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Purpose: The primary objective was to evaluate the clinical response of refractory cases of fungal keratitis to topical 1% posaconazole therapy., Methods: Prospective longitudinal non-randomized open label dual-cohort study of 70 eyes of refractory fungal keratitis, 35 were recruited as posaconazole treatment (PCZ) group for topical 1% posaconazole therapy and compared to 35 eyes on conventional antifungal therapy. Study parameters included demographic and treatment details, visual acuity, comprehensive slit-lamp biomicroscopy, clinical photography, ASOCT at recruitment and weekly (week 1, 2, 3 and 4 after treatment initiation). Clinical assessment included keratitis severity grade, time of healing, and healing response. Anti-fungal susceptibility testing was performed., Results: The mean age of 35 patients recruited in the PCZ treatment group was 45 ± 17.32 years and that for the conventional treatment group was 43.22 ± 15.04 years. Culture isolation was possible in 25 eyes (71.4%) in the PCZ treatment group, with Fusarium and Aspergillus spp. being the most common cornea pathogenic mycotic organisms. The mean healing time in the PCZ group was 27.13 ± 5.8 days and in the conventional treatment group was 26.41 ± 4.81 days. Healing response in the PCZ treatment showed that 27 eyes (77.14%) had healed, 3 (8.5%) had delayed healing, and 5 (14.28%) required therapeutic keratoplasty, whereas in the conventional treatment group, 26 (74.28%) healed, 2 (5.7%) had delayed healing, and 7 (20%) needed keratoplasty (P = 0.65, 0.72, 0.54, respectively). Topical 1% PCZ therapy of chronic mycotic keratitis was helpful in resolution in 85.7% of cases (30 eyes) with five eyes needing surgical intervention, which was comparable to that of conventional antimycotic therapy cohorts. Fusarium isolates showed greater susceptibility to natamycin in our study per MIC50 values, with susceptibility to the common antimycotic agents varying between the Aspergillus spp. in both PCZ treatment and conventional treatment groups. All isolates showed minimal values of MIC-50 with PCZ. Antifungal susceptibility testing in our study recruits showed that about 90% of the Fusarium spp. isolates to be best responsive to natamycin and PCZ, whereas Aspergillus niger isolates were sensitive to voriconazole, itraconazole, amphotericin B, and PCZ, Aspergillus flavus to voriconazole and PCZ, Aspergillus fumigatus to both polyenes and triazoles. Cladosporium spp. were best sensitive to natamycin and PCZ, Penicillium spp. to natamycin and azoles. Alternaria keratitis isolates were sensitive to voriconazole and PCZ, whereas Rhizopus isolate was best sensitive to PCZ., Conclusion: Topical 1% PCZ therapy in refractory fungal keratitis was comparable to that of conventional antimycotic agents, with lower MIC-50 against the common pathogenic fungi as compared to natamycin, amphotericin B, and voriconazole., (Copyright © 2024 Indian Journal of Ophthalmology.)

Corneal perforations are potentially sight-threatening conditions if not promptly treated. Management depends on the size, location, cause, and severity of the perforation. Various methods, including tissue adhesives, amniotic membrane grafting (AMG), and keratoplasty, are available. However, the limited availability of donor tissue in emergencies poses a significant challenge. Recently, Tenon's patch grafting (TPG) has emerged as a promising treatment option due to its autologous nature, availability, and lack of immunogenicity. This review provides a comprehensive overview of various aspects of TPG, along with relevant images. A literature search using keywords such as "Tenon's patch graft," "Tenon's capsule," "corneal patch graft," "amniotic membrane," and "corneal perforations" yielded 37 articles, included in this review. TPG is suitable for cases involving corneal tissue degradation leading to perforation, impending perforation, or descemetocele, with lesion sizes ranging from 2 to 6 mm. For larger perforations, the procedure may be modified by combining it with AMG or tissue adhesives. Postoperatively, the graft undergoes characteristic changes, including epithelialization and collagen deposition, resulting in the formation of a thick scar. Complications such as delayed epithelialization, wound leaks, and graft dehiscence can occur. High success rates have been reported, ranging from 74% to 87%. However, TPG may result in suboptimal visual outcomes, particularly when the graft is centrally located, necessitating future keratoplasty for visual rehabilitation. Overall, TPG is a safe and cost-effective technique for restoring structural integrity in corneal thinning disorders and perforations, especially in emergency settings when donor tissue is unavailable., (Copyright © 2024 Indian Journal of Ophthalmology.)

The Descemet membrane (DM) is the basement membrane of corneal endothelial cells, which are responsible for maintaining corneal transparency. DM detachment (DMD) can occur due to various reasons, with the most common etiology being post-surgical. Older age, blunt instruments, and faulty surgical technique predispose to the intraoperative or postoperative occurrence of DMD, and one should have a high index of suspicion for DMD in cases with unexplained or an atypical pattern of corneal edema after surgery. Prompt intervention for DMD management is imperative to effect early visual rehabilitation, decrease corneal morbidity, and avoid permanent damage leading to scarring of the cornea. Various classifications of DMD and management protocols have been described. Anterior-segment optical coherence tomography (AS-OCT) imaging is the most effective imaging to detect DMD and quantify its extent. Desmetopexy with air/gas is the initial treatment of choice and could be aided by suture fixation. Non-responsive cases might need endothelial keratoplasty., (Copyright © 2024 Copyright: © 2024 Indian Journal of Ophthalmology.)

This study aimed to comprehensively explore the intricacies of corneal neurotization (CN) and the nuanced factors that set it apart from routine clinical practice, exerting a substantial influence on its success. A symbiotic relationship is evident between corneal innervation and ocular surface health. The loss of corneal innervation results in a potentially challenging corneal condition known as neurotrophic keratopathy (NK). The majority of treatments are primarily focused on preventing epithelial breakdown rather than addressing the underlying pathogenesis. Consequently, to address the impaired corneal sensation (underlying etiology), a novel surgical approach has emerged, namely CN, which involves transferring healthy sensory nerve axons to the affected cornea. This review offers valuable insights into the existing body of supporting evidence for CN, meticulously examining clinical studies, case reports, and experimental findings. The aim is to enhance our understanding of the effectiveness and potential outcomes associated with this innovative surgical technique. The exploration of innovative therapeutic avenues holds promise for revolutionizing the management of NK, offering a potentially permanent solution to a condition once deemed incurable and severely debilitating., (Copyright © 2024 Copyright: © 2024 Indian Journal of Ophthalmology.)

