Posterior Eye Research Articles

Pachymeningitis in a Patient With Granulomatosis With Polyangiitis; A Case Report

Introduction: Granulomatosis with polyangiitis (GPA) is a systematic and necrotizing vasculitis with positive autoimmune antibodies. Some studies have reported the prevalence of eye involvement between 40%-50% of cases. Retro orbital granuloma is a rare complication of GPA which should be treated by surgical involvements, while pachymeningitis can be diagnosed by MRI and treated by medical management. In this study, we tried to present a case of GPA with optic neuritis and typical central nervous system (CNS) involvement, while there were no definite features of sinusitis or kidney injuries. Case Presentation: A 15-year-old girl was admitted because of blurred vision in her left eye. She was a known case of GPA three years ago with initial features, including left facial nerve paresis due to pan-sinusitis and pulmonary cavity. Neurologic evaluations, including sensory and motor features, were normal, too. Ophthalmologic examinations showed that visual acuity of the right eye was good, while the visual acuity in the left eye decreased to the point of finger counting at a distance of 20 cm. The left eye Marcus gunn test was positive (3+); anterior and posterior eye segments were normal. The patient was evaluated by brain MRI with gadolinium and a pathologic enhancement in the left cavernous was seen which had a pressure effect on the optic nerve. She was treated by intravenous methylprednisolone followed by rituximab. Conclusion: Reporting orbital mass in a patient who had GPA can be supposed as granuloma which needs a biopsy to confirm a diagnosis. In our case, the imaging manifestation was heterodox for granuloma, while neurosurgical consultation recommended drug treatment for pachymeningitis.

A Study of Posterior Segment Pathology in Cataractous Eyes Using B-scan Ultrasonography

Background: Ultrasonography (US) is a valuable diagnostic modality for detecting posterior segment eye diseases (PSEDs) in patients with cataractous eyes. This imaging modality can better facilitate planning surgery and predicting prognosis. The purpose of this study was to determine the role of B-scan US in evaluating posterior segment abnormalities of eyes in cataract patients pre-operatively to limit complications and visual impairment. Methods and Results: A prospective, cross‑sectional study to assess cataracts by US, as well as to detect posterior segment abnormalities of eyes in cataract patients, was conducted in Sudan at Albasar International Foundation (Makah Eye Complex in Omdurman) between December 2018 and December 2019. All patients (n=380; 48% males and 52% females; a mean age of 63±12.57 years) with non-visualization of the fundus, regardless of age and gender, were involved and were assumed to have orbital pathologies. Patients with high-risk extrusion of intraocular contents and a previous history of ocular surgery were excluded from the present study. All patients with dense cataracts were evaluated using standard US machines (Echoscan US-4000; NIDEK CO., LTD.) equipped with a real-time high-frequency probe. The typical age of the patients complaining of cataracts was between 61 and 70 years, which constituted 35% of cases, followed by age >70 years, which constituted 24.2% of cases. About 47.63% patients had ocular pathology in the posterior segment of the eye (Table 3). The most common PSEDs were vitreous abnormalities (46.2%). Among vitreous abnormalities, most abnormal eyes had vitreous changes (36.1%), followed by VD (3.7%); 1.3% of patients had retinal detachment. Conclusion: Ocular US should be the first screening modality in the evaluation of posterior segment pathologies in cataractous eyes and should be performed in cataract patients pre-operatively for better surgical planning and predicting post-operative visual prognosis.

Evaluation of the biomechanical properties of the posterior eye using Shear Wave Elastography in patients with increased intracranial pressure.

