The role of corneal biopsy in the management of microbial keratitis.

PURPOSE: Corneal biopsy helps in diagnosing deep-seated or recalcitrant lesions of microbial keratitis (MK). We aim to analyze its role in managing these challenging cases. METHODS: This is a retrospective review of 22 cases of corneal biopsy at our institute from January 2010 to December 2021. Data were retrospectively collected using the electronic medical record (EMR) system. Those cases of indolent, progressive MK or deep-seated lesions where cornea scraping was not possible were considered for corneal biopsy to establish the microbiological diagnosis. The primary aims of our study were to analyze the indications, success rates, and outcomes for biopsy patients in our series. Additional outcomes that were analyzed included the average time from presentation to biopsy, the type of causative organism isolated from the biopsy by either histopathological or microbiological method, and the frequency and outcome of surgical interventions performed. Descriptive statistics using mean (±standard deviation) and median (±range) were used to interpret the demographic data. RESULTS: Overall, 15 of 22 patients (68%) had a positive corneal biopsy after microbiological or histopathological examinations. The most identified organism was microsporidia (n = 4,30.7%), followed by mycobacteria (n = 2,15.4%), gram-negative bacilli (n = 2,15.4%), acid-fast bacilli (n = 1,7.6%), fungus (n = 2,15.4%), gram-positive cocci (n = 1,7.6%), and mixed bacterial infection (n = 1,7.6%). CONCLUSION: Corneal biopsy should be considered a diagnostic modality for patients with deep-seated or unresponsive MK. It can improve the treatment for MK, ensuring targeted therapy.

Indications and types of keratoplasties: Trends in the past 10 years (2011-2020) in Eastern India.

Purpose: To observe the trends of various types of keratoplasties in different etiologies over a period of 10 years (2011-2020) in a tertiary eye care center of eastern India. Methods: A retrospective review of patients undergoing keratoplasties from 2011 to 2020 was performed in a tertiary eye care hospital situated in eastern part of India. Apart from demographic data, primary indication for each surgery and type of procedure carried out was recorded. For comparison, data were divided into two time periods: Group I: Jan 2011 to Dec 2015 and Group II: Jan 2016 to Dec 2020. Results: Over a period of 10 years, a total of 2365 (Group I: 902, Group II: 1463) keratoplasties were performed. The average age of patients was 45.8 ± 19.9 and 46.9 ± 20.9 years in Group I and Group II, respectively. Among all the corneal grafts, 1747 (74%) surgeries were full-thickness. Although optical penetrating keratoplasty (OPK) was most the common indication for full-thickness keratoplasties, Descemet's stripping endothelial keratoplasty (DSEK) remained most performed lamellar keratoplasty. Keratitis, corneal scars, and bullous keratopathies remain to be most common indications in both groups. Number of lamellar keratoplasties increased significantly from Group I to Group II for corneal scars (P = 0.02), bullous keratopathies (P = 0.01), and endothelial dystrophies (P = 0.00). Conclusion: With change in time, the indication and technique of keratoplasty has witnessed a changing trend from full-thickness keratoplasty to lamellar keratoplasty. There is rise in trend of lamellar keratoplasties over the period.

Demographic profile and clinical characteristics of Fuchs' endothelial corneal dystrophy in a tertiary eye care center.

