Insights into the genomic features and lifestyle of B1 subcluster mycobacteriophages.

Bacteriophages infecting Mycobacterium smegmatis mc2155 are numerous and, hence, are classified into clusters based on nucleotide sequence similarity. Analyzing phages belonging to clusters/subclusters can help gain deeper insights into their biological features and potential therapeutic applications. In this study, for genomic characterization of B1 subcluster mycobacteriophages, a framework of online tools was developed, which enabled functional annotation of about 55% of the previously deemed hypothetical proteins in B1 phages. We also studied the phenotype, lysogeny status, and antimycobacterial activity of 10 B1 phages against biofilm and an antibiotic-resistant M. smegmatis strain (4XR1). All 10 phages belonged to the Siphoviridae family, appeared temperate based on their spontaneous release from the putative lysogens and showed antibiofilm activity. The highest inhibitory and disruptive effects on biofilm were 64% and 46%, respectively. This systematic characterization using a combination of genomic and experimental tools is a promising approach to furthering our understanding of viral dark matter.

Study of biomarkers p53, Ki-67, Bcl-2, and VEGF in pterygium.

PURPOSE: To study the biomarkers present in primary pterygium samples of patients of Indian ethnicity and compare it with the samples obtained from the unaffected conjunctiva of the same eye. METHODS: A prospective case-control study of 17 eyes in patients above 10 years of age with primary pterygium who underwent pterygium excision using limbal conjunctival autograft technique. The pterygium samples (cases) and conjunctival samples (controls) were sent for immunohistochemical (IHC) staining for the following biomarkers: p53, Bcl-2, Ki-67, and vascular endothelial growth factor (VEGF). RESULT: The immunohistochemistry of the samples and the controls revealed p53 positivity in 47.05% of pterygium samples and 29.4% of controls ( P < 0.587). Nine cases each in pterygium and control samples were positive for Ki-67 expression. Differences in the staining pattern between the two groups were not statistically significant ( P < 1.000). Bcl-2 positivity was seen in 10 pterygium samples (58.8%) and 12 controls (70.5%), with no statistical difference between the two groups ( P < 0.455). VEGF expression was seen in both epithelial and endothelial cells of the samples and controls, with no statistical difference between the two groups, with P = 1.000 for the epithelial staining and P = 0.637 for endothelial staining. CONCLUSION: The expression of biomarkers was comparable in both groups. We conclude that pterygium, against common belief, might not be a localized disease process but a global ocular phenomenon where the apparently healthy tissue also has some ongoing disease process at a molecular level.

Unlocking prophage potential: In silico and experimental analysis of a novel Mycobacterium fortuitum LysinB containing a peptidoglycan-binding domain.

Endolysins are highly evolved bacteriophage-encoded lytic enzymes produced to damage the bacterial cell wall for phage progeny release. They offer promising potential as highly specific lytic proteins with a low chance of bacterial resistance. The diversity in lysin sequences and domain organization can be staggering. In silico analysis of bacteriophage and prophage genomes can help identify endolysins exhibiting unique features and high antibacterial activity, hence feeding the pipeline of narrow-spectrum protein antibiotics. Mycobacteriophage lysis cassettes mostly have two lytic enzymes, LysinA and LysinB. The enzyme LysinA targets peptidoglycan in the cell wall and possesses a modular architecture. LysinB typically contains a single domain and acts upon the mycolyl ester linkages in mycolyl-arabinogalactan-peptidoglycan (Payne et al., 2010). This study aimed to find novel LysinBs against Mycobacterium fortuitum. After a detailed in silico characterization of lysis cassettes from three M. fortuitum prophages, we chose to work on a LysinB (hereafter described as LysinB_MF) found in an incomplete prophage (phiE1336, 9.4 kb in strain E1336). LysinB_MF showed low sequence similarity with any other endolysins in the database and formed a separate clade on phylogenetic analysis. LysinB_MF's structure, extracted from the AlphaFold Protein Structure Database, demonstrated a modular architecture with two structurally distinct domains: a peptidoglycan-binding domain (PGBD) at the N-terminal and the characteristic alpha/beta hydrolase domain connected via a linker peptide. We found the alpha/beta hydrolase domain, which is the enzyme-active domain (EAD), contains the conserved Ser-Asp-His catalytic triad with a tunnel-like topology and forms intermolecular hydrogen bonds. The PGBD shows structural similarity to the cell-wall binding domain of an amidase from Clostridium acetobutylicum, hinting at its acquisition due to domain mobility. Our in silico electrostatic potential analysis suggested that PGBD might be essential to the enzyme activity. This was experimentally validated by generating a truncated version of the enzyme, which demonstrated about six-fold decreased activity compared to its native form. The antimycobacterial activity of this enzyme was also compromised in its absence. Based on our analysis, PGBD emerged as an integral constituent of enzymes with diverse functional properties and is predicted to be a conserved cross-kingdom. Overall, this study highlights the importance of mining mycobacterial prophages as a novel endolysin source. It also provides unique insights into the diverse architecture of mycobacteriophage-encoded endolysins and the importance of functional domains for their catalytic activities.

