Characterising the tear bacterial microbiome in young adults.

Conjunctival swabs (CS) are the major source of sampling for ocular microbiome studies, however collecting CS from the diseased eyes is difficult and painful. In this study, as an alternative to CS, a less invasive approach of tear collection was used to establish the bacterial microbiome in healthy eyes. Tear bacterial microbiome was generated from the DNA of tears (n = 24; male = 16 and female = 8) of healthy volunteers aged from 20 to 52 years. Sequencing of V3-V4 region of 16S rRNA gene was performed on the Illumina platform. Reads were processed in QIIME to assign the taxa. Statistical analysis of the tear microbiome was done in R to assess the alphadiversity and betadiversity indices. Tear microbiome was generated in all the 24 tear samples. Eight out of the top 10 predominant bacterial genera remained same in both tear and CS microbiomes, which include genera such as Corynebacterium, Staphylococcus, Streptococcus, Mycobacterium, Escherichia-Shigella, Lactobacillus, Bacillus and Acinetobacter. The similarity network analysis indicates that 144 out of 145 genera of tear cohort matched with conjunctival swabs. However, tear and CS microbiomes differed in the abundance of the predominant bacterial genera. The bacterial microbiome of tears in adults appears to be stable and is comparable with that of CS microbiome.

Ocular surface pseudoepitheliomatous hyperplasia secondary to allergic eye disease: clinical features and management.

PURPOSE: To study the clinical characteristics and treatment outcomes of ocular surface pseudoepitheliomatous hyperplasia (PEH) associated with chronic vernal keratoconjunctivitis (VKC). METHODS: This retrospective study includes 39 eyes of 32 patients with VKC induced PEH who presented from 2016-2022. A database search was conducted for diagnosis of PEH, and data on clinical features, imaging characteristics, and treatment were analyzed. RESULTS: Of the 32 patients, 11 (34%) were children and adolescents, 21 (66%) were adults. PEH was common in males (72%) and ocular surface squamous neoplasia (OSSN) was the commonest referral diagnosis (43.7%). Mean age at presentation was 26.62 ± 10.18 (range: 6-52) years. While history of VKC was present in 21 patients, 11 were diagnosed with VKC at the time of diagnosis of PEH. The mean base/largest diameter was 5.2 ± 1.67 mm. Anterior segment optical coherence tomography (AS-OCT) showed irregular hyper-reflective epithelium, epithelial dipping, and sub-epithelial hyper-reflective lesion with shadowing in all lesions. Of the 31 eyes that received medical therapy, 21 (67%) and 10 (32%) eyes showed complete and partial resolution respectively with median time to resolution of 3(IQR:2-4) months. Eight eyes that underwent surgical excision showed complete resolution and one developed partial limbal stem cell deficiency. CONCLUSION: Ocular surface PEH is a manifestation of chronic VKC which closely mimics OSSN. Detailed history-taking, examination for signs of allergy, and AS-OCT imaging can distinguish it from OSSN. It responds well to medical therapy and should be considered first-line therapy before planning any surgical intervention.

Understanding and Optimizing Ocular Biometry for Cataract Surgery in Dry Eye Disease: A Review.

PURPOSE: To understand the impact of dry eye disease (DED) on the components of ocular biometry and ways to optimize the visual outcomes of cataract surgery in eyes with DED. METHODOLOGY: A thorough literature review of the components pertaining to this review was undertaken using the databases, PubMed (from the year 2000), MEDLINE, CENTRAL (including Cochrane Eyes and Vision Trials Register; Cochrane Library: Issue 12 of 12 December 2019), metaRegister of Controlled Trials (mRCT) (www.controlled-trials. com), ClinicalTrials.gov (www.clinicaltrial.gov) and WHO International Clinical Trials Registry Platform (www.who.int/ictrp/search/en). The keywords used for the search included "cataract surgery" or "phacoemulsification" combined with "dry eye", "dry eye disease","biometry", "keratometry". RESULTS: Publications considered for this review included meta-analysis, systematic reviews, case-control and cohort studies, case series, and laboratory-based studies. Published articles reporting tear film alteration in DED, its impact on the quality of vision and optical aberrations, the effect of topical medications on keratometry variations, and reports on optimizing the ocular surface before cataract surgery were included. CONCLUSIONS: DED is a common entity seen in patients presenting to routine cataract clinics and is known to impact the accuracy, reliability, and repeatability of ocular biometry and IOL power calculations in them. This review intends to emphasize the preoperative screening for the presence of DED, initiation of appropriate medical management for optimization of the ocular surface before cataract surgery, and recommendations for performing biometry. The algorithmic approach proposed will help the general ophthalmologists in routine practice to provide quality care and acceptable visual outcomes in patients with pre-existing DED.

