Vitrectomy in Myopic Maculopathy

Myopia is one of the most important causes of low vision in the world. While high myopia causes pathological changes in many tissues in the eye, it also causes degenerative changes in the retina. This review mentions the vitreoretinal surgical approach, difficulties in surgery, and new developments in maculopathies due to pathological myopia.

Outcomes of conbercept therapy for choroidal neovascularization secondary to pathological myopia

AIM: To evaluate the one-year outcome of intravitreal conbercept injections for the treatment of choroidal neovascularization secondary to pathological myopia (pm-CNV) by optical coherence tomography angiography (OCTA). METHODS: The medical records of 26 consecutive eyes of 23 patients who received intravitreal injections of conbercept for pm-CNV with a follow-up of one year were retrospectively reviewed. All the patients were diagnosed by fundus fluorescein angiography (FFA) and OCTA at the first visit. All approaches were performed as “1+PRN” treatment. Outcomes included best-corrected visual acuity (BCVA), central foveal thickness (CFT) and the mean CNV area by OCTA. RESULTS: Mean Logarithm BCVA improved from (0.66±0.51) at baseline to (0.39±0.38) at one year (t=3.528, P=0.004). The CFT before treatment and after one year after were 275.08±48.74) μm and (205.15±43.74) μm respectively (t=4.630, P=0.001). The mean pm-CNV areas before treatment and after one year treatment were (0.48±0.24) mm2 and (0.15±0.11) mm2 respectively, with a significant difference among them (t=5.329, P=0.000). Twenty-one eyes had no needs after the first treatment. Four eyes received 2 injections and only one eye received 3 injections. No severe adverse events were noted relevant to the therapy. CONCLUSION: Intravitreal conbercept can improve the vision and relieve CFT and CNV area for the treatment of pm-CNV with “1+PRN” by OCTA for one year, however, long-term follow-up still need to be performed.

Optical coherence tomography angiography for choroidal neovascularization in pathological myopia and neovascular age-related macular degeneration in combination with axial myopia in comparative analysis

Background. Optical coherence tomography angiography (OCTA) is currently an important method of visualization and assessment of fundus pathology in various diseases. The study of combined pathologies is not well covered.The aim: to compare OCTA features during choroidal neovascularization (CNV) in pathological myopia (PM) and in neovascular age-related macular degeneration in combination with axial myopia (nAMD + M) against the background of anti-VEGF therapy.Materials and methods. A prospective study included 70 eyes with active CNV. Comparative analysis of parameters was carried out between two groups: with PM – 47 eyes; with nAMD + M – 23 eyes.Results. 4 OCTA patterns were established in both groups: dense, loose, mixed and unidentifi able. With PM, dense pattern was found in 28 (59.57 %) eyes, loose pattern – in 16 (34.04 %), mixed pattern– in 2 (4.26 %), unidentifi able pattern – in 1 (2.13 %). In the nAMD + M group, dense pattern was rare – in 1 (4.35 %) eye, loose pattern – in 7 (30.44 %), mixed pattern – in 9 (39.13 %), unidentifi able pattern – in 6 (26.08 %). The fi rst group was characterized by a dense pattern that was found at a younger age, the second group was characterized by dense and mixed patterns. The greatest area and density of CNV were found with a loose pattern in both groups (p < 0.05). The observation period until the stabilization of CNV was achieved was longer in the loose and mixed patterns in the PM group, and in the loose and unidentifi able – in the nAMD + M group (p < 0.05). Loose and unidentifi able patterns require more injections. The halo was determined by the presence of intraretinal fluid in the retina. Conclusion. OCTA showed common features and distinctive features in the course of CNV in patients with PM and nAMD + M during anti-VEGF therapy. OCTA can be useful in assessing CNV activity and predicting the eff ect of treatment.

History and Basic Principles of Photodynamic Therapy Use in Ophthalmology

Photodynamic therapy (PDT) is a therapy that uses drugs, called photosensitizers or photosensitizing agents, and a specific type of light. When photosensitizers are exposed to certain wavelengths of light, they produce oxygen that kills nearby cells. PDT is achieved by a photodynamic reaction induced by the excitation of a photosensitizer exposed to light. In the field of ophthalmology, PDT was approved for the first time about ten years ago for cases of age-related macular degeneration (AMD). Neovascular age-related macular degeneration (AMD) is a vision-threatening disease characterized by pathological macular neovascularization. After that, PDT was approved for use in choroidal neovascularization (CNV) cases in pathological myopia.3 This literature review aims to describe the history of PDT use and the basic principles of photodynamic therapy in ophthalmology.

