Aurora Kinase A Is Overexpressed in Human Retinoblastoma and Correlates with Histopathologic High-Risk Factors: Implications for Targeted Therapy.

Retinoblastoma (RB) is an intraocular malignancy initiated by loss of RB1 function and/or dysregulation of MYCN oncogene. RB is primarily treated with chemotherapy; however, systemic toxicity and long-term adverse effects remain a significant challenge necessitating the identification of specific molecular targets. Aurora kinase A (AURKA), a critical cell cycle regulator, contributes to cancer pathogenesis, especially in RB1-deficient and MYCN-dysregulated tumors. Our immunohistochemistry study in patient specimens (n = 67) discovered that AURKA is overexpressed in RB, and elevated expression correlates with one or more histopathologic high-risk factors, such as tumor involvement of the optic nerve, choroid, sclera, and/or anterior segment. More specifically, AURKA is ubiquitously expressed in most advanced-stage RB tumors that show a suboptimal response to chemotherapy. shRNA-mediated depletion/pharmacologic inhibition studies in cell lines, patient-derived cells, in vivo xenografts, and enucleated patient specimens confirm that RB cells are highly sensitive to a lack of functional AURKA. In addition, we deciphered that AURKA and MYCN associate with each other to regulate their levels in RB cells. Overall, our results demonstrate a previously unknown up-regulation of AURKA in RB, facilitated by its crosstalk with MYCN, and elevated levels of this kinase may indicate unfavorable prognosis in tumors refractory to chemotherapy. This study provides a rationale and confirms that therapeutic targeting of elevated AURKA in RB could be a potential treatment approach.

Alterations of adipokines, pancreatic hormones and incretins in acute and convalescent COVID-19 children.

BACKGROUND: The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), accountable for Coronavirus disease 2019 (COVID-19), may cause hyperglycemia and additional systemic complexity in metabolic parameters. It is unsure even if the virus itself causes type 1 or type 2 diabetes mellitus (T1DM or T2DM). Furthermore, it is still unclear whether even recuperating COVID-19 individuals have an increased chance to develop new-onset diabetes. METHODS: We wanted to determine the impact of COVID-19 on the levels of adipokines, pancreatic hormones, incretins and cytokines in acute COVID-19, convalescent COVID-19 and control children through an observational study. We performed a multiplex immune assay analysis and compared the plasma levels of adipocytokines, pancreatic hormones, incretins and cytokines of children presenting with acute COVID-19 infection and convalescent COVID-19. RESULTS: Acute COVID-19 children had significantly elevated levels of adipsin, leptin, insulin, C-peptide, glucagon and ghrelin in comparison to convalescent COVID-19 and controls. Similarly, convalescent COVID-19 children had elevated levels of adipsin, leptin, insulin, C-peptide, glucagon, ghrelin and Glucagon-like peptide-1 (GLP-1) in comparison to control children. On the other hand, acute COVID-19 children had significantly decreased levels of adiponectin and Gastric Inhibitory Peptide (GIP) in comparison to convalescent COVID-19 and controls. Similarly, convalescent COVID-19 children had decreased levels of adiponectin and GIP in comparison to control children. Acute COVID-19 children had significantly elevated levels of cytokines, (Interferon (IFN)) IFNγ, Interleukins (IL)-2, TNFα, IL-1α, IL-1ß, IFNα, IFNß, IL-6, IL-12, IL-17A and Granulocyte-Colony Stimulating Factors (G-CSF) in comparison to convalescent COVID-19 and controls. Convalescent COVID-19 children had elevated levels of IFNγ, IL-2, TNFα, IL-1α, IL-1ß, IFNα, IFNß, IL-6, IL-12, IL-17A and G-CSF in comparison to control children. Additionally, Principal component Analysis (PCA) analysis distinguishes acute COVID-19 from convalescent COVID-19 and controls. The adipokines exhibited a significant correlation with the levels of pro-inflammatory cytokines. CONCLUSION: Children with acute COVID-19 show significant glycometabolic impairment and exaggerated cytokine responses, which is different from convalescent COVID-19 infection and controls.

Past, present, and prospects in microsporidial keratoconjunctivitis- A review.