Purpose: This study was performed to determine the demographic profile and clinical characteristics in patients with Fuchs' endothelial corneal dystrophy (FECD) reporting to a tertiary eye care center in India. It is a retrospective, single-center, observational study. Methods: The study included 280 patients (559 eyes) diagnosed with FECD presenting between January 2013 and December 2020. The data was collected from the electronic medical record system of the institute. Patient data included demographic features, clinical characteristics, investigations, and surgical interventions. Results: The mean age of the patients was 62 years. Late-onset FECD (95.7%) was more common than early-onset FECD (4.3%). Male: female ratio for late-onset FECD and early-onset FECD was 1:1.65 and 3:1, respectively. More than one-third of the patients had associated systemic history. Preexisting ocular diseases were seen in 5.9% of eyes. Blurring of vision was seen in 383 eyes (68.5%), 13 eyes (2.1%) had glare, and 163 eyes (29.2%) were asymptomatic. A total of 113 surgical interventions were done in 108 eyes (including repeat transplants). Only cataract surgery was done in 40 (7.2%) eyes, whereas penetrating keratoplasty, Descemet stripping endothelial keratoplasty, and Descemet membrane endothelial keratoplasty without or with cataract surgery (sequential or triple procedure) were done in 12 (2.1%), 47 (8.4%), and 14 (2.5%) eyes, respectively. Conclusion: Patients with FECD present mostly during the sixth decade. Posterior lamellar keratoplasty is the most common transplant procedure being performed on FECD patients.

Microsporidia-induced stromal keratitis: a new cause of presumed immune stromal (interstitial) keratitis.

BACKGROUND AND OBJECTIVE: To describe the clinical features, diagnosis and management of immune stromal keratitis/interstitial keratitis (IK) associated with microsporidial epithelial keratitis. METHODS: Between October 2020 and January 2021, medical records of IK patients microbiologically proven as microsporidia from samples collected from corneal epithelium on smear examination, and/ or molecular analysis were reviewed. Demography, clinical profile and treatment were analysed. Real-time PCR (RT-PCR) for adenovirus (ADV), Epstein-Barr virus (EBV), herpes simplex virus (HSV) and varicella-zoster virus (VZV) was done. RESULTS: Twenty of 152 (13%) microbiologically proven cases of microsporidial keratitis were diagnosed as IK during the study period, the mean age and duration of symptoms were 35.7±11.4 years and 46.3±27.7 days, respectively. Half had predisposing risk factors, like trauma; and 30% had prior recurrences. One-fourth of patients were using antivirals on presentation. Characteristic presentations included disciform keratitis(n=12), incomplete/complete ring(n=5), and combination(n=3), along with variable subepithelial infiltrates (n=14). All cases had stromal oedema, with an intact epithelium and fine pigment dusting on endothelium. Corneal epithelial scrapings had scanty microsporidia spores in smears of 17/20 (85%), and pan-microsporidial DNA was identified in 14/20 (70%), with Vittaforma corneae by sequencing in 11/20 (55%). Other viruses detected were ADV (14,70%), VZV (2,10%), EBV (1,5%) and HSV (1,5%). Rapid resolution of inflammation and oedema within 2 weeks of starting steroids was seen in all cases. CONCLUSION: Microsporidia epithelial keratitis induced stromal inflammatory keratitis; is distinguished from microsporidial keratoconjunctivitis and stromal keratitis, by characteristic clinical features, and response to topical steroids.

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.

Outcome of four-point fixated open loop polymethyl methacrylate anterior chamber intraocular lens.

PURPOSE: To study long-term visual and refractive outcomes and complications in eyes with anterior chamber intraocular lens (ACIOL) implantation. METHODS: Data of patients who underwent primary and secondary ACIOL implantation at L V Prasad Eye Institute, Bhubaneswar between 2011 and 2020 was collected, including details of post-operative visits. For analysis, sample was divided into: group Ia (primary ACIOL in cases without risk factors, n = 104); group Ib (primary ACIOL in cases with pre-existing risk factors, n = 49); and group II (secondary ACIOL, n = 40). RESULTS: A total of 193 eyes of 192 patients were included. Mean post-operative follow-up in groups I and II were 8.6 and 11.51 months, respectively. Mean pre-operative and last visit corrected distance visual acuity were 1.73 ± 0.11 and 0.42 ± 0.05 logMAR units in group Ia (p < 0.001), and 1.53 ± 0.14 and 0.49 ± 0.10 logMAR units in group Ib (p < 0.001). The mean spherical equivalent (MSE) for last refraction was -0.37 ± 0.18 diopters (D) and -0.15 ± 0.51 D in groups I and II, respectively. Of 76 eyes in which addition of 2.5 D (over the near emmetropic posterior chamber intraocular lens power) was taken for ACIOL, 40 (52.6%) had MSE within ± 0.5 D. Most common complications were transient corneal edema and anterior chamber reaction. Eyes on anti-glaucoma medications at last visit were eight (7.7%), 15 (30.6%), and two (5.0%) in groups Ia, Ib, and II, respectively. CONCLUSION: We observed that ACIOLs have good visual and refractive outcomes. Raised IOP is a concern in eyes with pseudoexfoliation, but can be managed with close monitoring. Hence ACIOL can be a good option for managing aphakia after cataract surgery.

