Enhancing Readability and Detection of Age-Related Macular Degeneration Using Optical Coherence Tomography Imaging: An AI Approach.

Artificial intelligence has been used effectively in medical diagnosis. The objective of this project is to examine the application of a collective AI model using weighted fusion of predicted probabilities from different AI architectures to diagnose various retinal conditions based on optical coherence tomography (OCT). A publicly available Noor dataset, comprising 16,822, images from 554 retinal OCT scans of 441 patients, was used to predict a diverse spectrum of age-related macular degeneration (AMD) stages: normal, drusen, or choroidal neovascularization. These predictions were compared with predictions from ResNet, EfficientNet, and Attention models, respectively, using precision, recall, F1 score, and confusion matric and receiver operating characteristics curves. Our collective model demonstrated superior accuracy in classifying AMD compared to individual ResNet, EfficientNet, and Attention models, showcasing the effectiveness of using trainable weights in the ensemble fusion process, where these weights dynamically adapt during training rather than being fixed values. Specifically, our ensemble model achieved an accuracy of 91.88%, precision of 92.54%, recall of 92.01%, and F1 score of 92.03%, outperforming individual models. Our model also highlights the refinement process undertaken through a thorough examination of initially misclassified cases, leading to significant improvements in the model's accuracy rate to 97%. This study also underscores the potential of AI as a valuable tool in ophthalmology. The proposed ensemble model, combining different mechanisms highlights the benefits of model fusion for complex medical image analysis.

PERIPHERAL ISCHEMIC RETINAL PHOTOCOAGULATION IN ADDITION TO INTRAVITREAL BEVACIZUMAB VERSUS INTRAVITREAL BEVACIZUMAB ALONE FOR THE TREATMENT OF MACULAR EDEMA SECONDARY TO CENTRAL RETINAL VEIN OCCLUSION: A Randomized Double-Masked Controlled Clinical Trial.

PURPOSE: To investigate the effects of peripheral ischemic retinal photocoagulation in addition to intravitreal bevacizumab (IVB) in the treatment of macular edema due to ischemic central retinal vein occlusion. METHODS: Forty-eight eyes of 48 treatment-naive patients were randomly selected and divided into 2 groups. Group A comprised 24 eyes that were treated with three consecutive monthly injections of IVB, and Group B comprised 24 eyes that were treated with IVB plus photocoagulation of the peripheral nonperfused retina. Further IVB injections were administered as needed in both groups. Monthly follow-up was conducted for 9 months after the first injection. RESULTS: The data of 46 patients were analyzed. Best-corrected visual acuity changes from the fourth to eighth month follow-up in comparison with the baseline were significantly higher in Group B (P = 0.002-0.044-0.002-0.002-0.012). In addition, significant differences were observed in central macular thickness in Group B throughout the study period (all P < 0.001). Group B required less frequent IVB injections during the 9-month study period. CONCLUSION: Photocoagulation of the retinal nonperfused area in patients with macular edema because of central retinal vein occlusion might amplify the beneficial effects of IVB on best-corrected visual acuity and central macular thickness and reduce the frequency of IVB injection.

Repeated Injection of Methotrexate into Silicone Oil-Filled Eyes for Grade C Proliferative Vitreoretinopathy: A Pilot Study.

PURPOSE: To evaluate the effects of repeated intra-silicone oil (SO) injections of methotrexate (MTX) on the outcomes of surgery for rhegmatogenous retinal detachment (RRD) with grade C proliferative vitreoretinopathy (PVR-C). METHODS: In this prospective pilot case series, eyes with RRD and PVR-C underwent pars plana vitrectomy and intraocular injection of SO. At the conclusion of the procedure, 250 µg of MTX was injected into the SO-filled vitreous cavity. Intra-SO injection was repeated at weeks 3 and 6; the minimum follow-up period was 6 months. The main outcome measure was retinal reattachment rate. RESULTS: Eleven eyes of 11 patients (mean age, 52.73 ± 18.01 years) were included. The mean follow-up period was 9 ± 3 months (range, 6-15 months). Total retinal detachment with anterior and/or posterior PVR-C was present in all eyes before surgery. Mean preoperative best-corrected visual acuity (BCVA) was 2.62 ± 0.04 logMAR. All operated eyes exhibited retinal reattachment posterior to the equator during the follow-up period. Mean postoperative BCVA was significantly improved to 1.02 ± 0.51 logMAR (p = 0.003). No ocular or systemic side effects were observed. CONCLUSION: Repeated intra-SO injection of MTX as an adjunctive therapy for RRD complicated by PVR showed promising results and was not associated with adverse effects. Further studies are needed to confirm its possible beneficial effects on the final anatomic and functional outcomes in these cases.

The effects of electromagnetic fields on cultured human retinal pigment epithelial cells.