Ocular microsporidiosis comprises two entirely different spectra of disease as keratoconjunctivitis and stromal keratitis. Microsporidial keratoconjunctivitis (MKC) has been increasingly reported in the past two decades, probably due to raised awareness, simpler diagnostic procedures, and a better understanding of the clinical presentation. It is characterized by the presence of raised, coarse, punctate, multifocal, round to oval, greyish-white corneal epithelial lesions which usually evolve into nummular scars before resolution. Conjunctivitis seen is non-purulent and of mild-moderate intensity, with mixed papillary-follicular reaction. The mode of transmission and pathogenesis is poorly understood. Despite lack of inflammatory response, uncommon associations reported were- endotheliitis, corneal edema, limbitis, uveitis, and sub-epithelial infiltrates. There has been no consensus on the management of MKC. It varies from the use of multiple antimicrobial agents to simple lubricants. The majority of the disease goes underdiagnosed or misdiagnosed and treated as adenoviral keratoconjunctivitis, with topical steroids or anti-virals empirically. Changing trends have been noticed in the pattern of infection, possibly with increasing evidence of Vittaforma corneae as causative organisms, previously reported to cause stromal keratitis. An elaborate review of the past and present literature on MKC is provided in this review article, along with gaps in knowledge, and future directions of research.

Use of different stains for microscopic evaluation for the diagnosis of Pythium keratitis.

PURPOSE: To evaluate the efficacy of various staining techniques for detection of Pythium in keratitis cases. METHODS: Data of nineteen consecutive culture-positive cases of Pythium keratitis were retrospectively analysed. Corneal scrapings and corneal buttons (in the cases which underwent therapeutic penetrating keratoplasty [TPK]) were sent for microbiological and histopathological examination. The direct smears were stained with Potassium hydroxide and calcofluor white (KOH â€‹+ â€‹CFW), Gram and Iodine-Potassium Iodide-Sulphuric Acid (IKI-H2SO4) stains. The corneal buttons were stained with Gomori's Methanamine Silver (GMS), Periodic Acid-Schiff (PAS) and Iodine-Potassium Iodide-Sulphuric Acid (IKI-H2SO4) stains. The positivity of various stains in detecting Pythium was studied. RESULTS: Gram and KOH â€‹+ â€‹CFW staining from smear was done in 16 out of 19 (84.2%) cases. KOH â€‹+ â€‹CFW and Gram stains were suggestive of Pythium in 10 (62.5%) and 7 (43.8%) cases, respectively. IKI-H2SO4 staining in scraping samples was positive for Pythium in all the 4 (100%) cases in which it was performed. Half corneal buttons were positive for Pythium with IKI-H2SO4 stain as well as GMS stain in all the 18 cases that underwent TPK (100%). PAS stain showed weak to faint pink staining of Pythium filaments in 7 out of 18 cases (38.9%). CONCLUSION: IKI-H2SO4 stain followed by KOH â€‹+ â€‹CFW stain detects Pythium filaments most accurately in corneal scraping samples from keratitis patients, although the differences were not statistically significant. The positivity of the stains depends on astute observation by an experienced ocular microbiologist and pathologist.

Evidence-based funding of new imaging applications and technologies by Medicare in Australia: How it happens and how it can be improved.

BACKGROUND: The Medical Services Advisory Committee (MSAC) is responsible for the assessment of medical imaging tests proposed for public funding. A number of factors related to the clinical or cost effectiveness of an imaging service may impact on the funding decision. OBJECTIVE: To determine what evidentiary and economic factors impact most on MSAC recommendations for the funding of imaging tests. METHODS: Information was extracted on health technology assessments (HTAs) of medical imaging tests published on the MSAC website, with a funding decision between 2006 to July 2021. Imaging tests with diagnostic, staging or screening indications were eligible. Data were extracted in test-indication pairs and included data on evidence quality, quantity, consistency of findings, cost-effectiveness and financial impact. Multivariate logistic regression analysis was performed with adjustments for clustered data. RESULTS: Overall, 42 imaging test applications to MSAC were included, representing 91 clinical indications. Most were diagnostic tests. The most common evidentiary concerns reported by MSAC were limited evidence (36%), low quality evidence (26%), and applicability of the data (22%). The reference standard for diagnostic accuracy was imperfect or not appropriate in 25% of the indications. In regression analyses, uncertainty about cost-effectiveness of an imaging service predicted most negative funding decisions. CONCLUSIONS: The single biggest contributor to a negative funding decision by MSAC was uncertainty about the cost-effectiveness of the imaging service. This was likely driven by uncertainty regarding the impact on patient health. HTAs that are able to demonstrate the clinical utility of a new imaging service are more likely to publicly funded.