Acute corneal hydrops (ACH) is a rare but sight-threatening complication of corneal ectasias. We aim to review the current literature on etiopathogenesis, histology, role of ancillary investigations, management, and outcomes of ACH by classifying the various management strategies based on their site of action and the underlying mechanism. A review of the literature was conducted by searching the following databases: PubMed (United States National Library of Medicine), Embase (Reed Elsevier Properties SA), Web of Science (Thomson Reuters), and Scopus (Elsevier BV) till April 2023. The literature search used various combinations of the following keywords: acute corneal hydrops, keratoconus, ectasia, management, keratoplasty. Nine hundred eighty-three articles were identified based on the above searches. Case reports which did not add any new modality of treatment to the existing literature, articles unrelated to management, those with no full text available, and foreign-language articles with no translation available were excluded. Eventually, 75 relevant articles that pertained to the management of ACH were shortlisted and reviewed. Recent studies have described newer surgical interventions like full-thickness or pre-Descemetic sutures, thermokeratoplasty, and plasma injection that aim to close the posterior stromal break. Posterior lamellar keratoplasties act by replacing the posterior torn Descemet's membrane (DM), and early deep anterior lamellar keratoplasty (DALK) has been attempted to combine the correction of the anatomical defect and visual rehabilitation in a single surgery. These surgical interventions may help by reducing the scarring and increasing the number of patients who can be visually rehabilitated with contact lenses rather than keratoplasty., (Copyright © 2024 Copyright: © 2024 Indian Journal of Ophthalmology.)

Purpose: To study the correlation of corneal topography, corneal biomechanical properties, and ocular aberrations with the magnitude of refractive error in myopic eyes., Methods: All myopic patients attending the clinic for refractive surgery were recruited. Data recorded included visual acuity, axial length (AL), central corneal thickness (CCT), manifest refraction spherical equivalent (MRSE), topography (Pentacam - Oculus), corneal biomechanical factors [ocular response analyzer (ORA)], and optical aberrations (iTrace). They were further categorized into group 1 (suitable for femto-LASIK) and group 2 (unsuitable for femto-LASIK)., Results: Sixty eyes (30 myopes) of mean age 22.78 ± 2.71 years were enrolled. A negative correlation of refractive error was noted with AL (ρ = -0.9; P < 0.001), total aberrations (ρ = 0.53; P < 0.001), and lower-order aberrations (LOA) (ρ = 0.54; P < 0.001). A strongly positive correlation was noted between CCT and corneal hysteresis (CH) (ρ = 0.63; P < 0.001), CCT and CRF (ρ = 0.56; P < 0.001), CH and corneal resistance factor (CRF) (ρ = 0.83; P < 0.001), and Goldmann equivalent intraocular pressure (IOPg) and corneal compensated intraocular pressure (IOPcc) (ρ = 0.78; P < 0.001). An increase in higher-order aberrations (HOAs) as well as lower-order aberrations (LOAs) was noted with increasing sim-K [HOA (r = 0.73, P = 0.001); LOA (r = 0.601, P = 0.014)] and increasing CRF [HOA (r = 0.5, P = 0.006); LOA (r = 0.732, P = 0.001)] in group 2. The amount of refractive error, axial length, central corneal thickness, and sim-K were significantly different in the two groups., Conclusion: Increasing degree of myopia is associated with an increase in axial length, total aberrations, and lower-order aberrations. Corneal biomechanical parameters have a strong correlation with each other. Lower corneal biomechanics are noted in high myopes as they have weaker and thinner corneas. Corneal biomechanics and ocular aberrations do not differ significantly between cases suitable for femto-LASIK and cases unsuitable for femto-LASIK., (Copyright © 2023 Copyright: © 2023 Indian Journal of Ophthalmology.)

High-precision biometry and accurate intraocular lens (IOL) power calculation have become essential components of cataract surgery. In clinical practice, IOL power calculation involves measuring parameters such as corneal power and axial length and then applying a power calculation formula. The importance of posterior corneal curvature in determining the true power of the cornea is increasingly being recognized, and newer investigative modalities that can estimate both the anterior and posterior corneal power are becoming the standard of care. Optical biometry, especially using swept-source biometers, with an accuracy of 0.01-0.02 mm, has become the state-of-the-art method in biometry. With the evolution of IOL formulas, the ultimate goal of achieving a given target refraction has also moved closer to accuracy. However, despite these technological efforts to standardize and calibrate methods of IOL power calculation, achieving a mean absolute error of zero for every patient undergoing cataract surgery may not be possible. This is due to inherent consistent bias and systematic errors in the measurement devices, IOL formulas, and the individual bias of the surgeon. Optimization and personalization of lens constants allow for the incorporation of these systematic errors as well as individual bias, thereby further improving IOL power prediction accuracy. Our review provides a comprehensive overview of parameters for accurate biometry, along with considerations to enhance IOL power prediction accuracy through optimization and personalization. We conducted a detailed search in PubMed and Google Scholar by using a combination of MeSH terms and specific keywords such as "ocular biometry," "IOL power calculations," "prediction accuracy of refractive outcome in cataract surgery," "effective lens position," "intraocular lens calculation formulas," and "optimization of A-constants" to find relevant literature. We identified and analyzed 121 relevant articles, and their findings were included., (Copyright © 2023 Copyright: © 2023 Indian Journal of Ophthalmology.)

Systemic coronavirus disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has had several ocular consequences. Many vaccines have been developed against the disease, with adverse events being reported as well. Various ocular adverse events secondary to coronavirus disease 2019 (COVID-19) vaccines have also featured in literature in recent times. This review features the reported corneal-related effects of COVID infection and vaccination. These include direct effects on corneal grafts and unilateral or bilateral corneal melts. The compilation of reported experiences from across the world in this systematic review will help clinicians recognize the possible presentations, pathogenesis, and management of the same., (Copyright © 2023 Copyright: © 2023 Indian Journal of Ophthalmology.)