Self-inflicted bilateral ocular injury with scissors in a psychiatric patient.

A young male was brought to the ophthalmic emergency by his family with severe bleeding from both eyes after self-inflicted injury with scissors in a fit of mania. He had a history of schizophrenia and has been on irregular treatment for the past 10 years. Both eyes were severely damaged with avulsion of all extraocular muscles in one eye and a large corneoscleral laceration in the other. We report this unique case of oedipism or self-enucleation where a sharp instrument was used. Self-inflicted injury to the eyes is a rather uncommon phenomenon described in psychiatric patients. It can range from minor abrasions to severe ocular mutilation and loss of sight. The strict observation of these patients while admitted to the hospital and a multidisciplinary approach to ensure their future safety are imperative.

Repeat deep anterior lamellar keratoplasty (DALK) for failed primary DALK.

Purpose: To evaluate the effectiveness of repeat deep anterior lamellar keratoplasty (DALK) in patients of previous failed DALK. Methods: : A retrospective analysis of records of seven patients who had undergone repeat DALK following the failure of the primary DALK was done. The indications for repeat surgery, time elapsed since the first surgery, and pre- & postoperative best-corrected visual acuity (BCVA) were noted for all the patients. Results: The follow-up period ranged between one- to four-year post repeat DALK. The indication of primary DALK was keratoconus with vernal keratoconjunctivitis (VKC) (n = 3), corneal amyloidosis (n = 2), Salzman nodular keratopathy (n = 1), and healed keratitis (n = 1). The need for repeat surgery arose when the BSCVA dropped to less than 20/200. The time interval elapsed since the first surgery ranged from two months to four years. Postoperatively, the BSCVA improved from 20/120 to 20/30 at the end of one-year post repeat DALK in all except one patient. All regrafts were clear at the most recent examination, performed after a mean period of 18 months after the secondary graft. No complication was encountered during the resurgery. The dissection of the host bed was easier in the second surgery owing to weaker adhesions. Conclusion: The prognosis for repeat DALK for failed DALK is excellent, and the outcomes of secondary grafts were comparable to those of primary DALK grafts. Re DALK offers the advantage of an easier dissection and lower chances of graft rejection compared to penetrating keratoplasty.

An atypical presentation of sympathetic ophthalmia following chemical ocular burns.

BACKGROUND: Sympathetic ophthalmia is a rare disease that can present as bilateral granulomatous uveitis after a penetrating trauma or surgery in one eye. FINDINGS: We report a case of a 47-year-old male with history of decreased vision in the right eye, six months after sustaining severe chemical injury in the left eye. He was diagnosed with sympathetic ophthalmia and was treated with corticosteroids and long-term immunosuppressive therapy, leading to complete resolution of intraocular inflammation. Final visual acuity was 20/30 at one year of follow up. CONCLUSIONS: Sympathetic Ophthalmia following chemical ocular burns is extremely uncommon. It can present as a diagnostic and therapeutic challenge. It warrants early diagnosis and management.

COVID-Associated Sinonasal Mucormycosis: Radiological Pathological Correlation and Prognostic Value of MR Imaging.

Purpose Our aim was to assess the sinonasal magnetic resonance imaging (MRI) features of acute invasive fungal rhinosinusitis (AIFRS) in coronavirus disease (COVID)-associated mucormycosis (CAM) and to correlate these with histopathology and patient outcome in terms of duration of hospital stay and survival at 10 weeks. Methods Twenty patients with histopathologically confirmed sinonasal CAM underwent MRI (including postcontrast T1-weighted and diffusion-weighted imaging). Histopathological findings (presence of coagulative necrosis, granulomatous reaction, and fungal burden) were recorded and all patients were followed up at 6 and 10 weeks. Statistical analysis was done using chi-square test and Fischer's exact test. Results Enhancement patterns seen in our subjects included homogeneous, heterogeneous, and lack of contrast enhancement (LOC), with LOC being the most common (65%). Diffusion restriction was found in 90% patients. Statistically significant correlation was found between LOC pattern and presence of coagulative necrosis ( p -value = 0.007), extent of fungal hyphae ( p -value = 0.047), and duration of hospital stay ( p -value = 0.004). Restricted diffusion was also seen to correlate with a high fungal load ( p -value = 0.007). Conclusion Our study describes the MRI findings of AIFRS in CAM and highlights the imaging features which may be surrogate markers for coagulative necrosis and fungal burden.

