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PubMed2026

Evaluation of a cornea-specialized large language model for diagnostic and management accuracy in complex corneal cases.

PURPOSE: To evaluate whether a cornea-specialized large language model (LLM) enhanced with retrieval-augmented generation (RAG) improves clinicians' diagnostic and management accuracy in complex corneal cases compared to a general-purpose GPT-4o model and unaided clinician performance. METHODS: This prospective, randomized, masked evaluation study involved three cornea trainees who each independently reviewed 39 real-world corneal cases under three experimental conditions: unaided, GPT-4o-assisted, and assisted by a cornea-specialized GPT-4o model. The cornea-specialized model was constructed by embedding over 200 publicly available Wikipedia articles into GPT-4o's RAG framework. Participants provided open-ended diagnoses and selected the next-step management options (multiple choice). They were allowed up to three GPT-4o queries per case, and the AI-assisted arms were randomized to minimize bias. Accuracy for both tasks was compared against expert reference standards using McNemar's test. RESULTS: Diagnostic accuracy was 48.7%, 20.5%, and 38.5% unaided, improving to 69.2%, 46.2%, and 59.0% with general GPT-4o (p<0.04). The cornea-specialized GPT-4o further improved accuracy to 71.8%, 48.7%, and 74.4%, with improvements over unaided performance for all clinicians (p<0.01). For next-step decisions, unaided accuracy was 76.9%, 87.2%, and 59.0%. With the specialized model, Ophthalmologist 3 improved to 71.8% (p<0.05), Ophthalmologist 1 remained high at 82.1%, and Ophthalmologist 2 declined to 64.1% (p<0.05). CONCLUSIONS: A cornea-specialized LLM enhanced with RAG improved diagnostic accuracy in complex corneal cases, particularly among clinicians with lower baseline performance. Effects on management accuracy were inconsistent. Future studies should explore the use of open-ended management tasks and examine whether smaller, curated retrieval corpora yield better model performance.

Humans↗

PubMed2026

Second-Generation ELZA-sub400 Protocol: Individualized High-Fluence Cross-Linking for Ultra-Thin Keratoconus Corneas.

PURPOSE: To evaluate the safety and efficacy of a second-generation individualized corneal cross-linking (CXL) protocol (ELZA-sub400) using high-fluence UV-A irradiation in ultrathin ectatic corneas. DESIGN: Retrospective, single-center, consecutive interventional case series. METHODS: Twenty-nine eyes of 24 patients with progressive keratoconus or post-LASIK ectasia and a post-soak intraoperative thinnest stromal thickness <400 µm were included. After epithelial removal and riboflavin soaking, continuous UV-A irradiation (365 nm) at 3 or 9 mW/cm² was delivered with total fluence titrated up to 10 J/cm² based on intraoperative ultrasound pachymetry and a previously published nomogram targeting an uncross-linked stromal margin of approximately 70 µm above the endothelium. Outcomes were assessed at baseline and up to 12 months using corrected distance visual acuity (CDVA) and corneal parameters measured using Scheimpflug tomography and anterior segment OCT (AS-OCT) with Placido-based topography. The main outcome measure was the proportion of eyes without progression at 12 months, defined as <1.0 D increase in maximum keratometry (Kmax). Secondary outcomes included changes in CDVA, refraction, Kmax, stromal thickness, demarcation line depth, densitometry, and safety parameters. RESULTS: At 12 months, 22/29 eyes (76%; 95% CI, 57.9%-87.8%) met the nonprogression criterion. Mean change in Kmax was -0.77 ± 5.10 D (95% CI, -2.71 to 1.17; P = .418). Mean demarcation line-to-anterior stroma distance was 205 ± 64 µm (95% CI, 180.7-229.3), and demarcation line-to-endothelium distance was 64 µm (IQR, 49-152). All demarcation lines remained within the stromal layer; 15/29 eyes (51.7%) had a demarcation line located ≤70 µm from the endothelium. Median CDVA changed from 0.10 to 0.32 logMAR (P = .142). Minimum stromal thickness showed a median change of -4.0 µm (P = .309). No significant change was observed in densitometry, and no eye developed deep stromal haze or endothelial decompensation. CONCLUSIONS: Second-generation ELZA-sub400 CXL halted ectasia progression in 76% of ultrathin corneas at 12 months and was associated with an acceptable short-term safety profile, including stromal-confined demarcation line formation and no observed endothelial decompensation. The numerical decline in spectacle CDVA observed in this severely affected cohort did not reach statistical significance but is clinically important and warrants confirmation in larger prospective studies.

