Evaluating Moisture Migration in Schirmer Test Strips: Exploring Brand-Specific Variations and Introducing Calibration and Conversion Methods

PURPOSE

Schirmer test results are widely used for ocular surface disease assessment, but Schirmer strips are not standardized. We compare the characteristics and tear volume with millimeter moisture migration in different brands of Schirmer strips and introduce methods for volume-based, brand-independent calibration.

METHODS

Physical parameters of Haag-Streit, EagleVision, TearFlo, Contacare, and MIPL/A6 Schirmer strip brands were compared. Schirmer strip millimeter moisture migration distances were assessed 5 minutes after application of incremental microliter volumes of human tears. Linear regression analysis of data points from each Schirmer strip brand was performed, and the root-mean-square deviation of data points to the best-fit linear regression was calculated. Calibration correction was performed by converting migration distance to the corresponding tear volume. A reference table and calibration method formulas were created.

RESULTS

Schirmer strips differed in design, shape, and manufacturing precision. Strip width, weight, and length were different between the 5 brands ( P < 0.05). A wide range of Schirmer strip moisture migration values for identical tear volumes was observed among brands. Statistical measurement resulted in a root-mean-square deviation of 2.9 mm for all data points from all brands. Millimeter to volume and weight to volume-based calibration correction methods resulted in a 2.2- and 3.1-fold measurement error reduction, respectively.

CONCLUSIONS

Our findings highlight the lack of standardization among different brands of Schirmer strips, raising concerns about potential sources of unintentional measurement errors. We propose volume-based Schirmer strip calibration methods and conversion of millimeter to microliter results to achieve brand-independent results and improve Schirmer test accuracy.

GZMK+CD8+ T cells Target a Specific Acinar Cell Type in Sjögren's Disease

Sjögren's Disease (SjD) is a systemic autoimmune disease without a clear etiology or effective therapy. Utilizing unbiased single-cell and spatial transcriptomics to analyze human minor salivary glands in health and disease we developed a comprehensive understanding of the cellular landscape of healthy salivary glands and how that landscape changes in SjD patients. We identified novel seromucous acinar cell types and identified a population of PRR4+CST3+WFDC2- seromucous acinar cells that are particularly targeted in SjD. Notably, GZMK+CD8 T cells, enriched in SjD, exhibited a cytotoxic phenotype and were physically associated with immune-engaged epithelial cells in disease. These findings shed light on the immune response's impact on transitioning acinar cells with high levels of secretion and explain the loss of this specific cell population in SjD. This study explores the complex interplay of varied cell types in the salivary glands and their role in the pathology of Sjögren's Disease.

Predictors and significance of kidney dysfunction in patients with chronic graft-versus-host disease

Kidney complications have been studied in allogeneic hematopoietic stem cell transplant patients but not specifically among chronic graft-versus-host disease (cGVHD) patients. Participants (n = 365) enrolled in the cross-sectional cGVHD natural history study (NCT00092235) were assessed for kidney dysfunction and overall survival. Kidney dysfunction was analyzed for associations in univariate and multivariable analyses. Kidney dysfunction (eGFR < 60) was found in 64 patients, and 29 patients had moderate-severe kidney dysfunction (eGFR < 45). Patients with kidney dysfunction were more likely treated with cyclosporine at evaluation or to have received it for GVHD prophylaxis, or prior treatment of GVHD. Patients with kidney dysfunction were less severely affected by cGVHD of skin, mouth, and joints/fascia. In multivariable modeling, history of cyclosporine use (OR = 2.19, 95% CI 1.13-4.25), angiotensin receptor blocker use (OR = 5.57, 95% CI 1.49-20.84), proteinuria (OR = 2.39, 95% CI 1.19-4.79), lower CRP (OR = 0.95, 95% CI 0.91-0.99), lower C3 (OR = 0.98, 95% CI 0.97-0.99), and lower hemoglobin (OR = 0.70, 95% CI 0.58-0.84) were jointly associated with kidney dysfunction. Overall survival was lower in those with moderate-severe kidney dysfunction (p = 0.015), demonstrating the importance of addressing kidney dysfunction in this population. The association of kidney dysfunction with less severe cGVHD suggests an etiology unrelated to cGVHD but potentially a consequence of drug-related toxicities.

Inhibition of JAK-STAT pathway corrects salivary gland inflammation and interferon driven immune activation in Sjögren's Disease

Objectives

Inflammatory cytokines that signal through the JAK- STAT pathway, especially interferons (IFNs), are implicated in Sjögren's Disease (SjD). Although inhibition of JAKs is effective in other autoimmune diseases, a systematic investigation of IFN-JAK-STAT signaling and effect of JAK inhibitor (JAKi) therapy in SjD-affected human tissues has not been reported.