This study aims to investigate the biomechanical properties of the posterior eye using the shear wave elastography (SWE) in increased intracranial pressure (ICP) patients and healthy subjects. This study enrolled 54 healthy subjects and 54 patients with increased ICP, including 29 patients with space-occupying lesions (SOLs) and 25 patients with intracranial haemorrhage (ICH). Optic nerve sheath diameter and the stiffness of the optic nerve head, peripapil-lary sclera and optic nerve were evaluated. Patients with increased ICP had a significantly higher optic nerve sheath diameter, Young's modulus of optic nerve head, and Young's modulus of peripapillary sclera than healthy subjects (p<0.01 for all). The optic nerve sheath diameter, Young's modulus of optic nerve head and Young's modulus of the peripapillary sclera were similar between the SOLs group and ICH group (p>0.05 for all). Young's modulus of the optic nerve in the ICH group was similar to the control group (p>0.05), whereas the SOLs group had higher Young's modulus of optic nerve comparing the control group (p<0.05). The stiffness of the optic nerve head and peripapillary sclera were higher in patients with increased ICP than healthy subjects, and the optic nerve stiffness of SOLs patients was the highest in all subjects. The SWE could provide a quantitative analysis of the posterior eye's biomechanical properties and help the clinic diagnose the degree of visual impairments.

A taxonomic revision of the spider genus Meriola Banks (Araneae: Trachelidae).

The genus Meriola Banks currently includes 24 known species of spiders distributed across America, especially in southern South America. They have a nearly straight and narrower posterior eye row compared to other American genera of Trachelidae, and elongated and sharply tipped ventral leg cuspules. The study of specimens of Meriola available in collections revealed two undescribed species, M. avalosi sp. nov. and M. peras sp. nov., and the previously unknown females of M. balcarce Platnick Ewing and M. quilicura Platnick Ewing, all of which are described here. The female of M. lineolata (Mello-Leitão) comb. nov., transferred from Cetonana Strand, is described for the first time. Two further new combinations are proposed here: M. macrocephala (Nicolet) comb. nov., transferred from Trachelopachys Simon, and M. setosa (Simon) comb. nov., transferred from Cetonana; these two species are also considered senior synonyms of M. barrosi (Mello-Leitão) and M. hyltonae (Mello-Leitão), respectively. Additionally, a new sex matching of M. ramirezi Platnick Ewing and M. davidi Grismado is proposed, with a redescription of the female of M. ramirezi provided. New geographical records are provided for all of the species, with images and a revised diagnosis for the genus and the previously known species.

Retinal Phenotyping of Ferrochelatase Mutant Mice Reveals Protoporphyrin Accumulation and Reduced Neovascular Response.

PurposeHeme depletion, through inhibition of ferrochelatase (FECH), blocks retinal and choroidal neovascularization. Both pharmacologic FECH inhibition and a partial loss-of-function Fech mutation (Fechm1Pas) are associated with decreased neovascularization. However, the ocular physiology of Fechm1Pas mice under basal conditions has not been characterized. Here, we aimed to characterize the retinal phenotype of Fechm1Pas mice.MethodsWe monitored retinal vasculature at postnatal day 17, 2 months, and 6 months in Fechm1Pas homozygotes, heterozygotes, and their wild-type littermates. We characterized Fech substrate protoporphyrin (PPIX) fluorescence in the eye (excitation = 403 nm, emission = 628 nm), retinal function by electroretinogram, visual acuity by optomotor reflex, and retinal morphology by optical coherence tomography and histology. We stained vasculature using isolectin B4 and fluorescein angiography. We determined endothelial sprouting of retinal and choroidal tissue ex vivo and bioenergetics of retinal punches using a Seahorse flux analyzer.ResultsFundi, retinal vasculature, venous width, and arterial tortuosity showed no aberrations. However, VEGF-induced retinal and choroidal sprouting was decreased in Fechm1Pas mutants. Homozygous Fechm1Pas mice had pronounced buildup of PPIX in the posterior eye with no damage to visual function, bioenergetics, and integrity of retinal layers.ConclusionsEven with a buildup of PPIX in the retinal vessels in Fechm1Pas homozygotes, the vasculature remains normal. Notably, stimulus-induced ex vivo angiogenesis was decreased in Fechm1Pas mutants, consistent with reduced pathologic angiogenesis seen previously in neovascular animal models. Our findings indicate that Fechm1Pas mice are a useful model for studying the effects of heme deficiency on neovascularization due to Fech blockade.