Humans↗

PubMed2025

Aging and Corneal Nerve Health: Mechanisms of Degeneration and Emerging Therapies for the Cornea.

Corneal nerves play a crucial role in maintaining ocular surface homeostasis by supporting the functional integrity of corneal epithelial, stromal, and endothelial cells; modulating tear secretion; and facilitating sensory responses essential for overall ocular health. With advancing age, these highly specialized peripheral sensory fibers undergo progressive attrition and morphologic distortion driven by the canonical hallmarks of aging including genomic instability, impaired proteostasis, mitochondrial dysfunction, and chronic low-grade inflammation. The resulting neuro-immune dysregulation reduces trophic support, delays wound healing, and predisposes older adults to dry-eye disease, neurotrophic keratopathy, and postsurgical hypoesthesia. Age-exacerbating cofactors including diabetes, dyslipidemia, neurodegenerative disorders, topical preservatives, chronic contact-lens wear, herpes zoster ophthalmicus, and ocular-surface hypoxia further accelerate sub-basal nerve rarefaction and functional decline. This review provides an overview of age-related physiological alterations in ocular surface nerves, with a particular emphasis on corneal innervation. It also discusses risk factors that speed up these changes. Given the inherently limited regenerative capacity of corneal nerves and their inability to fully restore to baseline conditions following injury or degeneration, it is critical to identify and develop effective strategies aimed at mitigating or delaying physiological nerve degeneration and promoting nerve regeneration. This review also brings up emerging therapeutic strategies, including regenerative medicine, neuroprotective agents, and lifestyle interventions aimed at mitigating age-related corneal nerve degeneration.

Humans↗

PubMed2017

Genome-wide analysis suggests a differential microRNA signature associated with normal and diabetic human corneal limbus.

Small non-coding RNAs, in particular microRNAs (miRNAs), regulate fine-tuning of gene expression and can impact a wide range of biological processes. However, their roles in normal and diseased limbal epithelial stem cells (LESC) remain unknown. Using deep sequencing analysis, we investigated miRNA expression profiles in central and limbal regions of normal and diabetic human corneas. We identified differentially expressed miRNAs in limbus vs. central cornea in normal and diabetic (DM) corneas including both type 1 (T1DM/IDDM) and type 2 (T2DM/NIDDM) diabetes. Some miRNAs such as miR-10b that was upregulated in limbus vs. central cornea and in diabetic vs. normal limbus also showed significant increase in T1DM vs. T2DM limbus. Overexpression of miR-10b increased Ki-67 staining in human organ-cultured corneas and proliferation rate in cultured corneal epithelial cells. MiR-10b transfected human organ-cultured corneas showed downregulation of PAX6 and DKK1 and upregulation of keratin 17 protein expression levels. In summary, we report for the first time differential miRNA signatures of T1DM and T2DM corneal limbus harboring LESC and show that miR-10b could be involved in the LESC maintenance and/or their early differentiation. Furthermore, miR-10b upregulation may be an important mechanism of corneal diabetic alterations especially in the T1DM patients.

Adult↗

PubMed2026

"Tissue-specific mitochondrial dysfunction in keratoconus: An integrated structural, genomic, and functional analysis".

PURPOSE: Keratoconus (KC) is a progressive corneal ectasia characterized by stromal thinning, conical protrusion, and irregular astigmatism, leading to visual impairment. Although oxidative stress is implicated in KC, the role of mitochondrial dysfunction remains unclear. We evaluated mitochondrial structural, genomic, and functional abnormalities in corneal tissues and blood from KC patients. METHODS: This prospective study enrolled 110 KC patients and 55 controls. Transmission electron microscopy (TEM) and immunohistochemistry (IHC) were performed on epithelial and stromal tissues from 10 KC to 5 control corneas assessing mitochondrial morphology, oxidative phosphorylation (OXPHOS) complexes and pro-apoptotic protein NOXA. Whole mitochondrial DNA (mtDNA) sequencing and relative mtDNA copy number analysis were performed on paired blood and corneal tissues from 50 KC patients and 35 controls including both epithelial and stromal samples. Gene expression of mitochondrial biogenesis and oxidative stress-related genes was analysed by qRT-PCR in corneal epithelium from independent 50 KC patients and 15 controls. RESULTS: TEM revealed cristolysis, membrane disruption, and reduced mitochondrial density in KC corneas. IHC showed reduced expression of OXPHOS complexes and increased NOXA expression (p < 0.05). Sequencing identified 1107 mtDNA variants, with more variants in corneal tissues than matched blood (929 vs. 576; p = 0.0002). Recurrent likely pathogenic variants were enriched in complex I-encoding genes (ND4, ND5). KC corneas showed reduced mtDNA copy number, downregulated POLRMT, upregulated NOX4, and significant downregulation of multiple antioxidant genes (p < 0.0001). CONCLUSION: KC patients exhibit tissue-specific mitochondrial abnormalities and impaired oxidative stress regulation, supporting a role for mitochondrial dysfunction in disease pathogenesis and highlighting potential therapeutic targets.