Optical Coherence Tomography Angiography Parameters of the Retina in SARS-CoV-2 Recovered Subjects.

INTRODUCTION: This study aims to evaluate retinochoroidal optical coherence tomography angiography (OCTA) parameters in patients recovered from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: This study was an observational study that included 80 subjects being discharged after having negative reports on the reverse transcription-polymerase chain reaction (RT-PCR) test for SARS-CoV-2 to evaluate OCTA parameters of the retina. The subjects underwent an ophthalmic evaluation that included best-corrected visual acuity (BCVA), intraocular pressure (IOP), color vision (CV), contrast sensitivity (CS), and optical coherence tomography (OCT) parameters. OCTA was done for all patients and was evaluated for foveal avascular zone (FAZ) area, perimeter, and circularity index, and vessel density (VD) in superficial capillary plexus (SCP), deep capillary plexus (DCP), outer retina (OR), outer retina chorio-capillaries (ORCC), chorio-capillaries (CC), and choroid (C) using 3 x 3 mm scans. The OCTA parameters were compared with normative data of the Indian population for various parameters in question. RESULTS: The subjects included 54/80 (67.5%) males and 26/80 (32.5%) females having a mean age of 52.40 ± 15.71 (18-60) years. The systemic evaluation revealed 38.75% of subjects had hypertension, 30% had diabetes, 20% had kidney disease, 5% had tuberculosis, and 3.75% had coronary artery disease. The mean distance BCVA was logarithm of the minimum angle of resolution (LogMAR) (1.17 ± 0.22), mean IOP was 17.0 ± 4.0 mmHg, mean CS was 2.13 ± 0.36, 50.62% of subjects had normal CV on Farnsworth test while 47% had tritanopia, and none of the subjects had red-green CV defect on Ishihara plates. The OCT scan was normal in 90% of eyes while the posterior vitreous detachment was seen in 4% of eyes, broad vitreomacular adhesion in 2.5% of eyes, and the globally adherent epiretinal membrane was seen in 2.5% of eyes. The mean central macular thickness (CMT) measured 245.14 ± 28.41 micrometers. The mean FAZ area measured 0.37 ± 0.15 mm2, the perimeter was 3.28 ± 1.08 mm, and the circularity index measured 0.41 ± 0.10. The average VD in SCP measured 16.06 ± 12.29, in DCP measured 9.11 ± 8.75, in OR measured 6.38 ± 7.37, in ORCC measured 42.53 ± 12.46, in CC measured 25.83 ± 16.31, and in C measured 25.52 ± 17.49. The VD in coronavirus disease 2019 (COVID-19) subjects was significantly lesser than that in the healthy Indian population in all layers except ORCC. CONCLUSIONS: The SARS-CoV-2 recovered subjects have a reduced VD in retinochoroidal layers from COVID-19, an underlying systemic disease, or both. The CS values fall within normal limits. Several subjects show tritanopia on the Farnsworth test but no red-green CV defect on Ishihara plates.

Orbital and ocular perfusion in thyroid eye disease.

Thyroid eye disease (TED) is characterized by enlargement of extraocular muscles, an increase in retrobulbar fat, orbital fibrosis, and fluctuations in plasma thyroid hormone levels in most patients, often associated with raised autoantibody titers. The occurrence of orbital space conflict compromises the orbital perfusion, unchecked progression of which results in irreversible loss of visual acuity and visual fields. The quantitative assessment of orbital perfusion can be done by measurement of blood flow velocities in the superior ophthalmic vein (SOV), ophthalmic artery (OA), central retinal artery (CRA), and posterior ciliary artery by color Doppler imaging. The retinal and choroidal microvasculature is studied by optical coherence tomography and optical coherence tomography angiography. The orbital and ocular perfusion fluctuates during the course of TED. Orbital congestion is reflected by the reduction or reversal of SOV flow and an increase in subfoveal choroidal thickness. The active phase is characterized by high blood flow velocities of the OA and CRA. The onset of dysthyroid optic neuropathy is associated with reduced arterial perfusion and reduction in parafoveal and peripapillary vascular density. Orbital decompression improves the SOV flow and decreases the resistivity index of CRA. Sequential evaluation of orbital hemodynamic changes can thus supplement the clinical scoring systems for monitoring and planning intervention in TED.