Immune characterization of thyroid neoplasm's and its variants using immunohistochemical markers: CK-19, Galectin-3 and Hector Battifora mesothelial-1.

BACKGROUND: Nodular lesions of the thyroid are amongst the common palpable lesions that are encountered by the pathologists in the fine needle aspiration clinics and not only aspiration smears, but even biopsy sections pose significant challenges in their characterization and further classification. Neoplastic lesions of the thyroid have shown a steady rise worldwide and are diagnosed at age younger than most other cancers. Histopathology remains the gold standard in diagnosis and classification of thyroid neoplasms, with variable sensitivity and specificity of immunohistochemical markers, also attributed to variation in the inclusion criteria. We classified the thyroid neoplasms based on WHO Classification (2017) and aimed to study the diagnostic utility of immunohistochemical markers - CK-19, Galectin-3 and Hector Battifora mesothelial-1 performed on manual tissue microarray sections to differentiate various variants of papillary carcinoma from its mimickers, specifically follicular patterned papillary neoplasms from other follicular patterned lesions. METHOD: Prospective study of neoplastic lesions of thyroid from July 2018 to August 2020. Authors describe the clinico-radiological, cytological, histo-morphological and immunohistochemical features of neoplastic nodular lesions of the thyroid. RESULTS: Prospective analysis of nodular thyroid lesions yielded 76 cases, of which 38 were neoplastic. Cytology showed discordance in 10/24 cases, amongst the discordant cases, 70% were confirmed as papillary carcinoma. CK-19 showed high expression in all variants of papillary carcinomas (24/24), low expression in well differentiated tumor of uncertain malignant potential (WD-TUMP) and medullary carcinoma. It was negative in follicular and Hurthle cell neoplasms. Galectin-3 showed 100% specificity and HBME-1 showed 100% sensitivity in diagnosis of papillary carcinoma and its variants. Adenomatoid nodules did not express Gal-3 which helped in their differentiation from FVPTC. CONCLUSIONS: Gal-3 in combination either with CK-19 or HBME-1 improves the sensitivity and specificity of detection of papillary carcinoma, its variants and its differentiation from follicular patterned lesions to 100% with a significant p value.

Microsporidial Endotheliitis Mimicking Graft Rejection After Deep Anterior Lamellar Keratoplasty.

PURPOSE: The purpose of this study was to report a case of microsporidial endotheliitis masquerading as graft rejection after deep anterior lamellar keratoplasty (DALK). METHODS: A 36-year-old man visited the clinic with complaints of blurred vision, redness, pain, watering, and whitish appearance of the black portion of his left eye. On evaluation, there was diffuse stromal edema with epithelial defect and hypopyon. Microbial keratitis resolved with macular grade scar. He underwent DALK. After 3 years, he presented with complaints of sudden diminution of vision in the same eye for 10 days. His unaided visual acuity was counting finger 1 meter. The clinical findings were circumcorneal congestion, diffuse graft edema, Descemet membrane folds, and diffuse keratic precipitates. A presumptive diagnosis of left eye graft rejection was made. Topical steroids were administered. There was significant improvement within a week. However, at 1 month, there was an increase in graft edema after the steroids were tapered. At this point, a diagnosis of endotheliitis of viral origin was made. He was then administered oral antivirals and steroids. There were 2 such waxing and waning episodes of graft edema before the graft failed. Patient underwent penetrating keratoplasty with cataract extraction with intraocular lens implantation. RESULTS: The previous donor and host Descemet endothelium complex was sent for histopathology and polymerase chain reaction. Both histology and polymerase chain reaction were positive for microsporidia. CONCLUSIONS: Microsporidial endotheliitis may present as graft rejection. There should be a suspicion of microsporidial infection in cases of features mimicking as endothelial rejection after DALK.

Identification of affective valence of Twitter generated sentiments during the COVID-19 outbreak.