Microbiological spectrum of microbial keratitis in patients presenting with nasolacrimal duct obstruction.

PURPOSE: To study the type of bacteria and their antibiotic susceptibility pattern from corneal scrapings of patients with infectious keratitis presenting with concurrent nasolacrimal duct obstruction. METHODS: A retrospective analysis was carried out of patients with microbial keratitis and co-existing nasolacrimal duct obstruction during a 5-year period (January 2012 to December 2016). Antibiotic susceptibility profile data was collected from the microbiology records. RESULTS: The study included 56 (M:F = 33:23; OD:OS = 34:22) eyes. The mean age of patients was 60.2 ± 12.3 years. Microscopic examination of corneal scrapings showed 52% of gram-positive (n = 29/55) and 2% of multiple (>1; n = 1/55) bacteria. Streptococcus pneumoniae (32%, n = 18/56), coagulase-negative Staphylococcus (25%, n = 14/56), and Staphylococcus aureus (11%, n = 6/56) were the most common bacteria. Streptococcus pneumoniae was found to be susceptible to ciprofloxacin (72.2%), ofloxacin (94.4%), gatifloxacin (61.1%), and moxifloxacin (83.3%). CONCLUSION: Corneal infection associated with nasolacrimal duct obstruction is commonly caused by gram-positive-bacteria. Irrigation of nasolacrimal duct should be mandatory test in microbial keratitis. The gram-positive bacteria isolated showed maximum susceptibility to vancomycin and cefazolin. Early treatment by surgery and appropriate medical management is recommended for its control.

Migratory serpiginous corneal epitheliopathy (MSCE)- details of 4 cases.

BACKGROUND AND OBJECTIVE: To describe four cases of recurrent, fleeting corneal epithelial lesion, migratory serpiginous corneal epitheliopathy (MSCE). METHOD: Description of cases, histopathology and discussion of treatment outcome. RESULTS: The study included 4 consecutive male patients; mean age was 21.25 years. Only one eye was affected. The common symptoms were irritation and tearing. Typical interpalpebral corneal lesion was a superficial greyish-white elevated corneal epithelium with stippled fluorescein staining in various geographic patterns. Corneal scrapings did not show any microorganisms and culture was negative; histopathology did not show corneal dysplasia. The lesions recurred within 1-3 weeks despite repeated scraping, application of a bandage contact lens, and a combination of topical antibiotics and lubricants. The recurrent lesion was of a different shape and eventually healed within 3-6 months without scarring. CONCLUSION: We describe a possibly new entity, unilateral migratory serpiginous corneal epitheliopathy (MSCE) affecting young males, with inconspicuous inflammation. Etiology is not known and usually takes several months to heal after repeated epithelial debridement.

Clinical Profile of Bilateral Microsporidial Keratoconjunctivitis in Healthy Individuals-A Case Series With Long-term Follow-up.