MST4: A Potential Oncogene and Therapeutic Target in Breast Cancer.

The mammalian STE 20-like protein kinase 4 (MST4) gene is highly expressed in several cancer types, but little is known about the role of MST4 in breast cancer, and the function of MST4 during epithelial-mesenchymal transition (EMT) has not been fully elucidated. Here we report that overexpression of MST4 in breast cancer results in enhanced cell growth, migration, and invasion, whereas inhibition of MST4 expression significantly attenuates these properties. Further study shows that MST4 promotes EMT by activating Akt and its downstream signaling molecules such as E-cadherin/N-cadherin, Snail, and Slug. MST4 also activates AKT and its downstream pro-survival pathway. Furthermore, by analyzing breast cancer patient tissue microarray and silicon datasets, we found that MST4 expression is much higher in breast tumor tissue compared to normal tissue, and significantly correlates with cancer stage, lymph node metastasis and a poor overall survival rate (p < 0.05). Taken together, our findings demonstrate the oncogenic potential of MST4 in breast cancer, highlighting its role in cancer cell proliferation, migration/invasion, survival, and EMT, suggesting a possibility that MST4 may serve as a novel therapeutic target for breast cancer.

Corneal aberrations, densitometry on scheimpflug imaging, and visual acuity after deep anterior lamellar keratoplasty.

PURPOSE: To evaluate visual acuity, corneal aberrations, and densitometry post deep anterior lamellar keratoplasty (DALK). METHODS: Twenty-five eyes of 25 patients who underwent DALK for corneal stromal diseases with normal endothelium were enrolled in a prospective interventional study. Evaluation for corneal aberrations and densitometry postoperatively was performed using Scheimpflug imaging at 6 months. Anterior Segment Optical Coherence Tomography (ASOCT) was done for host-graft morphology. Correlation analysis of postoperative best-corrected visual acuity with corneal aberrations and corneal densitometry (CD) was performed. RESULTS: Big bubble deep anterior lamellar keratoplasty (BB-DALK) was successful in 18 patients, while 7 eyes underwent manual dissection due to failed BB (Big Bubble) technique. The mean BSCVA was 1.35 ± 0.46 logMAR units pre-operatively which improved to 0.36 ± 0.19 logMAR units post DALK at 6 months (P < 0.001). The mean Root Mean Square (RMS) (µm) of the magnitude of total corneal aberrations, HOA and LOA from central 6mm zone of cornea were 14.6 ± 9.2, 4.7 ± 2.9, and 13.8 ± 8.8, respectively. The mean anterior (120µm), central and posterior corneal (60µm) densitometry in 0-2mm zone were 25.8 ± 7.7 GSU, 18.7 ± 4.16 GSU and 10.09 ± 3.9 GSU respectively. A statistically significant correlation of postoperative residual stromal bed thickness, total corneal HOA, LOA, total corneal aberrations, HOA front and posterior corneal densitometry (0-2mm zone) with postoperative BSCVA was found. CONCLUSION: Though there is a significant improvement in BSCVA after DALK, the quality of vision in terms of aberrometry and densitometry is suboptimal, especially in cases undergoing manual DALK compared to those undergoing big bubble formation.

Ocular sequelae in severe COVID-19 recovered patients of second wave.

Purpose: To evaluate the retinal microvascular changes in patients, recovered from severe COVID-19 during the second wave of the pandemic in North India. Methods: In this observational cross-sectional study, 70 eyes of 35 patients who recovered from severe COVID-19 during the second wave underwent detailed ophthalmic evaluation 4-6 weeks after discharge. Twelve controls were also enrolled, and the difference in the findings between the case and control groups on optical coherence tomography (OCTA) were studied. Result: The ages of study participants ranged from 27 to 60 years with the male:female ratio being 1.05:1. The fundus changes suggestive of ischemia in the form of cotton wool spots and vascular tortuosity were seen in 25 eyes (35.71%). Increased venous tortuosity was the most common finding seen in 23 eyes (32.85%), of which 10 eyes (28.57%) had concurrent hypertensive retinopathy (HTR) changes. There was a significant reduction in the mean vascular density (VD) and perfusion density (PD) for both the superficial capillary plexus (SCP) and deep capillary plexus (DCP) at inner, outer ring, and whole (P < 0.05). Foveal avascular zone was significantly enlarged in both the SCP (P = 0.01) and the DCP (P = 0.03). The mean ganglion cell-inner plexiform layer (GC-IPL) was significantly reduced in comparison to controls (P < 0.001). Conclusion: Severe COVID-19 can result in microvascular changes at the macula in the form of reduction in vascular and perfusion density, which can be evaluated using OCTA. As structural changes precede functional changes, a close watch is recommended in patients showing compromise in retinal microvasculature.

