RESTORATION PROCESS OF THE OUTER RETINAL LAYERS AFTER SURGICAL MACULAR HOLE CLOSURE.

PURPOSE: To investigate the interrelationship among the outer retinal layers after macular hole surgery and elucidate the restoration process. METHODS: This retrospective observational study included 50 eyes of 47 consecutive patients with closed macular holes in the first vitrectomy. Optical coherence tomography was obtained before surgery; at 1, 3, and 6 months postsurgery; and at the last visit. The complete continuous layer rate and mean defect length were evaluated for the outer nuclear layer (ONL), external limiting membrane (ELM), and ellipsoid zone (EZ). RESULTS: At all postoperative visits, the complete continuous layer rate was in the descending order of ELM, ONL, and EZ and the mean defect length was in the ascending order of ELM, ONL, and EZ. External limiting membrane was necessary for ONL restoration. External limiting membrane and ONL were necessary for EZ restoration. Hyperreflective protrusions were observed from the area lacking ELM into the subretinal space after surgery. Ellipsoid zone was not formed in coexistence with the hyperreflective protrusions. Intermediate reflective protrusions appeared under the ONL plus ELM after surgery and were eventually replaced by EZ. CONCLUSION: Restoration of the outer retinal layers after surgical macular hole closure occurs in the order of ELM, ONL, and EZ.

Application of direct stochastic optical reconstruction microscopy (dSTORM) to the histological analysis of human glomerular disease.

Electron microscopy (EM) following immunofluorescence (IF) imaging is a vital tool for the diagnosis of human glomerular diseases, but the implementation of EM is limited to specialised institutions and it is not available in many countries. Recent progress in fluorescence microscopy now enables conventional widefield fluorescence microscopes to be adapted at modest cost to provide resolution below 50 nm in biological specimens. We show that stochastically switched single-molecule localisation microscopy can be applied to clinical histological sections stained with standard IF techniques and that such super-resolved IF may provide an alternative means to resolve ultrastructure to aid the diagnosis of kidney disease where EM is not available. We have implemented the direct stochastic optical reconstruction microscopy technique with human kidney biopsy frozen sections stained with clinically approved immunofluorescent probes for the basal laminae and immunoglobulin G deposits. Using cases of membranous glomerulonephritis, thin basement membrane lesion, and lupus nephritis, we compare this approach to clinical EM images and demonstrate enhanced imaging compared to conventional IF microscopy. With minor modifications in established IF protocols of clinical frozen renal biopsies, we believe the cost-effective adaptation of conventional widefield microscopes can be widely implemented to provide super-resolved image information to aid diagnosis of human glomerular disease.

The internal limiting membrane: Roles in retinal development and implications for emerging ocular therapies.

Basement membranes help to establish, maintain, and separate their associated tissues. They also provide growth and signaling substrates for nearby resident cells. The internal limiting membrane (ILM) is the basement membrane at the ocular vitreoretinal interface. While the ILM is essential for normal retinal development, it is dispensable in adulthood. Moreover, the ILM may constitute a significant barrier to emerging ocular therapeutics, such as viral gene therapy or stem cell transplantation. Here we take a neurodevelopmental perspective in examining how retinal neurons, glia, and vasculature interact with individual extracellular matrix constituents at the ILM. In addition, we review evidence that the ILM may impede novel ocular therapies and discuss approaches for achieving retinal parenchymal targeting of gene vectors and cell transplants delivered into the vitreous cavity by manipulating interactions with the ILM.

Epiretinal Membrane Surgery Using Intraoperative OCT-Guided Membrane Removal in the DISCOVER Study versus Conventional Membrane Removal.