PURPOSE: To describe bilateral microsporidial keratoconjunctivitis in healthy individuals with long-term follow-up. METHODS: Six cases of smear-positive bilateral microsporidial keratoconjunctivitis were diagnosed and followed up during the study period August 2017 to January 2019. Associated risk factors, clinical features, coexistence with adenovirus, clinical course, and recurrence were studied. RESULTS: The mean age was 36.6 years (range: 10-65 years). The mean duration of symptoms was 13.6 days (range: 7-60 days). Predisposing risk factors were present in 4 of 6 cases. The best-corrected visual acuity at presentation was ≥20/30 in all eyes except in one. Typical microsporidial epithelial lesions were seen in only one case. Persistent lesions, clinically resembling Thygeson superficial punctate keratitis in both eyes, were observed in 3 cases. The lesions in 5 eyes resolved with topical lubricants, and the remaining 7 eyes were treated with topical steroids and tacrolimus 0.03%. Complete resolution was seen in 5 eyes at the end of 1 month, and superficial scarring at the last follow-up was seen in 5 eyes. The best-corrected visual acuity was ≤20/30 in 3 eyes at the last follow-up. The mean duration of follow-up was 7.3 months (range: 3-12 mo). CONCLUSIONS: Bilateral microsporidial keratoconjunctivitis in healthy patients has an atypical presentation with prolonged course. Microsporidia could be implicated as potential candidates in the etiopathogenesis of Thygeson superficial punctate keratitis.

Therapeutic efficacy of different routes of mesenchymal stem cell administration in corneal injury.

PURPOSE: Corneal injuries are associated with significant impairment in vision. Mesenchymal stem cells (MSCs) have been shown to limit inflammation and promote tissue repair at the ocular surface. Here, we evaluate the efficacies of different modes of MSC delivery (topical, subconjunctival, intraperitoneal [IP] and intravenous [IV]) to promote tissue repair and restore corneal transparency in a murine model of corneal injury. METHODS: MSCs were purified from the bone marrow of C57BL/6  mice and expanded using plastic adherence in vitro. Corneal injury was created using an Algerbrush, and 0.5 × 106 MSCs/mouse were administered via topical, subconjunctival, IP or IV routes. Qdot-labeled MSCs were employed to determine the effect of route of administration on corneal and conjunctival MSC frequencies. Corneal opacity scores were calculated using ImageJ. Expression of inflammatory cytokines was quantified by qPCR, and infiltration of CD45+ cells was evaluated by flow cytometry. RESULTS: Subconjunctival or IV administration results in increased frequencies of MSCs in ocular surface tissues following corneal injury, relative to topical or intraperitoneal delivery. Subconjunctival or IV administration reduces: (i) corneal opacity, (ii) tissue fibrosis as quantified by α-Sma expression, (iii) the expression of inflammatory cytokines (Il-1ß and Tnf-α) and (iv) CD45+ inflammatory cell infiltration relative to untreated injured control animals. Administration via subconjunctival or IV routes was observed to accelerate corneal repair by restoring tissue architecture and epithelial integrity. CONCLUSIONS: Our data suggest that subconjunctival or IV delivery of MSCs has superior therapeutic efficacy compared to topical or IP delivery following corneal injury.

Mesenchymal Stromal Cells Inhibit Neutrophil Effector Functions in a Murine Model of Ocular Inflammation.