Evaporative dry eye disease due to meibomian gland dysfunction: Preferred practice pattern guidelines for diagnosis and treatment.

Evaporative dry eye (EDE) due to meibomian gland dysfunction (MGD) is one of the common clinical problems encountered in ophthalmology. It is a major cause of dry eye disease (DED) and of ocular morbidity. In EDE, inadequate quantity or quality of lipids produced by the meibomian glands leads to faster evaporation of the preocular tear film and symptoms and signs of DED. Although the diagnosis is made using a combination of clinical features and special diagnostic test results, the management of the disease might be challenging as it is often difficult to distinguish EDE from other subtypes of DED. This is critical because the approach to the treatment of DED is guided by identifying the underlying subtype and cause. The traditional treatment of MGD consists of warm compresses, lid massage, and improving lid hygiene, all measures aimed at relieving glandular obstruction and facilitating meibum outflow. In recent years, newer diagnostic imaging modalities and therapies for EDE like vectored thermal pulsation and intense pulsed light therapy have emerged. However, the multitude of management options may confuse the treating ophthalmologist, and a customized rather than a generalized approach is necessary for these patients. This review aims to provide a simplified approach to diagnose EDE due to MGD and to individualize treatment for each patient. The review also emphasizes the role of lifestyle modifications and appropriate counseling so that patients can have realistic expectations and enjoy a better quality of life.

Tear film microbiome in Sjogren's and non-Sjogren's aqueous deficiency dry eye.

Purpose: To understand the bacterial microbiome changes associated with Sjogren's syndrome (SS) and non-Sjogren's syndrome (NSS) aqueous-deficient dry eyes compared to healthy eyes. Methods: Bacterial microbiome was generated from the deoxyribonucleic acid of tear film samples in healthy (n = 33), SS (n = 17), and NSS (n = 28) individuals. Sequencing of the V3-V4 region of the 16S rRNA gene was performed on the Illumina HiSeq2500 platform. Quantitative Insights Into Microbial Ecology (QIIME) pipeline was used to assign taxa to sequences. Statistical analysis was performed in R to assess the alpha diversity and beta diversity indices. Significant changes between the healthy, SS, and NSS cohorts were depicted by principal coordinate analysis (PCoA), differential abundance, and network analysis. Results: Tear microbiome was generated in healthy, SS, and NSS samples. Phyla Actinobacteria, Firmicutes, and Bacteroidetes showed significant changes in SS and NSS compared to healthy. Genera Lactobacillus and Bacillus were predominantly present in all samples. PCoA and heat map analysis showed distinct clusters for SS and NSS from the healthy cohort. Genera Prevotella, Coriobacteriaceae UCG-003, Enterococcus, Streptomyces, Rhodobacter, Ezakiella, and Microbacterium significantly increased in abundance in SS and NSS compared to a healthy cohort. Bacteria-bacteria interaction in SS, NSS, and healthy cohorts was predicted by CoNet network analysis. This analysis predicted a major hub of interaction for the pro-inflammatory bacterium Prevotella in the SS and NSS cohorts. Conclusion: The results of the study indicate significant changes in the phyla and genera in SS and NSS compared to healthy. Both discriminative analysis and network analysis indicated a possible association of predominant pro-inflammatory bacteria with SS and NSS.

