Mehrnaz Atighehchian

Background: Keratoconus causes characteristic spatial epithelial remodeling that may not be captured by conventional thickness measurements. Novel morphometric indices from MS-39 AS-OCT may better characterize these changes. Purpose: We aimed to evaluate novel MS-39 AS-OCT epithelial remodeling indices and compare their diagnostic accuracy with epithelial thickness and Pentacam tomography across the keratoconus spectrum, using an objective reference standard. Methods: This retrospective diagnostic accuracy study included 1319 eyes of 1286 patients with same-day Pentacam and MS-39 imaging at Noor Eye Hospital (2023–2025). Eyes were classified from the clinical records and Pentacam front-surface indices, without use of any epithelial data, as normal (n = 861), forme fruste keratoconus (FFKC; topographically normal fellow eye of very asymmetric ectasia; n = 40) or definite keratoconus (n = 418), graded mild, moderate or severe with the ABCD system. Generalized estimating equations, receiver operating characteristic (ROC) analysis with DeLong confidence intervals and cross-validated cut-offs, and bootstrap-validated logistic models were used. Results: The central epithelial remodeling index (CERI) and central epithelial thickness range (CETR) increased with severity (+0.137 and +6.13 µm per severity grade; both p < 0.001). For definite keratoconus, CERI (AUC 0.932; 95% CI 0.913–0.948) and CETR (0.930) outperformed central minimum epithelial thickness (0.839; p < 0.001) but not BAD-D (0.972). Their AUCs rose from 0.666–0.677 in mild to 0.993–0.995 in severe keratoconus, a gradient that partly reflects the disease spectrum. For FFKC, the best epithelial AUC was 0.668 (6 mm epithelial thickness range) versus 0.728 for BAD-D, and adding five epithelial indices to tomography did not improve validated discrimination (out-of-bag AUC gain +0.000 for definite keratoconus and +0.012, 95% interval −0.080 to +0.083, for FFKC). Conclusions: CERI and CETR quantify epithelial remodeling and discriminate established keratoconus well, but they add little validated discrimination to Pentacam tomography; in FFKC, their discrimination was modest and any added value remains uncertain. They may complement, but not replace, tomography and biomechanics.

Purpose: This study aimed to evaluate the presence of biofilm-producing Staphylococcus aureus in contact lens storage solutions (CLSS) used for both cosmetic and vision-correcting purposes. Microbiological assays and molecular methods were used to detect biofilm-associated genes, specifically icaA and icaD. The findings could provide molecular evidence of contamination in CLSS and identify behavioral risk factors associated with biofilm-forming strains. Methods: A total of 162 CLSS samples were collected from asymptomatic students living in dormitories and hospital staff. Bacterial isolation and identification were performed using standard culture methods and biochemical tests. Biofilm formation was evaluated phenotypically, and molecular confirmation of S. aureus and biofilm-associated genes (icaA and icaD) was performed using polymerase chain reaction (PCR). Associations between contamination and lens type, and also user behaviors, including lens-washing practices, showering, and swimming while wearing lenses, were analyzed. Results: This study evaluated 162 CLSS samples from 162 asymptomatic participants (mean age: 24.8 ± 4.2 years). Of these, 148 subjects (91.35%) were females. Staphylococcus aureus contamination was detected in 7 of 162 samples (4.32%), and 4 of the 7 isolates (57.14%) carried biofilm-associated icaA and icaD genes. Staphylococcus aureus contamination was found in 5 of 108 CLSS used for vision-correcting purposes (4.62%; P = 0.53). Contamination was significantly associated with lack of lens washing before wearing, which occurred in 4 of 141 participants (2.83%; P = 0.005), and lack of hand washing before handling contact lenses, which was observed in 7 of 159 participants (4.40%; P = 0.043). Conclusion: This study provides molecular evidence that CLSS can act as reservoirs for biofilm-producing S. aureus. The detection of icaA- and icaD-positive strains highlights the risk of persistent contamination and the potential development of contact lens-related infectious keratitis. Modifiable behaviors, especially proper lens washing, may significantly reduce the risk of contamination with biofilm-producing S. aureus.