PURPOSE: To provide a comparative assessment of clinical outcomes between patients undergoing intraoperative OCT (iOCT) and conventional surgery for pars plana vitrectomy (PPV) with epiretinal membrane (ERM) peel. DESIGN: Case-control retrospective, comparative assessment. PARTICIPANTS: Patients undergoing PPV with membrane peel for ERM with eyes pooled from the prospective Determination of Feasibility of Intraoperative Spectral Domain Microscope Combined/Integrated OCT Visualization During En Face Retinal and Ophthalmic Surgery (DISCOVER) iOCT study and eyes undergoing conventional ERM surgery without iOCT. METHODS: Visual acuity and OCT assessment before ERM surgery and at 1-, 3-, 6-, and 12-month follow-up after standard small-gauge PPV with iOCT feedback (iOCT DISCOVER group) or PPV with compulsory internal limiting membrane (ILM) peeling (conventional group). Visual acuity, central subfield thickness (CST), reoperation rate, and ERM recurrence were determined by record review and post hoc assessment of clinical OCTs after ERM peel. MAIN OUTCOME MEASURES: Visual acuity and ERM recurrence. RESULTS: A total of 262 eyes were included. Visual acuity (VA) improved 11.9 letters in the iOCT group (P < 0.0001) and 12.1 letters in the conventional group (P < 0.0001) at 12 months after ERM surgery. Visual acuity improvement did not differ between the iOCT and conventional groups at 1, 3, 6, or 12 months after surgery (P > 0.05 for each time point). Preoperative mean CST decreased in the iOCT group (P < 0.0001) and conventional group (P < 0.0001) with no difference between groups in CST reduction at 12 months (P = 0.36). No reoperations or visually significant recurrent ERMs occurred in either cohort. CONCLUSIONS: Intraoperative OCT-guided ERM removal without mandated ILM peeling provided similar VA and anatomic results to conventional ILM peeling for ERM. Future randomized prospective studies are needed to assess fully the possible role of iOCT in ERM surgery and to evaluate the potential impact of nonfoveal ERM persistence or recurrence in comparison with conventional surgery.

Novel use of fluorescent microscopy in determining basement membrane integrity in ambiguous cases.

Indistinct basement membrane due to inflammation always poses a problem to the pathologists for commenting on micro-invasive squamous cell carcinoma. In such a situation, even a special stain would not be able to correctly demonstrate the basement membrane, which is necessary for estimating the depth of invasion. In this paper, we have proposed a novel fluorescent microscopy assisted visualization of basement membrane in such difficult situations. To further validate this approach, we then retrospectively investigated twenty such cases under a fluorescent microscope and could able to repeat the same result. As routine hematoxylin and eosin stained sections are required for evaluation, it is technically less demanding and less time-consuming.

Evaluation of inner retinal dimples and internal limiting membrane flap configuration after temporal inverted ILM flap technique.

PURPOSE: To quantitatively evaluate structural changes associated with inner retinal dimples (IRDs) and qualitatively classify the internal limiting membrane (ILM) flap configuration after temporal inverted ILM flap technique using spectral domain optical coherence tomography (SD-OCT). METHODS: Twenty-three eyes of 23 patients with successfully closed idiopathic, large (>400 µm) macular hole were enrolled. Patients were treated with pars plana vitrectomy followed by temporal inverted ILM flap technique. A complete ophthalmologic examination including cross sectional and en face OCT in addition to multicolor blue reflectance imaging of confocal scanning laser ophthalmoscopy (cSLO) was performed preoperatively and at postoperative month-12. The location, number, depth, and width of the IRDs were analyzed using blue reflectance images of multicolor cSLO and en face OCT. The ILM flap is also classified as smooth, wrinkled, and folded with en face OCT. RESULTS: The mean number of IRDs visualized on en face OCT (n = 23.08 ± 22.05) was statistically significantly higher compared with multicolor cSLO blue reflectance module (5.91 ± 10.58; p < 0.001). The mean depth of IRDs measured on en face OCT was 8.08 ± 3.1 µm (3-14 µm) which referred to the nerve fiber layer. The final visual acuity was associated with neither ILM flap configuration (p = 0.408), nor number of the IRDs on en face OCT (p = 0.112). CONCLUSION: En face OCT is a novel imaging modality that offers improved visualization and accuracy in identifying the features of the IRDs and the ILM flap. Additionally, it provides clear visualization of the vitreoretinal interface to distinguish whether ILM was peeled or not in the initial surgery.

Conventional internal limiting membrane peeling versus temporal inverted internal limiting membrane flap for large macular holes.

