BACKGROUND: In severe Proliferative Diabetic Retinopathy (PDR), fibrovascular membrane (FVM) causes macular tractional retinal detachment (MTRD) which threatens vision and eventually leads to blindness. Here we present a case of separation between the inner and outer retina in tractional retinoschisis, induced during intraoperative FVM delamination.
METHODS: A 68-year-old woman presented with PDR in the right eye, characterized by a combined FVM and retinal detachment, for which a vitrectomy was performed. Multiple holes, large retinal detachment extending to all quadrants, and white-lined blood vessels with FVM were found during the procedure. When membrane delamination was performed, it strayed into the space between the inner and outer retinal layers without being noticed due to retinoschisis and multiple retinal holes. After removing the FVM and detaching the separated inner retina, fluid-gas and photocoagulation were performed. Retinal reattachment was successfully achieved after surgery, and the postoperative visual acuity was improved and maintained for 26 months postoperatively.
CONCLUSIONS: When tractional retinoschisis due to FVM is combined with retinal holes in tractional retinal detachment (TRD), care must be taken to prevent delamination from straying into retinoschisis during separation.

OBJECTIVE: To describe three anterior segment dysgenesis disorders with infantile corneal opacities, namely, congenital hereditary endothelial dystrophy (CHED), primary congenital glaucoma (PCG), and Peters anomaly (PA) in terms of clinical characteristics, histopathology, genetic association, and diagnostic imaging profiles using imaging modalities such as ultrasound biomicroscopy (UBM) and microscope-integrated intraoperative optical coherence tomography (i-OCT).
METHODS: Seventy-four eyes with 22 eyes of CHED, 28 eyes of PA, and 24 eyes of PCG were clinically evaluated and underwent imaging using UBM and i-OCT. Corneal buttons of 16 operated patients underwent histopathological analysis, while genetic analysis was done in 23 patients using whole-exome sequencing.
RESULTS: Corneal diameters (CD) and UBM parameters like anterior chamber depth (ACD), iris thickness (IT), and ciliary body (CB) thickness revealed a statistically significant difference between the three categories. In PA, 9 eyes had a third rare phenotype with only a posterior corneal defect with no iris adhesions. Genetic mutations were seen in all tested patients with CHED, in 83.3% of patients with PCG, and in 80% of patients with the third type of PA. i-OCT helped in the characterization of corneal opacity, identification of posterior corneal defects, iridocorneal adhesions, and contour of Descemet\'s membrane.
CONCLUSIONS: Overlapping phenotypes of the above disorders cause a diagnostic dilemma and parameters like CDs, UBM ACD, IT, and CB thickness help differentiate between them. i-OCT can help in classifying the diseases in a high resolution, non-contact manner, and can better delineate corneal characteristics. The rare third type of PA phenotype may have a genetic association.

This article reviews literature on the use of intraoperative optical coherence tomography (iOCT) in vitreoretinal surgery, describes the historical aspects of the development of this technology from portable devices to optical coherence tomographs integrated into the surgical microscope, considers the advantages, limitations and disadvantages of this technology, which are now becoming obvious due to the accumulated experience. The review also explores the prospects for the development of iOCT and possible ways to solve its problems. In addition, the review presents and systematizes clinical findings that can be revealed with iOCT in such diseases as rhegmatogenous retinal detachment, complications of proliferative diabetic retinopathy, macular pathology, etc.
Данный обзор литературы посвящен использованию интраоперационной оптической когерентной томографии (ИОКТ) в витреоретинальной хирургии. Рассмотрены исторические аспекты развития данной технологии — от портативных устройств до интегрированных в хирургический микроскоп оптических когерентных томографов. Внимание уделено не только преимуществам, рассмотрены также ограничения и ряд недостатков этой технологии, которые в настоящее время ввиду накопленного опыта становятся очевидными. В обзоре также рассмотрены перспективы развития ИОКТ и возможные пути решения проблем. Кроме того, приведены и систематизированы клинические находки, которые можно выявить при помощи ИОКТ при таких заболеваниях, как регматогенная отслойка сетчатки, осложнения пролиферативной диабетической ретинопатии, макулярная патология и др.