Methods

Human minor salivary glands (MSGs) and peripheral blood mononuclear cells (PBMCs) were investigated using bulk or single cell (sc) RNA sequencing (RNAseq), immunofluorescence microscopy (IF), and flow cytometry. Ex vivo culture assays on PBMCs and primary salivary gland epithelial cell (pSGEC) lines were performed to model changes in target tissues before and after JAKi.

Results

RNAseq and IF showed activated JAK-STAT pathway in SjD MSGs. Elevated IFN-stimulated gene (ISGs) expression associated with clinical variables (e.g., focus scores, anti-SSA positivity). scRNAseq of MSGs exhibited cell-type specific upregulation of JAK-STAT and ISGs; PBMCs showed similar trends, including markedly upregulated ISGs in monocytes. Ex vivo studies showed elevated basal pSTAT levels in SjD MSGs and PBMCs that were corrected with JAKi. SjD-derived pSGECs exhibited higher basal ISG expressions and exaggerated responses to IFNβ, which were normalized by JAKi without cytotoxicity.

Conclusions

SjD patients' tissues exhibit increased expression of ISGs and activation of the JAK-STAT pathway in a cell type-dependent manner. JAKi normalizes this aberrant signaling at the tissue level and in PBMCs, suggesting a putative viable therapy for SjD, targeting both glandular and extraglandular symptoms. Predicated on these data, a Phase Ib/IIa randomized controlled trial to treat SjD with tofacitinib was initiated.

Ocular Findings of Cryptococcal Meningitis in Previously Healthy Adults

BACKGROUND

Patients with cryptococcal meningitis (CM) often have ocular manifestations; although data are describing these findings in nonimmunosuppressed, previously healthy individuals are scarce.

METHODS

A retrospective chart review was performed for previously healthy patients with CM who underwent a complete ophthalmological examination within a 5-year period at the National Institutes of Health. Demographics, CSF parameters, findings on initial ophthalmological examination, and MRI abnormalities were analyzed.

RESULTS

Forty-four patients within a median of 12 weeks after CM diagnosis were included in our study; 27 patients (61%) reported abnormal vision on presentation. Seventy-one percent of patients were not shunted at the time of their initial eye examination. The most common ocular abnormalities were visual field defects in 21 (66%), decreased visual acuity in 14 (38%), and papilledema in 8 (26%) patients. Intraocular pressure was within normal range in all patients. Cranial nerve defects were identified in 5 patients and optic neuropathy in 2 patients. Patients who had hydrocephalus or did not receive a ventriculoperitoneal shunt were not noted to have worse ocular abnormalities.

CONCLUSIONS

The most common ocular findings in our cohort of nontransplant, non-HIV cryptococcal meningitis patients were visual field defects, decreased visual acuity, and papilledema. Our results emphasize the need for a comprehensive eye examination in patients with CM who may not always report a change in vision on presentation.

Infigratinib Reduces FGF23 and Increases Blood Phosphate in Tumor‐Induced Osteomalacia

Tumor‐induced osteomalacia (TIO) is a rare paraneoplastic syndrome caused by ectopic production of fibroblast growth factor 23 (FGF23) by phosphaturic mesenchymal tumors (PMTs). Acting on renal tubule cells, excess FGF23 decreases phosphate reabsorption and 1,25‐dihydroxy‐vitamin D (1,25D) production, leading to hypophosphatemia, impaired bone mineralization, pain, and fractures. Fibronectin 1‐fibroblast growth factor receptor 1 (FN1‐FGFR1) gene fusions have been identified as possible drivers in up to 40% of resected PMTs. Based on the presumptive role of FGFR1 signaling by chimeric FN1‐FGFR1 proteins, the effectiveness of infigratinib, a FGFR1‐3 tyrosine kinase inhibitor, was studied in an open‐label, single‐center, phase 2 trial. The primary endpoint was persistent normalization of blood phosphate and FGF23 after discontinuation. Four adults with TIO (two nonlocalized, two nonresectable PMTs) were treated with daily infigratinib for up to 24 weeks. All patients had a favorable biochemical response that included reduction in intact FGF23, and normalization of blood phosphate and 1,25D. However, these effects disappeared after drug discontinuation with biochemistries returning to baseline; no patients entered biochemical remission. In the two patients with identifiable tumors, 68Gallium (68Ga)‐DOTATATE and 18Fluoride (18F)‐Fluorodeoxyglucose (FDG) PET/CT scans showed a decrease in PMT activity without change in tumor size. Patients experienced mild to moderate, treatment‐related, dose‐limiting adverse events (AEs), but no serious AEs. Three patients had dose interruptions due to AEs; one patient continued on a low dose for the entire 24 weeks and one patient stopped therapy at 17 weeks due to an AE. The study closed early due to a failure to meet the primary endpoint and a higher‐than‐expected incidence of ocular AEs. Infigratinib treatment lowered FGF23, increased blood phosphate, and suppressed PMT activity, confirming the role of FGFR signaling in PMT pathogenesis. However, treatment‐related AEs at efficacy doses and disease persistence on discontinuation support restricting the use of infigratinib to patients with life‐limiting metastatic PMTs. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Vulvovaginal and ocular involvement and treatment in female patients with Stevens-Johnson syndrome and toxic epidermal necrolysis: A review