Mucopolysaccharidosis are group of inherited metabolic diseases caused by the absence or malfunctioning of lysosomal enzymes resulting in accumulation of glycosaminoglycans. Over time this accumulation damages cells, tissues, and organs. There are seven types of MPS and 13 subtypes that are associated with multiple organ systems, such as the respiratory, liver, spleen, central nervous systems, arteries, skeletons, eyes, joints, ears, skin, and/or teeth. The various types share some common ocular features that differ in terms of the severity of the affection. Visual loss in MPS patients is varied and can be due to corneal clouding, glaucoma, retinopathy, and optic neuropathy. The primary focus of this review is on changes in the cornea and anterior segment in MPS patients, including clinical and novel investigative modalities, current surgical management, effects of systemic therapy like hematopoietic stem cell transplants (HSCT)and enzyme replacement therapy (ERT), as well as significant research developments., Competing Interests: The authors declare that there are no conflicts of interests of this paper., (Copyright: © 2023 Taiwan J Ophthalmol.)

Corneal blindness ranks third among the causes of blindness worldwide, after cataract and glaucoma. Corneal transplantation offers us a means to address this, and is currently the most commonly performed transplantation procedure worldwide - restoring the gift of sight to many an eye. Eye banks play a very important role in these procedures. India was quick to develop its own eye bank in 1945 soon after the launch of world's first eye bank in 1944. The evolution over the past six decades has been tremendous, placing India on the top, with one of the largest eye-banking system in the world. As of 2023, around 740 members are registered under the Eye Bank Association of India. The highest-ever collection of 71,700 donor eyes was achieved in 2017-2018. The overall tissue utilisation rate ranged between 22 - 28 % for voluntary donations and 50% for hospital-based corneal retrieval programs. Though India has an excellent infrastructure and readiness for corneal transplantation surgery, the need of the hour is to create a strong and independent nodal system. It shall take care of the logistics and factor in technological advances - surgical and otherwise. Public awareness, a national corneal grid, and reducing the red-tape barriers, shall improve availability of grafts nationwide. This review aims to detail the evolution of eye banking in India, to provide a comprehensive understanding, and help the stakeholders focus on the road ahead to attain our targets faster., Competing Interests: None

Purpose: Barrett toric calculator (BTC) is known for its accuracy in toric IOL (tIOL) calculation over standard calculators; however, there is no study in literature to compare it with real-time intraoperative aberrometry (IA). The aim was to compare the accuracy of BTC and IA in predicting refractive outcomes in tIOL implantation., Methods: This was an institution-based prospective, observational study. Patients undergoing routine phacoemulsification with tIOL implantation were enrolled. Biometry was obtained from Lenstar-LS 900 and IOL power calculated using online BTC; however, IOL was implanted as per IA (Optiwave Refractive Analysis, ORA, Alcon) recommendation. Postoperative refractive astigmatism (RA) and spherical equivalent (SE) were recorded at one month, and respective prediction errors (PEs) were calculated using predicted refractive outcomes for both methods. The primary outcome measure was a comparison between mean PE with IA and BTC, and secondary outcome measures were uncorrected distance visual acuity (UCDVA), postoperative RA, and SE at one month. SPSS Version-21 was used; P < 0.05 considered significant., Results: Thirty eyes of 29 patients were included. Mean arithmetic and mean absolute PEs for RA were comparable between BTC (-0.70 ± 0.35D; 0.70 ± 0.34D) and IA (0.77 ± 0.32D; 0.80 ± 0.39D) (P = 0.09 and 0.09, respectively). Mean arithmetic PE for residual SE was significantly lower for BTC (-0.14 ± 0.32D) than IA (0.001 ± 0.33D) (-0.14 ± 0.32D; P = 0.002); however, there was no difference between respective mean absolute PEs (0.27 ± 0.21 D; 0.27 ± 0.18; P = 0.80). At one-month, mean UCDVA, RA, and SE were 0.09 ± 0.10D, -0.57 ± 0.26D, and -0.18 ± 0.27D, respectively., Conclusion: Both IA and BTC give reliable and comparable refractive results for tIOL implantation., Competing Interests: None

Purpose: To evaluate the efficacy of liposomal amphotericin B (L-AMB) for the treatment of fungal keratitis., Methods: Patients with fungal keratitis confirmed by potassium hydroxide (KOH) smear and/or confocal microscopy were administered topical L-AMB and randomized into three groups treated with three different formulations. The medication was administered two hourly till clinical improvement was achieved, followed by six hourly till complete resolution. The outcome measures were time to clinical improvement, resolution of epithelial defect, stromal infiltrate, hypopyon, extent and density of corneal opacity, neovascularization, and best corrected visual acuity (BCVA) at 3 months., Results: Mean age of the patients was 46.6 ± 14.8 years, and trauma with vegetative matter was the most common predisposing factor. Aspergillus flavus (36%) was the most common fungus cultured, followed by Fusarium (23%). Mean time to clinical improvement, time to resolution of epithelial defect, mean time to resolution of infiltrate, and time to resolution of hypopyon were 3.45 ± 1.38, 25.35 ± 8.46, 37.97 ± 9.94, and 13.33 ± 4.90 days, respectively, and they were comparable among the three groups. There was a significant difference between treatment failure and success cases in terms of days of presentation (P < 0.01), size of the epithelial defect (P-value 0.04), and infiltrate size at presentation (P-value 0.04). At 3 months follow-up, no statistically significant difference was noted in BCVA and mean scar size among groups., Conclusion: L-AMB in a gel form is an effective antifungal agent that promotes the healing of fungal ulcers with notably least vascularization and better tolerance., Trial Registration Number: CTRI/2020/04/024550., Competing Interests: None

