Filamentary keratitis: A review.

Filamentary keratitis (FK) is a clinical sign of underlying ocular and systemic conditions. FK can cause significant irritation, tearing, and photophobia in the eye. It is a refractory debilitating condition caused by dry eye that affects the day-to-day activities of patients. The etiopathogenesis of FK is not well known; there are numerous predisposing causes. The condition starts as a sub-epithelial or Bowman's membrane dysfunction and leads to the shedding of epithelial cells that take a strand-like form and attach to the cornea. These strands are surrounded by mucin and continue to elongate to become filaments. The filament formation is further aided by the shearing action caused by eyelid movements. Several management approaches, such as addressing the underlying causes of filamentary keratitis, administering copious lubricants, topical corticosteroids, mucolytic agents, bandage contact lenses, punctal plugs, and mechanical removal of filaments are available. The prognosis is fair, and most cases resolve with occasional recurrences. Traditionally FK has been treated with lubricants, mechanical removal, and bandage contact lenses. The newer treatments are topical immunomodulators especially that treat filamentary keratitis associated with aqueous deficient dry eye. The review describes the treatment as well as pathogenesis.

Keratoconus in India: Clinical presentation and demographic distribution based on big data analytics.

PURPOSE: This paper aims to describe the clinical presentation and demographic distribution of keratoconus (KCN) in India by analyzing the electronic medical records (EMR) of patients presenting at a multitier ophthalmology hospital network. METHODS: This cross-sectional hospital-based study included the data of 2,384,523 patients presenting between January 2012 and March 2020. Data were collected from an EMR system. Patients with a clinical diagnosis of KCN in at least one eye were included in this study. Univariate analysis was performed to identify the prevalence of KCN. A multiple logistic regression analysis was performed using R software (version 3.5.1), and the odds ratios are reported. RESULTS: Data were obtained for 14,749 (0.62%) patients with 27,703 eyes diagnosed with KCN and used for the analysis. The median age of the patients was 22 (inter-quartile range (IQR): 17-27). In total, 76.64% of adults (odds ratio = 8.77; P = <0.001) were affected the most. The majority of patients were male (61.25%), and bilateral (87.83%) affliction was the most common presentation. A significant proportion of the patients were students (63.98%). Most eyes had mild or no visual impairment (<20/70; 61.42%). Corneal signs included ectasia (41.35%), Fleischer ring (44.52%), prominent corneal nerves (45.75%), corneal scarring (13.60%), Vogts striae (18.97%), and hydrops (0.71%). Only 7.85% showed an association with allergic conjunctivitis. A contact lens clinic assessment was administered to 47.87% of patients. Overall, 10.23% of the eyes affected with KCN underwent a surgical procedure. the most common surgery was collagen cross-linking (8.05%), followed by deep anterior lamellar keratoplasty (1.13%) and penetrating keratoplasty (0.88%). CONCLUSION: KCN is usually bilateral and predominantly affects males. It commonly presents in the second and third decade of life, and only a tenth of the affected eyes require surgical treatment.

A survey of Asian Eye Institutions on perioperative antibiotic prophylaxis in cataract surgery.

PURPOSE: To determine current institutional practice patterns for the use of perioperative antibiotics and other measures to prevent infection after cataract surgery in Asia. METHODS: An online survey-based study of leading eye institutions in China, Hong Kong, India, Indonesia, Japan, Malaysia, Pakistan, Philippines, Singapore, South Korea, Taiwan, Thailand and Vietnam was conducted. The survey was administered to 26 representative key opinion leaders from prominent tertiary eye institutions that are also national academic teaching institutions in Asia. Survey responses were collated and anonymized during analysis. RESULTS: All surveyed institutions used povidone iodine for the preoperative antiseptic preparation of the eye, with notable variations in the concentration of povidone iodine used for conjunctival sac instillation. Preoperative topical antibiotics were prescribed by 61.5% and 69.2% of institutions in low-risk and high-risk cases, respectively. Regarding the use of intra-operative antibiotics, 60.0% and 66.7% of institutions administered intracameral antibiotics in low-risk and high-risk patients, respectively. Postoperative topical antibiotics use patterns were generally very similar in low-risk and high-risk patients. Over half of the institutions (52.2% and 68.0% in low-risk and high-risk patients, respectively) also indicated prolonged postoperative use of topical antibiotics (> 2 weeks). Not all surveyed institutions had established policies/protocols for perioperative antibiotic use in cataract surgery, endophthalmitis surveillance, and/or a monitoring program for emerging antimicrobial resistance. CONCLUSION: There are variations in antimicrobial prophylaxis approaches to preoperative, intra-operative and postoperative regimens in cataract surgery in Asia. More evidence-based research is needed to support the development of detailed guidelines for perioperative antibiotic prophylaxis to reduce postoperative infections.