Corneal pathology↗

PubMed2026

CHST5 gene mutations contribute to high myopia by disrupting collagen fiber organization.

High myopia (HM) is a leading cause of irreversible vision loss in working-age adults. Its pathogenesis is characterized by alterations in the microstructure and composition of collagen fibers, and genetic factors make a substantial contribution. In this study, we identify carbohydrate sulfotransferase 5 (CHST5) as a candidate gene for HM in humans and mice, with its mutations disrupting collagen fiber organization. The c.444C>A (p.S148R) variant in CHST5, a gene critical for sulfating corneal keratan sulfate (KS), completely co-segregates with HM in a Chinese family. Screening of CHST5 variants in 320 HM patients identifies two additional ones. We further find that Chst5 is expressed primarily in the cornea and sclera of mouse ocular tissues, and that the mutant protein CHST5S148R loses its Golgi localization. Homozygous mutant Chst5S126R mice exhibit HM phenotypes, including myopic refractive error (RE), significantly thinner sclera and cornea, notable microstructural changes in scleral and corneal collagen fibers, and shorter corneal KS chains. Our findings suggest that CHST5 NM_024533.5 c.444C>A (p.S148R) causes loss of proper protein localization, likely impairing its sulfotransferase function. This defect disrupts the organization of corneal and scleral collagen fibers and ultimately contributes to the development and progression of HM.

CHST5↗

PubMed2026

A validated sensitive LC-MS/MS method and its application in elucidating the unique ocular pharmacokinetic profile of 0.01% atropine underpinning its clinical utility for myopia.

A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to quantify atropine in ten rabbit ocular tissues enabling systematic characterization of the ocular pharmacokinetic profile of 0.01% atropine sulfate eye drops after a single topical administration. The method demonstrated excellent linearity (coefficient of determination, R2 ≥ 0.9908) across all matrices, with lower limits of quantification (LLOQ) of 0.05 ng/mL for most tissues and 0.10 ng/mL for retina and lens; intra- and inter-day accuracy, precision, matrix effects, extraction recoveries, and stability all met the acceptance criteria. Following a single bilateral topical dose (50 μL/eye) in New Zealand White rabbits, atropine distributed rapidly into all 12 ocular compartments (the sclera further divided into three anatomical regions) with marked heterogeneity-the highest exposures were found in conjunctiva and cornea, a distinct anterior-to-posterior concentration gradient was observed in the sclera, sustained retention was noted in the retina (mean residence time from zero to the last measurable time point, MRT0-t 3.30 h), while aqueous and vitreous humor eliminated rapidly (elimination half-life, t₁/₂ < 0.7 h), and all tissues except aqueous humor followed a two-compartment model. This validated method and the comprehensive pharmacokinetic data reveal that topically applied 0.01% atropine achieves sustained exposure in key myopia-regulating tissues (retina, choroid, posterior sclera) with low exposure in side-effect target tissues (iris, ciliary body, lens).

Animals↗

PubMed2024

Clinical characterizations and molecular genetic study of two co-segregating variants in PDZD7 and PDE6C genes leading simultaneously to non-syndromic hearing loss and achromatopsia.