Purpose: To study the antifungal susceptibility of common corneal pathogenic fungi to antifungal agents in the North Indian population., Methods: Prospective study of the antifungal sensitivity testing (natamycin, amphotericin B, voriconazole, itraconazole, fluconazole, posaconazole, caspofungin, micafungin) of fungal isolates from 50 cases of culture positive fungal keratitis by using E test method. Details noted included demographic data, visual acuity, clinical details, grade of keratitis, healing time, and success in medical management., Results: Of 50 patients with fungal keratitis (mean age: 40.28 ± 16.77 years), 12 eyes healed within 3 weeks, 14 had a delayed healing response, and 24 had chronic keratitis. Among the 15 cases of Fusarium isolates, 93.3% were sensitive to natamycin, while 40% to amphotericin B; 66.6% to voriconazole, 13.4% to itraconazole and fluconazole each. 80% of Fusarium cases (n = 12) showed susceptibility to posaconazole. Among Aspergillus flavus isolates, 53.4% (n = 8) were sensitive to natamycin, with only 40% (n = 7) showing sensitivity to amphotericin B and good susceptibility to azoles. MIC against susceptible Fusarium spp. for natamycin was 3-16 μg/mL, amphotericin B: 1-8 μg/mL, voriconazole: 0.5-1.5 μg/mL, itraconazole: 0.5-12 μg/mL, posaconazole: 0.094-1.5 μg/mL. MIC against Aspergillus flavus was natamycin: 8-32 μg/mL, amphotericin B: 0.5-16 μg/mL, voriconazole: 0.025-4 μg/mL, itraconazole: 0.125-8 μg/mL, posaconazole: 0.047-0.25 μg/mL; against Aspergillus niger isolates, to natamycin was 6 μg/mL (n=1), amphotericin B 8-12 μg/mL (n = 3), voriconazole: 0.125-0.19 μg/mL (n = 3), itraconazole: 0.38-0.75 μg/mL, posaconazole: 0.064-0.19 μg/mL and against Aspergillus fumigatus (n = 1), was natamycin4 μg/mL, amphotericin B - 8 μg/mL, voriconazole 0.25 μg/mL, itraconazole 1 μg/mL, and posaconazole 0.19 μg/mL. MIC against susceptible Acremonium spp. for natamycin was 1.5-16 μg/mL, amphotericin B: 0.5-8 μg/mL, voriconazole: 0.19-3 μg/mL, itraconazole: 0.125 μg/mL, posaconazole: 0.125-0.5 μg/mL and against susceptible Curvularia was natamycin 0.75-4 μg/mL, amphotericin B 0.5-1 μg/mL, voriconazole 0.125-0.19 μg/mL, itraconazole 0.047-0.094 μg/mL, posaconazole 0.047-0.094 μg/mL. MIC against Mucor spp.+ Rhizopus spp. (n = 1) was natamycin: 8 μg/mL, amphotericin B: 0.75 μg/mL, posaconazole: 1.5 μg/mL. MIC against of Alternaria (n = 1) was voriconazole: 0.19 μg/mL, posaconazole: 0.094 μg/mL. MIC against Penicillium (n=1) was natamycin: 8 μg/mL, voriconazole: 0.25 μg/mL, itraconazole: 0.5 μg/mL, and Posaconazole: 0.125 μg/mL., Conclusion: Our observations highlight the variations in susceptibility to antifungal agents. Posaconazole seems to be effective with low MIC against common corneal pathogenic fungal isolates., Competing Interests: None

Purpose: To analyze the pattern of bacterial pathogens causing infective keratitis and their resistance to the recommended antibiotics over six years., Methods: It was a retrospective study of 9,357 cases of bacterial keratitis from January 2015 to December 2020, at a tertiary care ophthalmic center. A total of 9,547 corneal specimens were obtained from the study subjects. Demographic details of the patients, pathogenic bacteria isolated, and their antimicrobial susceptibility were noted and analyzed., Results: Bacterial pathogens were identified in 23.52% of the specimens. The most common isolates were coagulase-negative Staphylococci (60.75%), followed by Pseudomonas aeruginosa (14.23%), Staphylococcus aureus (13.92%), gram negative bacilli of the family Enterobacterales (8.64%), Streptococcus spp. (1.72%), Acinetobacter spp. (0.13%), and other non-fermenting gram-negative bacilli (0.57%). In Staphylococci, 55-80% of isolates were resistant to erythromycin, and 40-70% to fluoroquinolones, while no resistance was observed against vancomycin. 40-60% of isolates of P. aeruginosa were resistant to cephalosporins, 40-55% to fluoroquinolones, and 30-60% to aminoglycosides. Also, 40-80% of isolates of Enterobacterales were resistant to cephalosporins, and 50-60% to fluoroquinolones. Most gram-negative isolates were susceptible to carbapenems and polymyxin B., Conclusion: To the best of our knowledge, our study is the largest compilation of microbiological profile of bacterial keratitis from North India. It highlights the current trend of the bacterial pathogens that cause infectious keratitis. Staphylococci and Pseudomonas were found to be the most common pathogens. Increased resistance was seen against some of the commonly prescribed empirical antibiotics. Such evidence is useful for restructuring the empirical prescription practices from time to time., Competing Interests: None

Purpose: To compare the efficacy of physiological, non-detergent eyelid wipes with conventional lid hygiene in patients with meibomian gland dysfunction (MGD)., Methods: Fifty participants with MGD were recruited and randomized into two groups. Participants in group I used Evolve Pure™ Eyewipes twice a day to clean the eyelid debris along with standard therapy (antibiotic and lubricants) and participants in group II followed lid hygiene with warm compresses along with standard therapy. Symptoms, ocular surface assessment (lipid layer thickness, tear meniscus height, non-invasive tear film breakup time, and meibography), slit-lamp biomicroscopy (eyelash contamination, meibomian gland blockage, meibomian gland secretion, and meibomian gland telangiectasia) and tear film osmolarity were noted at baseline and 90 days after therapy., Results: Significant improvement in symptoms and signs of MGD was observed in both groups after treatment (P < 0.001); however, the clinical improvement was better with the use of eyelid wipes. Lipid layer thickness increased significantly in group I (P = 0.0006) and group II (P = 0.0002), which was maintained even after adjusting for sociodemographic variables such as age, sex, and severity score of symptoms and signs., Conclusion: Lipid layer thickness of the tear film is a sensitive marker in monitoring response to treatment in patients with MGD. The use of physiological detergent-free eyelid wipes is non-inferior to lid hygiene and warm compresses, which remains the mainstay for treatment of MGD; the clinical improvement with eyelid wipes was noted to be better., Competing Interests: None

Infectious keratitis is a medical emergency resulting in significant visual morbidity. Indiscriminate use of antimicrobials leading to the emergence of resistant or refractory microorganisms has further worsened the prognosis. Coexisting ocular surface diseases, delay in diagnosis due to inadequate microbiological sample, a slow-growing/virulent organism, or systemic immunosuppressive state all contribute to the refractory response of the ulcer. With improved understanding of these varied ocular and systemic factors contributing to the refractory nature of the microbes, role of biofilm formation and recent research on improving the bioavailability of drugs along with the development of alternative therapies have helped provide the required multidimensional approach to effectively diagnose and manage cases of refractory corneal ulcers and prevent corneal perforations or further dissemination of disease. In this review, we explore the current literature and future directions of the diagnosis and treatment of refractory keratitis., Competing Interests: None