Donor related corneal graft infection: a review of literature and preventive strategies.

PURPOSE: Donor-related infections are a serious threat to patient safety after corneal transplantation. We provide a concise review of literature from the last decade on donor-related graft infections, sources of contamination and means to reduce the contamination of donor tissue and preservation media. METHODS: We reviewed 50 papers from year 2005 to 2021 related to donor-related graft infections. We included 14 studies related to the risk factors associated with post-keratoplasty infection and preventive methods. RESULTS: Incidence of post-keratoplasty infections has been reported to be approximately 0.2%-0.77% for endophthalmitis and 6.5%-10.5% for microbial keratitis. We analyzed six important studies regarding the risk factors related to donor contamination. It was observed that younger donor age, increased death to retrieval time, warming cycles and increased eye bank processing time and positive corneo-scleral rim cultures were important risk factors for donor-related infections post keratoplasty. Eye banks have adapted newer protocols over the time period for prevention of donor-related contamination. Recommended preventive strategies were published in about eight important studies over the past decade. In addition to meticulous donor screening, rapid warming cycles, double contact with povidone iodine during retrieval and addition of antifungals like amphotericin B, Voriconazole and cycloheximide have been suggested over the last decade although their use is still in debate with regard to the efficacy, toxicity and cost-effectiveness. CONCLUSION: The last decade has witnessed a relative rise of fungal infections and multidrug resistant bacterial infections post-keratoplasty. Eye bank prepared corneas for lamellar surgeries are at increased risk for donor contamination due to increased exposure to the higher temperatures during their processing. Addition of antifungals and broad spectrum antibiotics to the hypothermic preservation media needs to be considered in the new era of increasing trends of lamellar keratoplasty.

Challenges in management of microbial keratitis during COVID-19 pandemic related lockdown: a comparative analysis with pre pandemic data.

PURPOSE: To study the challenges of managing microbial keratitis(MK) during the COVID19 pandemic related lockdown and assess the outcomes of treatment at a tertiary cornea service. METHODS: Retrospective, non comparative study of electronic medical records of MK presenting to a network of four tertiary care cornea services. The medical history, presenting clinical features, microbiology work up and treatment outcomes were analyzed. The primary outcome measure was final outcome at last follow up. Secondary outcomes measures were non-compliance to treatment due to travel restrictions, therapeutic PKP not done due non availability of corneal tissues. Results- MK was noted in 330 eyes of 330 patients between April and May 2020. Of these 237(71.8%) were males. Median age was 45 years(IQR, 33-56). Low socioeconomic status noted in 102(30.9%). Patients travelling beyond the district from where the hospital was located comprised of 64.9%(n=214). At a median follow up of 32 days(IQR, 9-54), 118(35.8%) patients had resolved, with medical management, 73(22.1%) patients were under active treatment, 139(42.1%) were lost to follow up. Sixty-six patients(20%) were non-compliant to treatment of which 59 could not follow appointment schedule due to travel restrictions. Therapeutic PKP (TPK) was planned in 48/128 (37.5%) patients, but was performed in only 34/48 (70.8%) due to non-availability of donor corneas. CONCLUSIONS: Abnormal social circumstances due to the COVID pandemic and the ensuing impediments to travel for access to health care affected compliance to treatment of ocular emergencies such as microbial keratitis.