Nanoparticle-Hydrogel Composite Drug Delivery System for Potential Ocular Applications.

Intravitreal injections are clinically established procedures in the treatment of posterior eye diseases, such as wet age-related macular degeneration (wet AMD) which requires monthly intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) protein drugs that can lead to complications due to frequent dosing. In this study, we designed a composite drug delivery system (DDS) consisting of drug-loaded poly (lactide–co–glycolide) (PLGA) nanoparticles and a chemically crosslinked hyaluronan hydrogel to reduce the dosing frequency. The morphology, size, composition, and drug loading efficiency of the prepared nanoparticles were characterized. The properties of the modified hyaluronan polymers used were also examined. The degree of swelling/degradation and controlled release ability of the hyaluronan hydrogel and the composite DDS were identified using bovine serum albumin (BSA) as a model drug. The results show that this system can retain 75% of its wet weight without losing its integrity and release the model drug at the rate of 0.4 μg/day for more than two months under physiological conditions. In addition, the nanoparticulate formulation of the system can further improve bioavailability of the drugs by penetrating deep into the retinal layers. In conclusion, the proposed composite DDS is easily prepared with biocompatible materials and is promising for providing the sustained release of the protein drugs as a better treatment for ocular neovascular diseases like wet AMD.

Retinal Aquaporin-4 and Regulation of Water Inflow Into the Vitreous Body.

PurposeDetails of the posterior eye water dynamics are unclear. Aquaporin-4 (AQP4), a water channel, plays an important role in water dynamics in the central nervous system and is also present in the ocular tissue. The purpose of this study was to reveal the role of AQP4 in the water dynamics of the posterior eye using in vivo JJ vicinal coupling proton exchange (JJVCPE) magnetic resonance imaging (MRI) of AQP4 knockout (KO) mice and their wild-type littermates (controls).MethodsJJVCPE MRI of the eye was performed on five AQP4 KO mice and seven control mice. We assessed the normalized signal intensities of a region of interest (ROI) set in the vitreous body after H217O administration. The results of the two groups were compared using a two-tailed Mann-Whitney U test.ResultsA statistical analysis revealed that the normalized ROI signal intensities at the steady state were significantly lower (P = 0.010, <0.05) in the AQP4 KO mice (mean ± SD, 84.5% ± 2.7%) than the controls (mean ± SD, 88.8% ± 1.9%).ConclusionsThe present study using JJVCPE MRI of the eye demonstrated that retinal AQP4 has a potential role in the regulation of water inflow into the vitreous body. Absence of AQP4 in the KO mice probably induces lower water outflow from the vitreous body. Our results could help clarify the pathogenesis of various ocular diseases.

Design and Evaluation of Long Acting Biodegradable PLGA Microspheres for Ocular Drug Delivery

Background:: The research work involves the development of PLGA biodegradable microspheres loaded with dexamethasone for intraocular delivery. Objective:: The study aimed to design and evaluate long acting PLGA microspheres for ocular delivery of dexamethasone. Methods:: The present formulation involves the development of long-acting dexamethasone loaded microspheres composed of a biodegradable controlled release polymer, Poly(D,L-lactide-coglycolide) (PLGA), for the treatment of posterior segment eye disorders intravitreally. PLGA with a monomer ratio of 50:50 of lactic acid to glycolic acid was used to achieve a drug release for up to 45 days. Quality by Design approach was utilized for designing the experiments. Single emulsion solvent evaporation technique along with high-pressure homogenization was used to facilitate the formation of microspheres. Results:: Particle size evaluation, drug content and drug entrapment efficiency were determined for the microspheres. Particle size and morphology were observed using Field Emission Gun- Scanning Electron Microscopy (FEG-SEM) and microspheres were in the size range of 1-5 μm. Assessment of drug release was done using in vitro studies and trans retinal permeation was observed by ex vivo studies using goat retinal tissues. Conclusion:: Considering the dire need for prolonged therapeutic effect on diseases of the posterior eye, an intravitreal long-acting formulation was designed. The use of biodegradable polymer with biocompatible degradation products was a rational approach to achieve this aim. The outcome of the present research shows that developed microspheres would provide a long-acting drug profile and reduce the frequency of administration thereby improving patient compliance.

