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Christos Haritoglou,1 Ramin Tadayoni,2 Jean-Pierre Hubschman3 1Herzog Carl Theodor Eye Clinic, Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany; 2Department of Ophthalmology, Lariboisière Hospital, Assistance Publique-Hôpitaux de Paris, University Sorbonne Paris Cité, Paris, France; 3Retina Division, Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, USA Abstract: Lamellar macular holes present distinct morphological features including tractional or non-tractional epimacular membranes, foveal tissue alterations, defects of the outer retinal layers, or a separation of the retinal layers. At present, degenerative lamellar holes are differentiated from tractional holes based on the morphological characteristics seen in OCT. The current treatment approach is based on this gross differentiation. Considering the recent developments in high-resolution imaging, this classification needs to be revisited since morphological features may present simultaneously, making it difficult to separate these entities. In addition, a revisited classification may be of value to better standardize the indication for surgical treatment. Keywords: lamellar macular hole, degenerative lamellar hole, tractional lamellar hole, outer retina, lamellar macular hole-associated epimacular proliferation, LHEP

© 2015 IEEE. Terahertz (THz) spectral properties of human cornea are explored as a function of central corneal thickness (CCT) and corneal water content, and the clinical utility of THz-based corneal water content sensing is discussed. Three candidate corneal tissue water content (CTWC) perturbations, based on corneal physiology, are investigated that affect the axial water distribution and total thickness. The THz frequency reflectivity properties of the three CTWC perturbations were simulated and explored with varying system center frequency and bandwidths (Q-factors ). The modeling showed that at effective optical path lengths on the order of a wavelength the cornea presents a lossy etalon bordered by air at the anterior and the aqueous humor at the posterior. The simulated standing wave peak-to-valley ratio is pronounced at lower frequencies and its effect on acquired data can be modulated by adjusting the bandwidth of the sensing system. These observations are supported with experimental spectroscopic data. The results suggest that a priori knowledge of corneal thickness can be utilized for accurate assessments of corneal tissue water content. The physiologic variation of corneal thickness with respect to the wavelengths spanned by the THz band is extremely limited compared to all other structures in the body making CTWC sensing unique amongst all proposed applications of THz medical imaging.

Purpose: To evaluate the safety, functional, and anatomical outcomes of short-duration pattern scanning laser (PASCAL) macular photocoagulation in the treatment of macular edema related to branch retinal vein occlusion (BRVO). Methods: Consecutive retrospective analysis of visual acuity (VA), optical coherence tomography (OCT), and adverse events from eyes treated with PASCAL macular photocoagulation for BRVO-related macular edema. Two-tailed paired t-tests were used to compare pre- and post-treatment VA and central retinal thickness (CRT). Results: A total of 35 eyes from 35 patients and 18 eyes from 18 patients met study criteria for VA and OCT analysis, respectively. All treatments were delivered with the same PASCAL photocoagulation unit. Mean laser settings were 133-um spot size, 15-millisecond pulse duration, 250-mW power, and fluence of 29 J/cm(2) with an average of 1.4 treatments and 335 shots per patient. Adjunct treatment with intravitreal anti-VEGF injections and pan-retinal photocoagulation was administered in 27 and 16 eyes, respectively. At an average follow-up of 12 months (range 3-43 months) post-treatment, no laser-related ocular complications were observed. Visual acuity was not significantly changed (p = 0.07), although the number of patients with vision better than 20/40 doubled following treatment. CRT was reduced by an average of 110 um (p = 0.0009). Conclusion: Short-duration PASCAL macular photocoagulation appears to be a safe treatment option that results in significant anatomical improvement in macular edema related to BRVO. [ABSTRACT FROM AUTHOR]

Purpose of Review: Technologies in healthcare incorporating artificial intelligence tools are experiencing rapid growth in static-image-based applications such as diagnostic imaging. Given the proliferation of artificial intelligence (AI)-technologies created for video-based imaging, ophthalmic microsurgery is likely to experience significant benefits from the application of emerging technologies to multiple facets of the care of the surgical patient., Recent Findings: Proof-of-concept research and early phase clinical trials are in progress for AI-based surgical technologies that aim to provide preoperative planning and decision support, intraoperative image enhancement, surgical guidance, surgical decision-making support, tactical assistive technologies, enhanced surgical training and assessment of trainee progress, and semi-autonomous tool control or autonomous elements of surgical procedures., Summary: The proliferation of AI-based technologies in static imaging in clinical ophthalmology, continued refinement of AI tools designed for video-based applications, and development of AI-based digital tools in allied surgical fields suggest that ophthalmic surgery is poised for the integration of AI into our microsurgical paradigm., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To assess the natural history and surgical outcomes of lamellar macular holes (LMHs)., Design: Retrospective and consecutive case series., Subjects: Patients with LMHs from multiple tertiary care centers., Methods: Clinical charts and OCT scans were reviewed., Main Outcome Measures: The visual acuity (VA) changes and the occurrence rate of full-thickness macular hole (FTMH) were studied in both groups. Within the operated group, factors associated with 6-month VA and development of FTMH were explored., Results: One hundred seventy-eight eyes were included, of which 89 were monitored and 89 underwent surgery. In the observation group, the mean VA decreased from 0.25 ± 0.18 to 0.28 ± 0.18 logarithm of the minimum angle of resolution (logMAR; P = 0.13), with 14 eyes (15.7%) that lost ≥ 0.2 logMAR VA, after 45.7 ± 33.3 months. Nine eyes (10.1%) spontaneously developed an FTMH. In the operated group, the mean VA increased from 0.47 ± 0.23 to 0.35 ± 0.25 logMAR at 6 months (P < 0.001) and 0.36 ± 0.28 logMAR (P = 0.001) after 24.1 ± 30.1 months. By multivariate analysis, better baseline VA (P < 0.001), the presence of an epiretinal membrane (P = 0.03), and the peeling of the internal limiting membrane (ILM; P = 0.02), with a greater effect of ILM perihole sparing, were associated with a greater 6-month VA. Perihole epiretinal proliferation sparing was associated with a better postoperative VA by univariate analysis (P = 0.03), but this was not significant by multivariate analysis. Eight eyes (9.0%) developed a postoperative FTMH. Using Cox proportional hazard ratios [HRs], pseudophakia at baseline (HR, 0.06; 95% confidence interval [CI], 0.00-0.75; P = 0.03) and peeling of the ILM (HR, 0.05; 95% CI, 0.01-0.39; P = 0.004) were protective factors, while ellipsoid zone disruption (HR, 10.5; 95% CI, 1.04-105; P = 0.05) was associated with an increased risk of FTMH., Conclusion: Observed eyes with LMH experienced, on average, progressive VA loss. Patients with LMH and altered vision may benefit from surgery. Internal limiting membrane peeling, with perihole ILM sparing, represents a crucial step of the surgery associated with a greater VA and a lower risk of postoperative FTMH., Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article., (Copyright © 2023 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Background/aims: To identify clinical characteristics and factors associated with microcystic macular edema (MME) in patients with primary open-angle glaucoma (POAG)., Methods: We included 315 POAG eyes between 2010 and 2019 with good-quality macular volume scans that had reliable visual fields (VF) available within 6 months in this observational retrospective cohort study. Eyes with retinal pathologies except for epiretinal membrane (ERM) were excluded. The inner nuclear layer was qualitatively assessed for the presence of MME. Global mean deviation (MD) and Visual Field Index (VFI) decay rates, superior and inferior MD rates and pointwise total deviation rates of change were estimated with linear regression. Logistic regression was performed to identify baseline factors associated with the presence of MME and to determine whether MME is associated with progressive VF loss., Results: 25 out of 315 eyes (7.9%) demonstrated MME. The average (±SD) age and MD in eyes with and without MME was 57.2 (±8.7) versus 62.0 (±9.9) years (p=0.02) and -9.8 (±5.7) versus -4.9 (±5.3) dB (p<0.001), respectively. Worse global MD at baseline (p=0.001) and younger age (p=0.02) were associated with presence of MME. ERM was not associated with the presence of MME (p=0.84) in this cohort. MME was not associated with MD and VFI decay rates (p>0.49)., Conclusions: More severe glaucoma and younger age were associated with MME. MME was not associated with faster global VF decay in this cohort. MME may confound monitoring of glaucoma with full macular thickness., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: The purpose of this study was to assess the performance of ultrasonic (US) vitrectomy devices by quantifying and comparing its impact on extracted vitreous properties to conventional pneumatic blade (PB) cutters using micro-extensional rheology. US vitrectomy is a new technology that offers an alternative to PB cutters used in vitreo-retinal surgeries., Methods: Thirty-six porcine vitreous samples were extracted using US and PB cutters. Each sample was kept at 4°C and tested within 24 hours postmortem and 4 hours post-vitrectomy. A recently developed micro-extensional rheology technique is used to infer the relative protein fragment size of extracted vitreous by quantifying the extensional relaxation time., Results: US-extracted vitreous exhibited extensional relaxation times orders of magnitude lower than PB-extracted vitreous (0.37 ms and 27.25 ms, respectively). Relaxation time is directly correlated to the fragment size of the collagen fibers in the vitreous. The formation of beads-on-a-string droplets within the PB samples indicates the presence of larger collagen fragments. These droplets were not seen on US samples., Conclusions: This new micro-extensional rheology technique can identify significant differences in physical properties of extracted vitreous. Long relaxation times and beads-on-a-string droplets within the PB vitreous samples indicate larger protein fragments compared to the US samples., Translational Relevance: Higher fragmentation of vitreous and lower extensional relaxation times may improve retina safety due to a reduction in vitreo-retinal traction resulting from the continuous shear action and aspiration applied by ultrasonic vitrectomy technology.