Purpose: To assess the role of noninvasive ocular surface analyzer (OSA) in workup of meibomian gland dysfunction (MGD) and to estimate hospital-based prevalence of MGD using this objective device., Methods: The study recruited 113 consecutive participants attending the ophthalmology outpatient department of a tertiary care hospital. All participants were administered a symptom questionnaire. Participants underwent a comprehensive ocular examination, including slit-lamp biomicroscopy and meibomian gland expression. Lipid layer thickness (LLT), noninvasive tear breakup time (NIBUT), tear meniscus height (TMH), and meibomian gland loss (MGL) were assessed using OSA. The presence of either or both reduced/absent meibum secretion and cloudy to toothpaste-like secretion was diagnosed as MGD., Results: Prevalence of total MGD was 57.52% (95% confidence interval [95% CI]: 48.3%-66.8%) and that of symptomatic MGD was 42.5% (95% CI: 33.2%-51.7%). Prevalence of total and symptomatic MGD was highest in those aged ≥50 years (P < 0.001 and P = 0.004, respectively). Computer vision syndrome increased the odds of symptomatic MGD (odds ratio [OR]: 4.3). NIBUT and MGL significantly differed in MGD and non-MGD groups (P = 0.023 and P < 0.001, respectively). LLT significantly differed between asymptomatic and symptomatic cases (P = 0.033). MGL >25% increased the odds of having MGD (OR: 19.1). Significant negative correlations were observed between MGL and NIBUT (P = 0.04) and between MGL and LLT (P = 0.02). MGL demonstrated the highest diagnostic accuracy for MGD (AUC = 0.827, sensitivity = 75.4%, specificity = 85.4%, cut-off value: ≥26%)., Conclusion: MGD is a common disorder in adults attending the ophthalmology outpatient services of a tertiary eye care hospital. Incorporating noninvasive OSA in clinical practice can aid in rapid and reliable measurements of MGD-related parameters., Competing Interests: None

Pythium insidiosum is an oomycete and is also called "parafungus" as it closely mimics fungal keratitis. The last decade saw an unprecedented surge in Pythium keratitis cases, especially from Asia and India, probably due to growing research on the microorganism and improved diagnostic and treatment modalities. The clinical features such as subepithelial infiltrate, cotton wool-like fluffy stromal infiltrate, satellite lesions, corneal perforation, endoexudates, and anterior chamber hypopyon closely resemble fungus. The classical clinical features of Pythium that distinguish it from other microorganisms are reticular dots, tentacular projections, peripheral furrowing, and early limbal spread, which require a high index of clinical suspicion. Pythium also exhibits morphological and microbiological resemblance to fungus on routine smearing, revealing perpendicular or obtuse septate or aseptate branching hyphae. Culture on blood agar or any other nutritional agar is the gold standard for diagnosis. It grows as cream-colored white colonies with zoospores formation, further confirmed using the leaf incarnation method. Due to limited laboratory diagnostic modalities and delayed growth on culture, there was a recent shift toward various molecular diagnostic modalities such as polymerase chain reaction, confocal microscopy, ELISA, and immunodiffusion. As corneal scraping (10% KOH, Gram) reveals fungal hyphae, antifungals are started before the culture results are available. Recent in vitro molecular studies have suggested antibacterials as the first-line drugs in the form of 0.2% linezolid and 1% azithromycin. Early therapeutic keratoplasty is warranted in nonresolving cases. This review aims to describe the epidemiology, clinical features, laboratory and molecular diagnosis, and treatment of Pythium insidiosum keratitis., Competing Interests: None

Competing Interests: None

Ocular graft-versus-host disease (oGVHD) occurs as a complication following hematopoietic stem cell transplantation and is associated with significant ocular morbidity resulting in a marked reduction in the quality of life. With no current consensus on treatment protocols, management becomes challenging as recurrent oGVHD often refractory to conventional treatment. Most authors now diagnose and grade the disease based on criteria provided by the National Institutes of Health Consensus Conference (NIH CC) or the International Chronic oGVHD (ICCGVHD) consensus group. This article will provide an insight into the diagnostic criteria of oGVHD, its classification, and clinical severity grading scales. The inflammatory process in oGVHD can involve the entire ocular surface including the eyelids, meibomian gland, corneal, conjunctiva, and lacrimal system. The varied clinical presentations and treatment strategies employed to manage them have been discussed in the present study. The recent advances in ocular surface imaging in oGVHD patients such as the use of meibography and in vivo confocal microscopy may help in early diagnosis and prognostication of the disease. Researching tear proteomics and identification of novel potential tear biomarkers in oGVHD patients is an exciting field as they may help in objectively diagnosing the disease and monitoring the response to treatment., Competing Interests: None

Specular microscopy is a noninvasive diagnostic tool that allows for in vivo evaluation of corneal endothelium in health and various diseased states. Endothelial imaging helps in the diagnosis and management of several endothelial disorders. The review focuses on the principles of specular microscopy, limitations of endothelial imaging, and its interpretation in common conditions seen in the clinical practice. A thorough PubMed search was done using the keywords specular microscopy, corneal endothelium, and endothelial imaging., Competing Interests: None

Background: To evaluate the role of interferon alpha 2b (IFNα2b) in the management of primary/recurrent cases of ocular surface squamous neoplasia (OSSN)., Methodology: Medical records of 27 OSSN cases managed with IFNα2b (topical drops and/or perilesional injection) in 1 year were retrospectively reviewed., Results: The median age of presentation was 60 years with a male: female ratio of 3.5:1. American Joint Commission on Cancer tumor grading was T1 in 1 eye (3.7%) and T3 in 26 eyes (96.3%). Eighteen cases were treated with topical drops (1 million IU/ml), 4 cases with perilesional subconjunctival injection (3-6 million IU/ml), and 5 cases with combined therapy. Overall, treatment response was seen in 88% cases. Complete regression was achieved in 80% cases. Median time to complete regression of tumor was 3 months (range 1-11 months) in cases treated with topical interferon therapy and 2.5 months (range 0.7-3 months) in cases managed with injections or a combination of the two. The mean duration of follow-up was 24 months. All cases with partial/no response showed complete regression on subsequent management with topical mitomycin C. None of the patients required surgery. Acute ocular surface congestion was seen in two patients necessitating discontinuation of therapy., Conclusion: In view of excellent treatment outcome and few side-effects, interferons can be considered as a primary, safe, and cost-effective treatment option for OSSN not only in tertiary centers but also by peripheral ophthalmologists., Competing Interests: There are no conflicts of interest., (Copyright: © 2021 Oman Ophthalmic Society.)