Automated MRI-based quantification of posterior ocular globe flattening and recovery after long-duration spaceflight

Background/ObjectivesSpaceflight associated neuro-ocular syndrome (SANS), a health risk related to long-duration spaceflight, is hypothesized to result from a headward fluid shift that occurs with the loss of hydrostatic pressure gradients in weightlessness. Shifts in the vascular and cerebrospinal fluid compartments alter the mechanical forces at the posterior eye and lead to flattening of the posterior ocular globe. The goal of the present study was to develop a method to quantify globe flattening observed by magnetic resonance imaging after spaceflight.Subjects/MethodsVolumetric displacement of the posterior globe was quantified in 10 astronauts at 5 time points after spaceflight missions of ~6 months.ResultsMean globe volumetric displacement was 9.88 mm3 (95% CI 4.56–15.19 mm3, p < 0.001) on the first day of assessment after the mission (R[return]+ 1 day); 9.00 mm3 (95% CI 3.73–14.27 mm3, p = 0.001) at R + 30 days; 6.53 mm3 (95% CI 1.24–11.83 mm3, p < 0.05) at R + 90 days; 4.45 mm3 (95% CI −0.96 to 9.86 mm3, p = 0.12) at R + 180 days; and 7.21 mm3 (95% CI 1.82–12.60 mm3, p < 0.01) at R + 360 days.ConclusionsThere was a consistent inward displacement of the globe at the optic nerve, which had only partially resolved 1 year after landing. More pronounced globe flattening has been observed in previous studies of astronauts; however, those observations lacked quantitative measures and were subjective in nature. The novel automated method described here allows for detailed quantification of structural changes in the posterior globe that may lead to an improved understanding of SANS.

The Antifungal and Ocular Permeation of Ketoconazole from Ophthalmic Formulations Containing Trans-Ethosomes Nanoparticles.

Ketoconazole (KET), a synthetic imidazole broad-spectrum antifungal agent, is characterized by its poor aqueous solubility and high molecular weight, which might hamper its corneal permeation. The aim was to develop an ophthalmic formulation loaded with optimized trans-ethosomal vesicles to enhance KET ocular permeation, antifungal activity, rapid drug drainage, and short elimination half-life. Four formulation factors affecting the vesicles’ size, zeta potential, entrapment efficiency, and flexibility of the trans-ethosomes formulations were optimized. The optimum formulation was characterized, and their morphological and antifungal activity were studied. Different ophthalmic formulations loaded with the optimized vesicles were prepared and characterized. The ocular irritation and in vivo corneal permeation were investigated. Results revealed that the drug-to-phospholipid-molar ratio, the percentage of edge activator, the percentage of ethanol, and the percentage of stearyl amine significantly affect the characteristics of the vesicles. The optimized vesicles were spherical and showed an average size of 151.34 ± 8.73 nm, a zeta potential value of +34.82 ± 2.64 mV, an entrapment efficiency of 94.97 ± 5.41%, and flexibility of 95.44 ± 4.33%. The antifungal activity of KET was significantly improved following treatment with the optimized vesicles. The developed in situ gel formulations were found to be nonirritating to the cornea. The trans-ethosomes vesicles were able to penetrate deeper into the posterior eye segment without any toxic effects. Accordingly, the in situ developed gel formulation loaded with KET trans-ethosomes vesicles represents a promising ocular delivery system for the treatment of deep fungal eye infections.