This study aims to conduct text mining of affective valence of the sentiments generated on social media during the COVID-19 and measure their association with different outcomes of the disease. 50,000 tweets per day over 23 days during the pandemic were extracted using the VADER sentiment analysis tool. Overall, tweets could effectively be classified in terms of polarity, i.e., "positive," "negative" and "neutral" sentiments. Furthermore, on a day-to-day basis, the study identified a positive and significant relationship between COVID-19-related (a) global infections and negative tweets, (b) global deaths and negative tweets, (c) recoveries and negative tweets, and (d) recoveries and positive tweets. No significant association could be found between (e) infections and positive tweets and (f) deaths and positive tweets. Furthermore, the statistical analysis also indicated that the daily distribution of tweets based on polarity generates three distinct and significantly different numbers of tweets per category, i.e., positive, negative and neutral. As per the results generated through sentiment analysis of tweets in this study, the emergence of "positive" tweets in such a gloomy pandemic scenario shows the inherent resilience of humans. The significant association between news of COVID-19 recoveries and positive tweets seems to hint at a more optimistic scenario whenever the pandemic finally comes to an end or is controlled. Such public reactions-for good-have the potential to go viral and influence several others, especially those who are classified as "neutral" or fence-sitters.

The Oncogene MYCN Modulates Glycolytic and Invasive Genes to Enhance Cell Viability and Migration in Human Retinoblastoma.

Retinoblastoma is usually initiated by biallelic RB1 gene inactivation. In addition, MYCN copy number alterations also contribute to RB pathogenesis. However, MYCN expression, its role in disease progression and correlation with RB histological risk factors are not well understood. We studied the expression of MYCN in enucleated RB patient specimens by immunohistochemistry. MYCN is overexpressed in RB compared to control retina. Our microarray gene expression analysis followed by qRT-PCR validation revealed that genes involved in glucose metabolism and migration are significantly downregulated in MYCN knockdown cells. Further, targeting MYCN in RB cells using small molecule compounds or shRNAs led to decreased cell survival and migration, increased apoptosis and cell cycle arrest, suggesting that MYCN inhibition can be a potential therapeutic strategy. We also noted that MYCN inhibition results in reduction in glucose uptake, lactate production, ROS levels and gelatinolytic activity of active-MMP9, explaining a possible mechanism of MYCN in RB. Taking clues from our findings, we tested a combination treatment of RB cells with carboplatin and MYCN inhibitors to find enhanced therapeutic efficacy compared to single drug treatment. Thus, MYCN inhibition can be a potential therapeutic strategy in combination with existing chemotherapy drugs to restrict tumor cell growth in RB.

Changing patterns of posterior segment trauma during the COVID-19 pandemic: A regional analysis from the Bodhya Eye Consortium.

Purpose: To assess changes in the presentation patterns of posterior segment trauma during the COVID-19 pandemic from six tertiary eye care institutes of North and Central India. Methods: A multicenter, hospital-based, retrospective comparative analysis of patients presenting with posterior segment trauma was done during the COVID-19 (Group A) (March 25, 2020 - September 30, 2020) period and the pre-COVID-19 (Group B) (March 25, 2019 - September 30, 2019) period. Results: A total of 405 patients were diagnosed with posterior segment trauma (Group A: 206, Group B: 199). The time interval between onset of trauma and presentation was higher in Group A (16.59 ± 29.87 days) as compared to Group B (9.41 ± 19.19 days) (P = 0.004). A majority of patients in Group A had a history of prior consultation before presentation (P = 0.049). In Group A, 120 (58.2%) patients sustained ocular trauma at home as compared to 80 (40.2%) patients in Group B (P < 0.0001). Patients presenting with light perception were significantly more in Group A (43.7%) as compared to Group B (30.2%) (P = 0.004). In Group B, 37.6% patients had presenting visual acuity of counting finger or better as compared to 27.6% patients in Group A (P = 0.07). Patients in Group A had a significantly higher proportion of post-traumatic endophthalmitis with delayed presentation (P = 0.011) and retinal detachment (P = 0.041). Patients undergoing surgery for foreign-body removal were significantly fewer in Group A (P = 0.05). Conclusion: Although the number of patients presenting with posterior segment trauma was comparable in Groups A and B, a greater number of patients sustained home injuries during the COVID-19 pandemic. A majority of these patients had delayed presentation with poor presenting visual acuity and a higher tendency of retinal detachment.

Treatable Cause of Refractory Seizures in an Infant with a Novel Mutation.

Pyridoxine-dependent epilepsy is a treatable cause of epilepsy, which is very well known. It is most commonly caused by mutations in ALDH7A1 and PNPO genes. A 5-month-old infant presented with refractory seizures. Magnetic resonance imaging (MRI) brain was normal. Clinical exome sequencing showed a novel mutation in PROSC gene. He responded very well to pyridoxine and has been seizure free since the beginning of the treatment. PROSC gene mutations have been recently described as a cause for pyridoxine-dependent epilepsy. Here, we describe a first case report of PROSC mutation from India with a rare genetic variant presenting as pyridoxine-dependent epilepsy.