BACKGROUND: Autosomal recessive non-syndromic hearing loss (NSHL) and cone dystrophies (CODs) are highly genetically and phenotypically heterogeneous disorders. In this study, we applied the whole exome sequencing (WES) to find the cause of HL and COD in an Iranian consanguineous family with three affected individuals. METHODS: Three members from an Iranian consanguineous family who were suffering from NSHL and visual impairment were ascertained in this study. Comprehensive clinical evaluations and genetic analysis followed by bioinformatic and co-segregation studies were performed to diagnose the cause of these phenotypes. Data were collected from 2020 to 2022. RESULTS: All cases showed congenital bilateral NSHL, decreased visual acuity, poor color discrimination, photophobia and macular atrophy. Moreover, cornea, iris and anterior vitreous were within normal limit in both eyes, decreased foveal sensitivity, central scotoma and generalized depression of visual field were seen in three cases. WES results showed two variants, a novel null variant (p.Trp548Ter) in the PDE6C gene causing COD type 4 (Achromatopsia) and a previously reported variant (p.Ile84Thr) in the PDZD7 gene causing NSHL. Both variants were found in the cis configuration on chromosome 10 with a genetic distance of about 8.3 cM, leading to their co-inheritance. However, two diseases could appear independently in subsequent generations due to crossover during meiosis. CONCLUSIONS: Here, we could successfully determine the etiology of a seemingly complex phenotype in two adjacent genes. We identified a novel variant in the PDE6C gene, related to achromatopsia. Interestingly, this variant could cooperatively cause visual disorders: cone dystrophy and cone-rod dystrophy.

Adult↗

PubMed2026

Proteomic characterization of ocular tear fluid reveals preclinical markers of sulfur mustard toxicity.

Sulfur mustard (SM) vapor causes ocular injury after a short latent period, when molecular damage has occurred, but clinical signs are not yet apparent. Characterizing ocular responses during this early phase is important for understanding SM pathogenesis, identifying molecular readouts of injury progression, and developing biomarkers of exposure. Tear fluid is well-suited for this purpose because it can be collected noninvasively and captures responses from injured ocular tissues. We tested whether temporal changes in the tear fluid proteome reflect cellular and molecular responses to corneal SM exposure. Rabbits were exposed to SM vapor using a corneal vapor cap, and tear fluid was collected at baseline, 4 h, 1 d, and 5 d, corresponding to the latent period, acute lesion, and early recovery. A large proteomic response was detected at 4 h, involving extracellular injury signaling, epithelial injury, and innate immune activation. By 1 d, the tear fluid proteome transitioned to inflammatory cell activation with metabolic, redox, and proteostasis stress. By 5 d, evidence of acute injury response was reduced but the proteome retained a residual signature of immune, epithelial, and stress responses. This temporal progression is consistent with the molecular mechanisms of SM toxicity and provides insight into acute ocular vesicant injury. These findings establish tear fluid as a noninvasive molecular reporter of ocular SM injury progression. They also reveal a molecular signature of vesicant exposure, which emerges prior to clinical signs, and provide foundational data for developing tear-based biomarkers of chemical exposure, injury assessment, and therapeutic testing.

Animals↗

PubMed2026

Diagnostic Accuracy of a CRISPR-Based Assay in Smear- and Culture-Negative Fungal Keratitis.

IMPORTANCE: Diagnosing fungal keratitis (FK) in patients with negative smear and culture results remains clinically challenging, highlighting the need for alternative diagnostic approaches. OBJECTIVE: To determine the diagnostic accuracy of the clustered regularly interspaced short palindromic repeats (CRISPR)-based Rapid Identification of Mycoses using CRISPR (RID-MyC) assay for detecting FK in patients with negative smear and culture results using in vivo confocal microscopy (IVCM) as the reference standard. DESIGN, SETTING, AND PARTICIPANTS: This prospective diagnostic accuracy study was conducted from December 2024 to March 2025 at Aravind Eye Hospital, a tertiary ophthalmology referral hospital in Coimbatore, India. Consecutive patients clinically suspected to have microbial keratitis with negative smear and culture results were eligible for inclusion. Data were analyzed from March 2025 to June 2025. INTERVENTIONS: All included participants underwent corneal scraping for RID-MyC assay and imaging by IVCM. MAIN OUTCOMES AND MEASURES: The primary outcomes were sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic concordance of the RID-MyC assay compared with IVCM results. RESULTS: Of 245 consecutive patients clinically suspected to have microbial keratitis, 82 were smear negative. After exclusions due to contraindications or positive subsequent cultures, 41 patients with smear- and culture-negative results were ultimately included in the final analysis. Of these 41 patients (mean [SD] age, 51.0 [14.6] years; 21 [51.2%] women), RID-MyC demonstrated sensitivity of 82.1% (95% CI, 63%-94%) and specificity of 76.9% (95% CI, 46%-95%). Positive predictive value was 88.5% (95% CI, 74%-95%) and negative predictive value was 66.7% (95% CI, 46%-82%). Concordance between RID-MyC and IVCM was observed in 33 cases (80.5%). Notably, prior antifungal treatment was most frequent (4 of 5 [80%]) among patients with positive IVCM but negative RID-MyC results. Conversely, all patients (3 of 3 [100%]) with negative IVCM but positive RID-MyC findings had smaller, peripheral, or paracentral lesions. CONCLUSIONS AND RELEVANCE: In this diagnostic study, in patients with smear- and culture-negative FK, the RID-MyC assay showed good diagnostic accuracy comparable with IVCM and was feasible in all cases, including those in whom imaging was not possible. With its rapid turnaround and minimal equipment needs, RID-MyC may serve as a practical adjunct to conventional diagnostics, particularly in high-burden, resource-limited settings where IVCM is unavailable or contraindicated.

