The impact of short-term postoperative face-up position on unintentional retinal displacement after pars plana vitrectomy for rhegmatogenous retinal detachment.

OBJECTIVE: To assess the effectiveness and safety of a rigorous short-term supine position in preventing inadvertent retinal displacement after pars plana vitrectomy (PPV) with gas tamponade for rhegmatogenous retinal detachment (RRD). METHODS: We conducted a retrospective observational analysis of a case series at two ophthalmological surgical centers. We included eyes diagnosed with macula-off RRD that maintained a strict face-up position for three hours immediately after PPV with intraoperative perfluorocarbon liquid (PFCL) and 20% sulfur hexafluoride (SF6) tamponade. Fundus autofluorescence (FAF) imaging was performed at one month post-operatively to identify unintentional retinal displacement through the detection of retinal vessel prints (RVPs) on FAF imaging using an ultrawide-field (UWF) imaging system. RESULTS: A total of 29 eyes with macula-off RRD were included in the study. The average age of the participants was 59.62 years. RRD involved one quadrant in two eyes, two quadrants in fourteen eyes, three quadrants in seven eyes, and four quadrants in six eyes. UWF-FAF imaging at one month follow-up after complete reattachment of the retina revealed RVPs in seven out of the 29 eyes (24.13%), with a mean displacement of 0.22 mm. In every case the displacement occurred downward. CONCLUSION: Our results suggest that adhering to a strict face-up position for three hours after PPV with PFCL and gas tamponade for macula-off RRD may lead to a low frequency and severity of inadvertent post-operative retinal displacement.

Clinical and Genetic Characterization of RDH12-Retinal Dystrophy in a South American Cohort.

PURPOSE: To characterize the largest cohort of individuals with retinol dehydrogenase 12 (RDH12)-retinal dystrophy to date, and the first one from South America. DESIGN: Retrospective multicenter international study. SUBJECTS: Seventy-eight patients (66 families) with an inherited retinal dystrophy and biallelic variants in RDH12. METHODS: Review of clinical notes, ophthalmic images, and molecular diagnosis. MAIN OUTCOME MEASURES: Visual function, retinal imaging, and characteristics were evaluated and correlated. RESULTS: Thirty-seven individuals self-identified as Latino (51%) and 34 as White (47%). Sixty-nine individuals (88%) had Leber congenital amaurosis (LCA)/early-onset severe retinal dystrophy. Macular and midperipheral atrophy were seen in all patients from 3 years of age. A novel retinal finding was a hyperautofluorescent ring in 2 young children with LCA. Thirty-nine patients (50%) had subsequent visits, with mean follow-up of 6.8 ± 7.3 (range, 0-29) years. Eight variants (21%) were previously unreported, and the most frequent variant was c.295C>A, p.Leu99Ile, present in 52 alleles of 32 probands. Individuals with LCA homozygous for p.Leu99Ile (31%) had a later age of onset, a slower rate of best-corrected visual acuity decrease, the largest percentage of patients with mild visual impairment, and were predicted to reach legal blindness at an older age than the rest of the cohort. CONCLUSIONS: By describing the largest molecularly confirmed cohort to date, improved understanding of disease progression was possible. Our detailed characterization aims to support research and the development of novel therapies that may have the potential to reduce or prevent vision loss in individuals with RDH12-associated retinal dystrophy. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures.

Pegcetacoplan for the treatment of geographic atrophy secondary to age-related macular degeneration (OAKS and DERBY): two multicentre, randomised, double-masked, sham-controlled, phase 3 trials.