Cost-Effectiveness of Conbercept vs. Ranibizumab for Age-Related Macular Degeneration, Diabetic Macular Edema, and Pathological Myopia: Population-Based Cohort Study and Markov Model

Background: With the advent of aging society of China, fundus diseases related to pathological neovascularization, including age-related macular degeneration (AMD), diabetic macular edema (DME), and pathological myopia (PM), have become an increasingly serious medical and health problems. As effective drugs of the treatment, conbercept and ranibizumab have been commonly used and covered by the national basic medical insurance in China. However, the pharmacoeconomic evaluation of conbercept vs. ranibizumab for DME and PM remains lacking. This study would assess the cost-effectiveness of conbercept and ranibizumab for the treatment of AMD, DME, and PM from the perspective of Chinese payers.Methods: A Markov chain model was constructed based on the visual conditions of the patient indicated by the number of letters in best corrected visual acuity (BCVA). We conducted models based on real-world scenario to calculate the cost per the quality-adjusted life-year (QALY) gained. A 1-year cycle length and a 10-year simulation treatment were applied and the number of injections of conbercept and ranibizumab was assumed to the average number within 10 years. Transition probabilities, costs, utility data, and other parameters were obtained from literature searches. A 3.5% discounting rate was applied for both the costs and utilities.Results: The incremental cost-effectiveness ratios (ICERs) were more favorable for conbercept than ranibizumab in treatment of AMD, DME, and PM, with associated ICER of 66,669 renminbi (RMB), −258,813 RMB, and −373,185 RMB per QALY gained. Compared with ranibizumab, the incremental effectiveness of conbercept in treatment of AMD, DME, and PM was −0.665 QALYs, 0.215 QALYs, and 0.029 QALYs, respectively. The sensitivity analysis showed the same findings, although the ICER is sensitive to the costs of this program.Conclusion: Under the current Chinese healthcare setting, conbercept is suitable and cost-effective in treatment of AMD, DME, and PM compared with ranibizumab.

Prediction of Different Eye Diseases Based on Fundus Photography via Deep Transfer Learning

With recent advancements in machine learning, especially in deep learning, the prediction of eye diseases based on fundus photography using deep convolutional neural networks (DCNNs) has attracted great attention. However, studies focusing on identifying the right disease among several candidates, which is a better approximation of clinical diagnosis in practice comparing with the case that aims to distinguish one particular eye disease from normal controls, are limited. The performance of existing algorithms for multi-class classification of fundus images is at most mediocre. Moreover, in many studies consisting of different eye diseases, labeled images are quite limited mainly due to privacy concern of patients. In this case, it is infeasible to train huge DCNNs, which usually have millions of parameters. To address these challenges, we propose to utilize a lightweight deep learning architecture called MobileNetV2 and transfer learning to distinguish four common eye diseases, including Glaucoma, Maculopathy, Pathological Myopia, and Retinitis Pigmentosa, from normal controls using a small training data. We also apply a visualization approach to highlight the loci that are most related to the disease labels to make the model more explainable. The highlighted area chosen by the algorithm itself may give some hints for further fundus image studies. Our experimental results show that our system achieves an average accuracy of 96.2%, sensitivity of 90.4%, and specificity of 97.6% on the test data via five independent runs, and outperforms two other deep learning-based algorithms both in terms of accuracy and efficiency.

Development of deep learning-based detecting systems for pathologic myopia using retinal fundus images

Globally, cases of myopia have reached epidemic levels. High myopia and pathological myopia (PM) are the leading cause of visual impairment and blindness in China, demanding a large volume of myopia screening tasks to control the rapid growing myopic prevalence. It is desirable to develop the automatically intelligent system to facilitate these time- and labor- consuming tasks. In this study, we designed a series of deep learning systems to detect PM and myopic macular lesions according to a recent international photographic classification system (META-PM) classification based on color fundus images. Notably, our systems recorded robust performance both in the test and external validation dataset. The performance was comparable to the general ophthalmologist and retinal specialist. With the extensive adoption of this technology, effective mass screening for myopic population will become feasible on a national scale.