Purpose: To report two cases of spontaneous closure of lamellar macular holes with epiretinal proliferation (ERP)., Methods: Observational cases report., Results: Two patients affected with lamellar macular hole showed progressive and spontaneous closure of the hole associated with ERP development. At presentation, both patients presented with irregular foveal contour, and foveal cavitation with apparent loss of retinal tissue. In both cases, ERP, also called "lamellar hole-associated epiretinal proliferation", was present and increased in size over time. This proliferation progressively developed across the hole with apparent restoration of the foveal contour and preservation of visual acuity., Conclusion: This report describes two cases of lamellar macular hole in which ERP increased over time, resulting in lamellar macular hole closure. Such observations may suggest a spontaneous healing process driven by glial cell proliferation.

Purpose: To determine incidence, risks factors for, and outcomes of idiopathic vitritis (IV) after Boston type 1 keratoprosthesis (KPro) implantation., Methods: Retrospective, consecutive case series. Risk factors were analyzed between IV group and No IV group., Results: IV occurred in 32/350 procedures (9.1%), for an average incidence of 0.02 cases per procedure-year. Presumed infectious keratitis was the only risk factor identified (HR = 7.65) Corneal necrosis and retinal detachment occurred significantly more frequently in IV group (all P < .05). By last follow-up, the cumulative proportion of eyes that maintained a visual acuity >20/200 was significantly lower in IV group ( P = .01), as was the KPro retention rate (HR = 0.26)., Conclusions: IV is associated with infectious keratitis, indicating that the vitritis may not be a sterile process. The increased incidence of subsequent complications leads to significantly decreased visual acuity and KPro retention in affected eyes.

Purpose: To evaluate the mid-term outcomes of pars plana vitrectomy performed for retinal detachment (RD) repair after Boston Type 1 keratoprosthesis (KPro) implantation., Methods: Retrospective review of medical records of KPro implanted at the Stein Eye Institute presenting with RD and treated by pars plana vitrectomy. Functional success was defined as a postoperative visual acuity maintained within 2 Snellen lines of the corrected distance visual acuity measured before the development of the RD (baseline) and anatomical success as an attached retina after the pars plana vitrectomy. Kaplan-Meyer survival analyses were performed., Results: Among the 224 KPro performed, 28 (15.2%) RD were identified; of which, 21 (9.4%) were included. The mean follow-up was 42.5 ± 27.3 months. Vitreoretinal proliferation was present in 18 of 21 eyes (85.7%). Surgical techniques were adapted to the complex anterior segment anatomy of KPro eyes. Anatomical success was achieved in 18 of 21 eyes (85.7%). Functional success occurred in 17 of 21 eyes (81.0%), and 5 of 21 eyes (23.8%) reached 20/400 or better visual acuity at the final follow-up. The KPro was retained in 11 in 21 eyes (52.4%). The retention rate decreased from 94.7% at 1 year to 53.5% at 5 years. The most frequent complications were retroprosthetic membrane (47.6%) and corneal melt (23.8%)., Conclusion: Modified pars plana vitrectomy techniques resulted in relatively good mid-term anatomical, functional, and retention rate outcomes, given the severity of RD at presentation and the numerous preoperative comorbidities of KPro eyes.

