ABSTRACT
Purpose: To explore the vitreous humor proteome from type 2 diabetes subjects with proliferative diabetic retinopathy (PDR) in the Indian population. Methods: We performed mass spectrometry?based label?free quantitative analysis of vitreous proteome of PDR (n = 13) and idiopathic macular hole (IMH; control) subjects (n = 14). Nine samples of PDR and 10 samples of IMH were pooled as case and control, respectively, and compared. Four samples each of PDR and IMH were analyzed individually without pooling to validate the results of the pooled analysis. Comparative quantification was performed using Scaffold software which calculated the fold changes of differential expression. Bioinformatics analysis was performed using DAVID and STRING software. Results: We identified 469 proteins in PDR and 517 proteins in IMH vitreous, with an overlap of 172 proteins. Also, 297 unique proteins were identified in PDR and 345 in IMH. In PDR vitreous, 37 proteins were upregulated (P < 0.05) and 19 proteins were downregulated compared to IMH. Protein distribution analysis clearly demonstrated a separation of protein expression in PDR and IMH. Significantly upregulated proteins included fibrinogen gamma chain, fibrinogen beta chain, and carbonic anhydrase 1 and downregulated proteins included alpha?1?antitrypsin, retinol?binding protein 3, neuroserpin, cystatin C, carboxypeptidase E and cathepsin?D. Conclusion: Diabetic retinopathy pathogenesis involves proteins which belong to inflammation, visual transduction, and extracellular matrix pathways. Validation?based experiments using enzyme?linked immunosorbent assay (ELISA) or western blotting are needed to establish cause and effect relationships of these proteins to the disease state, to develop them as biomarkers or drug molecules
ABSTRACT
Purpose: To analyze and describe the proteome of the vitreous humour in eyes with idiopathic macular holes. Methods: We performed mass spectrometry (MS)?based label?free quantitative analysis of the vitreous proteome of idiopathic macular hole (IMH) and control donor vitreous. Comparative quantification was performed using SCAFFOLD software which calculated fold changes of differential expression. Bioinformatics analysis was performed using DAVID and STRING software. Results: A total of 448 proteins were identified by LC?MS/MS in IMH and cadaveric eye vitreous samples, of which 199 proteins were common. IMH samples had 189 proteins that were unique and 60 proteins were present only in the control cadaveric vitreous. We found upregulation of several extracellular matrix (ECM) and cytoskeletal proteins, namely collagen alpha?1 (XVIII) chain, N?cadherin, EFEMP1/fibulin?3, basement membrane?specific heparan sulfate proteoglycan core protein, and target of Nesh?3. Several cytoskeleton proteins, namely tubulin, actin, and fibronectin levels, were significantly lower in IMH vitreous, probably reflecting increased ECM degradation. IMH vitreous also had a downregulation of unfolded protein response?mediated?mediated apoptosis proteins, possibly related to a state of increased cell survival and proliferation, along with a remodelling and aberrant production of ECM contents. Conclusion: The pathogenesis of macular holes may involve ECM remodelling, epithelial–mesenchymal transformation, downregulation of apoptosis, protein folding defects, and complement pathway. The vitreo?retinal milieu in macular holes contain molecules related to both ECM degradation and inhibition of the same, thereby maintaining a homeostasis.
ABSTRACT
Purpose: The coronavirus disease 19 (COVID?19) pandemic has resulted in a huge impact on the health care system. Diversion of health care workforce toward management of a high number of COVID?19 cases and lockdown restrictions have affected the follow?up of patients. The objective of this study was to analyze the impact of this situation on the control of diabetes, eventually resulting in related neuro?ophthalmological complications. Methods: This retrospective case series included diabetic patients visiting the neuro?ophthalmology clinic at a tertiary care eye center in India from 25 March 2020 to 25 September 2020 during the lockdown. The incidence of diabetes?related neuro?ophthalmological complications, including third, fourth, sixth nerve palsies and non?arteritic anterior ischemic optic neuropathy (NAION) was evaluated and compared with that of the same period during 2019. Results: Overall disease incidence rate was significantly higher in the year 2020 (60.2%) compared to the previous year of 2019 (29.8%). The proportion of third nerve palsy (4.8% vs 16.3%, P < 0.001) and NAION (0.3% vs 14.3%, P < 0.001) had increased. Even though the percentage of sixth nerve palsy was 25% in 2020, this was not significantly different from 2019. There was a reduction in the percentage of fourth nerve palsy cases from the year 2019 to 2020. Conclusion: There was a significant increase in diabetes?related neuro?ophthalmic complications during the COVID?19 lockdown. This can possibly be attributed to worsening of glycemic control in diabetic patients.
ABSTRACT
Purpose: To study the role of digitally assisted vitreoretinal surgery (DAVS) as a learning and teaching tool compared to that of the standard binocular side?scope of the conventional analog microscope (CAM). Methods: This was a cross?sectional, observational study conducted at a tertiary eye care center and teaching institute in South India. Postgraduate residents and clinical fellows observed a predecided set of retinal surgical procedures using both DAVS and CAM. A detailed questionnaire was used to compare the participants’ subjective scoring of both the platforms in terms of level of comfort, clarity of image and stereopsis, level of understanding, and overall impression. Results: Thirty?six participants, including 20 residents and 16 fellows, took part in this study. DAVS obtained a higher score for all 15 questions compared to CAM and the differences were statistically significant. DAVS obtained a mean score of 4.80 (median: 5) whereas CAM obtained a mean score of 3.14 (median: 3) on a grading scale of 1–5 with regard to the overall experience of surgical viewing through either platform (P < 0.01). Conclusion: DAVS is a better learning and teaching tool compared to the side scope of the CAM from a learner’s perspective. Thus, DAVS can help beginners in the field of vitreoretinal surgery obtain a better understanding of the surgical steps prior to the initiation of hands?on training