Gauging stromal dissection depth is crucial to successfully perform deep anterior lamellar keratoplasty (DALK) surgery. Intraoperative optical coherence tomography (iOCT) offers a promising tool to aid DALK surgery but visualization of surgical maneuvers is impaired due to artifacts from metallic instruments. We describe a novel surgical technique utilizing suture-assisted iOCT guidance that facilitates clear visualization of corneal dissection planes during DALK. A stromal dissection tunnel is performed with a Fogla probe and its depth is subsequently identified by threading a 1 cm segment of 8-0 nylon into the tunnel. In contrast to the Fogla probe, the 8-0 nylon is conspicuously highlighted on iOCT. If the tunnel is too superficial, a separate, deeper stromal tunnel can be created and visualized again with the 8-0 nylon suture and iOCT. This iterative process facilitates a deep stromal dissection, increasing the probability of successful big-bubble formation and Descemet baring DALK surgery. This technique was utilized for a successful big-bubble DALK in a patient with severe keratoconus.

OBJECTIVE: To measure the difference of intraoperative central macular thickness (CMT) before, during, and after membrane peeling and investigate the influence of intraoperative macular stretching on postoperative best corrected visual acuity (BCVA) outcome and postoperative CMT development.
METHODS: A total of 59 eyes of 59 patients who underwent vitreoretinal surgery for epiretinal membrane was analyzed. Videos with intraoperative optical coherence tomography (OCT) were recorded. Difference of intraoperative CMT before, during, and after peeling was measured. Pre- and postoperatively obtained BCVA and spectral-domain OCT images were analyzed.
RESULTS: Mean age of the patients was 70±8.13y (range 46-86y). Mean baseline BCVA was 0.49±0.27 logMAR (range 0.1-1.3). Three and six months postoperatively the mean BCVA was 0.36±0.25 (P=0.01 vs baseline) and 0.38±0.35 (P=0.08 vs baseline) logMAR respectively. Mean stretch of the macula during surgery was 29% from baseline (range 2%-159%). Intraoperative findings of macular stretching did not correlate with visual acuity outcome within 6mo after surgery (r=-0.06, P=0.72). However, extent of macular stretching during surgery significantly correlated with less reduction of CMT at the fovea centralis (r=-0.43, P<0.01) and 1 mm nasal and temporal from the fovea (r=-0.37, P=0.02 and r=-0.50, P<0.01 respectively) 3mo postoperatively.
CONCLUSIONS: The extent of retinal stretching during membrane peeling may predict the development of postoperative central retinal thickness, though there is no correlation with visual acuity development within the first 6mo postoperatively.

OBJECTIVE: We sought to verify the effect of intraoperative optical coherence tomography (iOCT) on vitrectomy for the treatment of proliferative diabetic retinopathy (PDR).
METHODS: Retrospective study.
METHODS: We reviewed 178 eyes with PDR treated with 25-gauge vitrectomy by a single surgeon between April 2013 and December 2017. In total, 98 eyes of 77 patients with PDR (mean age, 52.5 ± 11.7 years) treated with vitrectomy using iOCT (iOCT group) and 80 eyes of 60 patients with PDR (mean age, 53.1 ± 10.9 years) treated without iOCT (non-iOCT group) were included in the study. To determine the effects of combining vitrectomy with iOCT, a comparison was made of patients treated with this combination and patients treated with vitrectomy without iOCT. The effects of these treatments were assessed on the basis of intraoperative complications, reoperation ratios, postoperative complications, operation times, and postoperative visual acuity.
RESULTS: The operation time was significantly reduced for the iOCT group (72.9 ± 23.9 min) when compared with the non-iOCT group (91.3 ± 31.2 min) (P = .001). The incidences of intraoperative complications, reoperation, and postoperative complications did not differ significantly between the 2 groups (P = .542, 0.258, and 0.860 respectively). Six months after surgery, the postoperative visual acuity did not differ significantly between the 2 groups (P = .508). Multiple linear regression analysis revealed that the operation time was significantly correlated with iOCT (beta [standard partial regression coefficient] = - 0.28, P < .001), the fibrovascular proliferative membrane (beta = 0.17, P = .009), cataract surgery (beta = 0.22, P = .016), preoperative retinal photocoagulation (beta = - 0.14, P = .021), intraoperative complications (beta = 0.16, P = .023), and posterior vitreous detachment (beta = - 0.14, P = .04).
CONCLUSIONS: Use of iOCT reduced the operation time without affecting the incidence rates of intraoperative and postoperative complications, reoperation ratios, or postoperative visual acuities in patients who underwent vitreous surgery for PDR.