Purpose: To determine the characteristics and appearance rate of epiretinal proliferation (ERP) on SD-OCT after surgery for rhegmatogenous retinal detachment (RRD) repair., Methods: One hundred eight eyes of 108 patients who underwent one or more surgeries for RRD were enrolled. The eyes with other maculopathies that were directly related to RRD were excluded. Image acquisition was performed with SD-OCT (Heidelberg Engineering, Germany). Clinical charts were reviewed to assess clinical and surgical findings. Statistical analyses were performed using XLSTAT (Assinsoft, Paris, France)., Results: ERP was found in 9.3% eyes (n = 10). The mean initial visual acuity (logMAR) was 1.34 ± 0.82 in the ERP group compared to 0.49 ± 0.70 in the non-ERP group. PVR was present in 70.0% and chronic macular edema was found in 80.0% of eyes which developed ERP. The mean number of vitreoretinal surgeries in eyes with ERP was 3.3 ± 1.19 and only 1.44 ± 1.02 in eyes without. Silicone oil was used in 60.0% of eyes which developed ERP compared to 13.9% in the non-ERP group., Conclusion: ERP is a late-onset postoperative finding in eyes with RRD and can occur in absence of macular holes. Overall, ERP is more frequent in eyes with complicated courses of RRD including multiple operations, PVR, usage of silicone oil, and chronic macular edema., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: We describe our offline deep learning algorithm (DLA) and validation of its diagnostic ability to identify vitreoretinal abnormalities (VRA) on ocular ultrasound (OUS)., Methods: Enrolled participants underwent OUS. All images were classified as normal or abnormal by two masked vitreoretinal specialists (AS, AM). A data set of 4902 OUS images was collected, and 4740 images of satisfactory quality were used. Of this, 4319 were processed for further training and development of DLA, and 421 images were graded by vitreoretinal specialists (AS and AM) to obtain ground truth. The main outcome measures were sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and area under receiver operating characteristic (AUROC)., Results: Our algorithm demonstrated high sensitivity and specificity in identifying VRA on OUS ([90.8%; 95% confidence interval (CI): 86.1-94.3%] and [97.1% (95% CI: 93.7-98.9%], respectively). PPV and NPV of the algorithm were also high ([97.0%; 95% CI: 93.7-98.9%] and [90.8%; 95% CI: 86.2-94.3%], respectively). The AUROC was high at 0.939, and the intergrader agreement was nearly perfect with Cohen's kappa of 0.938. The model demonstrated high sensitivity in predicting vitreous hemorrhage (100%), retinal detachment (97.4%), and choroidal detachment (100%)., Conclusion: Our offline DLA software demonstrated reliable performance (high sensitivity, specificity, AUROC, PPV, NPV, and intergrader agreement) for predicting VRA on OUS. This might serve as an important tool for the ophthalmic technicians who are involved in community eye screening at rural settings where trained ophthalmologists are not available., Competing Interests: None

Objective: The objective of this work was to develop and experimentally validate a bioimpedance-based framework to identify tissues in contact with the surgical instrument during cataract surgery., Methods: This work introduces an integrated hardware and software solution based on the unique bioimpedance of different intraocular tissues. The developed hardware can be readily integrated with commonly used surgical instruments. The proposed software framework, which encompasses data acquisition and a machine-learning classifier, is fast enough to be deployed in real-time surgical interventions. The experimental protocol included bioimpedance data collected from 31 ex vivo pig eyes targeting four intraocular tissues: Iris, Cornea, Lens, and Vitreous., Results: A classifier based on a support vector machine exhibited an overall accuracy of 91% across all trials. The algorithm provided substantial performance in detecting the intraocular tissues with 100% reliability and 95% sensitivity for the lens, along with 88% reliability and 94% sensitivity for the vitreous., Conclusion: The developed impedance-based framework demonstrated successful intraocular tissue identification., Significance: Clinical implications include the ability to ensure safe operations by detecting posterior capsule rapture with 94% probability and improving surgical efficacy through lens detection with 100% reliability.

Purpose: We aimed to investigate non-exudative microcystoid macular abnormalities for visual and anatomical outcome in patients with retinal vein occlusion (RVO) with and without glaucomatous optic neuropathy (GON)., Methods: Medical records of 124 eyes (105 patients) with RVO were reviewed and analyzed. Eyes demonstrating microcystoid macular abnormalities were divided into 2 groups, those with evidence of glaucoma (group A) and those without glaucoma (group B). Best-corrected visual acuity (BCVA), the prevalence and number of microcystoid macular abnormalities, and number of intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections were compared at baseline and follow-up., Results: Seventy-one out of 105 eyes (67.6%) with RVO displayed microcystoid macular abnormalities. Thirty-eight out of 71 eyes (53.5%) presented with concomitant glaucoma (group A), while the remaining 33 eyes (42.6%) had no history of glaucoma (group B). At the end of the follow-up period, mean BCVA was worse in group A versus group B (20/80 versus 20/40, respectively; p = .003). The mean number of anti-VEGF injections was 10.1 ± 9.2 in group A versus 5.9 ± 6.9 in group B (p = .03)., Conclusion: Eyes with RVO and concomitant glaucoma exhibited a significantly higher number of microcystoid macular abnormalities and worse BCVA versus eyes with RVO without glaucoma., (© 2021. The Author(s).)

Purpose: To identify the incidence of, risk factors for, and outcomes of posterior segment complications (PSC) after Boston Type 1 keratoprosthesis (KPro) implantation., Methods: Retrospective, consecutive case series of KPro procedures at the Stein Eye Institute. Data regarding ocular history, intraoperative details, postoperative management, and outcomes were collected. Eyes with at least one PSC (PSC group) were compared with eyes without PSC (No PSC group), and risk factors for PSC were determined., Results: Ninety-five PSC occurred in 69/169 eyes (40.8%), at a mean of 20.1 months after KPro implantation (0.01 complications/eye month). The median follow-up after KPro implantation was 44.0 months (range 3.0-174.4). The most common PSC were epiretinal membrane (16.6%), cystoid macular edema (12.4%), vitritis (11.2%), and retinal detachment (9.5%). Previous retinal detachment repair, concomitant intraocular lens removal, postoperative aphakia, and vitritis were risk factors for retinal detachment. Postoperative infectious keratitis was a risk factor for epiretinal membrane, cystoid macular edema, and vitritis. The posterior segment complication group had a significantly higher rate of eyes failing to maintain visual acuity ≥20/200 (HR = 2.28; 95% CI = 1.35-3.85) and KPro retention failure rate (HR = 1.66; 95% CI = 0.95-2.91)., Conclusion: Posterior segment complications occur in approximately 40% of eyes after KPro implantation, resulting in reduced visual outcomes and KPro retention.

Purpose : To discuss the pathophysiology of metamorphopsia, its characterisation using retinal imaging and methods of assessment of patient symptoms and visual function. Methods : A literature search of electronic databases was performed Results : Metamorphopsia has commonly been associated with vitreomacular interface disorders (such as epiretinal membrane) and has also regularly been noted in diseases of the retina and choroid, particularly age-related macular degeneration and central serous chorioretinopathy. Developments in optical coherence tomography retinal imaging have enabled improved imaging of the foveal microstructure and have led to the localisation of the pathophysiology of metamorphopsia within the retinal layers of the macula. Alteration of alignment of inner and outer retinal layers at various retinal loci has been identified using multimodal imaging in patients with metamorphopsia in a range of conditions. Although the Amsler Grid assessment of metamorphopsia is a useful clinical indicator, new emerging methods of metamorphopsia assessment with psychophysical tests such as M-CHARTS and preferential hyperacuity perimetry, have been developed. Conclusions : It appears that there is a complex relationship between visual acuity and metamorphopsia symptoms that vary between retinal conditions. Although metamorphopsia has traditionally been challenging to measure in the clinic, advances in technology promise more robust, easy-to-use tests. It is possible that home assessment of metamorphopsia, particularly in conditions such as age-related macular degeneration, may help to guide the need for further clinic evaluation and consideration of treatment.