Keratoconus is an ectatic corneal disease characterized by progressive stromal thinning, irregular astigmatism, and defective vision. It can be unilateral or bilateral with asymmetric presentation. It starts at puberty and either progresses rapidly to an advanced stage of the disease or stops in case of delayed onset and slow progression. Pediatric keratoconus is more aggressive than in adults and the management protocols differ because of various rationales such as accelerated progression, advanced stage of disease at the time of diagnosis and co-morbidities. It poses a burden to the society as it affects the quality of life, social, and educational development in children. Hence early diagnosis, recognition of progression, and timely intervention with collagen crosslinking is imperative to arrest the worsening. Association with systemic syndromes and ocular comorbidities can be of concern in pediatric keratoconus. Severe ocular allergy when associated hastens progress and complicates timely intervention of crosslinking treatment and compliance to contact lens wear. Keratoplasty in pediatric keratoconus has good outcomes but can encounter frequent suture-related concerns. This article discusses the epidemiology, etiopathogenesis, clinical challenges, and current perspectives of management of pediatric keratoconus., Competing Interests: None

Purpose: To evaluate corneal biomechanical changes and their correlation with the percentage of tissue altered (PTA) in myopic femtosecond (FS)-flap LASIK., Methods: Prospective longitudinal observational study of 80 eyes of FS LASIK. Demographic details, LASIK parameters, preoperative and postoperative (day 1, month 1, 3, and 6), UCVA, BCVA, refraction, corneal topography, corneal hysteresis (CH), and a corneal resistance factor (CRF) were noted. Change in CH and CRF and its correlation with PTA were analyzed. Data were analyzed in three subgroups [subgroup 1: PTA 23 to <27%; subgroup 2: 27 to <33%; subgroup 3: 33 to <40%]., Results: FS LASIK for MRSE -3.5D ± 1.6D with mean PTA of 31.6 ± 4.4% (range 23.8-39.8%), showed statistically significant decrease in CH and CRF. Mean CH decreased from a preoperative value of 10.4 ± 1.9 to 8.1 ± 1.1; mean CRF from 10.5 ± 1.6 to 7.5 ± 1.3 at 6-months postoperative period, respectively. Mean preoperative CH decreased by 25%, 24%, 23%, and 21% and mean preoperative CRF decreased by 34%, 28%, 28%, and 28% at postoperative day 1, month 1, 3, and 6 follow-ups. Mean CH and CRF showed a significant negative correlation with PTA (CH: r = - 0.33 [P = <0.0001], CRF: r = -0.34 [P = <0.001]. Subgroup analysis noted greater decrease in CRF and CH in eyes with higher PTA (subgroup 3)., Conclusion: Myopic FS LASIK causes a decrease in corneal biomechanics with a significant negative correlation with PTA indicating a greater decrease in corneal biomechanics with higher PTA., Competing Interests: None

Purpose: To quantitatively assess anterior chamber and angle parameters by anterior segment optical coherence tomography (AS-OCT) in myopic eyes undergoing Implantable Collamer Lens (ICL V4c) implantation., Methods: Prospective noncomparative observational case series. Pre and postoperative (1 st and 3 rd month) AS-OCT angle parameters (anterior chamber depth [ACD], anterior chamber angle [ACA], Angle opening distance [AOD], trabecular iris space area [TISA], scleral spur angle [SSA]) were evaluated in 32 eyes (16 patients). SPSS version 20 with paired t-test for intragroup and Mann-Whitney U value test for intergroup comparisons., Results: It included 6 (37.5%) males and 10 (62.5%) females. Preoperative ACA of 34.6 ± 2.3° reduced to 32.2 ± 2.4°, 31.9 ± 2.5° at 1 and 3 months postoperatively (P = 0.001). Preoperative mean AOD500, AOD750, TISA500, TISA750, SSA of 0.34 ± 0.06 mm, 0.52 ± 0.15 mm, 0.09 ± 0.02 mm 2 , 0.20 ± 0.04 mm 2 , 34.27 ± 4.6° decreased to 0.32 ± 0.06 mm, 0.48 ± 0.15 mm, 0.08 ± 0.02 mm 2 , 0.17 ± 0.05 mm 2 , 32.5 ± 4.3° at 1-month (P = 0.001); 0.32 ± 0.06 mm, 0.47 ± 0.13 mm, 0.08 ± 0.02 mm 2 , 0.17 ± 0.05 mm 2 and 32.4 ± 4.6° (P = 0.001) at 3-months, respectively. Correlation analysis between preoperative ACD/intraocular pressure (IOP) was - 0.62 (P = 0.0002) [1 st month], -0.40 (0.024) [third month]; between IOP/postoperative ACA, AOD500, AOD750, TISA500, TISA750, SSA was - 0.04 (0.81), -0.03 (0.85), -0.08 (0.64), -0.12 (0.48), -0.10 (0.57), -0.06 (0.73) at 1 month; -0.09 (0.58), 0.04 (0.78), 0.12 (0.48), -0.02 (0.9), -0.04 (0.79), 0.02 (0.88) at 3 months; between ICL vault/ACA, AOD500, AOD750, TISA500, TISA750, SSA was 0.38 (0.02), 0.24 (0.17), 0.21 (0.25), 0.05 (0.75), 0.15 (0.41), 0.27 (0.13) at 1 st month; 0.19 (0.28), 0.06 (0.71), -0.03 (0.85), 0.005 (0.97), 0.05 (0.78), 0.07 (0.68) at 3 rd month., Conclusion: Postoperatively significant angle narrowing was noted. There was a negative correlation between IOP and preoperative ACD. There was no significant correlation between IOP and ICL vault with postoperative AS-OCT angle parameters., Competing Interests: None