Overview of Short-Term and Intermediate-Term Corneal Storage Solution: Comparison of Clinical Outcomes and Need For Future Research.

ABSTRACT: Corneal donor tissue preservation techniques have incrementally improved since the introduction of McCarey-Kaufman storage solution from short-term storage to intermediate duration of storage with the advent of organ culture and Optisol GS storage solutions. Improved understanding of the corneal endothelial cell physiology has helped in designing newer storage solutions, such as the Life 4C and Cornea Cold. The incorporation of antibiotics, ATP precursors, minerals, and vitamins has improved the viability of tissues. In addition, these modifications to the newer storage solutions have increased the endothelial longevity and metabolic activity. Despite these advances, the duration of tissue storage has largely been restricted to 2 weeks in Optisol GS and 4 weeks in organ culture. The role and cost-effectiveness of antifungal supplementation and the need for improved epithelial preservation are additional areas that need to be explored. This review intends to summarize the efficacy and viability of donor corneas in different tissue storage solution and compare clinical outcomes while providing an insight into the challenges in developing newer methods of corneal preservation.

Polymeric Drug Delivery Devices: Role in Cornea and External Disease.

ABSTRACT: The field of ophthalmic drug delivery is undergoing rapid changes not only in the evolution of pharmacologic agents but also in the novel drug delivery vehicles. The ocular surface has limitations to drug penetration because of the presence of tight junctions between basal epithelial cells, which limits the amount of drug that can be absorbed after topical instillation. In addition, nasolacrimal drainage reduces the precorneal residence time significantly. Contact lenses (CLs) have been considered as possible carriers for topical medications because they reside on the ocular surface for a sufficient length of time, and pharmacologic agents may be copolymerized with hydrogels allowing controlled drug diffusion. This strategy reduces the frequency of dosage while improving compliance. Modification of drug delivery vehicles is essential to allow sustained release of the drug from a polymeric complex, facilitate stability and residence time of the drug on the precorneal tear film, and improve penetration into biologic membranes. This review focuses on updates in CL-based and non-CL-based strategies in ophthalmic drug delivery.

Patterns of Non-Infectious Scleritis across a Tertiary Eye Care Network Using the Indigenously Developed Electronic Medical Record System-eyeSmart.

PURPOSE: To report the pattern of noninfectious scleritis across a tertiary eye-care network. METHODS: A three-year retrospective review of patients diagnosed with noninfectious scleritis was performed. Data were retrieved using diagnostic terms assigned to scleritis through the in-house eyeSmart-electronic medical record system. RESULTS: 1103 patients, with a mean age of 44.33 ± 14.38 years and a median follow-up of 199.5 days (range 32-685) were enrolled. Unilateral disease was noted in 85%. Diffuse anterior scleritis (n = 542, 42.51%) and nodular scleritis (n = 482, 38.12%) were the commonest subtypes. Systemic immune disease association was present in 65 (5.89%). Treatment at onset was topical corticosteroids (n = 372, 36.54%) followed by oral non-steroidal anti-inflammatory drugs (n = 351, 34.45%), oral corticosteroids in 184 (19.04%), and immunomodulators in 32 patients (3.54%). CONCLUSIONS: This study depicts the pattern of various noninfectious scleritis in a large cohort of patients. The present study helped to further customize the electronic medical records to minimize several data capture limitations.

Effect of Donor Age and Corneal Endothelial Cell Density on Non-utilization of Donor Corneal Tissues: A Study From Indian Eye Banks.