Purpose: To describe the clinical features and surgical outcomes of patients experiencing a spontaneous conversion of a lamellar macular hole (LMH) to a full-thickness macular hole (FTMH)., Design: Retrospective, multicenter, observational case series., Participants: Patients with LMH who experienced a spontaneous conversion to FTMH and underwent FTMH surgery., Methods: Clinical charts and OCT features of 20 eyes of 20 patients were reviewed., Main Outcome Measures: OCT features and surgical outcomes of FTMH derived from LMH., Results: The mean baseline visual acuity (VA) was 0.21 ± 0.19 logarithm of the minimum angle of resolution (logMAR) (20/32 Snellen equivalent [SE]). Epiretinal proliferation was noted in 18 eyes (90%), and 14 eyes (75%) had an epiretinal membrane. At the diagnosis of FTMH, the mean VA decreased to 0.61 ± 0.50 logMAR (20/81 SE) (P = 0.001). The mean FTMH diameter was 224.4 ± 194.8 μm, with 15 (75%) small (≤250 μm), 2 (10%) medium (>250-≤400 μm), and 3 (15%) large (>400 μm) FTMHs. Eighteen (90%) FTMHs were sealed after 1 surgery, and 2 (10%) required an additional procedure. At the last follow-up, the mean VA was increased to 0.29 ± 0.23 logMAR (20/38 SE) (P = 0.003), but did not significantly differ from the baseline VA (P = 0.071)., Conclusions: Patients with LMH may develop an FTMH with no evidence of vitreomacular traction. A tangential traction from an epiretinal membrane may contribute to its genesis, but a progressive loss of retinal tissue and an inherent weakness of the foveal architecture in LMH eyes could be sufficient. Most FTMHs derived from LMH had a small diameter, showed epiretinal proliferation, showed limited retinal hydration, and were associated with relatively poor surgical outcomes compared with idiopathic FTMH., (Copyright © 2021 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Retinal vein occlusion is one of the most common causes of vision loss, occurring when a blood clot or other obstruction occludes a retinal vein. A potential remedy for retinal vein occlusion is retinal vein cannulation, a surgical procedure that involves infusing the occluded vein with a fibrinolytic drug to restore blood flow through the vascular lumen. This work presents an image-guided robotic system capable of performing automated cannulation on silicone retinal vein phantoms. The system is integrated with an optical coherence tomography probe and camera to provide visual feedback to guide the robotic system. Through automation, the developed system targets a vein phantom to within 20 μm and automatically cannulates and infuses the vascular lumen with dyed water. The system was evaluated through 30 experimental trials and shown to be capable of performing automated cannulation of retinal vein phantoms with no reported cases of failure.

Purpose: To describe the clinical characteristics, surgical outcomes, and management recommendations in patients with traumatic rhegmatogenous retinal detachment (RRD) resulting from self-injurious behavior (SIB)., Design: International, multicenter, retrospective, interventional case series., Participants: Patients with SIB from 23 centers with RRD in at least 1 eye., Methods: Clinical histories, preoperative assessment, surgical details, postoperative management, behavioral intervention, and follow-up examination findings were reviewed., Main Outcome Measures: The rate of single-surgery anatomic success (SSAS) was the primary outcome. Other outcomes included new RRD in formerly attached eyes, final retinal reattachment, and final visual acuity., Results: One hundred seven eyes with RRDs were included from 78 patients. Fifty-four percent of patients had bilateral RRD or phthisis bulbi in the fellow eye at final follow-up. The most common systemic diagnoses were autism spectrum disorder (35.9%) and trisomy 21 (21.8%) and the most common behavior was face hitting (74.4%). The average follow-up time was 3.3 ± 2.8 years, and surgical outcomes for operable eyes were restricted to patients with at least 3 months of follow-up (81 eyes). Primary initial surgeries were vitrectomy alone (33.3%), primary scleral buckle (SB; 26.9%), and vitrectomy with SB (39.7%), and 5 prophylactic SBs were placed. Twenty-three eyes (21.5%) with RRDs were inoperable. The SSAS was 23.1% without tamponade (37.2% if including silicone oil), and final reattachment was attained in 80% (36.3% without silicone oil tamponade). Funnel-configured RRD (P = 0.006) and the presence of grade C proliferative vitreoretinopathy (P = 0.002) correlated with re-detachment. The use of an SB predicted the final attachment rate during the initial surgery (P = 0.005) or at any surgery (P = 0.008. These associations held if restricting to 64 patients with ≥12 months followup. Anatomic reattachment correlated with better visual acuity (P < 0.001)., Conclusions: RRD resulting from SIB poses therapeutic challenges because of limited patient cooperation, bilateral involvement, chronicity, and ongoing trauma in vulnerable and neglected patients. The surgical success rates were some of the lowest in the modern retinal detachment literature. The use of an SB may result in better outcomes, and visual function can be restored in some patients., (Copyright © 2020 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

The overarching goal of this work is to demonstrate the feasibility of using optical coherence tomography (OCT) to guide a robotic system to extract lens fragments from ex vivo pig eyes. A convolutional neural network (CNN) was developed to semantically segment four intraocular structures (lens material, capsule, cornea, and iris) from OCT images. The neural network was trained on images from ten pig eyes, validated on images from eight different eyes, and tested on images from another ten eyes. This segmentation algorithm was incorporated into the Intraocular Robotic Interventional Surgical System (IRISS) to realize semi-automated detection and extraction of lens material. To demonstrate the system, the semi-automated detection and extraction task was performed on seven separate ex vivo pig eyes. The developed neural network exhibited 78.20% for the validation set and 83.89% for the test set in mean intersection over union metrics. Successful implementation and efficacy of the developed method were confirmed by comparing the preoperative and postoperative OCT volume scans from the seven experiments.

Background: In cataract surgery, polishing of the posterior capsule (PC) can lead to improved surgical outcomes but is currently avoided due to its high-risk nature. This work developed a robotic system capable of performing PC polishing on ex vivo pig eyes using optical coherence tomography (OCT) guidance., Methods: The lenses of five ex vivo pig eyes were extracted and a thin layer of glue deposited onto the PC. Transpupillary OCT scans of the anterior segment were used to generate a PC-polishing trajectory. During polishing, OCT B-scans tracked the tool tip and were displayed to the operator., Results: Complete removal of the glue was accomplished in all five trials with no PC rupture reported., Conclusions: The feasibility of using a robotic system guided by OCT to perform PC polishing on a biological model was demonstrated. Contributions include modelling of the PC anatomy, intraoperative OCT visualization, and automated tool-tip motion with scheduled aspiration pressures., (© 2021 John Wiley & Sons Ltd.)

Using high-resolution imaging, such as optical coherence tomography (OCT), the different layers of the retina as well as the vitreoretinal interface and its alterations can be very clearly differentiated. This includes the morphological characteristics of tractive maculopathies, such as epiretinal gliosis and vitreomacular traction syndrome. Additionally, structural alterations of the various layers of the neurosensory retina as a result of traction due to these pathologies can be demarcated. The latter have been investigated in clinical trials and evaluated as OCT biomarkers with respect to their prognostic and predictive value. In this review we would like to present and discuss various OCT biomarkers in the context of epimacular membranes and vitreomacular traction syndrome.