Purpose: To describe the clinical presentation, diagnostic challenges, and management of fungal keratitis (FK) caused by Aspergillus spp. presenting with a delayed immune-like ring infiltrate. Methods: We report a case describing the clinical course, diagnostic workup, and treatment of a patient with FK initially misdiagnosed as herpes simplex keratitis. Results: A 68-year-old woman presented with a three-week history of decreased vision and ocular pain in the right eye. She had previously been treated with topical chloramphenicol 0.5%, frequent topical betamethasone, and oral acyclovir for presumed herpes simplex keratitis. Despite two weeks of treatment, the corneal findings progressed. At presentation to our center, a yellow-white stromal infiltrate with a surrounding immune-like ring in the inferonasal periphery was observed, along with stromal thinning and signs of impending perforation. Corneal scraping confirmed Aspergillus spp. Topical betamethasone was discontinued, and topical voriconazole 1% with chlorhexidine 0.2% was initiated. Cyanoacrylate glue was applied to manage stromal melting. Following antifungal therapy and withdrawal of topical corticosteroids, the condition stabilized. Conclusion: Immune-like ring formation may be observed in FK due to immune-mediated mechanisms. Despite this immune component, topical corticosteroids should not be used empirically, as they may exacerbate fungal infection and worsen clinical outcomes. It is essential to perform corneal sampling and microbiological confirmation before initiating steroids in cases of immune-like ring lesions. This helps rule out infectious causes, especially FK.

Purpose To evaluate the microbial spectrum and management of contact lens-associated infectious keratitis (CL-AIK), with an emphasis on behavioral risk factors. Methods This retrospective study was conducted between 2021 and 2023 and involved seventy-four eyes of 70 consecutive diagnosed with CL-AIK at a tertiary care eye hospital. The hygiene practices, clinical and diagnostic findings, including corneal smear and culture, in vivo confocal microscopy (IVCM), and polymerase chain reaction (PCR), were analyzed. The associations between risk behaviors and clinical outcomes were examined. Results A total of 74 eyes from 70 patients (47 females, 63.5%; mean age: 31.24 ± 10.08 years) were reviewed for cases of CL-AIK. The initial best-corrected visual acuity (BCVA) was 1.28 ± 1.27 LogMAR. Diagnostic confirmation was obtained using multiple methods: chocolate agar culture (97.3% usage, 37 (51.4%) positivity), non-nutrient agar with Escherichia coli culture (79.7% usage, 7(11.86%) positivity), PCR testing (79.7% usage, 15 (25.4%) positivity), and IVCM (81.1% usage,18 (29.3%) positivity for Acanthamoeba spp.). Among the 70 patients, 24 (32.4%) rinsed their lenses with tap water, 22 (29.7%) wore lenses overnight, and 14 (18.9%) had exposed to water during showering or swimming. Exposure to water while wearing contact lenses was significantly more common in patients with fungal keratitis (3/4,75%, p = 0.002). The use of expired lenses (3/23, 13.04%; p = 0.008) and prolonged wear (> 12 h; 14/23, 60.8%; p = 0.04) were significantly higher in Acanthamoeba keratitis (AK). Conclusion Although many individuals reported good hygiene practices, high-risk behaviors such as swimming or showering while wearing contact lenses and prolonged daily use (> 12 h) remain important contributors to ocular complications. Prevention strategies should focus not only on general hygiene practices but also on addressing these high-risk behaviors. Additionally, the routine use of multimodal diagnostic techniques has dramatically improved the detection of atypical microorganisms, particularly Acanthamoeba spp.

Purpose: To report a rare case of post-penetrating keratoplasty infectious crystalline keratopathy caused by Cytomegalovirus (CMV). Methods: The patient's history, clinical presentation, laboratory, and imaging analysis were reviewed. Results: A 55-year-old male patient was referred to our hospital with a medical history of 3 prior penetrating keratoplasty procedures because of post-refractive surgery infectious keratitis and epithelial downgrowth. He has been on both systemic and topical immunosuppressive medications. The patient presented with decreased vision, and on examination, a needle-like branching corneal lesions was identified, consistent with the diagnosis of infectious crystalline keratopathy. After negative results from smear and culture of corneal samples, molecular evaluation using polymerase chain reaction testing revealed the presence of CMV. Consequently, immunosuppressive therapy was adjusted, and systemic and topical antiviral treatments were initiated, resulting in a favorable clinical response. Conclusions: This case emphasizes the importance of considering CMV infection in progressive and nonresponsive infectious crystalline keratopathy to antimicrobial medications, particularly in immunosuppressed individuals. In addition, polymerase chain reaction is an appropriate laboratory molecular diagnostic test for the accurate diagnosis of CMV keratitis.