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are serious adverse cutaneous drug reactions, characterized by epidermal detachment and mucous membrane involvement. SJS/TEN is more common in female patients, with unique findings in the ocular and vulvar regions. Early recognition and intervention, as well as long-term follow-up, are crucial to prevent devastating scarring and sequelae. This review examines the vulvar and ocular manifestations of SJS/TEN and describes the current treatment recommendations for female patients, requiring close consultation and collaboration among dermatology, ophthalmology, and gynecology.

Deep Learning Automated Diagnosis and Quantitative Classification of Cataract Type and Severity

PURPOSE

To develop and evaluate deep learning models to perform automated diagnosis and quantitative classification of age-related cataract, including all three anatomical types, from anterior segment photographs.

DESIGN

Application of deep learning models to Age-Related Eye Disease Study (AREDS) dataset.

PARTICIPANTS

18,999 photographs (6,333 triplets) from longitudinal follow-up of 1,137 eyes (576 AREDS participants).

METHODS

Deep learning models were trained to detect and quantify nuclear cataract (NS; scale 0.9-7.1) from 45-degree slit-lamp photographs and cortical (CLO; scale 0-100%) and posterior subcapsular (PSC; scale 0-100%) cataract from retroillumination photographs. Model performance was compared with that of 14 ophthalmologists and 24 medical students. The ground truth labels were from reading center grading.

MAIN OUTCOME MEASURES

Mean squared error (MSE).

RESULTS

On the full test set, mean MSE values for the deep learning models were: 0.23 (SD 0.01) for NS, 13.1 (SD 1.6) for CLO, and 16.6 (SD 2.4) for PSC. On a subset of the test set (substantially enriched for positive cases of CLO and PSC), for NS, mean MSE for the models was 0.23 (SD 0.02), compared to 0.98 (SD 0.23; p=0.000001) for the ophthalmologists, and 1.24 (SD 0.33; p=0.000005) for the medical students. For CLO, mean MSE values were 53.5 (SD 14.8), compared to 134.9 (SD 89.9; p=0.003) and 422.0 (SD 944.4; p=0.0007), respectively. For PSC, mean MSE values were 171.9 (SD 38.9), compared to 176.8 (SD 98.0; p=0.67) and 395.2 (SD 632.5; p=0.18), respectively. In external validation on the Singapore Malay Eye Study (sampled to reflect the distribution of cataract severity in AREDS), MSE was 1.27 for NS and 25.5 for PSC.

CONCLUSIONS

A deep learning framework was able to perform automated and quantitative classification of cataract severity for all three types of age-related cataract. For the two most common types (NS and CLO), the accuracy was significantly superior to that of ophthalmologists; for the least common type (PSC), the accuracy was similar. The framework may have wide potential applications in both clinical and research domains. In the future, such approaches may increase the accessibility of cataract assessment globally. The code and models are publicly available at https://XXX.

Multimodal, multitask, multiattention (M3) deep learning detection of reticular pseudodrusen: Toward automated and accessible classification of age-related macular degeneration

OBJECTIVE

Reticular pseudodrusen (RPD), a key feature of age-related macular degeneration (AMD), are poorly detected by human experts on standard color fundus photography (CFP) and typically require advanced imaging modalities such as fundus autofluorescence (FAF). The objective was to develop and evaluate the performance of a novel multimodal, multitask, multiattention (M3) deep learning framework on RPD detection.

MATERIALS AND METHODS

A deep learning framework (M3) was developed to detect RPD presence accurately using CFP alone, FAF alone, or both, employing >8000 CFP-FAF image pairs obtained prospectively (Age-Related Eye Disease Study 2). The M3 framework includes multimodal (detection from single or multiple image modalities), multitask (training different tasks simultaneously to improve generalizability), and multiattention (improving ensembled feature representation) operation. Performance on RPD detection was compared with state-of-the-art deep learning models and 13 ophthalmologists; performance on detection of 2 other AMD features (geographic atrophy and pigmentary abnormalities) was also evaluated.