PURPOSE: To compare the functional, anatomical, and morphological results of conventional internal limiting membrane peeling versus temporal inverted internal limiting membrane flap technique for the treatment of macular holes larger than 400 µm. DESIGN: Retrospective, comparative case series. METHODS: A total of 33 patients were included, of whom 18 were treated with internal limiting membrane peeling (Group 1) and 15 were treated with temporal inverted internal limiting membrane flap technique (Group 2). Complete ophthalmic examination, such as microperimetry and optical coherence tomography, was performed preoperatively and at 12 months after surgery. RESULTS: The closure rates accomplished in Groups 1 and 2 were 72.2% and 100%, respectively (p = 0.036). The mean improvement in best-corrected visual acuity was logMAR 0.49 ± 0.17 in Group 1 and logMAR 0.91 ± 0.15 in Group 2 (p = 0.037). U-shaped closure was achieved in one eye in Group 1 and 12 eyes in Group 2 (p < 0.001). Complete restoration of external limiting membrane and ellipsoid zone rates were significantly higher in Group 2 (p = 0.027 and p = 0.001, respectively). CONCLUSION: The single-layered temporal inverted internal limiting membrane flap technique improves not only anatomical and morphological but also functional outcomes of surgery for large macular holes. Furthermore, this technique seems to minimize the risk of iatrogenic trauma to the nasal part of the fovea and the corresponding papillomacular bundle fibers.

Effect of Foveal Vitreous Cortex Removal to Prevent Epiretinal Membrane after Vitrectomy for Rhegmatogenous Retinal Detachment.

PURPOSE: To determine the effect of foveal vitreous cortex removal during pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD) on the prevention of postoperative epiretinal membrane (ERM) development without internal limiting membrane (ILM) peeling. DESIGN: Case-control study. PARTICIPANTS: A total of 105 consecutive eyes of 105 patients who underwent primary PPV for RRD between September 2018 and August 2019 and were followed for at least 6 months. METHODS: The presence of foveal vitreous cortex during PPV was determined by examining the images obtained by a widefield viewing system in 52 eyes (WF group) operated in the first half of the study period and obtained by a high-magnification floating lens in 53 eyes (FL group) operated in the latter half of the study period. Triamcinolone acetonide was used to make the vitreous cortex more visible during PPV. The foveal vitreous cortex was removed if detected by forceps with a high-magnification floating lens without ILM peeling or use of dye staining. The presence of postoperative ERM was examined by using OCT. MAIN OUTCOME MEASURES: The rate of detected and removed foveal vitreous cortex during PPV and the incidence of postoperative ERM of each group. RESULTS: The rate of detected and removed foveal vitreous cortex during PPV was significantly higher in the FL group than in the WF group (41.5% vs. 15.4%, P = 0.004). The incidence of postoperative ERM was significantly lower in the FL group than in the WF group (1.9% vs. 13.5%, P = 0.03). None of the eyes required additional surgery for the postoperative ERM during the follow-up period. The retinal reattachment rate was not significantly different (98.1% vs. 100%, P = 0.99), and the final retinal attachment rate was 100% in both groups. A dissociated optic nerve fiber layer appearance and a temporal macular thinning were not detected postoperatively in any of the eyes with removal of the foveal vitreous cortex during PPV. CONCLUSIONS: The detection and removal of foveal vitreous cortex with the high-magnification floating lens during PPV for RRD significantly reduce the incidence of postoperative ERM without adverse findings.

Optimizing Visualization of Membranes in Macular Surgery With Heads-Up Display.

BACKGROUND AND OBJECTIVE: To determine which optical parameter profiles (OPPs) can be utilized to improve the visualization of epiretinal membranes (ERMs) and the internal limiting membrane (ILM) using a three-dimensional heads-up microscope during 25-gauge pars plana vitrectomy. PATIENTS AND METHODS: Fourteen independent graders were asked to complete a questionnaire comparing each of the OPPs against the unaltered control image for each given surgical case. RESULTS: Analysis of the graders' responses indicated that higher values of hue are correlated with better visualization of ERM/ILM before and after dye application. There was overall agreement that OPPs could be used to enhance the visualization of the ERM and ILM during surgery. CONCLUSIONS: The use of OPPs to improve the visualization of specific structures is still new and heavily dependent on surgeon preference. The authors' study shows that some OPPs may enhance the visualization of the ERM and ILM during macular surgery. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:584-587.].