Purpose: To evaluate the frequency and the association of Thrombospondin 1 (THBS1) gene single nucleotide polymorphisms (SNPs) in Asian Indian patients with optical full thickness corneal grafting surgery., Methods: Prospective case-control analysis of optical penetrating keratoplasty patients with and without immune rejection and controls for genotyping of 3 THBS1 gene SNPs (rs1478604 A>G; rs2228261 C>T; rs2228262 A>G) by Amplification Refractory Mutation System-Polymerase Chain Reaction (ARMS PCR)., Results: Among 58 patients [45 with immune allograft rejection (DNA isolation was possible in 38 samples) and 13 without immune corneal allograft rejection] and 65 controls, allele frequencies observed for rs1478604 (A>G) are A: 69.7% and 72.6%, G: 30.2% and 27.3%; for rs2228261 (C>T) are T: 70.2% and 62.3%, C: 29.7% and 37.6%; and for rs2228262 (A>G) A: 97.4% and 98.4%; G 2.5% and 1.5% respectively. Genotype frequencies were rs1478604 (A>G) AA: 57.8% and 59.3%, AG 23.6% and 26.5%; GG 18.4% and 14%; for rs2228261 (C>T) TT: 40.5% and 33.8%, TC: 59% and 56.9%, CC: 0% and 9.2%; for rs2228262 (A>G) AA: 94.8% and 96.8%, AG: 5.1% and 3.1% in rejection and controls respectively. The allele and genotype frequency for the 3 described THSB1 SNPs did not show any difference between the corneal graft immune rejection patients and controls., Conclusion: Asian Indian population evaluated for THBS1 gene SNPs by ARMS PCR genotyping in Asian Indian population did not show any genetic association to immune rejection occurrence in our study., Competing Interests: None

Purpose: Barrett Universal II (BU-II) is considered as one of the most accurate intraocular lens (IOL) power calculation formulas; however, there is no literature studying the same in Indian population., The Aim of This Study Was to: evaluate the accuracy of BU-II formula in prediction of IOL power for cataract surgery in Asian Indian population., This Was an Institutional,: prospective, observational study., Methods: Patients with senile cataract who underwent phacoemulsification with posterior chamber IOL implantation were enrolled in the study. Biometry data from Lenstar-LS900 was used and IOL power was calculated using four IOL formulas: modified SRK-II, SRK/T, Olsen, and BU-II. Primary outcome was measured as the prediction error in postoperative refraction for each formula and secondary outcome was measured as the difference in mean absolute errors between the four formulas. SPSS Version-21 with P < 0.05 considered significant., Results: A total of 244 eyes were included in the study and were divided into three groups in accordance to axial length (AL): Group 1 (AL: 22-24.5 mm; N = 135), Group 2 (AL <22 mm; N = 53), and Group 3 (AL >24.5 mm; N = 56). BU-II formula gave the lowest mean absolute error (0.37 ± 0.27D) and median absolute error (0.34) in predicted postoperative refraction in the entire study population. When compared with the other formulas, mean absolute error was significantly lower in all three groups (P < 0.0005) as well, except for Olsen formula in the normal AL group, where the results were comparable (P = 0.742)., Conclusion: BU-II performed as the most accurate formula in the prediction of postoperative refraction over a wide range of ALs., Competing Interests: None

Purpose: The aim is to study the clinicodemographic profile and treatment outcome of ocular surface squamous neoplasia (OSSN)., Methods: This was a retrospective observational study of 57 eyes (56 cases) with clinically diagnosed OSSN, presenting in our center over the past year., Results: The median age of presentation was 55 years with male:female ratio being 4.5:1. Systemic predisposing conditions were xeroderma pigmentosa (1) postkidney transplant immunosuppression (1), and human immunodeficiency virus infection (1). Patients with predisposing conditions had a younger median age of onset (33 years). The majority of tumors were nodular (61.4%), gelatinous (61.4%), and had limbal involvement (96%). On ultrasound biomicroscopy (UBM), mean tumor height was 2.93 ± 1.02 mm, and intraocular extension was evident in seven eyes. OSSN with intraocular extension had a mean tumor height of 4.3 ± 1.32 mm. Nodal metastasis was seen in one case at presentation. As per American Joint Committee for Cancer Classification seventh edition staging-two cases were T1, one was T2, 46 were T3 and eight were T4. Treatment advised included conservative therapy for 39; wide local excision (4 mm margin clearance) with cryotherapy for seven; enucleation in four; and exenteration in four eyes. Overall, complete regression was achieved in 88% of cases during a mean follow-up of 13.5 ± 4.6 months. Recurrence was seen in three cases, which were treated with exenteration, radical neck dissection, and palliative chemo-radiotherapy, respectively., Conclusion: Although associated with old age, earlier onset of OSSN is seen in patients with systemic predisposing conditions. Thicker tumors in the setting of a previous surgery or immunocompromised status should be considered high-risk features for intraocular extension and should be evaluated on UBM.

Purpose: The purpose of this study is to determine the effect of phacoemulsification cataract extraction on measurement of retinal nerve fiber layer and optic nerve head parameters using spectral domain optical coherence tomography., Material and Methods: A prospective, hospital-based study of 100 patients of 40 years of age and above, with no other ocular morbidity except cataract and planned for phacoemulsification with IOL implantation (SN60WF) at a tertiary centre at AIIMS, New Delhi, India. All patients underwent imaging with Cirrus SD-OCT model 400 and the optic disc cube 200x200 protocol at baseline and at 1 month follow up. Paired sample t -test was used to compare the RNFL parameters and ONH parameters., Results: The mean age of subjects was 56.6 ± 12.3 years (70 males, 30 females). The average RNFL increased from 92.6 ± 5.4 μm to 101.3 ± 5.6 μm after phacoemulsification, an increase of 9% ( P = 0.003) and the signal strength increased from 5.6 ± 0.5 to 7.6 ± 0.7, increasing by 35.7% ( P = 0.004). There was a significant increase in the disc area ( P = 0.004) and rim area ( P = 0.004) but no significant change in vertical cup-disc ratio ( P = 0.45) or average cup-disc ratio ( P = 0.075). The quadrant-wise RNFL thickness increase in inferior, superior, nasal, and temporal quadrants was 12.6% ( P = 0.001), 10% ( P = 0.001), 5.6% ( P = 0.001), and 3.2% ( P = 0.001), respectively. The change in RNFL thickness was maximum in posterior subcapsular cataract ( P = 0.001) followed by cortical ( P = 0.001) and nuclear ( P = 0.001) subtypes., Conclusions: A significant increase in RNFL thickness and signal strength was observed after cataract surgery using SD-OCT. The maximum change in RNFL thickness was in the inferior quadrant, where RNFL thinning is a significant predictor of glaucoma progression. The posterior subcapsular cataract interfered with RNFL measurement maximally due to its density and proximity to nodal point. After the cataract surgery, a new baseline needs to be established by obtaining fresh OCT images for assessing the longitudinal follow-up of a glaucoma patient., Competing Interests: There are no conflicts of interest.