Purpose: To report a case of branch retinal artery wall rupture and subsequent branch retinal artery occlusion occurring during a routine pars plana vitrectomy with epiretinal membrane and internal limiting membrane peeling., Methods: Case report. Multimodal imaging including fluorescein angiography, spectral domain optical coherence tomography (OCT), en face OCT, and OCT angiography were performed., Results: An 86-year-old woman presented with a symptomatic epiretinal membrane in the right eye. Pars plana vitrectomy with epiretinal membrane and internal limiting membrane peel was performed. During the peel, spontaneous preretinal and intraretinal hemorrhage emanating from an adjacent branch retinal artery developed. At postoperative Week 1, OCT showed retinal thinning and hyperreflectivity suggestive of vascular accident. At postoperative Year 1, OCT imaging revealed retinal atrophy while fluorescein angiography demonstrated the arterial occlusion, and OCT angiography illustrated reduction in retinal perfusion in the region of the branch retinal artery occlusion., Conclusion: The authors report an unusual case of retinal arterial wall rupture and hemorrhaging during routine pars plana vitrectomy with membrane peel resulting in a branch retinal artery occlusion and subsequent retinal atrophy. Surgeons must limit stress on the underlying retina during membrane peel to avoid this surgical complication.

Purpose: To investigate risk factors, imaging characteristics, and treatment responses of cystoid macular edema (CME) after rhegmatogenous retinal detachment (RRD) repair., Methods: Consecutive, retrospective case-control series of patients who underwent pars plana vitrectomy (PPV) and/or scleral buckling (SB) for RRD, with at least six months of follow-up. Clinical and surgical parameters of patients with and without CME (nCME), based on spectral-domain optical coherence tomography (OCT), were compared., Results: Of 99 eyes enrolled, 25 had CME while 74 had nCME. Patients with CME underwent greater numbers of surgeries (P < 0.0001). After adjusting for number of surgeries, macula-off RRD (P = 0.06), proliferative vitreoretinopathy (PVR) (P = 0.09), surgical approach (PPV and/or SB, P = 0.21), and tamponade type (P = 0.10) were not statistically significant, although they all achieved significance on univariate analysis (P = 0.001 or less). Intraoperative retinectomy (P = 0.009) and postoperative pseudophakia or aphakia (P = 0.008) were more frequent in the CME group, even after adjustment. Characteristics of cCME on OCT included diffuse distribution, confluent cysts, and absence of subretinal fluid or intraretinal hyperreflective foci. Macular thickness improved significantly with intravitreal triamcinolone (P = 0.016), but not with anti-vascular endothelial growth factor agents (P = 0.828) or dexamethasone implant (P = 0.125). After adjusting for number of surgeries and macular detachment, final visual acuities remained significantly lower in the CME vs nCME group (P = 0.012)., Conclusion: Risk factors of CME include complex retinal detachment repairs requiring multiple surgeries, and pseudophakic or aphakic lens status. Although this cCME was associated with poor therapeutic response, corticosteroids were the most effective studied treatments.

Purpose: To evaluate and compare the rate and characteristics of vitreoretinal disorders in fellow eyes of lamellar macular holes (LMH) versus epiretinal membrane foveoschisis (ERMF)., Methods: Included patients in this retrospective study were divided into two groups based on spectral-domain optical coherence tomography (SD-OCT) features of their primary eye: LMH (group A) and ERMF (group B)., Results: Ninety-four patients were enrolled: 59 (62.8%) in group A and 35 (37.2%) in group B. Fellow eyes in group A had a higher rate of retinal detachment (8/59 [13.6%] vs. 0/35 [0%], P = 0.024), and full-thickness macular hole (FTMH) (11/59 [18.6%] vs. 2/35 [5.7%], P = 0.079), compared with fellow eyes in group B. In group A, 4/59 patients (6.8%) showed a bilateral LMH while none from group B had a LMH in their fellow eye (0/35 [0%]), P = 0.293. Additionally, epiretinal proliferation was noted in 30/59 (50.8%) fellow eyes in group A versus 3/35 (8.6%) fellow eyes in group B, P < 0.001. Longitudinal data were available for 80/94 patients. Over a mean follow-up of 37.4 ± 29.9 months, 1/48 (2.1%) fellow eyes from group A developed a FTMH and 2/48 (4.2%) developed a LMH, while no FTMH or LMH occurred in fellow eyes of group B., Conclusions: Fellow eyes of LMH showed a high rate of macular and peripheral vitreoretinal disorders. In addition, epiretinal proliferation was detected in a higher number of fellow eyes of LMH versus ERMF. These findings suggest a bilateral process in eyes of patients with LMH.

Background: A consensus on an optical coherence tomography definition of lamellar macular hole (LMH) and similar conditions is needed., Methods: The panel reviewed relevant peer-reviewed literature to reach an accord on LMH definition and to differentiate LMH from other similar conditions., Results: The panel reached a consensus on the definition of three clinical entities: LMH, epiretinal membrane (ERM) foveoschisis and macular pseudohole (MPH). LMH definition is based on three mandatory criteria and three optional anatomical features. The three mandatory criteria are the presence of irregular foveal contour, the presence of a foveal cavity with undermined edges and the apparent loss of foveal tissue. Optional anatomical features include the presence of epiretinal proliferation, the presence of a central foveal bump and the disruption of the ellipsoid zone. ERM foveoschisis definition is based on two mandatory criteria: the presence of ERM and the presence of schisis at the level of Henle's fibre layer. Three optional anatomical features can also be present: the presence of microcystoid spaces in the inner nuclear layer (INL), an increase of retinal thickness and the presence of retinal wrinkling. MPH definition is based on three mandatory criteria and two optional anatomical features. Mandatory criteria include the presence of a foveal sparing ERM, the presence of a steepened foveal profile and an increased central retinal thickness. Optional anatomical features are the presence of microcystoid spaces in the INL and a normal retinal thickness., Conclusions: The use of the proposed definitions may provide uniform language for clinicians and future research., Competing Interests: Competing interests: JPH: consultant for Alcon (Fort Wort, TX, USA), Allergan (Dublin, Ireland); Novartis (Basel, Switzerland), Bausch & Lomb (St Louis, USA); RFS: Consultant for Topcon Medical Systems (Tokyo, Japan). DS: consultant: Alcon (Fort Wort, Texas, USA), Orbit Biomedical (Ambler, Pennsylvania, USA) Zeiss (Oberkochen, Germany) Research funding: Alcon (Fort Wort, Texas, USA), Bayer (Leverkusen, Germany). MSF: consultant for Novartis (Basel, Switzerland), Alcon (Fort Wort, Texas, USA), Bayer (Leverkusen, Germany), Allergan (Dublin, Ireland), Hoffman LaRoche (Basel, Switzerland), Zeiss (Oberkochen, Germany); JS: consultant for Hoffman LaRoche (Basel, Switzerland); Zeiss (Oberkochen, Germany), EgbaVision; AG: personal fees from Novartis (Basel, Switzerland), personal fees from Bayer Healthcare (Leverkusen, Germany), personal fees from Thrombogenics; GS: financial support—Heidelberg Engineering (Heidelberg, Germany), Zeiss Meditec, Optovue, Optos, Centervue, Nidek, Novartis, Bayer, Allergan, Alcon; JTT: Genetech (Roche)—grant support and consultant Opthea—Grant support; EHR Command Center, LLC—Equity ownership; SC: Genentech—consultant (DSMC) Lowy Medical Research Institute—DSMC, uncompensated consultant Alcon—Travel reimbursement, FB: consultant for Novartis (Basel, Switzerland), Bayer (Leverkusen, Germany); RT: personal fees—Novartis (Basel, Switzerland), Bayer (Leverkusen, Germany), Roche (Basel, Switzerland), Genentech (San Francisco, California, USA), Allergan (Dublin, Ireland), Zeiss (Oberkochen, Germany), Alcon (Fort Wort, Texas, USA)., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

In this paper, an overview of advanced robotic surgical systems in ophthalmology is provided. The systems are introduced as representative examples of the degree of human vs. robotic control during surgical procedures. The details are presented on each system and the latest advancements of each are described. Future potential applications for surgical robotics in ophthalmology are discussed in detail, with representative examples provided alongside recent progress.