Complications of corneal collagen cross-linking.

Corneal collagen cross-linking (CXL) is an effective treatment for arresting progression in patients with keratoconus. CXL was approved by United States Food and Drug Administration for the treatment of progressive keratoconus in 2016. It is a relatively safe procedure with a low complication rate. As this approach becomes more popular, it is paramount to be familiar with the potential complications associated with the procedure and its management. This article aims to report and review the complications of CXL for the treatment of keratoconus and post-LASIK ectasia.

Bilateral sequential non-arteritic optic neuropathy post-COVID-19.

Corona virus disease 2019 (COVID-19) has been documented to have a spectrum of neuro-ophthalmic manifestations. However, bilateral non-arteritic anterior ischemic optic neuropathy (NAION) post-COVID-19 has not been reported in the literature. We studied the case of a 45-year-old male who presented to our outpatient department (OPD) with bilateral blurring of vision following an episode of COVID-19, 1 month back. Examination and investigations were conclusive of a bilateral NAION. The patient was given a trial of oral steroids. However, the vision loss could not be recovered. Thus, through this case report, we would like to highlight the importance of a close follow-up of patients following COVID-19 infection to detect any sequelae.

Immunocytochemistry of the ocular surface after different techniques of limbal stem cell transplantation for chronic chemical burns.

AIM: To compare the immunocytochemistry (ICC) on impression cytology of corneal surface epithelium after simple limbal epithelial transplantation (SLET) and conjunctival-limbal autograft (CLAU). METHODS: A prospective study of 20 patients above 1 year of age with chronic chemical burns, who underwent limbal stem cell transplantation (LSCT). They were divided equally in group A (SLET) and group B (CLAU). ICC was done for cytokeratin 3 (CK3) and cytokeratin 19 (CK19), preoperatively and postoperatively at 6 months. RESULTS: Four cases were excluded due to inadequate cellularity in preoperative or postoperative samples. On ICC analysis, in the remaining 16 patients mean CK3 and CK19 positivity changed from 2.06%±1.73% and 83.56%±8.69% preoperatively to 70.62%±13.2% (p<0.0001) and 5.93%±4.17% (p<0.0001), respectively, at 6 months post LSCT. In group A (8 patients) mean CK3 and CK19 positivity of 2%±1.8% and 84.5%±8.4% preoperatively changed to 70%±13.8% (p<0.0001) and 6.25%±5.1% (p<0.0001) at 6 months respectively. While in group B (8 patients), it was 2.12%±1.7% and 82.62%±9.4% preoperatively and 71.25%±013.5% (p<0.0001) and 5.62%±3.2% (p<0.0001) at 6 months. There was no significant difference in expression of CK3 (p=0.084) and CK19 (p=0.744) post SLET or CLAU.Three patients with complete reversion had clear corneas at 6 months. CONCLUSION: Reversion of the epithelium to corneal phenotype was documented post LSCT with no difference in expression of CK3 between the two procedures (SLET/CLAU).

COVID associated mucormycosis: A preliminary study from a dedicated COVID Hospital in Delhi.