Lacrimal and meibomian gland evaluation in dry eye disease: A mini-review.

Lacrimal and meibomian glands contribute to the aqueous and lipid components of tear film, respectively. Their evaluation remains central to diagnosing and managing dry eye disease (DED). The review discusses the differences and reliability of various diagnostic tests and commercially available devices used for DED diagnosis. Slit-lamp-based techniques are direct palpebral lobe and tear flow assessment, Schirmer test, meibum quality and expressibility, and evaluation of tear meniscus height. Non-invasive tear meniscus height (TMH), tear break-up time (TBUT), lipid layer thickness (LLT), and meibography are machine-based diagnostic tests. The structure-function correlation of the tear-producing glands gives more comprehensive details than either information alone. Many devices are available in the market, which make DED diagnosis an easy feat, but the tests should be interpreted keeping in mind the intra-observer and inter-observer repeatability. Also, the tear film displays a huge variability as per the environmental conditions and impact of blinking. Hence, the examiner should be well versed with the techniques and repeat the test two to three times to obtain an average reading, which is more reliable. The recommended sequence of tests for diagnosing DED is a dry eye questionnaire, TMH, LLT, NIBUT (FBUT if non-invasive test is unavailable but should be performed after osmolarity), tear osmolarity, meibography, and ocular surface staining. Invasive tests such as Schirmer should be performed after the non-invasive tear film diagnostic testing.

Keratoprosthesis in dry eye disease.

Bilateral corneal blindness with severe dry eye disease (DED), total limbal stem cell deficiency with underlying corneal stromal scarring and vascularization, combined with adnexal complications secondary to chronic cicatrizing conjunctivitis is a highly complex situation to treat. In such eyes, procedures such as penetrating keratoplasty alone or combined with limbal stem cell transplantation are doomed to fail. In these eyes, keratoprosthesis (Kpro) or an artificial cornea is the most viable option, eliminating corneal blindness even in eyes with autoimmune disorders such as Stevens-Johnson syndrome, ocular mucous membrane pemphigoid, Sjogren's syndrome, and nonautoimmune disorders such as chemical/thermal ocular burns, all of which are complex pathologies. Performing a Kpro in these eyes also eliminates the need for systemic immunosuppression and may provide relatively early visual recovery. In such eyes, the donor cornea around the central cylinder of the Kpro needs to be covered with a second layer of protection to avoid desiccation and progressive stromal melt of the underlying cornea, which is a common complication in eyes with severe DED. In this review, we will focus on Kpro designs that have been developed to survive in eyes with the hostile environment of severe DED. Their outcomes in such eyes will be discussed.

A review of rabbit models of meibomian gland dysfunction and scope for translational research.

Dry eye disease (DED) is an emerging global health concern with meibomian gland dysfunction (MGD) being the most common subtype of DED. Despite being quite prevalent, the pathophysiological mechanisms governing MGD are poorly understood. Animal models for MGD can be a valuable resource to advance our understanding of this entity and explore novel diagnostic and therapeutic modalities. Although a lot of literature on rodent MGD models exists, a comprehensive review on rabbit animal models is lacking. Rabbits offer a great advantage over other animals as models for studying both DED and MGD. Rabbits have a widely exposed ocular surface and meibomian gland anatomy comparable with humans, which makes performing dry eye diagnostic tests possible using clinically validated imaging platforms. The existing MGD models in rabbits can broadly be classified as pharmacologically induced and surgically induced models. Most models show keratinization of the meibomian gland orifice with plugging as the final common pathway for developing MGD. Thus, understanding the advantages and disadvantages of each rabbit MGD model can help researchers choose the appropriate experimental plan based on the objective of the study. In this review, we discuss the comparative anatomy of the meibomian glands in humans and rabbits, various rabbit models of MGD, translational applications, unmet needs, and future directions in developing MGD models in rabbits.