The viscoelastic behavior of vitreous gel is due to the presence of biopolymers in its structure. Fluid properties of the vitreous is mainly the result of interactions between the characteristics of collagen type II and Hyaluronic Acid networks. Having a better understanding of the structure of each component and their changes during aging and various diseases such as diabetes can lead to better monitoring and treatment options. We study the effects of collagenase type II on 44 samples of porcine vitreous using an in situ rheological experiment in comparison with 18 eyes in a control group injected with Phosphate Buffered Saline Solution. We analyze the behavior of each component over time in both groups. We focus on the changes of viscosity and elasticity of the collagen network within the vitreous. The results of the analysis in this study show that the changes in the fluid properties of the vitreous after collagenase injection is driven by the structural alterations of the collagen network. Creep compliance values of the collagen network are significantly higher in the first group compared to the control group one hour and twenty-four hours after the injection. In contrast, creep compliance of the HA network shows no statistically significant change one hour after the injection in both groups. The results of the reported analysis of individual components in this study support the previous findings on the alterations within the vitreous structure in its entirety., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: To describe the presence of epiretinal proliferation in eyes with various retinal and vitreoretinal interface conditions., Methods: Consecutive patients seen at the Stein Eye Institute, by one retina specialist, from December 2018 to March 2019, and demonstrating epiretinal proliferation on optical coherence tomography (OCT) were enrolled in this cross-sectional study. Included patients were divided into two groups: vitreoretinal interface pathologies group or retinal diseases group. Presence of epiretinal proliferation and its localization within the 9 macular sectors, as defined by the Early Treatment Diabetic Retinopathy Study (ETDRS), were assessed on OCT., Results: 77 eyes from 69 patients demonstrated epiretinal proliferation on OCT. The most frequently involved ETDRS sector was the 1-mm central subfield, followed by inner temporal and inner nasal sectors. Localization of epiretinal proliferation correlated with the presence of any retinal abnormalities in the same quadrant (r = 0.962; P < 0.0001). 31 eyes (40.3%) demonstrated symptomatic vitreoretinal interface pathologies including lamellar macular hole, full-thickness macular hole, epiretinal membrane and history of macular peeling. 46 eyes (59.7%) manifested various retinal diseases, including age-related macular degeneration, diabetic retinopathy, refractory macular edema, vein occlusion and high myopia., Conclusions: Epiretinal proliferation was noted in several retinal conditions and not limited only to full-thickness and lamellar macular holes. Different mechanisms affecting retinal homeostasis might trigger Müller cells dysregulation, potentially leading to abnormal retinal remodeling., Competing Interests: Competing interestsJean-Pierre Hubschman: Alcon (C), Allergan (C), Bausch and Lomb (C), Novartis (C), Carl Zeiss Meditec (C); SriniVas R. Sadda: Amgen (C), Allergan (C), Carl Zeiss Meditec (F), CenterVue (C), Genentech (C), Heidelberg engineering (C,F), 4DMT (C), Novartis (C), Optos (C), Oxurion (C), Samsung Biopses (C). The following authors have no financial disclosures: Ismael Chehaibou; Moritz Pettenkofer; Andrea Govetto; Gilad Rabina., (© The Author(s) 2020.)

Purpose: To investigate whether age-related macular degeneration (AMD) has an influence on the prevalence and anatomical characteristics of lamellar macular holes (LMHs)., Methods: Clinical records and spectral-domain optical coherence tomography images of 756 eyes of 423 consecutive patients diagnosed with AMD were reviewed and analyzed. Spectral-domain optical coherence tomography was used to identify degenerative or tractional LMH subtypes and assess their morphology. The clinical and optical coherence tomography findings of AMD eyes with LMH were compared with those of a control group of eyes with LMH without AMD from a previously published report., Results: Lamellar macular holes were identified in 25 eyes of 23 patients (3.3%; 25 of 756). Seventeen of 25 eyes (68%) presented with degenerative LMH and underlying late neovascular AMD. Mean best-corrected visual acuity was worse in eyes with AMD and LMH eyes than in those with AMD and no LMH (20/230 vs. 20/98; P = 0.02). The mean outer diameter was greater in the group with degenerative LMH with concomitant AMD than in the control group of degenerative LMH without AMD (1,323.9 ± 999.1 µm vs. 905.9 ± 356.8 µm, respectively; P = 0.01)., Conclusion: The incidence of degenerative LMH increased in advanced forms of AMD, whereas the presence of tractional LMH subtype may be unrelated to AMD evolution.

Purpose: To evaluate the depth and pattern of retinal hemorrhage in acute central retinal vein occlusion (CRVO) and to correlate these with visual and anatomic outcomes., Methods: Retinal hemorrhages were evaluated with color fundus photography and fluorescein angiography at baseline and follow-up. Snellen visual acuity (VA), central foveal thickness (CFT), extent of retinal ischemia, and development of neovascularization were analyzed., Results: 108 eyes from 108 patients were evaluated. Mean age was 63.6 ± 16.1 years with a predilection for the right eye (73.1%). Average follow-up was 17.2 ± 19.2 months. Mean VA at baseline was 20/126 and 20/80 at final follow-up. Baseline (P = 0.005) and final VA (P = 0.02) in eyes with perivascular nerve fiber layer (NFL) hemorrhages were significantly worse than in eyes with deep hemorrhages alone. Baseline CFT was greater in the group with perivascular hemorrhages (826 ± 394 µm) compared to the group with deep hemorrhages alone (455 ± 273 µm, P < 0.001). The 10 disc areas of retinal ischemia was more common in patients with perivascular (80.0%) and peripapillary (31.3%) versus deep hemorrhages alone (16.1%, P < 0.001). Neovascularization of the iris was more common, although this differrence was not significant, in the groups with peripapillary (14.3%) and perivascular (2.0%) NFL versus deep hemorrhages alone (0.0%)., Conclusions: NFL retinal hemorrhages at baseline correlate with more severe forms of CRVO, with greater macular edema, poorer visual outcomes, and greater risk of ischemia and neovascularization. This may be related to the organization of the retinal capillary plexus. The depth and pattern of distribution of retinal hemorrhages in CRVO may provide an easily identifiable early biomarker of CRVO prognosis.