Purpose: Neutrophil-secreted effector molecules are one of the primary causes of tissue damage during corneal inflammation. In the present study, we have investigated the effect of stromal cells in regulating neutrophil expression of tissue-damaging enzymes, myeloperoxidase (MPO), and N-elastase (ELANE). Methods: Bone marrow-purified nonhematopoietic mesenchymal stromal cells and formyl-methionyl-leucyl-phenylalanine-activated neutrophils were cocultured in the presence or absence of Transwell inserts for 1 hour. Neutrophil effector molecules, MPO and ELANE, were quantified using ELISA. In mice, corneal injury was created by mechanical removal of the corneal epithelium and anterior stroma approximating one third of total corneal thickness, and mesenchymal stromal cells were then intravenously injected 1 hour post injury. Corneas were harvested to evaluate MPO expression and infiltration of CD11b+Ly6G+ neutrophils. Results: Activated neutrophils cocultured with mesenchymal stromal cells showed a significant 2-fold decrease in secretion of MPO and ELANE compared to neutrophils activated alone (P < 0.05). This suppressive effect was cell-cell contact dependent, as stromal cells cocultured with neutrophils in the presence of Transwell failed to suppress the secretion of neutrophil effector molecules. Following corneal injury, stromal cell-treated mice showed a significant 40% decrease in MPO expression by neutrophils and lower neutrophil frequencies compared to untreated injured controls (P < 0.05). Reduced MPO expression by neutrophils was also accompanied by normalization of corneal tissue structure following stromal cell treatment. Conclusions: Mesenchymal stromal cells inhibit neutrophil effector functions via direct cell-cell contact interaction during inflammation. The current findings could have implications for the treatment of inflammatory ocular disorders caused by excessive neutrophil activation.

Mesenchymal Stem Cells Modulate Differentiation of Myeloid Progenitor Cells During Inflammation.

Mesenchymal stem cells (MSCs) possess distinct immunomodulatory properties and have tremendous potential for use in therapeutic applications in various inflammatory diseases. MSCs have been shown to regulate pathogenic functions of mature myeloid inflammatory cells, such as macrophages and neutrophils. Intriguingly, the capacity of MSCs to modulate differentiation of myeloid progenitors (MPs) to mature inflammatory cells remains unknown to date. Here, we report the novel finding that MSCs inhibit the expression of differentiation markers on MPs under inflammatory conditions. We demonstrate that the inhibitory effect of MSCs is dependent on direct cell-cell contact and that this intercellular contact is mediated through interaction of CD200 expressed by MSCs and CD200R1 expressed by MPs. Furthermore, using an injury model of sterile inflammation, we show that MSCs promote MP frequencies and suppress infiltration of inflammatory cells in the inflamed tissue. We also find that downregulation of CD200 in MSCs correlates with abrogation of their immunoregulatory function. Collectively, our study provides unequivocal evidence that MSCs inhibit differentiation of MPs in the inflammatory environment via CD200-CD200R1 interaction. Stem Cells 2017;35:1532-1541.

Restoration of Corneal Transparency by Mesenchymal Stem Cells.

Transparency of the cornea is indispensable for optimal vision. Ocular trauma is a leading cause of corneal opacity, leading to 25 million cases of blindness annually. Recently, mesenchymal stem cells (MSCs) have gained prominence due to their inflammation-suppressing and tissue repair functions. Here, we investigate the potential of MSCs to restore corneal transparency following ocular injury. Using an in vivo mouse model of ocular injury, we report that MSCs have the capacity to restore corneal transparency by secreting high levels of hepatocyte growth factor (HGF). Interestingly, our data also show that HGF alone can restore corneal transparency, an observation that has translational implications for the development of HGF-based therapy.

Reevaluating intracameral cefuroxime as a prophylaxis against endophthalmitis after cataract surgery in India.