The role of Tenonplasty in the management of limbal and scleral ischemia due to acute ocular chemical burns.

Of the various manifestations of ocular chemical burns (OCBs), ischemia of the limbus and the peri-limbal sclera indicates poor prognosis and in severe cases threaten the integrity of the globe. Tenonplasty is a surgical procedure which involves advancing the Tenon's capsule over the ischemic areas to provide a vascular supply and to enable migration of the conjunctival epithelium. This review aims to provide an overview of the diagnosis of limbal ischemia and its management with Tenonplasty. A literature review was conducted using the keywords "Tenonplasty," "Tenon's capsule," "ocular chemical injury," "ocular thermal injury," "Tenon advancement," "scleral ischemia," and "limbal ischemia," and outcomes were studied from seven selected articles. In addition to clinical evaluation, in vivo imaging techniques such as anterior segment optical coherence tomography angiography can provide an objective method of measuring and monitoring the ischemia and re-perfusion of the peri-limbal vasculature. Tenonplasty can be performed in eyes with acute OCBs with scleral or limbal ischemia by dissecting the Tenon's layer from the orbit and securing it to the limbus. The indications, mechanism of action, peri-operative considerations, surgical technique, and post-operative care of Tenonplasty are discussed in detail. The average time for post-operative re-epithelization ranges from 1 to 6 months with the formation of a symblepharon being the most common complication. In conclusion, Tenonplasty is a globe-salvaging procedure in cases with severe limbal and scleral ischemia because of OCBs and has good anatomical outcomes priming the globe for subsequent re-constructive and vision-restoring surgeries.

Drug induced cicatrizing conjunctivitis: A case series with review of etiopathogenesis, diagnosis and management.

Drug induced cicatrizing conjunctivitis (DICC) is defined as a disease in which conjunctival cicatrization develops as a response to the chronic use of inciting topical and, rarely, systemic medications. DICC accounts for up to one third of cases of pseudopemphigoid, a large group of cicatrizing conjunctival diseases sharing similar clinical features to those of mucous membrane pemphigoid (MMP) but generally without the morbidity of progressive scarring or the need for systemic immunosuppression. The preservatives in topical anti-glaucoma medications (AGM) are the most frequently implicated inciting causes of DICC although topical antivirals, vasoconstrictors and mydriatics and some systemic drugs have been implicated. The literature review summarizes the classification, epidemiology, etiopathogenesis, histopathology, clinical presentation, diagnosis, management, and treatment outcomes of DICC in the context of a case series of 23 patients (42 eyes) with AGM induced DICC, from India and the UK. In this series all subjects reacted to preserved AGM with one exception, who also reacted to non-preserved AGM. At diagnosis >70% of eyes showed punctal scarring, inflammation, and forniceal shortening. Pemphigoid studies were negative in the 19/23 patients in whom they were carried out. DICC can be classified as non-progressive, progressive with positive pemphigoid immunopathology or progressive with negative pemphigoid immunopathology. It is unclear whether progressive DICC is a stand-alone disease, or concurrent (or drug induced) ocular MMP. Progressive cases should currently be treated as ocular MMP. The diagnosis can be made clinically when there is rapid resolution of symptoms and inflammation, usually within 1-16 weeks, after withdrawal of suspected inciting medications, ideally by temporary substitution of oral carbonic anhydrase inhibitors. If the response to withdrawal is uncertain, or the progression of inflammation and scarring continues then patients must be evaluated to exclude concurrent (or drug induced) MMP, and other potential causes of CC, for which the treatment and prognosis is different. Management, in addition to withdrawing inciting medications, may require short-term treatment of conjunctival inflammation with steroids, treatment of associated corneal disease with contact lenses or surface reconstructive surgery, control of intra-ocular pressure with non-preserved AGM and, in some, surgery for glaucoma or for trichiasis and entropion.

Dye-based identification of the orientation of tissue for Descemet stripping automated endothelial keratoplasty: A laboratory-based study.