Humans↗

PubMed2026

Comparison of Ketamine and Pregabalin on Postoperative Opioid Usage and Pain Management in Spinal Fusion: Systematic Review and Network Meta-analysis.

BACKGROUND CONTEXT: Spinal fusion is associated with substantial early postoperative pain and opioid exposure. Both ketamine and pregabalin are widely incorporated into Enhanced Recovery After Surgery (ERAS) protocols as opioid-sparing adjuncts. However, their comparative efficacy and safety in this specific setting remain uncertain. Our objective was to compare ketamine and pregabalin indirectly for early postoperative opioid consumption, pain, and adverse events in adults undergoing spinal fusion. METHODS: Pubmed, Embase, and Cochrane Trials were searched from inception through October 2025. Eligible studies were randomized trials enrolling adults undergoing instrumented spinal fusion, randomized to perioperative ketamine, pregabalin, or control, and reported extractable 24-hour opioid consumption or pain outcomes. Continuous outcomes were pooled as mean differences in MME or VAS units, and adverse events were reported descriptively. A connected treatment network was analyzed using random-effects models. Risk of bias (RoB) was assessed with the Cochrane RoB 2 tool. RESULTS: Thirteen trials (n=879) were included: ketamine (n=210), pregabalin (n=271), and control (n=398). Six trials contributed opioid data (3 ketamine, 3 pregabalin). Using pregabalin 150 mg as reference, ketamine was associated with lower 0-24-hour opioid use (MD -56.99 mg MME; 95% CI -99.56 to -14.43). Control (MD +21.31; 95% CI -1.05 to +43.66) and pregabalin 300 mg (MD -13.22; 95% CI -40.41 to +13.96) did not significantly differ from pregabalin 150 mg. Seven trials contributed 24-hour VAS data, with control being associated with higher pain versus pregabalin 150 mg (MD +0.84; 95% CI +0.01 to +1.66), while ketamine and pregabalin 300 mg were not k significantly different. Adverse events were generally infrequent and similar to control. CONCLUSIONS: Both ketamine and pregabalin provide early opioid sparing with comparable 24-hour analgesia. Ketamine showed a larger opioid-sparing point estimate, but indirect comparisons are imprecise. Adequately powered head-to-head trials with standardized protocols and adverse event reporting are needed.

Humans↗

PubMed2026

Xerophthalmia and ocular manifestations of vitamin A deficiency in children in high-income countries: A systematic review.

Xerophthalmia is a vision-threatening eye condition caused by vitamin A deficiency (VAD). Cases of xerophthalmia in high-income countries (HICs) are vulnerable to misdiagnosis, causing delays in treatment and adverse visual outcomes. We define the features, causes and complications of VAD and xerophthalmia in children of HICs. Our study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines (CRD42024492023). We performed a search for eligible articles on Scopus, Web of Science, Cochrane, PubMed and Medline. Cases reporting on children under 18 years of age residing in HICs with ocular features of VAD were eligible for inclusion. The search yielded 2474 results; 43 case reports and case series met the inclusion criteria consisting of a total of 61 cases (mean age 9.9 ± 4.2 years, range 3-17 years). Xerophthalmia was graded according to the most advanced finding for each case: 21.3% had night blindness only; 29.5% had conjunctival xerosis or Bitot spots; 29.5% had corneal xerosis, ulceration or scarring; 1.6% had xerophthalmia fundus only; and 18.0% had ocular manifestations associated with VAD that are not encompassed under the WHO classification. These features included swollen optic discs, optic neuropathy, or ocular dryness. Restrictive dietary practises were the most common mechanism of deficiency (75%), and autism was the most common underlying condition (49%). This shows that VAD remains a cause of severe visual impairment in HICs, especially when associated with delays in diagnosis and treatment. Further research is required to establish the prevalence of xerophthalmia in HICs.

Humans↗