PURPOSE: To study the causes of non-utilization of donor corneas and assess whether non-utilized tissues differ from utilized tissues with regard to age and endothelial cell density (ECD). METHODS: Aretrospective, cross-sectional analyses of all donor corneas collected from a network of 4 eye banks of a tertiary eye care institute in India during a 1-year period (January to December 2019) was conducted. All donor corneas were assessed for tissue quality by slit lamp evaluation, donor age, and specular microscopy. The causes of non-utilization and effect of donor age and ECD on tissue utilization were studied. RESULTS: A total of 10,969 corneas were harvested during the study period; 4618 (42.1%) tissues were discarded. The main causes of non-utilization were poor tissue quality accounting for 86.16% (n = 3979) of all discarded corneas. The mean donor age was 50.7 ± 2.9 years and 63.3 ± 2.3 years for used and discarded corneas, respectively (P < 0.0001). The mean ECD of donor tissues was significantly (P < 0.0001) higher in the utilization group (2787.3 ± 77.4 cells/mm2) than that in the non-utilization group (2394.4 ± 82.5 cells/mm2). Donor age and ECD and their interaction were significant (P < 0.001) predictors of tissue utilization rate. CONCLUSIONS: Donor age and ECD and their interaction were significantly associated with the rate of utilization of donor corneal tissues.

Ocular Surface Squamous Neoplasia With Coexistent Microbial Keratitis: Incidence, Risk Factors, Clinical Features, Microbiological Profile, and Treatment Outcome.

PURPOSE: The purpose of this study was to evaluate the incidence, clinical features, microbiology, risk factors, and treatment outcomes in cases of ocular surface squamous neoplasia (OSSN) with coexisting microbial keratitis (MK). METHODS: This was a retrospective case-control study from a cohort of 939 cases with OSSN. RESULTS: Twenty eyes (2%) with OSSN and MK were included in the study group and 100 age-matched eyes with only OSSN as controls. Most common presentation was a combination of pain, redness, watering, and decreased vision (50%) over a median duration of 14 days. Mean corneal surface involvement by MK was 48% with corneal perforation in 6 cases (30%). Microbiology showed 10 culture positive cases for Gram-positive organisms (n = 5), fungus (n = 4), or mixed infection (n = 1). In the salvaged eyes, MK resolved in 9 eyes (90%) on medical treatment at a mean duration of 30 days and keratoplasty was performed in 1 eye. OSSN treatment included wide excisional biopsy (n = 9/18; 50%), extended enucleation (n = 7/18; 39%), and orbital exenteration in 1. Over a mean follow-up of 12 months, vision salvage was achieved in 7 of 18 (39%) and globe salvage in 10 of 18 (55%). Logistic regression analysis showed the following significant risk factors for MK in OSSN: male sex, human immunodeficiency virus seropositivity, increasing tumor diameter, limbal epicenter, temporal quadrant, noduloulcerative morphology, pigmentation, scleral invasion, keratin, and corneal component of the OSSN lesion. CONCLUSIONS: Rarely, MK can coexist with OSSN leading to a poor treatment outcome. Male sex, human immunodeficiency virus seropositivity, large limbal pigmented OSSN lesion with keratin and corneal component, noduloulcerative morphology, and scleral invasion were risk factors for this association.

Clinical profile and microbiological trends of therapeutic keratoplasty at a network of tertiary care ophthalmology centers in India.

OBJECTIVE: To describe the clinical profile and microbiology trends in patients undergoing therapeutic keratoplasty at a multi-tier ophthalmology hospital network in India. METHODS: This cross-sectional hospital-based study included 3147 eyes undergoing therapeutic keratoplasty between Jan 2016 and Dec 2020 (5 years period) as cases. The demographic data, clinical profile and microbiological analysis were collected using an electronic medical record system. RESULTS: Of a total of 13,625 eyes with microbial keratitis(non-viral), 3147 (23.1%) underwent therapeutic keratoplasty during the study duration. Majority of patients were males (68.35%), from a rural geography (49.89%) and in 51-60 years age bracket (23.74%). The mean age of the patients was 50.54 ± 15.83 years. Two-thirds of patients were from lower socio-economic strata (66.63%) with an agrarian background (36.51%). Of the 3,147 eyes, fungus (51.8%) was the most common indication of therapeutic keratoplasty followed by bacteria (16.87%) and parasite (1.27%). No organisms could be identified in about a third (29.33%) of the cases. Between 2016 and 2020, the trend of therapeutic keratoplasties for fungal infections steadily grew (39.9% vs 45.49%) while the bacterial infections showed a steady decline (23.15% vs 11.81%). CONCLUSIONS: Medical cure rate was seen in majority of those with microbial keratitis, and 23.1% eventually required management with therapeutic keratoplasty. Fungal keratitis was the most common indication for therapeutic keratoplasty. Male gender, rural setting, low socio-economic background and agricultural occupation are common risk factors for patients undergoing therapeutic keratoplasty in India.