Purpose: To describe the features enabling the identification of the orientation of Descemet stripping automated endothelial keratoplasty (DSAEK) lenticule with the assistance of vital dyes. Methods: This is a blinded experimental lab-based study, including 30 microkeratome prepared precut DSAEK lenticules. The lenticules were divided into control and study arms which included 10 unstained and 20 stained lenticules, respectively. In the study arm, vital dyes like trypan blue (TB), brilliant blue (BB), indocyanine green (ICG) and fluorescein stain (FS) were used to stain 5 lenticules each. They were examined by experienced (group 1) and novice surgeons (group 2) to identify the correct orientation of the lenticule. The results were tabulated and analyzed. Results: Of the 30 lenticules examined, the average of total scores obtained by each observer was higher (78%) in group 1 as compared to group 2 (65.3%) which was statistically significant (P < 0.005). In group 1, the accuracy of identifying the correct orientation of unstained lenticules was 70% which improved to 82% on staining. The accuracy in group 2 was 58% with unstained lenticules which improved to 69% on staining. Within the study arm, irrespective of surgical experience, the accuracy was highest with BB (86%), followed by TB (82%), ICG (72%) and FS (62%). Conclusion: This study found that the accuracy of identifying the orientation of DSAEK lenticules increased with experience and with the assistance of staining using vital dyes. This accuracy improved with blue dyes like brilliant blue and trypan blue, irrespective of the level of experience.

A case series of ocular involvement in bullous pemphigoid: clinical features, management, and outcomes.

Ocular involvement in cases of bullous pemphigoid is rare and when present, the signs are usually subtle and in the form of fine tarsal scarring and dry eye disease. The current report aims to describe the clinical features and management protocols in a series of cases with aggressive ocular manifestations at presentation. All cases of bullous pemphigoid seen between 2017 and 2020 were included in this retrospective case series. Data regarding the clinical features, treatment administered, and outcomes was collected. Five cases (n=10 eyes) of bullous pemphigoid disease with ocular involvement were included. All eyes had significant cicatricial conjunctival changes in the form of symblephara, inferior forniceal shortening, and tarsal conjunctival scarring. Conjunctival granulomas were present in 3/10 eyes. Corneal involvement in the form of punctate keratitis was present in all eyes while 4/10 eyes had an epithelial defect as well. The management of these cases involved topical therapy with corticosteroids and lubricants (n=10 eyes) while pulse doses of intravenous methyl prednisolone were administered in 5/5 cases. Pulse intravenous cyclophosphamide was supplemented in 2/5 cases. Adequate control of the disease was noted in 3/5 cases while one case had a recalcitrant form of the disease and developed a dermalised ocular surface in both eyes. The last patient was lost to follow up during the course of therapy. Bullous pemphigoid can present with an aggressive form of cicatrizing conjunctivitis similar to other variants of autoimmune blistering disorders and must be considered as a differential in cases presenting with ocular cicatricial disease. Long-term intensive immunosuppression is required for the management of these cases to preserve the visual function and the integrity of the globe.

High-Resolution Optical Coherence Tomography Angiography Characteristics of Limbal Stem Cell Deficiency.

This study aimed to identify the anterior segment high-resolution optical coherence tomography (HR-OCT) and HR-OCT angiography (HR-OCTA) features suggestive of limbal stem cell deficiency (LSCD) as confirmed by both impression cytology (IC) and in vivo confocal microscopy (IVCM). This was a single-centre prospective cross-sectional study including 24 eyes of 22 patients with clinical suspicion of LSCD based on peripheral superficial corneal vascularisation and scarring. On IC and IVCM, performed and interpreted by blinded observers, 12 eyes each were diagnosed with and without LSCD. Additionally, 10 eyes of 5 healthy volunteers with no ocular pathology were also imaged. The 136 HR-OCT/A images of these 34 eyes were analysed with respect to 12 imaging parameters; the parameters most suggestive of LSCD were identified and the sensitivity and specificity were calculated. In the LSCD group, the most common aetiology was ocular chemical burns (83%), whereas in the non-LSCD group, the most common aetiology was viral keratitis (67%). Multiple logistic regression analysis revealed that mean epithelial reflectivity, mean stromal reflectivity, and mean superficial vascular density were the parameters that were diagnostic of LSCD on HR-OCT/A (p < 0.0001). A ratio of the mean epithelial reflectivity to stromal reflectivity of >1.29 corresponded with a high sensitivity (91.7%) and specificity (98.75%); while a mean superficial vascular density score of >0.38 corresponded with a sensitivity of 97.9% and specificity of 73.8%. In conclusion, HR-OCT/A as a non-invasive imaging modality could prove to be a useful tool for confirming the diagnosis of LSCD, with potential clinical and research applications.