BACKGROUND: Geographic atrophy is a leading cause of progressive, irreversible vision loss. The objectives of OAKS and DERBY were to assess the efficacy and safety of pegcetacoplan compared with sham treatment in patients with geographic atrophy. METHODS: OAKS and DERBY were two 24-month, multicentre, randomised, double-masked, sham-controlled, phase 3 studies, in which patients aged 60 years and older with geographic atrophy secondary to age-related macular degeneration were enrolled at 110 clinical sites and 122 clinical sites worldwide, respectively. Patients were randomly assigned (2:2:1:1) by central web-based randomisation system to intravitreal 15 mg per 0·1 mL pegcetacoplan monthly or every other month, or sham monthly or every other month using stratified permuted block randomisation (stratified by geographic atrophy lesion area at screening, history or presence of active choroidal neovascularisation in the eye not under assessment, and block size of six). Study site staff, patients, reading centre personnel, evaluating physicians, and the funder were masked to group assignment. Sham groups were pooled for the analyses. The primary endpoint was the change from baseline to month 12 in the total area of geographic atrophy lesions in the study eye based on fundus autofluorescence imaging, in the modified intention-to-treat population (ie, all patients who received one or more injections of pegcetacoplan or sham and had a baseline and at least one post-baseline value of lesion area). Key secondary endpoints (measured at 24 months) were change in monocular maximum reading speed of the study eye, change from baseline in mean functional reading independence index score, change from baseline in normal luminance best-corrected visual acuity score, and change from baseline in the mean threshold sensitivity of all points in the study eye by mesopic microperimetry (OAKS only). Safety analyses included patients who were randomly assigned and received at least one injection of pegcetacoplan or sham. The now completed studies are registered with ClinicalTrials.gov, NCT03525613 (OAKS) and NCT03525600 (DERBY). FINDINGS: Between Aug 30, 2018, and July 3, 2020, 1258 patients were enrolled in OAKS and DERBY. The modified intention-to-treat populations comprised 614 (96%) of 637 patients in OAKS (202 receiving pegcetacoplan monthly, 205 pegcetacoplan every other month, and 207 sham) and 597 (96%) of 621 patients in DERBY (201 receiving pegcetacoplan monthly, 201 pegcetacoplan every other month, and 195 sham). In OAKS, pegcetacoplan monthly and pegcetacoplan every other month significantly slowed geographic atrophy lesion growth by 21% (absolute difference in least-squares mean -0·41 mm2, 95% CI -0·64 to -0·18; p=0·0004) and 16% (-0·32 mm2, -0·54 to -0·09; p=0·0055), respectively, compared with sham at 12 months. In DERBY, pegcetacoplan monthly and pegcetacoplan every other month slowed geographic atrophy lesion growth, although it did not reach significance, by 12% (-0·23 mm2, -0·47 to 0·01; p=0·062) and 11% (-0·21 mm2, -0·44 to 0·03; p=0·085), respectively, compared with sham at 12 months. At 24 months, pegcetacoplan monthly and pegcetacoplan every other month slowed geographic atrophy lesion growth by 22% (-0·90 mm2, -1·30 to -0·50; p<0·0001) and 18% (-0·74 mm2, -1·13 to -0·36; p=0·0002) in OAKS, and by 19% (-0·75 mm2, -1·15 to -0·34; p=0·0004) and 16% (-0·63 mm2, -1·05 to -0·22; p=0·0030) in DERBY, respectively, compared with sham. There were no differences in key secondary visual function endpoints at 24 months. Serious ocular treatment-emergent adverse events were reported in five (2%) of 213, four (2%) of 212, and one (<1%) of 211 patients in OAKS, and in four (2%) of 206, two (1%) of 208, and two (1%) of 206 patients in DERBY receiving pegcetacoplan monthly, pegcetacoplan every other month, and sham, respectively, at 24 months. New-onset exudative age-related macular degeneration was reported in 24 (11%), 16 (8%), and four (2%) patients in OAKS, and in 27 (13%), 12 (6%), and nine (4%) patients in DERBY receiving pegcetacoplan monthly, pegcetacoplan every other month, and sham, respectively, at 24 months. INTERPRETATION: Pegcetacoplan, the first treatment approved by the US Food and Drug Administration for geographic atrophy, slowed geographic atrophy lesion growth with an acceptable safety profile. FUNDING: Apellis Pharmaceuticals.

Nationwide genetic analysis of more than 600 families with inherited eye diseases in Argentina.

This study corresponds to the first large-scale genetic analysis of inherited eye diseases (IED) in Argentina and describes the comprehensive genetic profile of a large cohort of patients. Medical records of 22 ophthalmology and genetics services throughout 13 Argentinian provinces were analyzed retrospectively. Patients with a clinical diagnosis of an ophthalmic genetic disease and a history of genetic testing were included. Medical, ophthalmological and family history was collected. A total of 773 patients from 637 families were included, with 98% having inherited retinal disease. The most common phenotype was retinitis pigmentosa (RP, 62%). Causative variants were detected in 379 (59%) patients. USH2A, RPGR, and ABCA4 were the most common disease-associated genes. USH2A was the most frequent gene associated with RP, RDH12 early-onset severe retinal dystrophy, ABCA4 Stargardt disease, PROM1 cone-rod dystrophy, and BEST1 macular dystrophy. The most frequent variants were RPGR c.1345 C > T, p.(Arg449*) and USH2A c.15089 C > A, p.(Ser5030*). The study revealed 156/448 (35%) previously unreported pathogenic/likely pathogenic variants and 8 possible founder mutations. We present the genetic landscape of IED in Argentina and the largest cohort in South America. This data will serve as a reference for future genetic studies, aid diagnosis, inform counseling, and assist in addressing the largely unmet need for clinical trials to be conducted in the region.