Spontaneous Resolution of Foveal Sub-internal Limiting Membrane Hemorrhage with Excellent Visual and Anatomical Outcome in a Patient with Acute Myeloid Leukemia.

Sub-internal limiting membrane (sub-ILM) hemorrhage is a distinct type of retinal hemorrhage in which the blood accumulates between ILM and nerve fiber layer. Little is known about visual prognosis as well as ideal management of foveal sub-ILM hemorrhage in patients with acute leukemia. Herein, we presented a case of acute myeloid leukemia with foveal sub-ILM hemorrhage. Observation alone resulted in complete resolution of hemorrhage with good visual and anatomical outcome.

Serum Biomarkers for Connective Tissue and Basement Membrane Remodeling are Associated with Vertebral Endplate Bone Marrow Lesions as Seen on MRI (Modic Changes).

Vertebral endplate bone marrow lesions, visualized on magnetic resonance imaging (MRI) as Modic changes (MC), are associated with chronic low back pain (cLBP). Since guidelines recommend against routine spinal MRI for cLBP in primary care, MC may be underdiagnosed. Serum biomarkers for MC would allow early diagnosis, inform clinical care decisions, and supplement treatment monitoring. We aimed to discover biomarkers in the blood serum that correlate with MC pathophysiological processes. For this single-site cross-sectional study, we recruited 54 subjects with 38 cLBP patients and 16 volunteers without a history of LBP. All subjects completed an Oswestry Disability Index (ODI) questionnaire and 10-cm Visual Analog Score (VAS) for LBP (VASback) and leg pain. Lumbar T1-weighted and fat-saturated T2-weighted MRI were acquired at 3T and used for MC classification in each endplate. Blood serum was collected on the day of MRI. Biomarkers related to disc resorption and bone marrow fibrosis were analyzed with enzyme-linked immune-absorbent assays. The concentration of biomarkers between no MC and any type of MC (AnyMC), MC1, and MC2 were compared. The Area Under the Curve (AUC) of the Receiver Operating Characteristics were calculated for each biomarker and for bivariable biomarker models. We found that biomarkers related to type III and type IV collagen degradation and formation tended to correlate with the presence of MC (p = 0.060-0.088). The bivariable model with the highest AUC was PRO-C3 + C4M and had a moderate diagnostic value for AnyMC in cLBP patients (AUC = 0.73, specificity = 78.9%, sensitivity = 73.7%). In conclusion, serum biomarkers related to the formation and degradation of type III and type IV collagen, which are key molecules in bone marrow fibrosis, correlated with MC presence. Bone marrow fibrosis may be an important pathophysiological process in MC that should be targeted in larger biomarker and treatment studies.

Sub-perfluoro-n-octane injection of ocular viscoelastic device assisted inverted internal limiting membrane flap for macular hole retinal detachment surgery: a novel technique.

BACKGROUND: To evaluate the feasibility of a surgical technique using a sub-perfluoro-n-octane (PFO) injection of ocular viscoelastic device (OVD) to stabilize inverted internal limiting membrane (ILM) flap for the treatment of macular hole retinal detachment (MHRD). METHODS: This study was a retrospective, consecutive, interventional case series. Patients who underwent MHRD surgery with sub-PFO injection of OVD to stabilize inverted ILM flap onto the macular hole (MH) were reviewed. The color fundus and optical coherence tomography (OCT) images were collected and evaluated. The best-corrected visual acuity (BCVA) before and after surgery were compared as the functional outcome. RESULTS: The study included 8 eyes of 8 consecutive patients (mean age: 61.8 ± 7.1 years; mean follow-up period: 9.0 ± 2.5 months). All eyes (100%) achieved successful MH closure; 7 eyes (87.5%) demonstrated complete retinal reattachment, and 1 eye (12.5%) had minimal residual subretinal fluid parafoveally. Of the 8 patients, 7 patients (87.5%) had achieved improvement in BCVA after the primary surgery, whereas 1 eye remained stable. The average BCVA before and after the surgery at the last visit improved from 20/843 (1.63 ± 0.48 logMAR) to 20/200 (1.00 ± 0.39 logMAR) (P = 0.016). Anatomically, near-normal foveal contour was noted in five (62.5%) eyes at the final follow-up. CONCLUSIONS: The use of sub-PFO injection of OVD in MHRD surgery could stabilize inverted ILM flaps, achieve good anatomical results and improve postoperative BCVA.