A great deal of evidence has confirmed that electromagnetic fields (EMFs) can affect the central nervous system. In this study, cultured neonatal human retinal pigment epithelial (hRPE) cells were exposed to pulsed EMF of 1 mT intensity and 50 Hz frequency 8 h daily for 3 days. In addition to cell proliferation and cell death assays, immunocytochemistry for RPE65, PAX6, nestin, and cytokeratin 8/18 proteins were performed. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) was performed for NES, PAX6, RPE65, and ACTA2 gene expression. Exposed hRPE cells did not demonstrate significant change in terms of cytomorphology, cell proliferation, or cell death. Protein expression of PAX6 was decreased in treated cells compared to controls and remained unchanged for RPE65, cytokeratin 8/18, and nestin. Gene expressions of NES, RPE65, and PAX6 were decreased in treated cells as compared to controls. Gene expression of ACTA2 did not significantly change. In conclusion, viability of cultivated neonatal hRPE cells did not change after short exposure to a safe dose of pulsed EMF albeit that both gene and protein expressions of retinal progenitor cell markers were reduced. Whether longer exposure durations that are being constantly produced by widely-used electronic devices may induce significant changes in these cells, needs further investigation. Bioelectromagnetics. 39:585-594, 2018. © 2018 Wiley Periodicals, Inc.

The effects of platelet gel on cultured human retinal pigment epithelial (hRPE) cells.

The positive role of platelet gel (PG) in tissue regeneration is well known, however, other characteristics of PG still remain to be determined. We investigated cellular and molecular changes in cultured human retinal pigment epithelial (hRPE) cells when treated with different concentrations of PG named PG1, PG2, and PG3. hRPE cells were isolated from donor eyes of two newborn children, within 24 hours after their death. The cells were treated with three concentrations of PG for 7 days: 3 × 104/ml (PG1), 6 × 104/ml (PG2), and 9 × 104/ml (PG3). Fetal bovine serum was used as a control. Immunocytochemistry was performed with anti-RPE65 (H-85), anti-Cytokeratin 8/18 (NCL-5D3), and anti-PAX6 antibody. We used MTT assay to determine cell viability. Gene expressions of PAX6, MMP2, RPE65, ACTA2, MKI67, MMP9, and KDR were analyzed using real-time PCR. A significant increase in viability was observed for PG3-treated cells compared to control (p = 0.044) and compared to PG1 group (p = 0.027), on day 7. Cellular elongation together with dendritiform extensions were observed in PG-treated cells on days 1 and 3, while epithelioid morphology was observed on day 7. All cells were immunoreactive for RPE65, cytokeratin 8/18, and PAX6. No significant change was observed in the expression of MKI67 and PAX6, but the expressions of MMP2, MMP9, ACTA2, and KDR were significantly higher in PG2-treated cells compared to controls (p < 0.05). Our results indicate that increased concentration of PG and extended exposure time have positive effects on viability of hRPE cells. PG may be useful for hRPE cell encapsulation in retinal cell replacement therapy.

Cultivation of Retinoblastoma Cells: Correlation Between In Vitro Growth Pattern and Histopathology.

PURPOSE: To investigate the correlation between floating versus adherent growth pattern of cultivated retinoblastoma (RB) cells from three patients with RB and their histopathologic features. METHODS: RB cells from three Iranian patients (MM, NR, and MS) were cultivated in Dulbecco's modified eagle medium (DMEM) supplemented with 15% fetal bovine serum (FBS) for four weeks in each passage. Fresh medium was added on a weekly basis and immunocytochemistry for Synaptophysin was performed. All experiments were performed in duplicate. Growth pattern of the cultivated RB cells was studied during the three consecutive passages and compared among three cases in the light of histopathologic data. RESULTS: Cultivated RB cells from MM and NR demonstrated an adherent growth pattern in the 2nd week and the pattern was enhanced by the 4th week. The RB tumorspheres adhered to the bottom of the flask while surrounded by fibroblasts. Histopathologic diagnosis in MM and NR was a well-differentiated RB without optic nerve involvement. Such an adherent growth was not observed in cultivated RB cells from MS, in which the histopathologic analysis revealed a poorly-differentiated RB with optic nerve intrusion and prominent choroidal invasion. CONCLUSION: The adherent growth pattern of cultivated RB cells might be associated with tumor differentiation and the lack of optic nerve involvement in histopathology.

Macular and retinal nerve fiber layer thickness in unilateral anisometropic or strabismic amblyopia.

PURPOSE: To compare the macular and nerve fiber layer thicknesses as measured by optical coherence tomography (OCT) in amblyopic and fellow eyes. METHODS: Fifty patients with monocular strabismic (n = 25) or anisometropic (n = 25) amblyopia (best corrected visual acuity (BCVA) ranging from 20/40 to 20/400) were included in a prospective cross-sectional descriptive study. A refractive error more than 5 diopters in either eye or an axial length difference between the eyes of more than 1 mm was excluded in the anisometropic group. In all cases, the thickness of the macular area and the peripapillary nerve fiber layer were measured by OCT in both amblyopic and fellow eyes and compared with each other. RESULTS: The mean age of patients was 10 ± 3.1 years (range: 6 to 18 years) in the anisometropic group and 8.9 ± 3.7 years (range: 6 to 18 years) in the strabismic group. In the anisometropic group, the mean macular thickness was significantly increased in the amblyopic eyes (222.6 ± 47.8 µm) versus the fellow eyes (205.6 ± 33.3 µm) (P = .002), although there was no significant difference observed when comparing with the prepapillary nerve fiber layer (P = .55). There was no significant correlation of above-mentioned matters in the strabismic group (P = .07 and .52). CONCLUSION: A thicker macula was found in anisometropic amblyopic eyes, but the increase of macular thickness in strabismic amblyopic eyes was not significant. Retinal involvement was not observed in the peripapillary nerve fiber layer of amblyopic eyes.