BACKGROUND: It is an incontrovertible fact that the Rhino Orbital Cerebral Mucormycosis (ROCM) upsurge is being seen in the context of COVID-19 in India. Briefly presented is evidence that in patients with uncontrolled diabetes, a dysfunctional immune system due to SARS-COV-2 and injudicious use of corticosteroids may be largely responsible for this malady. OBJECTIVE: To find the possible impact of COVID 19 infection and various co-morbidities on occurrence of ROCM and demonstrate the outcome based on medical and surgical interventions. METHODOLOGY: Prospective longitudinal study included patients diagnosed with acute invasive fungal rhinosinusitis after a recent COVID-19 infection. Diagnostic nasal endoscopy (DNE) was performed on each patient and swabs were taken and sent for fungal KOH staining and microscopy. Medical management included Injection Liposomal Amphotericin B, Posaconazole and Voriconazole. Surgical treatment was restricted to patients with RT PCR negative results for COVID-19. Endoscopic, open, and combined approaches were utilized to eradicate infection. Follow-up for survived patients was maintained regularly for the first postoperative month. RESULTS: Out of total 131 patients, 111 patients had prior history of SARS COVID 19 infection, confirmed with a positive RT-PCR report and the rest 20 patients had no such history. Steroids were received as a part of treatment in 67 patients infected with COVID 19. Among 131 patients, 124 recovered, 1 worsened and 6 died. Out of 101 known diabetics, 98 recovered and 3 had fatal outcomes. 7 patients with previous history of COVID infection did not have any evidence of Diabetes mellitus, steroid intake or any other comorbidity. CONCLUSION: It can be concluded that ROCM upsurge seen in the context of COVID-19 in India was mainly seen in patients with uncontrolled diabetes, a dysfunctional immune system due to SARS-COV-2 infection and injudicious use of corticosteroids.

Ocular Manifestations in Patients of HIV(Human Immunodeficiency Virus) Infection on Combined Anti-Retroviral Therapy (CART).

AIM: To determine the prevalence and spectrum of ocular manifestations in PLHIV (people living with Human Immunodeficiency Virus) on cART (combined Antiretroviral Therapy) and correlate them with WHO clinical staging, CD4 count, duration & type of cART. METHODS: Observational cross-sectional study. Ophthalmic evaluation of 350 PLHIV on cART (at least 6 months) was done. Logistic regression was done to correlate ocular findings with different variables. Results: Prevalence of ocular, anterior & posterior segment manifestations was 15.71%, 10.86%, and 4.00%, respectively. Dry eye(8.00%) being the most common finding. PLHIV with CD4 count ≤350 (OR = 3.1,p < 0.001), in WHO stage 3 (OR = 26.9,p = 0.004) & 4(OR = 60.7,p < 0.001) & on 3rdlineART were at much higher risk of ocular manifestations as compared to those on 2nd (OR = 2.83) and 1stline (OR = 6.6) of therapy. Duration of treatment had a protective (p = 0.01) effect on bilateral manifestations. CONCLUSION: With early initiation of ART, there is significant reduction in the overall prevalence of ocular findings, in the number of opportunistic ophthalmic infections and blinding disorders. Of all the reported ocular findings, anterior segment disorder emerged more often.

Clinico-Radiological-Pathological Correlation of Visual Loss in COVID-Associated Rhino-Orbito-Cerebral Mucormycosis.

PURPOSE: To correlate the clinical, radiological, and histopathological features in Covid-associated Rhino-orbito-cerebral mucormycosis cases presenting with acute visual loss. DESIGN: Cross-sectional study. METHODS: Covid-associated Rhino-orbito-cerebral mucormycosis cases with unilateral visual loss, planned for exenteration, underwent orbital and ophthalmological ocular examination. The available radiological sequences, doppler ultrasonography and histopathology findings were correlated with clinical manifestations. RESULTS: The median age was 51 years and the male: female ratio was 3:1. All except one presented with unilateral ophthalmoplegia. The ocular media were hazy in 2 eyes. In 8 eyes, retinal changes were suggestive of occlusion of CRA (6), combined occlusion of CRA and central retinal vein (1), and myopic degeneration with hypertensive retinopathy (1). The contralateral eye showed retinal ischemic changes in one patient. Radiological imaging showed orbital apex involvement in the 10 affected eyes and one contralateral eye. Ipsilateral cavernous sinus thrombosis, diffusion restriction on MRI of optic nerve, internal carotid artery narrowing/thrombosis, and cortical watershed infarcts were seen in 8, 4, 4, and 2 cases, respectively. The blood flow in CRA and ophthalmic artery was absent or reduced in all the 10 affected eyes and in 1 contralateral eye. On histopathology, orbital fat necrosis, fungal hyphae, acute inflammation, granuloma formation, ischemic thrombosis of ophthalmic artery was observed in 10 specimens. CRA was patent in 9 and thrombosed in 1 eye. Optic nerve was ischemic in 8 and viable in 2 eyes. CONCLUSION: Acute visual loss in ROCM cases is associated with orbital apex involvement and thrombotic ischemia of ophthalmic artery. Cessation of flow in CRA possibly occurs secondary to ophthalmic artery thrombosis.