Tailored internal limiting membrane flap technique for primary macular hole.

PURPOSE: To investigate the outcomes of primary full-thickness macular hole (MH) after surgical intervention with tailored internal limiting membrane (ILM) flap technique. METHODS: Patients were reviewed for their clinical characteristics and surgical outcomes. The technique included incomplete circular peeling of the perifoveal ILM which was then trimmed according to the size of the MH. Fluid-gas exchange was done without further manipulation. RESULTS: Nineteen eyes of 19 patients were included. The patients were in average 61 years old (range 41-83) and had an average follow-up period of 11.0 months. At baseline visit, minimal linear diameter of the MH was 311.6 µm (range 80-768). After a single surgery, the MH closed in all cases with improvement of mean visual acuity (from 0.9 to 0.4 logarithm of the minimum angle of resolution units, p < 0.0001, Wilcoxon signed-rank test). At the final visit, 15 (78.9%) eyes achieved a visual acuity ≥ 20/40. Outer retinal gliosis was found to be associated with less favorable postoperative visual acuity. Factors related to the formation of outer retinal gliosis were worse preoperative visual acuity and a large MH with a diameter > 400 µm. CONCLUSION: Tailored ILM flap technique is an effective method for favorable anatomical and visual outcomes for treatment of primary MH.

Histopathological Changes and Clinical Outcomes following Intervention for Sub-Internal Limiting Membrane Haemorrhage.

INTRODUCTION: Haemorrhage confined to the sub-internal limiting membrane (ILM) space can be associated with good visual recovery. There is controversy as to the best management of purely sub-ILM haemorrhage, which ranges from observation to immediate surgical intervention. METHODS: We studied a retrospective case series of patients with sub-ILM haemorrhage who underwent vitrectomy with subsequent histological analysis of the removed ILM. RESULTS: Sixteen patients underwent vitrectomy for sub-ILM haemorrhage. Five patients had underlying Terson syndrome, 6 had ruptured macro-aneurysms, and 5 had Valsalva retinopathy. Seven patients demonstrated cellular proliferation on the retinal surface of the ILM with staining for glial fibrillary acidic protein and cytokeratin 7, as well as CD68pg and Prussian blue. All but 1 of these cases were isolated from patients undergoing surgery >4 weeks following initial symptoms, the other presented at >2 weeks. Serial optical coherence tomography (OCT) was available in 8 patients; serial OCT in patients with delayed intervention demonstrated persistent inner retinal layer hyper-reflectance. Fourteen of 15 patients demonstrated symptomatic recovery and showed visual improvement with acuity ranging from -0.1 to 1.8 (mean 0.43) within 3 months of intervention (1 was lost to follow-up). The post-operative vision was 0.11 logMAR (mean; range -0.1 to 0.4) at 3 months in the group with intervention within 2 weeks of symptoms, and 0.9 logMAR (mean; range 0.0 to HM) in the group with delayed surgery. CONCLUSIONS: Early surgical intervention for sub-ILM haemorrhage resulted in good visual outcomes; delayed surgery may lead to proliferative vitreoretinopathy-like changes on the inner retinal surface of the ILM, and untreated cases may demonstrate persistent inner retinal changes potentially limiting visual prognosis despite subsequent surgical intervention.

Fovea-sparing internal limiting membrane peeling versus complete internal limiting membrane peeling for myopic traction maculopathy.