Purpose: To determine whether neurosensory retinal detachment complicating degenerative retinoschisis (RS) can be reliably detected with ultra-widefield fundus autofluorescence evaluation., Methods: Consecutive patients diagnosed with RS who had ultra-widefield fundus autofluorescence imaging were included in this retrospective case series. According to the fundus autofluorescence patterns, we divided the eyes into two groups: 1) eyes with RS and a hyperautofluorescent leading edge and 2) eyes with RS and without hyperautofluorescence. Peripheral spectral domain optical coherence tomography images at the level of RS were obtained., Results: Thirty-eight eyes that met eligibility criteria were identified. Review of ultra-widefield fundus autofluorescence demonstrated 21/39 (55%) eyes with distinctive hyperautofluorescence over the area of RS (Group A) and 17/38 (45%) eyes without any form of hyperautofluorescence (Group B). Spectral domain optical coherence tomography images confirmed the presence of full-thickness neurosensory retina separation from the underlying retinal pigment epithelium in the areas of hyperautofluorescence in 10/10 eyes (100%) from Group A. None (0/11; 0%) of the eyes from Group B showed full-thickness neurosensory retina separation on the spectral domain optical coherence tomography imaging of the retina-RS interface., Conclusion: Hyperautofluorescent findings suggest the presence of a neurosensory retinal detachment. Retinal detachment associated with RS can be reliably detected on ultra-widefield fundus autofluorescence and may be a useful diagnostic imaging modality.

Purpose: To determine the prevalence of a central hyperreflective line in eyes with full-thickness macular holes (FTMH) and lamellar macular holes (LMH) and to elucidate the pathoanatomic importance of this optical coherence tomography (OCT) sign., Methods: This retrospective analysis evaluated patients with FTMH and LMH at the Stein Eye Institute. Clinical data was collected and SD-OCT volume scans were analyzed for the presence of a central vertical hyperreflective line in 3 separate cohorts: patients with SD-OCT preceding FTMH development, patients with SD-OCT after pars plana vitrectomy (PPVT) treatment for FTMH, and patients with SD-OCT of LMH., Results: In total, 93 eyes with FTMH and 88 eyes with LMH were identified. Of the 93 FTMH eyes, SD-OCT volume scans were available before development of the FTMH in 12 eyes. Of these, 6 (50%) displayed a vertical hyperreflective line preceding the development of the FTMH. Fifty-one eyes underwent PPVT with resolution of the FTMH, and 26 displayed a hyperreflective line after resolution (51%). Of the 88 eyes with LMH, 22 displayed a hyperreflective line (25%). All hyperreflective lines were noted at the central fovea., Conclusions: SD-OCT illustrated the presence of a central vertical hyperreflective line preceding FTMH and after resolution of FTMH after PPVT in approximately one-half of cases, and concurrent with LMH in 25% of cases. This vertical hyperreflective line may represent an early SD-OCT marker for the development of FTMH, and may be a sign of central foveal dehiscence owing to disruption of the Muller cell cone.

Purpose: To evaluate the surgical technique for subretinal implantation of two sizes of PRIMA photovoltaic wireless microchip in two animal models, and refine these surgical procedures for human trials., Methods: Cats and Macaca fascicularis primates with healthy retina underwent vitrectomy surgery and were implanted with subretinal wireless photovoltaic microchip at the macula/central retina. The 1.5mm PRIMA chip was initially studied in feline eyes. PRIMA implant (2mm,1.5mm sizes) arrays were studied in primates. Feasibility of subretinal chip implantation was evaluated with a newly-developed surgical technique, with surgical complications and adverse events recorded., Results: The 1.5mm implant was placed in the central retina of 11 feline eyes, with implantation duration 43-106 days. The 1.5mm implant was correctly positioned into central macula of 11 primate eyes, with follow-up periods of minimum 6 weeks (n = 11), 2 years (n = 2), and one eye for 3 years. One primate eye underwent multi-chip 1.5mm implantation using two 1.5mm chips. The 2mm implant was delivered to 4 primate eyes. Optical coherence tomography confirmed correct surgical placement of photovoltaic arrays in the subretinal space in all 26 eyes. Intraoperative complications in primate eyes included retinal tear, macular hole, retinal detachment, and vitreous hemorrhage that resolved spontaneously. Postoperatively, there was no case of significant ocular inflammation in the 1.5mm implant group., Conclusions: We report subretinal implantation of 1.5mm and 2mm photovoltaic arrays in the central retina of feline and central macula of primate eyes with a low rate of device-related complications. The in vivo PRIMA implantation technique has been developed and refined for use for a 2mm PRIMA implant in ongoing human trials., Competing Interests: MMK Muqit, (Consultant for Pixium Vision); JP Hubschman, (Consultant for Pixium Vision); Serge Picaud (Consultant for Pixium Vision and Gensight Biologics; Financial interests in Pixium Vision, Gensight Biologics); DB McCreery, None; JC van Meurs, (Consultant for Pixium Vision); R Hornig, Pixium Vision (Employee for Pixium Vision); G Buc, Pixium Vision (Employee for Pixium Vision); M Deterre, Pixium Vision (Employee for Pixium Vision); C Nouvel-Jaillard, None; E Bouillet, Pixium Vision (Employee for Pixium Vision); C-M Fovet, None; P Hantraye, None; J Sahel, Pixium (Investor in Pixium Vision, Consultant for Pixium Vision); Y Le Mer, (Consultant for Pixium Vision). The SightAgain project was managed by Bpifrance and Pixium Vision. French state funds were managed by the Agence Nationale de la Recherche within the Investissements d'Avenir program. Any commercial affiliation for the authors does not alter our adherence to PLOS ONE policies on sharing data and materials.