Pythium keratitis: Clinical profile, laboratory diagnosis, treatment, and histopathology features post-treatment at a tertiary eye care center in Eastern India.

Purpose: The aim of this work was to study demography, clinical profile, laboratory diagnosis, and management of Pythium keratitis at a tertiary eye care center in Eastern India. Methods: Eighteen patients with culture-positive Pythium keratitis managed at our center between January 2016 and December 2018 were included in this retrospective study. Clinical features, laboratory investigations, treatment, and outcomes were analysed. Results: Pythium keratitis commonly affects middle-aged males with low socioeconomic profile and history of trauma. Samples stained with Gomori methenamine silver showed 93.8% positivity and Iodine-potassium iodide-sulfuric acid showed 100% positivity. Periodic acid-Schiff's showed negative staining in 62.5% and weak in 37.5%. Kirby-Bauer disc diffusion method showed zone of inhibition as 30.25 ± 4.61 mm for Linezolid and 23.56 ± 6.86 mm for Azithromycin. Medical management included topical/oral linezolid and azithromycin. Therapeutic penetrating keratoplasty (TPK) was done in 15 eyes (83.3%), repeat TPK in 4 eyes, and evisceration in 3 eyes (16.7%). One patient required only medical treatment. Globe salvation was obtained in 15 (83.3%) eyes, and good visual outcome in 7 eyes (38. 9%). There was graft failure in six eyes (40%) and two (11.1%) eyes went into phthisis. Patients were divided into early and late presenters. Late presenters had more complications and worse final visual outcome. Conclusion: Pythium keratitis can be differentiated from fungal keratitis by its characteristic appearance on slit-lamp examination, smear, culture, and histopathology. Early presentation, detection, and treatment with antibacterial drugs like linezolid and azithromycin results in a better prognosis. Early full-thickness corneal transplant should be considered for Pythium keratitis not responding to treatment.

Peters Anomaly in Nail-Patella Syndrome: A Case Report and Clinico-Genetic Correlation.

PURPOSE: The purpose of this study was to report the clinicopathological features of Peters anomaly in a child with nail-patella syndrome. METHODS: Nail-patella syndrome (NPS) is a rare autosomal dominant connective tissue disorder characterized by several anomalies of the extremities, joints and nails, glomerulopathy, and rarely ocular involvement. NPS is caused by heterozygous loss-of-functional mutations in the LMX1B gene that encodes the LIM homeodomain proteins. RESULTS: This case reports a new association of Peters anomaly in a child with NPS that also had classic skeletal/nail anomalies and protein losing nephropathy. Furthermore, DNA sequence analysis identified a novel missense heterozygous mutation in the LMX1B gene (Transcript ID: NM_001174146) resulting in the replacement of tryptophan by serine in codon 266, suggesting that the mutation (p.Trp.266Ser) affects LMX1B function by disturbing its interactions with other proteins. To the best of our knowledge, this association of Peters anomaly is novel and has not been reported earlier in the ophthalmic and systemic literature on NPS. CONCLUSION: The corneal findings in our case with NPS are similar to those seen in congenital corneal opacification because of Peters anomaly. This novel association of Peters anomaly with NPS may be related to the effects of the LMX1B mutation on corneal development.

Aurora Kinase B Expression, Its Regulation and Therapeutic Targeting in Human Retinoblastoma.

Purpose: Aurora kinase B (AURKB) plays a pivotal role in the regulation of mitosis and is gaining prominence as a therapeutic target in cancers; however, the role of AURKB in retinoblastoma (RB) has not been studied. The purpose of this study was to determine if AURKB plays a role in RB, how its expression is regulated, and whether it could be specifically targeted. Methods: The protein expression of AURKB was determined using immunohistochemistry in human RB patient specimens and immunoblotting in cell lines. Pharmacological inhibition and shRNA-mediated knockdown were used to understand the role of AURKB in cell viability, apoptosis, and cell cycle distribution. Cell viability in response to AURKB inhibition was also assessed in enucleated RB specimens. Immunoblotting was employed to determine the protein levels of phospho-histone H3, p53, p21, and MYCN. Chromatin immunoprecipitation-qPCR was performed to verify the binding of MYCN on the promoter region of AURKB. Results: The expression of AURKB was found to be markedly elevated in human RB tissues, and the overexpression significantly correlated with optic nerve and anterior chamber invasion. Targeting AURKB with small-molecule inhibitors and shRNAs resulted in reduced cell survival and increased apoptosis and cell cycle arrest at the G2/M phase. More importantly, primary RB specimens showed decreased cell viability in response to pharmacological AURKB inhibition. Additional studies have demonstrated that the MYCN oncogene regulates the expression of AURKB in RB. Conclusions: AURKB is overexpressed in RB, and targeting it could serve as a novel therapeutic strategy to restrict tumor cell growth.