PURPOSE: To compare the outcomes of vitrectomy with fovea-sparing internal limiting membrane peeling (FSIP) and complete internal limiting membrane peeling (ILMP) for myopic traction maculopathy (MTM). STUDY DESIGN: A retrospective, observational study. PATIENTS AND METHODS: In this study, we included 22 eyes of 21 consecutive patients who underwent vitrectomy with FSIP or ILMP for MTM and were monitored for at least 6 months. Eleven eyes were treated with FSIP, and 11, with ILMP. RESULTS: With FSIP, the postoperative best-corrected visual acuity (BCVA) significantly improved from 0.61 (20/82) to 0.34 (20/44; P = .009) logarithm of the minimum angle of resolution (logMAR) units. With ILMP, the postoperative BCVA improved from 0.65 (20/89) to 0.52 (20/66) logMAR units, but was not significant (P = .106). The postoperative final central foveal thickness (CFT) reduced significantly after FSIP (from 557.6 to 128.8 µm, P = .003) and ILMP (from 547.3 to 130.3 µm, P = .008). The postoperative incidence of a macular hole was 0% (0/11 eyes) with FSIP and 27.3% (3/11 eyes) with ILMP. All patients with a macular hole had foveal detachment in association with a thin fovea preoperatively. With ILMP, postoperative BCVA with a macular hole worsened by -3.5 letters; in contrast, postoperative BCVA without a macular hole improved by +10.5 letters. With FSIP, postoperative BCVA without a macular hole significantly improved by +13.5 letters (P = .009). CONCLUSIONS: FSIP resulted in significant improvement in MTM and prevented postoperative macular hole development.

A NOVEL FINDING OF HYPERREFLECTIVE MATERIAL IN THE SILICONE-RETINA INTERFACE: An Optical Coherence Tomographic and Histopathological Study.

PURPOSE: To describe novel findings of hyperreflective material in the silicone-retina interphase on spectral domain optical coherence tomography (SD-OCT) imaging in eyes with silicone oil tamponade. METHODS: Retrospective observational clinical study of consecutive patients who underwent primary pars plana vitrectomy with silicone oil tamponade for rhegmatogenous retinal detachment. Repeat clinical examination and spectral domain optical coherence tomography macular imaging performed 3 months after surgery were evaluated to identify any macular pathologies, including formation of epiretinal membranes, intraretinal changes, subretinal fluid, and edema before scheduled secondary vitrectomy for silicone oil removal. RESULTS: Eighty-two patients (mean age 54 years, range 22-89) were included. Twelve eyes (14%) showed discrete preretinal hyperreflective organized coarse material in the silicone-retina interphase on spectral domain optical coherence tomography. The material was scattered in the posterior pole, with several foci showing additional hyperreflectivity of the inner retinal layers beneath. These findings did not resemble silicone oil emulsification in size, shape, or reflectivity. CONCLUSION: This is the first report on hyperreflective material detected by spectral domain optical coherence tomography in the silicone-retina interphase in eyes with silicone oil tamponade. These findings may represent an inflammatory response to silicone oil exposure that may be the initial manifestation of a future proliferative process, warranting a rigorous follow-up protocol for affected patients.

RELATIONSHIP BETWEEN PREOPERATIVE FOVEAL MICROSTRUCTURE AND VISUAL ACUITY IN MACULA-OFF RHEGMATOGENOUS RETINAL DETACHMENT: Imaging Analysis by Swept Source Optical Coherence Tomography.

PURPOSE: To visualize foveal microstructures in macula-off rhegmatogenous retinal detachment using swept source optical coherence tomography preoperatively and postoperatively and to investigate the relationship between foveal microstructures and postoperative visual acuity. METHODS: We retrospectively analyzed 42 eyes of 42 consecutive patients diagnosed with macula-off rhegmatogenous retinal detachment who underwent anatomically successful repair surgery and were followed up for 6 months. We used swept source optical coherence tomography to investigate the relationship between preoperative and postoperative continuity of both the external limiting membrane (ELM) and ellipsoid zone (Ez) and preoperative and postoperative best-corrected visual acuity. RESULTS: Both preoperative ELM and Ez were continuous in 9 eyes (21%; ELM+/Ez+ eyes), only the ELM was continuous in 25 eyes (60%; ELM+/Ez- eyes), and neither was continuous in 8 eyes (19%; ELM-/Ez- eyes). Postoperative best-corrected visual acuity in ELM+/Ez+ eyes (-0.05 ± 0.04 logarithm of the minimum angle of resolution units, Snellen equivalent 20/18) was significantly better than that in both ELM+/Ez- (0.16 ± 0.16, 20/29; P = 0.03) and ELM-/Ez- (0.86 ± 0.37, 20/145; P < 0.001) eyes. Postoperative best-corrected visual acuity was significantly better in ELM+/Ez- than in ELM-/Ez- eyes (P < 0.001). CONCLUSION: In macula-off rhegmatogenous retinal detachment, preoperative continuity of the ELM and Ez may be a predictor of postoperative best-corrected visual acuity.