Laser-Activated Drug Implant for Controlled Release to the Posterior Segment of the Eye.

To treat chronic posterior eye diseases, frequent intravitreal injections or sustained-release drug implants are the current standard of care. Sustained-release drug implants often involve burst release of the drugs and the dosage from the implants cannot be controlled after implantation, which may lead to local side effects. The present study attempts to develop a dosage-controllable drug delivery implant that consists of a nanoporous biodegradable PLGA capsule and light-activated liposomes. Controllable drug release from the implant was achieved using a pulsed near-infrared (NIR) laser both in vitro and in vivo. The in vitro drug release kinetics from two different initial dose implants, 1000 and 500 μg, was analyzed by fitting zero-order and first-order kinetics, as well as the Korsmeyer-Peppas and Higuchi models. The 1000 and 500 μg implants fit the first-order and zero-order kinetics model, respectively, the best. The multiple drug releases in the vitreous were determined by an in vivo fluorimeter, which was consistent with the in vitro data. The dose released was also clinically relevant. Histology and optical and ultrasound imaging data showed no abnormality in the eyes received implant treatment, suggesting that the drug delivery system was safe to the retina. This on-demand dose-controllable drug delivery system could be potentially used for long-term posterior eye disease treatment to avoid frequent invasive injections.

Detection of Posterior Segment Eye Disease in Rural Eye Camps in South India: A Nonrandomized Cluster Trial

Rural screening camps in India historically have focused on detection of cataract and uncorrected refractive error. This study aimed to increase detection, referral, and follow-up for posterior segment diseases (PSDs) in rural eye camps using a novel technology-driven eye camp model. A clustered nonrandomized trial in the catchment area of Aravind Eye Care System (AECS) Pondicherry, to compare 2 eye camp models: the traditional AECS eye camp model and the novel, technology-driven, eye camp model. Patients 40 to 75 years of age who attended free camps conducted by AECS Pondicherry. Those with corneal pathologic features were excluded because this precluded an adequate view of the posterior segment to screen for PSD. The clinical protocols in the 2 arms were standardized and the same study team was used in both study arms. The unit of allocation to the 2 study arms was at the level of the eye camp, rather than the level of the individual study participant. The primary study outcome was detection of suspected PSD (glaucoma, diabetic retinopathy, age-related macular degeneration, other PSDs). Secondary outcomes included: (1) the proportion of referred participants who underwent an examination at the base hospital and (2) the proportion with confirmed PSD on examination at the base hospital. The study included 11 traditional and 18 novel eye camps with a total of 3048 participants (50% in each study arm). The mean age of all participants was 58.4 ± 9.1 years and 1434 participants (47%) were men. The proportion receiving a referral for PSD was significantly greater in the novel (8.3%) compared with the traditional (3.6%) eye camp (P < 0.001; risk ratio, 2.31; 95% confidence interval, 2.30-2.34). Among the 183 participants referred from the camps for PSD, 73 (39.9%) followed up for further evaluation at the base hospital. In a resource-constrained setting, use of digital fundus photography in novel eye camps resulted in increased detection of and referral for PSD. Further research is needed to determine whether this intervention is cost effective and may contribute to prevention of avoidable blindness and visual impairment in South India. Further research also is needed to improve follow-up of patients referred from camps for suspicion of PSD.