PURPOSE: To determine whether an intracameral injection of cefuroxime sodium at the conclusion of cataract surgery lowers the incidence of acute-onset postoperative endophthalmitis. SETTING: Tertiary eye care center, Bhubaneswar, India. DESIGN: Prospective comparative interventional cohort study. METHODS: Under a uniform protocol, cataract surgery with posterior chamber intraocular lens (PC IOL) implantation was performed from September 27, 2006, to July 31, 2010 (Group 1). All eyes were evaluated 1 day, 7 days, and 5 weeks ± 1 (SD) postoperatively. Treatment of eyes suspected to have developed infectious endophthalmitis was managed by retina-vitreous surgeons. From August 1, 2010, to August 31, 2012, the same surgeons performed cataract surgery with PC IOL implantation in another group of eyes, in which they administered intracameral cefuroxime prophylaxis (Group 2). All other protocols of postoperative care and microbiological investigation of the vitreous samples were similar. The rate of clinical and culture-positive endophthalmitis was compared between the 2 study groups: eyes without intracameral cefuroxime (Group 1) and eyes with intracameral cefuroxime (Group 2). RESULTS: The incidence of clinical endophthalmitis in Group 1 (0.155% [12/7756 eyes]) and in Group 2 (0.108% [8/7366 eyes]) was not significantly different (P = .57). The culture positivity rate in Group 1 (0.09 % [7 eyes]) and in Group 2 (0.04% [3 eyes]) was also not significantly different (P = .38). In the treatment without intracameral cefuroxime, there was a minimal, statistically insignificant increase in postoperative acute endophthalmitis (odds ratio, 1.42; 95% confidence interval, 0.53-4.02; P = .506). CONCLUSION: There is not strong evidence to support use of intracameral cefuroxime to reduce the rate of acute endophthalmitis after cataract surgery; however, the marginal benefit might justify its use. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Clinicomicrobiological characteristics and treatment outcome of sclerocorneal tunnel infection.

PURPOSE: To analyze the clinical presentation, microbiological evaluation, and management of post-cataract surgery sclerocorneal tunnel infection. METHODS: This is a retrospective chart review of 11 patients with sclerocorneal tunnel infection after cataract surgery, managed between November 2006 and October 2009. The clinical characteristics and treatment outcomes were analyzed. RESULTS: All patients presented within 1 to 10 weeks of primary surgery. The presenting visual acuity ranged from hand motions to 20/50. Ten of 11 patients had sclerocorneal involvement, and 4 patients had associated endophthalmitis. The causative organisms were fungus (n = 6), bacteria (n = 4), or both (n = 1). Deroofing of the tunnel and sclerocorneal patch graft was done in 4 patients. Intensive medication was administered to all patients. The final visual acuity ranged from light perception to 20/50 at a mean follow-up of 119 days (median, 66 days; range, 2-357 days). Five patients had ≥20/100 vision. The mean interval between presentation to resolution of infiltrate and formation of peripheral scarring was 20 days (median, 11 days; range, 2-66 days). CONCLUSIONS: Sclerocorneal tunnel infection must be microbiologically evaluated. Intensive medical management, wound revision and repair may lead to a favorable outcome.

Fungal periorbital necrotizing fasciitis in an immunocompetent adult.

A 55-year-old man presented with profound swelling of the upper face and fever with a history of preceding insect bite. He was nonalcoholic and immunocompetent. Orbital CT showed a predominantly preseptal soft-tissue swelling. Empiric treatment with broad-spectrum antibiotics resulted in partial response. Surgical debridement and microbiologic evaluation of the necrotic tissue were performed. Gram stain showed budding yeast cells. Candida and Aspergillus spp. grew in culture after 48 hours. The patient received oral fluconazole, 200 mg once a day for 8 weeks. Complete resolution was documented at 16 weeks. In tropical regions, Candida and Aspergillus spp. may cause periorbital necrotizing fasciitis in immunocompetent adults.

Acanthamoeba keratitis presenting as a plaque.

PURPOSE: To report a case of Acanthamoeba keratitis clinically presenting with a plaque-like lesion typical of fungal keratitis. METHODS: A 55-year-old woman presented with a yellow plaque-like lesion on the cornea surrounded by an infiltrate. Smears and culture were taken. The plaque was removed and subjected to histopathological investigation. RESULTS: Smear, culture, and histopathology results confirmed Acanthamoeba (cysts). The patient was treated with intensive topical medication. The infection resolved after 8 weeks of treatment. CONCLUSIONS: Acanthamoeba infection of cornea may present as a plaque-like lesion. In addition to topical medication, plaque removal helps in early resolution of the infection.