A beginner's guide to mucous membrane grafting for lid margin keratinization: Review of indications, surgical technique and clinical outcomes.

The posterior lid margin, where the mucocutaneous junction (MCJ) between the eyelid skin and tarsal conjunctiva is located, plays a critical role in maintaining the homeostasis of the ocular surface. Posterior migration of the MCJ leads to lid-margin keratinization (LMK), which has a domino effect on the delicate balance of the ocular surface microenvironment. This occurs most commonly following Stevens-Johnson syndrome/toxic epidermal necrolysis and is not known to regress spontaneously or with medical therapy. Over time, LMK causes blink-related chronic inflammatory damage to the corneal surface which may have blinding consequences. Lid-margin mucous membrane grafting (MMG) is the only definitive therapy for LMK. Timely MMG can significantly alter the natural course of the disease and not only preserve but even improve vision in affected eyes. Literature searches were conducted on PubMed, using the keywords "mucous membrane grafts," "lid margin keratinization," "Stevens-Johnson syndrome," "toxic epidermal necrolysis," "lid related keratopathy," and "lid wiper epitheliopathy". This review, which is a blend of evidence and experience, attempts to describe the indications, timing, surgical technique, postoperative regimen, and clinical outcomes of MMG for LMK. The review also covers the possible complications and pearls on how they can be effectively managed, including how suboptimal cosmetic outcomes can be avoided. The authors hope that this review will aid ophthalmologists, including cornea and oculoplasty specialists, to learn and perform this vision-saving surgery better, with the aim of helping their patients with chronic ocular surface disorders, relieving their suffering, and improving their quality of life.

Dry eye disease in children and adolescents in India.

PURPOSE: To describe the etiological causes and clinical profile of dry eye disease (DED) among children and adolescents seeking eye care in India. METHODS: This was a cross-sectional study of 1023 new patients (≤21 years of age) diagnosed with DED presenting between 2010 and 2018 to a multi-tier ophthalmology hospital network. Children and adolescents with both symptoms and signs of dry eyes were considered as subjects. The data entry and retrieval were done using an electronic medical record system and analyzed using appropriate statistical tests. RESULTS: The mean age of the patients was 15.2 ± 5.6 years and 76% were in their early and late adolescence. Overall, the main etiologies responsible for DED in children and adolescents were Meibomian gland dysfunction (MGD) in 49% of cases, Stevens-Johnson Syndrome (SJS) in 33% and Vitamin A deficiency (VAD) in 9%. Aqueous deficiency dry eye (ADDE) because of SJS and VAD accounted for most of the cases in infancy (92%), toddlerhood (96%), early childhood (76%) and middle childhood (68%). While Meibomian gland dysfunction (MGD) related evaporative dry eye (EDE) was the leading cause of DED in early (51%) and late adolescence (66%). Severe visual impairment and blindness was significantly greater in eyes with ADDE as compared to those with EDE (p < 0.0001), 81% of which were affected by SJS. CONCLUSION: The causes of and visual morbidity due to DED varied significantly in different age-groups. Most of the visual morbidity in children and adolescents was limited to eyes with ADDE due to SJS.

Clinical clues predictive of Stevens-Johnson syndrome as the cause of chronic cicatrising conjunctivitis.