Biopolymer-based nanoparticles with tunable mucoadhesivity efficiently deliver therapeutics across the corneal barrier

To overcome the natural barriers of the ocular system that limit the topical delivery of therapeutically active molecules to the posterior eye, nanoscale drug carriers can be used to improve transcorneal drug transport. So far, using mucoadhesive drug carriers has been put forward as the most promising strategy to optimize drug transport. However, if the mucoadhesivity of a drug carrier is too high, this might limit the diffusive entry of molecules/drug carriers into the vitreous. In this study, we show how modulating the net charge of biopolymer-based drug carrier particles alters not only their mucoadhesivity but also other important properties, e.g., their stability, drug loading capacity and drug release profiles. Compared to simple aqueous solutions of free drug molecules as used in current treatments, nanoparticulate drug carriers with intermediate mucoadhesivity show improved drug transport across the corneal barrier. Therefore, our study shows that mucoadhesion of drug carrier particles is a feature that needs to be considered with great care – not only for ocular delivery attempts but for all drug delivery approaches dealing with mucosal barriers.

Computational modeling of intraocular drug delivery supplied by porous implants.

New and efficient drug delivery to the posterior part of the eye is a growing health necessity worldwide. Current treatment of eye diseases, such as age-related macular degeneration (AMD), relies on repeated intravitreal injections of drug-containing solutions. Such a drug delivery has major drawbacks including short drug life, significant medical service, and high medical cost. In this study, we explored a new approach to controlled drug delivery by introducing unique porous implants. Our computational modeling contained key physiological and anatomical traits. Incompressible flow in a porous media field, including the sclera, choroid, and retina layers, is governed by Darcy law and the time evolution of the drug concentration was solved via three convection-diffusion equations in the three layers, respectively. The computational model was validated by established results from independent studies and experimental data. Simulations of the IgG1 Fab drug delivery to the posterior eye were performed to evaluate the effectiveness of the porous implants for controlled delivery. Overall, our results indicate that drug therapeutic levels in the posterior eye sustain for eight weeks similarly to those using intravitreal injection. We first evaluated the effects of the porous implants on the drug delivery in the posterior layers. Subsequent simulations were carried out with varying porosity values in a porous episcleral implant. We found that the time evolution of drug concentration is distinctively correlated to drug source location and pore size. A correlation between porosity and fluid properties for selected porous implants was revealed for the first time in this study.

Predicting Age From Optical Coherence Tomography Scans With Deep Learning.

PurposeTo assess whether age can be predicted from deep learning analysis of peripapillary spectral-domain optical coherence tomography (SD-OCT) B-scans and to determine the importance of specific retinal areas on the predictions.MethodsDeep learning (DL) convolutional neural networks were developed to predict chronological age in healthy subjects using peripapillary SD-OCT B-scan images. Models were built using the whole B-scan, as well as using specific regions through image ablation. Cross-validation was used for training and testing the model. Mean absolute error (MAE) and correlations between predicted and observed age were used to evaluate model performance.ResultsA total of 7271 images from 542 eyes of 278 healthy subjects were included. DL predictions of age using the whole B-scan were strongly correlated with chronological age (MAE = 5.82 years; r = 0.860, P < 0.001). The model also accurately discriminated between the lowest and highest tertiles of age, with an area under the receiver operating characteristic curve of 0.962. In general, class activation maps tended to show a diffuse pattern of activation throughout the scan image. For specific structures of the B-scan, the layers with the strongest correlations with chronological age were the choroid and vitreous (both r = 0.736), whereas retinal nerve fiber layer had the lowest correlation (r = 0.492).ConclusionsA DL algorithm was able to accurately predict age from whole peripapillary SD-OCT B-scans.Translational RelevanceDL models applied to SD-OCT scans suggest that aging appears to affect several layers in the posterior eye segment.

The influence of hyperglycemia on the safety of ultrasound in retinal pigment epithelial cells.