Purpose: To determine clear-cut distinctions between tractional and exudative intraretinal cystoid spaces subtypes., Design: Retrospective, multicenter, observational case series., Methods: A cohort of patients diagnosed with intraretinal cystoid spaces and imaged with optical coherence tomography (OCT), fluorescein angiography (FA), blue fundus autofluorescence (BFAF), en face OCT, and OCT angiography (OCT-A) was included in the study. All images were qualitatively and quantitatively evaluated., Results: In this study were included 72 eyes of 69 patients. Exudative intraretinal cystoid spaces (36/72 eyes, 50%) displayed a "petaloid" morphology as seen with en face OCT, FA, and BFAF. Tractional intraretinal cystoid spaces (24/72 eyes, 33.3%), displayed a radial "spoke-wheel" en face OCT pattern. There was no leakage with FA and BFAF did not reveal specific patterns. Eyes with full-thickness macular hole (FTMH, 12/72 eyes, 16.7%) displayed a "sunflower" en face OCT appearance. FTMH showed OCT, OCT-A, and BFAF features of both exudative and tractional cystoid spaces, but without any FA leakage. Inner nuclear layer (INL) thickness was significantly lower in tractional cystoid spaces (P < .001). There were a greater number of INL cystoid spaces in both the exudative and FTMH subgroups (P = .001). The surface area of INL cystoid spaces was significantly lower in the tractional subgroup (P < .001). There was a significant reduction of the microvascular density in eyes with exudative vs tractional (P = .002) and FTMH (P < .001) subgroups., Conclusions: Exudative and tractional intraretinal cystoid spaces displayed characteristic multimodal imaging features and they may represent 2 different pathologic conditions with equally different clinical implications., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: To explore the role of foveal and parafoveal Müller cells in the morphology and pathophysiology of tractional macular disorders with a mathematical model of mechanical force transmission., Methods: In this retrospective observational study, spectral-domain optical coherence tomography images of tractional lamellar macular holes and patients with myopic foveoschisis were reviewed and analysed with a mathematical model of force transmission. Parafoveal z-shaped Müller cells were modelled as a structure composed of three rigid rods, named R1, R2 and R3. The angle formed between the rods was referred to as θ . R1, R2 and R3 lengths as well as the variation of the angle θ were measured and correlated with best corrected visual acuity (BCVA)., Results: In tractional lamellar macular holes, there was a significant reduction of the angle θ towards the foveal centre (p<0.001). By contrast, there were no significant differences in θ in myopic foveoschisis (p=0.570). R2 segments were more vertical in myopic foveoschisis. There was a significant association between lower θ angles at 200 µm temporal and nasal to the fovea and lower BCVA (p<0.001 and p=0.005, respectively). The stiffness of parafoveal Müller cells was predicted to be function of the angle θ , and it grew very rapidly as the θ decreased., Conclusion: Parafoveal Müller cells in the Henle fibre layer may guarantee structural stability of the parafovea by increasing retinal compliance and resistance to mechanical stress. Small values of the angle θ were related to worse BCVA possibly due to damage to Müller cell processes and photoreceptor's axons., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: Functional and anatomical outcomes of vitrectomy with membrane peeling were compared in tractional lamellar macular holes (LMH)/macular pseudoholes (MPH) versus degenerative LMH., Methods: This multicenter retrospective study enrolled patients with a minimum follow-up of 6 months. The association of spectral domain optical coherence tomography parameters with preoperative and postoperative best-corrected visual acuity was analyzed., Results: Seventy-seven (74.8%) tractional LMH/MPH and 26 (25.2%) degenerative LMH were included. Preoperative best-corrected visual acuity was better in tractional LMH/MPH (0.39 ± 0.2 logarithm of the minimal angle of resolution, 20/50 Snellen equivalent) than degenerative LMH (0.56 ± 0.2 logarithm of the minimal angle of resolution, 20/66 Snellen equivalent; P < 0.001). Premacular membranes were found in all tractional LMH/MPH, whereas LMH-associated epiretinal proliferation (LHEP) was present in all degenerative LMH. Primary anatomical success was achieved in 97/103 eyes (94.2%), with foveal restoration occurring earlier in degenerative LMH (1.6 ± 2.3 vs. 3.3 ± 3.6 months; P = 0.025). Best-corrected visual acuity improved in both tractional LMH/MPH and degenerative LMH (P < 0.001 and P = 0.012, respectively) but was better in tractional LMH/MPH (P = 0.001)., Conclusion: The presence of premacular membranes and absence of LMH-associated epiretinal proliferation in all tractional LMH/MPH further distinguishes this from degenerative LMH. Best-corrected visual acuity improved in both subgroups but more so in tractional LMH/MPH. Complete anatomical restoration of foveal microanatomy was rare in degenerative LMH, reflecting significant morphological and pathophysiological differences between the two lesions.

Purpose: To evaluate semiautomated surgical lens extraction procedures using the optical coherence tomography (OCT)-integrated Intraocular Robotic Interventional Surgical System., Setting: Stein Eye Institute and Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, USA., Design: Experimental study., Methods: Semiautomated lens extraction was performed on postmortem pig eyes using a robotic platform integrated with an OCT imaging system. Lens extraction was performed using a series of automated steps including robot-to-eye alignment, irrigation/aspiration (I/A) handpiece insertion, anatomic modeling, surgical path planning, and I/A handpiece navigation. Intraoperative surgical supervision and human intervention were enabled by real-time OCT image feedback to the surgeon via a graphical user interface. Manual preparation of the pig-eye models, including the corneal incision and capsulorhexis, was performed by a trained cataract surgeon before the semiautomated lens extraction procedures. A scoring system was used to assess surgical complications in a postoperative evaluation., Results: Complete lens extraction was achieved in 25 of 30 eyes. In the remaining 5 eyes, small lens pieces (≤1.0 mm 3 ) were detected near the lens equator, where transpupillary OCT could not image. No posterior capsule rupture or corneal leakage occurred. The mean surgical duration was 277 seconds ± 42 (SD). Based on a 3-point scale (0 = no damage), damage to the iris was 0.33 ± 0.20, damage to the cornea was 1.47 ± 0.20 (due to tissue dehydration), and stress at the incision was 0.97 ± 0.11., Conclusions: No posterior capsule rupture was reported. Complete lens removal was achieved in 25 trials without significant surgical complications. Refinements to the procedures are required before fully automated lens extraction can be realized., (Copyright © 2019 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.)

The purpose of this study is to quantify the impact of enzyme activity on the vitreous humor structure over time to understand the mechanical characteristics of the vitreous humor gel. Changes in the mechanical behavior of the vitreous occur due to many reasons including aging, which may lead to many vitreoretinal diseases. The degeneration process of the vitreous has been studied; however, in situ experimental procedures to validate the existing hypotheses are limited. We examined thirty-eight porcine eyes using in situ rheological creep tests to measure the mechanical properties of the vitreous humor of the eyes prior to, 1 h and 24 h after the intravitreal injection. Eyes in one group were injected with collagenase type II solution and eyes in the control group were injected with phosphate buffered saline solution (PBS) with calcium and magnesium chloride. Prior to the injection, viscosity and creep compliance intercept values between both groups were not statistically different. At 1 h and 24 h after the injection, vitreous properties in the eyes from the first group showed a statistically significant increase in the J intercept values (representing the inverse of elasticity) compared to the control group. In addition, 1 h and 24 h after the injection, vitreous viscosity was lower in the eyes from the first group than in the eyes from the control group. These findings are a foundation for future studies on the effectiveness of intravitreal drugs that modify the mechanical properties of the vitreous humor., (Copyright © 2019 by ASME.)

Purpose: We determine whether haptic feedback improves surgical performance and outcome during simulated a preretinal membrane peeling procedure., Methods: A haptic-enabled virtual reality preretinal membrane peeling simulator was developed using a surgical cockpit with two multifinger haptic devices. Six subjects (three trained retina surgeons and three nonsurgeons) performed the preretinal membrane peeling surgical procedure using two modes of operation: visual and haptic feedback, and visual feedback only., Results: Task completion time, tool tip path trajectory, tool-retina collision force, and retinal damage were all reduced with haptic feedback used and compared to modes where haptic feedback was disabled., Conclusions: Haptic feedback improves efficiency and safety during preretinal membrane peeling simulation., Translational Relevance: These findings highlight the potential benefit of haptic feedback for improving performance and safety of vitreoretinal surgery.