Extensive internal limiting membrane peeling for proliferative vitreoretinopathy.

PURPOSE: The aim of this study was to describe the anatomical outcomes of Brilliant Blue G (BBG)-assisted extensive internal limiting membrane peeling for proliferative vitreoretinopathy (PVR) under three-dimensional (3D) visualization. METHODS: This study constitutes a retrospective case series conducted in a private retina practice, of 14 consecutive patients (14 eyes) with rhegmatogenous retinal detachment complicated by PVR who underwent pars plana vitrectomy between January 2019 and January 2020. The internal limiting membrane (ILM) was selectively stained with BBG, and perspectives were enhanced with a 3D visualization system. We peeled off the ILM beyond the vascular arcades up to the periphery. The main outcome was anatomical success, defined as persistent retinal reattachment after removal of the silicone oil tamponade. RESULTS: Anatomic success was achieved with a single surgery in 11 of 14 (78.6%) eyes, and eventual success was achieved in all eyes. The mean patient follow-up time was 12.3 months (range, 7-16 months). The mean preoperative best-corrected visual acuity (BCVA) was 2.93 ± 0.79 logMAR which improved to 1.75 + 0.91 at the last follow-up. CONCLUSION: Extensive ILM peeling allowed the creation of a cleavage plane underlying the PVR membranes that facilitated its complete removal, thereby achieving anatomically reattached retina and reducing the risk of recurrence of retinal detachment. The long-term effects of this technique need further research.

Ophthalmic artery angioplasty for age-related macular degeneration.

BACKGROUND: There is considerable overlap of contributors to cardiovascular disease and the development of age-related macular degeneration (AMD). Compromised ocular microcirculation due to aging and vascular disease contribute to retinal dysfunction and vision loss. Decreased choroidal perfusion is evident in eyes with dry AMD and is thought to play a role in retinal pigment epithelial dysfunction, the rate of development of geographic atrophy, and the development of neovascularization. The aim of the study was to demonstrate that AMD is correlated with a compromised blood flow in the ocular pathway and show OA angioplasty as a potential treatment of late-stage AMD. METHODS: Based on the potential for the ophthalmic artery (OA) to be an anatomical target for the treatment of AMD as outlined above, five patients were found to be eligible for compassionate use treatment, presenting clinically significant late-stage AMD with profound vision loss in one or both eyes, and are included in this retrospective study. RESULTS: OA narrowing, or significant calcium burden at the ophthalmic segment of the internal carotid artery compromising the origin of the OA was confirmed in all cases. Subsequent OA cannulation was achieved in all patients with some difficulty. Subjective patient reports indicated that all patients perceived a benefit following the procedure; however, improved postoperative visual acuity did not confirm that perceived benefit for one of the patients. CONCLUSIONS: Feasibility and safety of the OA angioplasty were demonstrated, and a benefit perceived in five patients with profound vision loss and a desire to achieve improved quality of life. A clinical trial with controlled schedule, imaging, and methodologies is needed to confirm these results.

Evaluation of non-exudative microcystoid macular abnormalities secondary to retinal vein occlusion.

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.

Near-Infrared Reflectance Imaging to Detect an Incipient Retinal Arterial Macroaneurysm.

Retinal arterial macroaneurysms (RAM) are characterized by a saccular or fusiform dilation of the retinal artery wall. An 84-year-old Caucasian woman with a medical history of poorly controlled hypertension was diagnosed with RAM in the left eye. Previous macular spectral-domain optical coherence tomography images from the patient were available for comparison. Near-infrared reflectance imaging (NIR-R), taken 3 years before, demonstrated a cuff-type thickening of the arteriolar vessel wall at the site of the current complicated RAM that had gone completely unnoticed. These findings suggest that NIR-R may contribute to the detection of early damage of the arterial wall that may predict arterial aneurysm formation in hypertensive patients.

EFFECT OF LASER PHOTOCOAGULATION ON MACULAR EDEMA ASSOCIATED WITH MACULAR HOLES.

PURPOSE: To report the outcomes of laser therapy to barricade eccentric full-thickness macular hole with associated cystoid macular edema. METHODS: We report two patients who developed an eccentric full-thickness macular hole with persistent cystoid macular edema after pars plan vitrectomy with and without internal limiting membrane peel for epiretinal membrane and the results of argon laser therapy. RESULTS: Barricade argon laser therapy was applied concentric to the full-thickness macular hole. Associated cystoid macular edema was noted to resolve within 1 to 3 months of therapy in both cases. CONCLUSION: Barricade laser therapy surrounding a macular hole can lead to resolution of associated cystoid macular edema. Pathogenic mechanisms to explain this favorable outcome are discussed.