Intermediate outcomes of therapeutic penetrating keratoplasty for severe microbial keratitis using glycerol-preserved donor corneas during the COVID-19 pandemic.

Purpose: To report the intermediate outcomes of therapeutic penetrating keratoplasty (TPK) performed for severe microbial keratitis using glycerol-preserved corneas during the Corona virus diseases of 2019 (COVID-19). Methods: Retrospective non-comparative case series from April to August 2020 in a network of tertiary eye care centers. Glycerol-preserved tissues were used for therapeutic keratoplasty (TPK). We reviewed the demographics, microbiology, surgical outcomes such as wound integrity, recurrence, graft melt, epithelialization, and complications. Results: A total of 49 eyes that underwent TPK with glycerol-preserved corneal tissues were analyzed. The primary indication was severe microbial keratitis in 47 eyes. The majority was a fungal infection in 33 eyes (67.3%). The mean age was 53.8 ± 12.2 years, with male predominance (3:1). The corneas were stored for an average of 85.5 ± 53 days prior to transplant. The median donor age was 65 years. The grafts were tectonically stable in 32/36 eyes (88.9%) at 1 month and 20/24 eyes (83.3%) at 3 months. The graft melt was noted in three eyes at 1 and 3 months. The recurrence of the infection was noted in four eyes and all were of fungal etiology. The graft epithelialization was delayed with a mean duration of 48.9 ± 25 days after surgery. Post-TPK, raised intra-ocular pressure (>21 mm Hg) was noted in 51.2% at 1 week, 17.4% at 1 month, and 11.8% at 3 months. Conclusion: Glycerol preservation is a reliable alternative with good therapeutic outcomes in the short and interim postoperative period. Delayed epithelialization and secondary glaucoma were the commonest postoperative complications.

Thygeson's superficial punctate keratopathy: A review and case series.

Thygeson's superficial punctate keratitis (TSPK) is a chronic disorder with episodes of exacerbations and remissions which span over years to decades. Typical features of the disease include multiple, grayish white, intraepithelial corneal lesions with minimal or no conjunctival involvement. The exact etiopathogenesis of this entity is unknown. However, it may have a genetic association with HLA-DR3, an antigen proved to be associated with immunogenic responses. Treatment of the disease consists of artificial tears, topical corticosteroids, topical cyclosporine, topical tacrolimus, or usage of soft contact lenses. TSPK should be considered as a diagnosis of exclusion in cases of bilateral superficial punctate keratopathy of long duration. Thirteen patients of TSPK were examined during the last 6 years (2014-2019) at our Institute. Visual acuity was 20/20 to 20/30 in majority cases. All patients required lubricants.

Seropositivity of blood samples of 31,355 cornea donors from a tertiary care network of eye banks.

PURPOSE: To evaluate the seropositivity of human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV) and syphilis from blood samples of cornea donors and assess correlation between seropositivity for HIV and syphilis. METHODS: Retrospective analysis of blood samples of 31,355 cornea donors for HIV, HBV, HCV, and syphilis was performed. Postmortem blood samples were analyzed by a rapid screening test for anti-HIV envelope antibodies against HIV 1 and 2, HBV surface antigen, antibody to HCV and anti-cardiolipin antibodies for syphilis by rapid plasma reagin test. RESULTS: The overall seropositivity rate was 4.28% (1343/31,355 donors). All positive donors were reactive for a single serological test. The seropositivity rate for HIV was 0.93% (95% CI 0.83-1.04%), for HBsAg was 1.56% (95% CI 1.43-1.7%), for HCV was 1.19% (95% CI 1.08-1.33%) and for syphilis was 0.59% (95% CI 0.52-0.69%). The trends in seropositivity rates showed a decline for three viral markers: HIV (2010, 1.17% to 2018, 0.72%, p = 0.02), HBsAg (2010, 1.98% to 2018, 1.05%, p = 0.0006) and HCV (2010, 1.32% to 2018, 0.43%, p < 0.0001). The seropositivity rates for syphilis showed a progressive increase when compared to baseline (2010, 0.14% to 2018, 1.14%, p < 0.0001). There was no relationship between seropositivity for HIV and syphilis (p = 0.18). CONCLUSIONS: The overall seropositivity for HIV, HBV, HCV and syphilis was 4.28%. Seropositivity was highest for HBV. The study did not find correlation between seropositivity of HIV and syphilis.