Descemet Membrane Endothelial Keratoplasty in Congenital Hereditary Endothelial Dystrophy: Initial Experiences.

PURPOSE: To report our early experiences with Descemet membrane endothelial keratoplasty (DMEK) in congenital hereditary endothelial dystrophy (CHED). METHODS: Retrospective analysis of medical records of eyes with CHED that underwent DMEK between January 1, 2018, and April 30, 2019, and had a minimum of 1-year follow-up. RESULTS: Three eyes of 2 CHED patients (a 10-year-old girl and a 22-year-old man) were included. Both had decreased vision and hazy corneas from birth and underwent DMEK during the study period. Surgery was performed by a single surgeon and was uneventful in all 3 eyes. Within 1 month of surgery, the corneal edema cleared, and vision improved significantly. The mean decimal visual acuity improved from 0.15 ± 0.08 (baseline) to 0.33 ± 0.19 at 3 months. The mean central corneal thickness improved from 928 ± 2.3 µm (baseline) to 555.3 ± 25.8 µm at 3 months. The final visual outcome was less in 1 eye because of dense amblyopia. In all 3 eyes, a subtle stromal haze persisted even after resolution of edema. One eye had graft rejection 7 months after surgery because of discontinuation of medications, effectively managed by increasing the frequency of topical steroids. CONCLUSIONS: DMEK may be a viable option in phakic eyes with CHED.

Dematiaceous fungal invasion of a bandage contact lens.

A 61-year-old man presented with a 1-month history of reduced vision, redness and pain in the right eye. Examination revealed a bandage contact lens (BCL) in situ with diffuse, pigmented deposits. On removal, the underlying cornea was found to be clear. He had been prescribed the BCL 6 months ago following a deep-seated corneal foreign body removal and was unable to follow-up subsequently.The BCL was sent for microbiological and histopathological evaluation. The culture revealed growth of Cladosporium spp, a dematiaceous fungi. Periodic acid-Schiff staining revealed infiltration of pigmented fungal filaments into the substance of the BCL.While contact lens deposits are a frequent finding, fungal deposits are seldom noted. Irregular follow-up and improper lens maintenance are significant risk factors for the same. Early identification and subsequent removal of the lens is vital to prevent infection of the underlying ocular structures.

Improved Outcome of Pythium Keratitis With a Combined Triple Drug Regimen of Linezolid and Azithromycin.

PURPOSE: To describe the clinical features, microbiological profile, and outcome of a series of cases of Pythium keratitis treated with topical and oral linezolid and topical azithromycin eye drops. METHODS: This was a retrospective interventional case series of microbiologically and/or histopathologically proven cases of Pythium keratitis seen between October 2016 and December 2019. All patients received a combination of topical linezolid and/or azithromycin eye drops with oral linezolid. Analysis of demographic data, predisposing risk factors, microbiological results, treatment regimen, visual acuity, surgical intervention, and final outcome was performed. A subgroup analysis of cases >6 mm in size was performed. Success was defined as complete resolution on medical management. Failure was defined as worsening of infection necessitating therapeutic penetrating keratoplasty or evisceration. RESULTS: Of 21 cases, 2 were lost to follow up, 1 was diagnosed on histopathology, and 1 received only topical linezolid. Characteristic microbiological features were noted on 10% potassium hydroxide calcofluor white wet mount in 20/21 (95.23%) and Gram stain in 18/21 (85.71%). On triple drug regimen, 14/17 cases (82.35%) resolved. Average time to resolution was 87.64 ± 44.44 days. More than 60% infiltrates (13/21) were large, and 66.66% infiltrates resolved in 109.3 ± 57.06 days. Of the 5 failures, 4 needed therapeutic keratoplasty and 1 needed evisceration. All grafts failed. CONCLUSIONS: The dual topical drug regimen with oral linezolid has good cure rates (over 80%) for Pythium keratitis over prolonged duration. It is recommended to persevere with medical therapy even in large infiltrates because more than two thirds resolved.