Automatic detection of pathological myopia using machine learning

Pathological myopia is a severe case of myopia, i.e., nearsightedness. Pathological myopia is also known as degenerative myopia because it ultimately leads to blindness. In pathological myopia, certain myopia-specific pathologies occur at the eye’s posterior i.e., Foster-Fuchs’s spot, Cystoid degeneration, Liquefaction, Macular degeneration, Vitreous opacities, Weiss’s reflex, Posterior staphyloma, etc. This research is aimed at developing a machine learning (ML) approach for the automatic detection of pathological myopia based on fundus images. A deep learning technique of convolutional neural network (CNN) is employed for this purpose. A CNN model is developed in Spyder. The fundus images are first preprocessed. The preprocessed images are then fed to the designed CNN model. The CNN model automatically extracts the features from the input images and classifies the images i.e., normal image or pathological myopia. The best performing CNN model achieved an AUC score of 0.9845. The best validation loss obtained is 0.1457. The results show that the model can be successfully employed to detect pathological myopia from the fundus images.

Optical coherence tomography in the diagnosis of choroidal neovascularization in children

AIM: Report cases of choroidal neovascularization (CNV) in children and describe structural and hemodynamic changes in retina associated with this pathology detected by Optical Coherence Tomography (OCT) and OCT-angiography (OCTA). MATERIALS AND METHODS: 6 children (4 girls, 2 boys) aged from 7 to 17 years with CNV associated with pathological myopia, post-traumatic choroid rupture and optic disc abnormalities were examined. The activity of neovascular complexes was evaluated by ophthalmoscopy, OCT, and OCTA. The maximum follow-up period was 4 years. RESULTS: 7 cases of CNV were detected. One child had a two-way process. Myopic and posttraumatic membranes were localized sub- and juxtafoveally and were the membranes of type 2. In children with optic disc anomalies of the 1 type membrane and mixed (1st and 2nd) type was located extrafoveally. The decrease in visual acuity was determined by the localization of membranes, the severity of edema, and the severity of dystrophic changes in the retina. On OCT, subretinal fluid and hyperreflective material corresponding to hemorrhages were visualized in the projection of active membranes. OCTA revealed a network of small capillaries with a large number of loops and anastomoses. Intravitreal angiogenesis inhibitors injections were performed in 5 cases. A persistent effect after a single injection was observed in 2 cases. The return of membrane activity in 3 cases allowed us to justify the repeated administration of angiogenesis inhibitors. Along with a decrease in the activity of CNV, progressive dystrophic changes in the pigment epithelium around the membrane were detected. CONCLUSIONS: High sensitivity of OCT was demonstrated for early detection of structural and hemodynamic retinal disorders, determining the activity of neovascular complexes, predicting outcomes of the disease, and evaluating the effectiveness of therapeutic measures. The progression of dystrophic changes in the retinal pigment epithelium in response to therapy with angiogenesis inhibitors requires long-term monitoring of children and determining the optimal strategy for treating CNV in children.

PI3K/AKT/mTOR signaling participates in insulin‐mediated regulation of pathological myopia‐related factors in retinal pigment epithelial cells

Background Insulin positively correlates with the length of the eye axis and is increased in the vitreous and serum of patients with pathological myopia (PM). How insulin influences the physiological process of retinal pigment epithelial (RPE) cells in PM remains unclear. This study aimed to explore the effect of insulin on the ultrastructure and function of RPE cells and the role of PI3K/AKT/mTOR signaling involved in the development of PM. Methods The ARPE-19 cells were treated with different concentrations of insulin to analyze the cell morphology, cell viability, the protein level of insulin receptor β, and the mRNA and protein levels of and PM-related factors (TIMP-2, MMP-2, bFGF, and IGF-1). The ultrastructure of APRE-19 cells was also observed after insulin treatment. Besides, the PI3K/AKT/mTOR signaling was studied with or without the PI3K inhibitor LY294002 in ARPE-19 cells. Results Insulin enhanced the cell viability of ARPE-19 cells and caused the endoplasmic reticulum to expand and vesiculate, suggesting increased secretion of growth factors and degeneration in ARPE-19 cells. Furthermore, the insulin receptor β was stimulated with insulin treatment, subsequently, the phosphorylation of AKT and mTOR was positively activated, which was adversely suppressed in the presence of LY294002. The secretion of TIMP-2 and bFGF was significantly decreased, and the secretion of MMP-2 and IGF-1 was highly elevated with insulin treatment depending on the concentration in ARPE-19 cells. Furthermore, the effect of insulin on PM-related proteins was restored with the addition of LY294002. Conclusions Our results indicated that insulin regulated the secretion of PM-related factors via the PI3K/AKT/mTOR signaling pathway in retinal pigment epithelial cells, and thus probably promoted the development of PM through transducing regulation signals from retina to choroid and sclera.