Impact of nationwide COVID-19 lockdown on keratoplasty and eye banking in India: A survey of cornea surgeons and eye banks.

PURPOSE: The aim of this study was to analyze the impact of COVID-19 lockdown on keratoplasty and Eye Banking in India. METHODS: An e-mail survey was conducted among cornea surgeons and eye bankers of India. Participants were asked to report their practice patterns for the management of corneal perforation during lockdown, different preservative media used during and before lockdown, and waiting time and waiting time before COVID-19 lockdown. RESULTS: Eight of 20 eye banks did not collect corneal tissue during April-June 2020; in contrast, 9 eye banks used to collect around 100 corneas per month during pre-COVID-19 time. Two-third of the surgeons (66.1%, n = 41/62) did not perform any corneal tissue transplant between April and June 2020. Cyanoacrylate tissue adhesive application was the most commonly, performed procedure (79%, n = 49/62) for tectonic purpose during this period. Glycerol was the most preferred alternative preservation method considered by both the groups. More than half of the surgeons (64.5%, n = 40/62) had an average waiting time of <1 week for scheduling patients for keratoplasty in pre-COVID-19 period. CONCLUSION: There is was a significant drop in both corneal tissue retrieval and utilization during during COVID-19 lockdown. There was a felt need for an alternate long term storage media.

A review of long-term corneal preservation techniques: Relevance and renewed interests in the COVID-19 era.

The growth of eye banking in India was showing positive trends until the nation was hit by unprecedented times as a result of the COVID-19 pandemic. The impact of this has led to a downward spiraling in eye banking activities globally. Several measures had to be implemented to tide over the crisis and strategies planned for future to prepare for the needs of corneal transplantation. While eye banks in India have been practicing short- term and intermediate storage preservation media, there is a definite need to evolve other methods of very long-term preservation. This review discusses various methods of long term corneal preservation, their relevance and applications in the present times. We reviewed relevant medical literature in English from PUBMED with the key words "Corneal preservation", "Cryopreservation", "Glycerol preservation", Gamma Irradiation", "Eye Banking" ,"COVID-19".

Novel drug delivery methods for the treatment of keratitis: moving away from surgical intervention.

Introduction: Corneal ulceration is one of the leading causes of blindness especially in low- and mid-income countries (LMICs). Surgical treatment of microbial keratitis is associated with multiple challenges that include non-availability of donor corneal tissues, lack of trained corneal surgeons, and poor compliance to follow up care. As a result, the surgery fails in 70-90% cases. Therefore, improving outcome of medical treatment and thereby avoiding the need for the surgery is an unmet need in the care of corneal ulcer cases.Areas covered: In this review article, the authors have tried to compile information on the novel drug-delivery systems that have potential to enhance success of medical management. We have discussed the following systems: cyclodextrins, gel formulations, colloidal system, nanoformulations, drug-eluting contact lens, microneedle patch, and ocular inserts.Expert opinion: The goals of corneal ulcer treatment are as follows: rapid eradication of causative microorganisms, control of damage from induced inflammation and microbial toxins, and facilitation of repair. The ocular surface anatomy poses several challenges for drug delivery using standard topical therapy. The novel drug-delivery systems mentioned above aim to enhanced tear solubility; superior stability; improved bio-availability; reduced toxicity; besides facilitating targeted drug delivery and convenience of administration.