinal membrane severity. However, late stages presented with earlier development of epiretinal membrane ( P = 0.012). CONCLUSION: Increasing morphologic stage of RRD is associated with delayed recovery of outer retinal bands in the first year and faster development of epiretinal membrane after RRD repair. The results of this study suggest that the stages may serve as a prognostic biomarker for postoperative photoreceptor recovery.

In-Office Suprachoroidal Viscopexy for Rhegmatogenous Retinal Detachment Repair.

Importance: In-office suprachoroidal viscopexy (SCVEXY) is a minimally invasive technique for rhegmatogenous retinal detachment (RRD) repair that can be performed with no incision, no tamponade agent, and no positioning requirements. This technique has the potential to be a step forward in the armamentarium to treat RRDs. Objective: To describe in-office SCVEXY for RRD repair. Design, Setting, and Participant: In this single-case report with short follow-up, a man in his 50s with pseudophakia and recent visual loss presented to St Michael's Hospital, Unity Health Toronto, with a fovea-off RRD in the right eye, extending from 6 to 10 o'clock, with no visible causative retinal break. Exposure: Injection of suprachoroidal sodium hyaluronate, 1%, in the region of the suspected break, using a 30-gauge needle with a custom-made guard that exposed only 1 mm of the needle. Main Outcome and Measures: Ability to perform in-office SCVEXY and to obtain a visible choroidal indentation. Results: After the procedure, a dome-shaped choroidal convexity was present in the superior temporal area. The patient achieved macular reattachment in less than 24 hours with no postoperative abnormalities, such as outer retinal folds, residual subfoveal fluid, or retinal displacement, with rapid recovery of the outer retinal bands on optical coherence tomography. The optical coherence tomography scans acquired in the area of the choroidal convexity demonstrated the location of the viscoelastic material in the suprachoroidal space. Laser retinopexy was applied in the suspected region of the retinal tear, and the patient was able to resume normal activity immediately after the procedure with no restrictions. Conclusions and Relevance: Suprachoroidal viscopexy is feasible as an in-office technique to create a temporary choroidal buckle for RRD repair. It is a minimally invasive procedure with the potential to maximize anatomical outcomes of integrity and postoperative functional outcomes in RRD because its mechanism of action does not require drainage of subretinal fluid or intraocular gas tamponade. Nevertheless, this was a single-case report with short follow-up, which limits the ability to determine the procedure's benefits, potential adverse events, failure rates, and best-case selection. Further work is required to refine the procedure and assess its efficacy and safety.

Outer Retinal Hyperreflective Dots: A Potential Imaging Biomarker in Rhegmatogenous Retinal Detachment.

PURPOSE: To investigate hyperreflective dots (HRDs) on baseline OCT in rhegmatogenous retinal detachment (RRD). DESIGN: Retrospective cohort study. SUBJECTS: Consecutive primary fovea-off RRDs presenting between January 2012 and September 2022. METHODS: Visual acuity (VA) was obtained at baseline, 3, 6, and 12 months. Baseline foveal OCT scans were graded for the presence of HRDs in the outer retina, morphologic stage of RRD in the parafovea, and foveal photoreceptor integrity (intact, patchy or complete loss of the bacillary layer). Epiretinal membrane (ERM) and cystoid macular edema (CME) were graded after surgery. MAIN OUTCOME MEASURES: The primary outcome was the proportion of patients in each morphologic stage with HRDs present on OCT and their association with postoperative VA. Secondary outcomes included association with the height of foveal detachment, duration of central vision loss, RRD extent, and development of ERM/CME. RESULTS: A total of 351 patients were included. The presence of HRDs by morphologic stage of RRD was 0% in stage 1, 4.5% (2/42) in stage 2, 13% (7/54) in stage 3a, 16% (20/126) in stage 3b, 48% (40/83) in stage 4, and 85% (35/41) in stage 5. Hyperreflective dots were associated with increasing stage of RRD (P < 0.001), reduced integrity of foveal photoreceptors (P < 0.001), and reduced postoperative VA at 3, 6, and 12 months (P < 0.001), after excluding visually significant cataracts and adjusting for covariates. There was also a significant association between HRDs and height of foveal detachment, duration of central vision loss, and RRD extent (P < 0.001). Hyperreflective dots were neither associated with postoperative ERM formation nor with its severity (P = 0.27). Nevertheless, they were associated with the occurrence of CME at 3 and 6 months after surgery (P = 0.01; P = 0.006). CONCLUSIONS: Hyperreflective dots have been hypothesized to consist of intraretinal inflammatory cells. We found that HRDs were significantly associated with the morphologic stage, extent, duration, and height of the RRD before surgery and with reduced VA and CME after surgery. Our results suggest that HRDs are associated with photoreceptor degeneration, as longstanding and extensive RRDs are more likely to present with HRDs. The association of HRDs with CME provides insight into the possible importance of inflammatory processes in RRD before and after surgery. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.