This report describes the case of a 28-year-old woman, who presented with a two-week history of severe ocular pain and photophobia in her right eye. She was a soft contact lens wearer with no history of ocular trauma or systemic illness. Ophthalmic examination revealed conjunctival hyperemia, epithelial irregularities, and a developing ring-shaped stromal infiltrate. In vivo confocal microscopy demonstrated double-walled hyperreflective cysts, and culture followed by PCR and sequencing confirmed the presence of Acanthamoeba T4 genotype. Despite intensive treatment with topical polyhexamethylene biguanide, chlorhexidine, propamidine, and voriconazole, as well as oral miltefosine, the infection progressed, leading to stromal necrosis. The patient underwent two therapeutic penetrating keratoplasties; however, the disease continued to advance, eventually resulting in phthisis bulbi and permanent vision loss. This case highlights the potential for aggressive, clinically refractory Acanthamoeba keratitis caused by the T4 genotype, emphasizing the importance of early diagnosis, vigilant monitoring, and timely surgical intervention in resistant cases.

Nocardia keratitis (NK) is an uncommon infectious keratitis that may present with characteristic or atypical corneal morphology. We report two patients with contrasting clinical appearances and diagnostic courses, highlighting the differing contribution of in vivo confocal microscopy (IVCM) and microbiological testing. A 19‐year‐old male farmer presented after suspected dust exposure with multiple superficial pinhead infiltrates arranged in a wreath‐like pattern. Gram staining showed Gram‐positive branching bacilli, and high‐quality IVCM demonstrated fine hyperreflective branching structures at the ulcer margin. A 37‐year‐old male welder presented after ocular trauma with a sharply demarcated paracentral infiltrate. Initial Gram staining was negative, and an IVCM examination performed at a different site was technically limited and non‐diagnostic; however, culture on chocolate agar grew Nocardia species after 3 days, and modified acid‐fast staining confirmed partially acid‐fast branching filaments. Both patients were diagnosed with NK and improved with amikacin‐based topical therapy and sulfacetamide. These cases show that NK may have classic or atypical morphology and that a technically limited or inconclusive IVCM examination does not exclude the diagnosis. Corneal scraping, appropriate staining, and culture remain essential when NK is clinically possible.

This study discusses four cases of fungal keratitis (FK) caused by uncommon fungal pathogens. It’s important to note that FK caused by these species is either rare or has not been reported before. Rare fungal pathogens including Subramaniula lateralis, Inocutis levis, Neoscytalidium dimidiatum, and Bipolaris panini-miliacei were identified in corneal scraping specimens. Patients were treated with systemic and topical antifungal agents, and surgical intervention was performed when necessary. This report emphasizes the importance of considering rare fungal species in cases of keratitis, highlighting the necessity of recognizing and awareness of these less common fungal species.

Purpose To examine the impact of corneal curvature on the optic nerve head (ONH) area size measured by optical coherence tomography in non-glaucomatous keratoconus (KC) patients. Methods This study was conducted at Farabi Eye Hospital between 2022 and 2024. Patients with a confirmed diagnosis of KC, based on clinical examinations and corneal topography, were included. Heidelberg spectral-domain optical coherence tomography (SD-OCT) was used to examine the Bruch’s Membrane Opening (BMO) area size, in order to determine the size of the optic nerve head (ONH) area. This was performed twice: once using a default corneal curvature of 7.7 mm and once using the patient’s anterior corneal radius of curvature obtained from the Pentacam. The changes in the ONH area size were then compared and analyzed. Results In this study, we evaluated a total of 102 eyes from 51 patients diagnosed with KC. The average area of the BMO, measured using corneal curvature based on Pentacam, was 1.822 ± 0.457 mm². In contrast, the BMO size measured using a standard corneal curvature (SCC) value of 7.7 mm was 1.955 ± 0. 497mm². The mean difference between the BMO area measurements obtained with Pentacam-based corneal curvature (PCC) and the SCC value of 7.7 mm was − 0.133 ± 0.221 mm²(95% CI − 0.175 to 0.091, p < 0.001). The 95% limits of agreement (LoA) for the differences between these measurements ranged from − 0.56 to 0.30 mm². Conclusion The study emphasizes the importance of corneal curvature measurements in determining the size of the ONH area in individuals diagnosed with KC. It suggests that changes in corneal curvature size directly affect the size of the BMO area. This information is crucial for accurately calculating the actual size of the ONH, especially in non-glaucomatous KC patients.