Ultrasound (US) assisted drug delivery is receiving interest in treating posterior eye diseases, such as diabetic retinopathy due to its ability to maximize drug penetration into difficult to reach tissues. Despite its promise, the technique has only been investigated using healthy cell and tissue models, with no evidence to date about its safety in active disease. As a result, the aim of this study was to evaluate the safety of US administration in vitro in retinal pigment epithelial cells under normal and high glucose conditions. US protocols within the presently accepted safety threshold were applied and their influence on cell membrane and tight junction integrity as well as intracellular inflammation was evaluated using lactate dehydrogenase (LDH), zona occludens-1 (ZO-1), fluorescein isothiocyanate (FITC)-dextran dye leak and nuclear factor-kappaB (NF-κB) assays, respectively. Under high glucose conditions, US application increased LDH release and resulted in loss of ZO-1 labeling at 2 h; however, normal levels were restored within 24 h. US within its safety parameters did not induce any FITC-dextran dye leak or NF-κB nuclear translocation in normal or high glucose conditions. In conclusion, our results suggest that while high glucose conditions increase cell susceptibility to US-mediated stress, basal conditions can be restored within 24 h without long-lasting cell damage.

Diagnostic Accuracy of B-scan Ultrasonography for Posterior Segment Eye Disorders- A Cross-sectional Study

Introduction: Ophthalmic Ultrasound (USG) produces real time high resolution images of the eye and orbit. It can categorise, predict location and diagnose posterior segment pathology of the eye very well and is usually used in preoperative evaluation. However, the diagnostic accuracy, in terms of predicting probability of Posterior Segment Disease (PSD) post-USG, has usually not been studied, that too in Indian set-up. Hence, this study was conducted. Aim: To find out the prevalence and pattern of PSD among patients referred to radiology department using B-scan USG, and to find out the diagnostic accuracy of B-scan USG in such cases. Materials and Methods: The study was cross-sectional in nature conducted over a period of two years (2007-09) and conducted in the Department of Radiodiagnosis and Ophthalmology of a tertiary care centre of Eastern India. Patients were referred to the Radiology department for ruling out intraocular pathology using B-scan ophthalmic USG were included in the study, irrespective of any age and gender. Data were captured on an excel sheet and analysed using Stata 12.1. Prevalence and pattern of PSDs were established from the data while diagnostic accuracy was calculated in terms of sensitivity, specificity, predictive values and log Likelihood Ratios (LR). Accuracy of B-scan USG was also estimated and adjusted for verification bias. Results: The mean age of 84 study participants was 37.4±19.5 years, with maximum in between 41-50 years. Males predominated (72.6%). A 50% presented with low vision, and most commonly associated with cataract 45 cases (54%). Prevalence of posterior segment eye disorders was 13.1%. Adjusted sensitivity, adjusted specificity and Negative Predictive Values (NPV) were 100%. Positive Predictive Value (PPV) was 45.33%. Post-test probability was 46.6%, while after adjustment it was infinite. Adjusted accuracy was 100%. Conclusion: Prevalence of posterior segment eye disorders was 13.1% for cases referred to radiology department. The most common PSD that was found was retinal mass. Using B-scan USG for preoperative assessment and confirmation of diagnosis increases the probability of detecting presence or absence of posterior segment pathology. Absence of PSD using this is also very helpful in ruling out disease entirely. It also has a very high sensitivity and hence has a scope to be used even in rural health centres.

Teleophthalmology as a Model for Detecting Ocular Diseases in Tribal Areas of a North West State in India.

Background:Lahaul and Spiti district of Himachal Pradesh, a high altitude tribal district, situated at altitudes varying from 10,000 to 15, 000 ft. above mean sea level is cut off from the rest of the country for nearly 6 months due to heavy snowfall in the mountain passes. In the absence of any ophthalmologist and ophthalmic technician, the provision of eye care is virtually absent. The current study (part of a research project funded by the Indian Council of Medical Research) was conducted with the aim to explore teleophthalmology as a model for detecting posterior segment eye diseases in tribal and inaccessible areas.Materials and Methods:Fundus images (taken through fundus photography) of 1000 individuals above 5 years of age with no improvement in vision to 6/6 on refraction and individuals with known history of diabetes mellitus, systemic hypertension, or long standing headache with features of raised intracranial tension irrespective of whether their vision improved to 6/6 or not were sent to tertiary care center (base hospital) from regional hospital (field hospital). Transmitted images (through internet after attaching the details and patient particulars on the excel sheet) were analyzed by the ophthalmologists and the final diagnosis along with the line of management if any was transmitted back.Results:Eighty-five percent of the images transmitted were of good quality. Retinal, vitreous, optic nerve head, and choroidal diseases could be detected.Conclusions:In the present situation, where trained workforce is unavailable in these areas, teleophthamology is an appropriate tool by which a number of eye diseases can be detected at early stages. Most of them can be treated in these early stages by lifestyle modification and medical management.