Purpose: Early presentation of rejection facilitates early initiation of treatment which can favor a reversible rejection and better outcome. We analyzed the incidence, clinical features including rejection-treatment period and outcomes following graft rejection in our series of pediatric corneal graft., Materials and Methods: Case records of pediatric penetrating keratoplasty (PK) were reviewed retrospectively, and parameters noted demographic profile, indication of surgery, surgery-rejection period, rejection-treatment interval, graft outcome, and complications., Results: PK was performed in 66 eyes of 66 children <12 years, with an average follow-up of 21.12 ± 11.36 months (range 4-48 month). The median age at the time of surgery was 4.0 years (range 2 months to 12 years). Most of the children belonged to rural background. Scarring after keratitis (22, 33.4%) was the most common indication. Graft rejection occurred in eight eyes (12.12%) (acquired nontraumatic - 3, congenital hereditary endothelial dystrophy [CHED] - 2, nonCHED - 1, congenital glaucoma - 1, regraft - 1). The mean surgery-rejection period was 10.5 ± 7.3 months and mean rejection-treatment interval was 10.9 ± 7.02 days., Conclusion: This study showed irreversible graft rejection was the leading cause of graft failure of pediatric PK. Though, the incidence (12.1%) of graft rejection in current study was not high, but the percentage of reversal (25%) was one of the lowest in literature because of delayed presentation and longer interval between corneal graft rejection and treatment. In addition, categorization of the type of graft rejection was very difficult and cumbersome in pediatric patients.

Aim: The aim was to evaluate the outcome of Ahmed glaucoma valve (AGV) in post-penetrating-keratoplasty glaucoma (PKPG)., Materials and Methods: In this prospective study, 20 eyes of 20 adult patients with post-PKPG with intraocular pressure (IOP) >21 mmHg, on two or more antiglaucoma medications, underwent AG (model FP7) implantation and were followed up for a minimum of 6 months. Absolute success was defined as 5 < IOP < 21 mmHg and qualified success as 5 < IOP < 21 mmHg with medications or minor procedures., Results: The mean IOP decreased from 42.95 ± 10.24 to 17.69 ± 3.64 mmHg (P < 0.001) and the use of medications dropped from 2.92 to 0.39 (P < 0.001) after AGV implantation. The absolute success was achieved in 11 eyes and qualified success in 9. There was no significant change in best corrected visual acuity, graft clarity, or graft thickness. Six device-related complications occurred after AGV implantations which were successfully managed with medical or minor surgical therapy., Conclusions: Postkeratoplasty refractory glaucoma managed by AGV implantation revealed a satisfactory outcome up to 6 months of follow-up.

Glaucoma drainage devices are an option in refractory glaucomas for control of intraocular pressure (IOP). We evaluated the outcome of pars plana Ahmed glaucoma valve along with triamcinolone-assisted vitrectomy in 11 eyes with uncontrolled IOP on maximum tolerable antiglaucoma therapy. The mean preoperative IOP of 33.64 +/- 5.99 (range 26 to 44 mmHg) decreased to 17.09 +/- 2.26 (range 14 to 20 mmHg) and 17.45 +/- 1.81 mm of Hg (range 14 to 24 mmHg) at 6 and 12 months following surgery. The mean number of antiglaucoma medications decreased from 3.27 +/- 0.05 to 0.64 +/- 0.67 and 0.55 +/- 0.6 at 6 and 12 months following surgery.

Objective: To study the cellular populations of healthy corneas of Indian eyes using confocal microscopy and to evaluate the correlation with age, gender and laterality., Methods: The central corneas of 100 eyes of 50 healthy subjects were examined using an in-vivo slit scanning confocal microscope (Confoscan 2). Images were analysed for cell densities of the epithelium, stroma and endothelium., Results: Good quality images enabling analysis of all cell layer populations were obtained in 74 eyes of 43 healthy subjects (22 males and 21 females) with a mean age of 31.89 +/- 13.47 (range 19-71 years). The basal epithelial cell density was 3601.38 +/- 408.19 cells/mm2 (range 3017.3-4231.1 cells/mm2). The mean keratocyte nuclei density in the anterior stroma was 1005.02 +/- 396.86 cells/mm2 (range 571.6-1249.6 cells/mm2) and in the posterior stroma was 654.32 +/- 147.09 cells/mm2 (range 402.6-1049.1 cells/mm2). Posterior keratocyte nuclei density was 30.76% less than the anterior stromal keratocyte nuclei density. The difference in keratocyte nuclei density was statistically significant (P=0.001). The mean endothelial cell density was 2818.1 +/- 361.03 cells/mm2 (range 2118.9-4434 cells/mm2) and the mean endothelial cell area was found to be 385.44 +/- 42.66 mm2 (range 268.9-489.2 mm2). Hexagonal cells formed 22.5-69.4% of the endothelial cell populations (mean 42.04 +/- 11.81%). Mean coefficient of cell size variation was 32.29 +/- 3.06 (range 27.2-39.2). No statistically significant differences were found in cell densities of any corneal layer either between female and male patients or between right and left eyes. Basal epithelial cell density, anterior stromal keratocyte nuclei and posterior stromal keratocyte nuclei density were unaffected by age (r=0.12, 0.07, -0.12 respectively) (P=0.001). There was a statistically significant negative correlation between mean endothelial cell density and increase in age (r=-0.42, P=0.001). Coefficient of cell size variation and age were positively correlated (r=0.73, P=0.001)., Conclusion: In-vivo slit scanning confocal microscopy is useful for the study of corneal cell populations. Our study provides normative data of these cell populations.