Comparison of vitreoretinal disorders in fellow eyes of lamellar macular holes versus epiretinal membrane foveoschisis.

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.

LAMELLAR MACULAR HOLES IN THE PRESENCE OF AGE-RELATED MACULAR DEGENERATION.

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.

DETECTION OF NEUROSENSORY RETINAL DETACHMENT COMPLICATING DEGENERATIVE RETINOSCHISIS BY ULTRA-WIDEFIELD FUNDUS AUTOFLUORESCENCE IMAGING.

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.

Retrospective comparative analysis of intraocular lens calculation formulas after hyperopic refractive surgery.

PURPOSE: To compare the intraocular lens calculation formulas and evaluate postoperative refractive results of patients with previous hyperopic corneal refractive surgery. DESIGN: Retrospective, comparative, observational study. SETTING: Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA. METHODS: Clinical charts and optical biometric data of 39 eyes from 24 consecutive patients diagnosed with previous hyperopic laser vision correction and cataract surgery were reviewed and analyzed. The Intraocular lens (IOL) power calculation using the Holladay 2 formula (Lenstar) and the American Society of Cataract and Refractive Surgery (ASCRS) Post-Refractive IOL Calculator (version 4.9, 2017) were compared to the actual manifest refractive spherical equivalent (MRSE) following cataract surgery. No pre-Lasik / PRK or post-Lasik / PRK information was used in any of the calculations. The IOL prediction error, the mean IOL prediction error, the median absolute refractive prediction error, and the percentages of eyes within ±0.50 diopter (D) and ±1.00 D of the predicted refraction were calculated. RESULTS: The Holladay 2 formula produced a mean arithmetic IOL prediction error significantly different from zero (P = 0.003). Surprisingly, the mean arithmetic IOL prediction errors generated by Shammas, Haigis-L and Barret True K No History formulas were not significantly different from zero (P = 0.14, P = 0.49, P = 0.81, respectively).There were no significant differences in the median absolute refractive prediction error or percentage of eyes within ± 0.50 D or ± 1.00 D of the predicted refraction between formulas or methods. CONCLUSION: In eyes with previous hyperopic LASIK/PRK and no prior data, there were no significant differences in the accuracy of IOL power calculation between the Holladay 2 formula and the ASCRS Post-refractive IOL calculator.

Semiautomated optical coherence tomography-guided robotic surgery for porcine lens removal.

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 mm3) 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.

The Effect of Haptic Feedback on Efficiency and Safety During Preretinal Membrane Peeling Simulation.

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.

Effects of Collagenase Type II on Vitreous Humor-An In Situ Rheological Study.

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.

Bilateral Acquired Progressive Retinal Nerve Fiber Layer Myelination.

The authors present the multimodal imaging findings of an unusual case of bilateral acquired progressive myelination of the optic disc during a 10-year follow-up period in a hyperopic adolescent patient in the absence of an underlying ocular or systemic abnormality. Myelination of the left optic disc was noted at age 7 and of the right optic disc at age 13, but no other ocular or systemic abnormalities were identified. Cross-sectional optical coherence tomography (OCT) and en face OCT angiography confirmed the presence of myelination of the retinal nerve fiber layer and excluded other etiologic possibilities including an astrocytic hamartoma. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:e147-e150.].

Intraocular robotic interventional surgical system (IRISS): Semi-automated OCT-guided cataract removal.

BACKGROUND: With the development of laser-assisted platforms, the outcomes of cataract surgery have been improved by automating several procedures. The cataract-extraction step continues to be manually performed, but due to deficiencies in sensing capabilities, surgical complications such as posterior capsule rupture and incomplete cataract removal remain. METHODS: An optical coherence tomography (OCT) system is integrated into our intraocular robotic interventional surgical system (IRISS) robot. The OCT images are used for preoperative planning and intraoperative intervention in a series of automated procedures. Real-time intervention allows surgeons to evaluate the progress and override the operation. RESULTS: The developed system was validated by performing lens extraction on 30 postmortem pig eyes. Complete lens extraction was achieved on 25 eyes, and "almost complete" extraction was achieved on the remainder due to an inability to image small lens particles behind the iris. No capsule rupture was found. CONCLUSION: The IRISS successfully demonstrated semiautomated OCT-guided lens removal with real-time supervision and intervention.