PURPOSE: This study aimed to identify the clinical clues in patients with chronic cicatrising conjunctivitis (CCC), that were suggestive of Stevens-Johnson syndrome (SJS) as the aetiology. METHODS: This was a cross-sectional observational study of 75 patients presenting with CCC from 2016 to 2018. Those with a documented diagnosis of SJS (n=43) were included as cases; while those with a positive serology or tissue biopsy for a non-SJS condition were included as controls (n=32). The features in the medical history and clinical examination that were positively and negatively associated with SJS were scored +1 and -1, respectively. A receiver operating characteristic (ROC) curve analysis was performed to detect the threshold score for optimal sensitivity and specificity of the scoring system. RESULTS: No single feature had absolute sensitivity and specify for SJS. The 10 positive features suggestive of SJS (p<0.0001) included (1) history of: acute conjunctivitis, fever or drug intake preceding conjunctivitis, peeling of skin on pressure, loss of nails and severe morbidity with hospital admission; and (2) clinical features of: skin discoloration, nail disfigurement, lip-margin dermalisation, lid-margin keratinisation and distichiasis. The two negative criteria were history of mucosal ulcers without skin involvement and recurrent mucosal ulceration. On ROC analysis, a score of >5 showed a sensitivity of 90.7% and specificity of 93.8% for the diagnosis of SJS. CONCLUSIONS: The combination of clinical clues identified in this study can help clinicians confirm SJS as the aetiology of conjunctival cicatrisation, especially when reliable documentation of the acute episode is not available.

Outcomes of Corneal Transplantation Using Donor Corneas Retrieved From Snakebite Victims.

PURPOSE: To report the outcomes of corneal transplantation using donor corneas retrieved from snakebite victims. METHODS: This study was a retrospective analysis of 30 corneal transplants performed from 2014 to 2016 using donor corneas retrieved from snakebite victims. The details of the donor corneal characteristics and the transplant recipients were collected from the eye bank and the medical records department. RESULTS: The mean age of the donors was 30.4 ± 17.5 years. The median death-to-preservation time was 3.3 hours [interquartile range: 1.3-5.6 hours]. Ninety percent (27/30) of the corneas were evaluated as optical grade, and 10% (3/30) of the corneas were deemed as therapeutic grade. The mean endothelial cell density on specular microscopy of the donor corneas was 2943 ± 615 cells/mm, and median corneal thickness was 514 µm (interquartile range: 506-520). Seventy-five percent of the corneas transplanted had cleared, with a mean follow-up duration of 1.5 ± 1.0 years (range: 0.4-3.7) years and mean logarithm of the minimum angle of resolution (LogMAR) visual acuity of 0.51 ± 0.27 (range: 0-1.2) at the last follow-up. CONCLUSIONS: The donor corneas retrieved from snakebite victims are apparently safe and suitable for transplantation, and screening for such donor corneas should include a thorough examination of ocular adnexa to rule out local envenomation before corneal retrieval in addition to the routine evaluation protocol.

Incidence, demographics, types and risk factors of dry eye disease in India: Electronic medical records driven big data analytics report I.

PURPOSE: To describe the incidence, demographics, types and risk-factors of dry eye disease (DED) in patients presenting to a multi-tier ophthalmology hospital network in India. METHODS: This was an observational hospital-based study of 1,458,830 new patients presenting between 2010 and 2018. Patients with recent onset of both symptoms and signs, as defined by the tear film and ocular surface society dry eye work shop (TFOS DEWS) II guidelines, were considered as DED subjects. The data was prospectively collected using an electronic medical record system. Multiple logistic regression with odds ratio (OR) estimation was performed to identify the high risk-factors of DED. RESULTS: Overall, 21,290 (1.46%) patients were diagnosed with recent-onset DED. The incidence of DED was 2688 and 16,482 per million population in children and adults, respectively (p < 0.0001). While incidence was significantly greater in males in 3rd, 4th, 9th and 10th decade (p < 0.03), it was greater in females in 5th and 6th decade (p < 0.0001) of life. Classified etiologically 35.5%, 20.6% and 39.9% of patients had evaporative, aqueous deficient and mixed type of DED, respectively. Age (OR 3.7-13.5), urban residence (OR 1.6), professional work (OR 1.5); homemaking (OR 1.42), retirement/unemployment (OR 1.24) and socio-economic affluence (OR 1.6-3.2) were identified as high risk-factors for developing DED. CONCLUSION: The study results indicate that age, sex, residence, occupation, and socio-economic status have significant impact on development of DED. Since India is an emerging economy with a growing middle-class, increasing urban-migration and large aging population, the country is on the brink of a DED epidemic.