Comparison of Surgical Performance of Internal Limiting Membrane Peeling Using a 3-D Visualization System With Conventional Microscope.

BACKGROUND AND OBJECTIVE: To compare the surgical performance of internal limiting membrane (ILM) peeling in idiopathic macular hole using a digitally assisted vitreoretinal system (DAVS) and an analog microscope (AM). PATIENTS AND METHODS: Patients were operated on using an AM (Group A) and a DAVS (Group B). The data analyzed included surgical time required to complete ILM peeling, number of attempts to create ILM flap and complete ILM peeling, and intraoperative complications. RESULTS: Each group included 20 patients. The average surgical time for ILM peeling in groups A and B was 123.05 seconds ± 42.23 seconds and 142.35 seconds ± 31.49 seconds, respectively (P = .109). The mean number of surgical attempts to create the ILM flap was 1.05 ± 0.22 and 1.70 ± 1.22 respectively (P = .008). The mean number of surgical attempts to complete ILM peeling was 22.85 ± 9.95 and 27.20 ± 7.16, respectively (P = .121). Retinal touch occurred in one and three patients, respectively (P = .534). CONCLUSIONS: DAVS provides similar surgical performance to AM; however, the creation of ILM flap is difficult with DAVS compared to AM. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:941-945.].

Photothermal optical coherence tomography of indocyanine green in ex vivo eyes.

Indocyanine green (ICG) is routinely used during surgery to stain the inner limiting membrane (ILM) and provide contrast on white light surgical microscopy. While translation of optical coherence tomography (OCT) for intraoperative imaging during ophthalmic surgery has enhanced visualization, the ILM remains difficult to distinguish from underlying retinal structures and ICG does not provide additional OCT contrast. We present photothermal OCT (PT-OCT) for high-specificity detection of ICG on retinal OCT images. We demonstrate our technique by performing an ILM peel in ex vivo eyes using low ICG concentrations and laser powers. These results establish the feasibility of PT-OCT for intraoperative guidance during retinal surgery.

Endobronchial biopsy in the final diagnosis of chronic obstructive pulmonary disease and asthma: a clinicopathological study.

BACKGROUND: Asthma and chronic obstructive pulmonary disease (COPD) are chronic conditions with an increasing prevalence in developing countries. The evaluation of endobronchial biopsies has emerged as a tool to differentiate between both conditions via the measurement of the reticular basement membrane (RBM) thickness with various conclusions drawn from different studies. OBJECTIVES: Compare the thickness of the RBM between asthma and COPD and evaluate other histomorphological features in both groups. DESIGN: Prospective, descriptive and analytical. SETTING: University teaching hospital. PATIENTS AND METHODS: The study included patients with COPD and irreversible and reversible asthma with diagnosis based on clinical assessment, pulmonary function tests and high-resolution computed tomography scans. Endobronchial biopsies were obtained from all patients and, using a light microscope and a computerized image analyzer, the thickness of the reticular basement membrane was calculated in all patients. We also made a qualitative assessment of other histo-morphological features. MAIN OUTCOME MEASURES: Mean RBM thickness. SAMPLE SIZE: Thirty male patients. RESULTS: The mean RBM thickness in asthmatic patients was 8.9 (2.4) micro m. The mean RBM thickness in COPD patients was 5.3 (1.1) micro m. However, there was no thickening of the RBM in patients with reversible asthma. The RBM was significantly thicker in patients with irreversible asthma than in patients with COPD or reversible asthma. There were no significant differences in epithelial desquamation or metaplasia, mucosal or submucosal inflammation, the presence of eosinophils, submucosal glandular hyperplasia or submucosal smooth muscle hyperplasia between groups. CONCLUSIONS: The thickness of the RBM is the only reproducible histopathological feature to differentiate COPD from irreversible asthma. LIMITATIONS: The study included a limited number of patients. A qualitative approach was used to compare epithelial cell injury, inflammation, submucosal glandular and muscular hyperplasia. CONFLICT OF INTEREST: None.