OBJECTIVE: We investigated intraoperative OCT (iOCT)-guided epiretinal membrane (ERM) and internal limiting membrane (ILM) removal using a novel forceps with a laser-ablated tip surface; it was designed to help prevent indentation force, shear stress, or tractional trauma when grasping very fine membranes.
METHODS: This retrospective study included patients who underwent 23- and 25-gauge pars plana vitrectomy (PPV) for vitreoretinal interface disorders. ERM and ILM peeling was performed under guidance with microscope-integrated iOCT using novel ILM forceps with laser-ablated tip surfaces. These forceps were engineered to enhance friction when grasping tissue. Evaluation of ERM/ILM manipulation included postoperative slow-motion video analysis of the number of grasping attempts, initial ILM mobilization, and observed damage to retinal tissue.
RESULTS: ERM/ILM removal was successfully performed in all patients, with an average of four grasp actions to initial membrane mobilization (91%). Additional use of a diamond-dusted membrane scraper was used in two cases (9%). Mean best-recorded visual acuity (BRVA) logMAR improved from 0.5 ± 0.34 to 0.33 ± 0.36 (p = 0.05) and mean central retinal thickness (CRT) improved from 462 ± 146 µm to 359 ± 78 µm (p = 0.002). Postoperative iOCT video analysis demonstrated hyper-reflectivity of the inner retinal layers associated with retinal hemorrhage in five eyes (22%), but no grasping-related retinal breaks.
CONCLUSIONS: The texturized surface on the tips of the ILM forceps were found to be helpful for mobilizing ILM edges from the retinal surface. iOCT-guided ERM surgery also allowed for improved intraoperative tissue visualization. We believe that these two technologies helped reduce both unnecessary surgical maneuvers and retinal damage.

UNASSIGNED: To evaluate the feasibility and practicability of intraoperative optical coherence tomography (IOCT) in the surgery of idiopathic macular epiretinal membrane (IMM) without internal limiting membrane staining in all patients.
UNASSIGNED: Patients were selected from July 2018 to June 2020, and 32 patients (32 eyes) with IMM were operated with the use of IOCT. All patients underwent standard 23g vitrectomy. The internal limiting membrane was peeled off if there were obvious retinal folds. Intraoperative and postoperative complications, macular microstructural changes, and integrity of the detached membranes were recorded. The preoperative and postoperative best corrected visual acuity were compared.
UNASSIGNED: The macular epiretinal membrane was completely removed in 75% (24 eyes) patients without internal limiting membrane staining, and in 15.6% (5 eyes) patients with combined internal limiting membrane stripping. The \"starting point\" of macular epiretinal membrane stripping was found in 75% (24 eyes), and the time required to find the best starting point ranged from 28s to 140s (mean 66 ± 15s). At 3 months after operation, 96.8% of the patients had stable or improved BCVA (p < 0.05). The central macular thickness of the affected eyes decreased significantly at 1 and 3 months after operation (p < 0.05).
UNASSIGNED: IOCT can significantly reduce the use of internal limiting membrane staining in idiopathic macular epiretinal membrane surgery, and it is safe, feasible and practical in idiopathic macular epiretinal membrane surgery without internal limiting membrane staining in all patients.

UNASSIGNED: To report on the utility of intraoperative optical coherence tomography (iOCT) in the treatment of a traumatic iris cyst with aspiration and alcohol injection.
UNASSIGNED: A 61-year-old male, with a past ocular history of a left corneoscleral laceration in 1982, presented with gradual onset of blurring of vision in 2021. Examination revealed a large iris stromal cyst. He subsequently underwent iOCT guided iris stromal cyst aspiration and absolute alcohol injection.
UNASSIGNED: Our case demonstrated the efficacy of iOCT to aid in direct visualization and safe guidance of the alcohol into the iris cyst, reducing the risk of collateral damage.

UNASSIGNED: To present a novel microscope-integrated optical coherence tomography (iOCT)-guided surgical technique wherein Descemet\'s membrane detachment (DMD), occurring during vitrectomy, was treated intraoperatively in a patient who had previously undergone Descemet\'s stripping automated endothelial keratoplasty (DSAEK).
UNASSIGNED: The surgical technique was performed on a 75-year-old man with a history of DSAEK to intraoperatively treat DMD, which occurred during vitrectomy in the left eye. A fine needle mounted on a syringe was inserted into the supra-Descemet\'s space under iOCT guidance. The location of the needle was easily identified by its high reflection. The interface fluid was safely aspirated under excellent visualization of the needle tip and the interface. Successful aspiration of the interface fluid was confirmed via iOCT imaging at the end of the surgery. The graft has remained well attached to the cornea throughout the one-year postoperative follow-up.
UNASSIGNED: iOCT-guided surgical interventions provide a safe and accurate approach for treating intraoperative complications in eyes with a history of DSAEK.