Posterior Segment Retained Intraocular Foreign Body: A Study from Western Nepal.

Posterior segment retained Intraocular foreign body (IOFB) management is challenging. Facility of pars plana vitrectomy (PPV) and availability of well trained vitreo retina surgeons are the basic need to accomplish this work. Encircling band provide permanent 360° support to close the anterior retinal break and prevent traction on the retina. The objective of this study is to analyse the clinical characteristics and predictors of the final visual outcome and survival of the globe in cases of retained IOFB in the posterior eye segment. A hospital based retrospective observational study was conducted. All the patients of retained IOFB in the posterior segment presented from January 2016 to June 2019 were enrolled. Patients presented with visual acuity of NPL were excluded. Statistical analysis was performed using a variety of tests using SPSS version 21. Forty eyes of 40 patients were included. The mean age was 27.08±10.68 years (range 5-66). 95% of our patients were male. Most of them (52.5%) worked on the farm. 26(65%) of 40 eyes had Zone I injury. The median time spent before presentation was 13.5 day. Retinal detachment, vitreous hemorrhage, and endophthalmitis were present in 15, 23 and 5 eyes, respectively, before IOFB removal. The mean LogMAR visual acuity was improved significantly from 2.50±0.87 to 1.33± 1.01 (p=0.003). Poor presenting visual acuity, retinal detachment and large diameter of IOFB were found as the predictor of poor final visual acuity. Pars plana vitrectomy by a vitreo retinal surgeon can give encouraging results in the cases of retained posterior segment IOFB. Poor presenting visual acuity, large diameter of IOFB and RD before IOFB removal are predictors of poor visual outcome.

Bacterial Keratitis in Type 1 Diabetic Patients: Course and Consequences

<i>The purpose</i> was to define the peculiarities of the course and consequences of bacterial keratitis in patients with type 1 diabetes mellitus (DM1) depending on the stage of its severity. <i>Methods.</i> 34 DM1 patients (34 eyes) with bacterial keratitis whose initial bacteriological examination revealed pathogen sensitivity to the antibiotic ofloxacin participated in this study. All patients were treated topically with ofloxacin, antiseptics, repairing agents, antioxidants, mydriatics, artificial tears and systemically with anti-inflammatory agents. Patients were divided into two groups according to the severity of bacterial keratitis at the first visit. Research methods were as follows: visual acuity, tonometry, slit-lamp biomicroscopy of anterior and posterior eye segments, fluorescein dye test, non-contact corneal esthesiometry, anterior eye OCT and bacteriological studies. <i>Results.</i> Compared to the stage I, DM1 patients with stage II severity bacterial keratitis showed higher degree of pericorneal injection, larger and deeper corneal ulcer defect, deeper corneal infiltration and edema, higher mean corneal sensitivity threshold at all time point of the study, p<0.05. DM1 patients with stage II severity bacterial keratitis were more prone for longer duration of the disease and worse consequences. Therefore, on day 24 in 33.3% diabetic patients with stage II severity bacterial keratitis corneal ulcer was not found to be healed.<i> Conclusions.</i> Course and consequences of bacterial keratitis in type 1 diabetes mellitus patients depend on the stage of severity of bacterial keratitis.