Evaporative dry eye disease due to meibomian gland dysfunction: Preferred practice pattern guidelines for diagnosis and treatment

Evaporative dry eye (EDE) due to meibomian gland dysfunction (MGD) is one of the common clinical problems encountered in ophthalmology. It is a major cause of dry eye disease (DED) and of ocular morbidity. In EDE, inadequate quantity or quality of lipids produced by the meibomian glands leads to faster evaporation of the preocular tear film and symptoms and signs of DED. Although the diagnosis is made using a combination of clinical features and special diagnostic test results, the management of the disease might be challenging as it is often difficult to distinguish EDE from other subtypes of DED. This is critical because the approach to the treatment of DED is guided by identifying the underlying subtype and cause. The traditional treatment of MGD consists of warm compresses, lid massage, and improving lid hygiene, all measures aimed at relieving glandular obstruction and facilitating meibum outflow. In recent years, newer diagnostic imaging modalities and therapies for EDE like vectored thermal pulsation and intense pulsed light therapy have emerged. However, the multitude of management options may confuse the treating ophthalmologist, and a customized rather than a generalized approach is necessary for these patients. This review aims to provide a simplified approach to diagnose EDE due to MGD and to individualize treatment for each patient. The review also emphasizes the role of lifestyle modifications and appropriate counseling so that patients can have realistic expectations and enjoy a better quality of life.

Tear film microbiome in Sjogren’s and non-Sjogren’s aqueous deficiency dry eye

Purpose: To understand the bacterial microbiome changes associated with Sjogren’s syndrome (SS) and non?Sjogren’s syndrome (NSS) aqueous?deficient dry eyes compared to healthy eyes. Methods: Bacterial microbiome was generated from the deoxyribonucleic acid of tear film samples in healthy (n = 33), SS (n = 17), and NSS (n = 28) individuals. Sequencing of the V3?V4 region of the 16S rRNA gene was performed on the Illumina HiSeq2500 platform. Quantitative Insights Into Microbial Ecology (QIIME) pipeline was used to assign taxa to sequences. Statistical analysis was performed in R to assess the alpha diversity and beta diversity indices. Significant changes between the healthy, SS, and NSS cohorts were depicted by principal coordinate analysis (PCoA), differential abundance, and network analysis. Results: Tear microbiome was generated in healthy, SS, and NSS samples. Phyla Actinobacteria, Firmicutes, and Bacteroidetes showed significant changes in SS and NSS compared to healthy. Genera Lactobacillus and Bacillus were predominantly present in all samples. PCoA and heat map analysis showed distinct clusters for SS and NSS from the healthy cohort. Genera Prevotella, Coriobacteriaceae UCG?003, Enterococcus, Streptomyces, Rhodobacter, Ezakiella, and Microbacterium significantly increased in abundance in SS and NSS compared to a healthy cohort. Bacteria–bacteria interaction in SS, NSS, and healthy cohorts was predicted by CoNet network analysis. This analysis predicted a major hub of interaction for the pro?inflammatory bacterium Prevotella in the SS and NSS cohorts. Conclusion: The results of the study indicate significant changes in the phyla and genera in SS and NSS compared to healthy. Both discriminative analysis and network analysis indicated a possible association of predominant pro?inflammatory bacteria with SS and NSS.