RESULTS

For RPD detection, M3 achieved an area under the receiver-operating characteristic curve (AUROC) of 0.832, 0.931, and 0.933 for CFP alone, FAF alone, and both, respectively. M3 performance on CFP was very substantially superior to human retinal specialists (median F1 score = 0.644 vs 0.350). External validation (the Rotterdam Study) demonstrated high accuracy on CFP alone (AUROC, 0.965). The M3 framework also accurately detected geographic atrophy and pigmentary abnormalities (AUROC, 0.909 and 0.912, respectively), demonstrating its generalizability.

CONCLUSIONS

This study demonstrates the successful development, robust evaluation, and external validation of a novel deep learning framework that enables accessible, accurate, and automated AMD diagnosis and prognosis.

Outcomes in Previously Healthy Cryptococcal Meningoencephalitis Patients treated with Pulse - Taper Corticosteroids for Post-infectious Inflammatory Syndrome

BACKGROUND

Cryptococcal meningoencephalitis (CM) is a major cause of mortality in immunosuppressed patients and previously healthy individuals. In the latter, a post-infectious inflammatory response syndrome (PIIRS) is associated with poor clinical response despite antifungal therapy and negative CSF cultures. Data on effective treatment are limited.

METHODS

Between March 2015 and March 2020, 15 consecutive previously healthy patients with CM and PIIRS were treated with adjunctive pulse corticosteroid taper therapy (PCT) consisting of intravenous methylprednisolone 1 gm daily for 1 week followed by oral prednisone 1 mg/kg/d, tapered based on clinical and radiological response plus oral fluconazole. Montreal Cognitive Assessments (MOCA), Karnofsky Performance scores, MRI brain scanning, ophthalmic and audiologic exams, CSF parameters including cellular and soluble immune responses were compared at PIIRS diagnosis and after methylprednisolone completion.

RESULTS

The median time from antifungal treatment to steroid initiation was 6 weeks. The most common symptoms at PIIRS diagnosis were altered mental status and vision changes. All patients demonstrated significant improvements in MOCA and Karnofsky scores at 1 month (p<0.0003), which was accompanied by improvements in CSF glucose, WBC, protein, cellular and soluble inflammatory markers 1 week after receiving corticosteroids (CS) (p<0.003). All patients with papilledema and visual field deficits also exhibited improvement (p<0.0005). Five out of 7 patients who underwent audiological testing demonstrated hearing improvement. Brain MRI showed significant improvement of radiological findings (p=0.001). CSF cultures remained negative.

CONCLUSIONS

PCT in this small cohort of PIIRS was associated with improvements in CM-related complications with minimal toxicity in the acute setting.

Autoinflammatory Eye Disease Due to NLRP3 Inflammasome-Associated Mutations and Excessive IL-1β Responses may be Driven by Ocular Exposure to Commensals

In previous studies we have shown that the healthy murine ocular surface is colonized by a commensal, Corynebacterium mastitidis, that elicits IL-17 from γδ T cells and promotes local host defense. Based on that, we hypothesized that ocular inflammation in patients with NLRP3-associated mutations, including those with Cryopyrin Associated Periodic Syndrome (CAPS), may be triggered by an overactive response to their own eye surface commensals. We found that, unlike wild type mice, mice with a CAPS mutant NLRP3 gene and increased IL-1β and IL-17 responses, develop conjunctival neutrophilia and ocular inflammation following ocular exposure to C. mast. Single cell transcriptomics confirmed that conjunctival γδ T cells were the major source of IL-17 and identified increased amounts of ccr2 and s100a8 mRNA, accounting for the neutrophil infiltration. In parallel studies of patients with inflammasome-associated mutations (NLRP3 or CARD8 mutations) we found that patient PBMCs cultured with C. mast produced increased amounts of IL-17A compared to healthy controls (C. mast. status of subjects: unknown). Patient immune cells (conjunctival and PBMC) showed upregulation of RORC, BATF and STAT3 as well as interferon-related genes (IRF1, STAT1). However, unlike in mice, IL-17-related genes appeared to be more upregulated in αβ than in γδ T cells, suggesting that in patients this response may be mediated by other cells, and/or that other commensals than in mice may be the stimulus. Thus, commensals can elicit an exaggerated immune response in humans and mice with NLRP3-related autoinflammatory disease. If indeed the conjunctivitis in CAPS patients reflects a response to their own commensals, adjunct antimicrobial therapy may be considered.

Long-Term Outcomes of Refractive Surgery Performed During the Military

INTRODUCTION

To evaluate the long-term refractive results of laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) performed by the military in a veteran population.

MATERIALS AND METHODS

Three Department of Veterans Affairs (VA) hospital sites (Puget Sound, Buffalo, and Washington D.C.) obtained IRB approval for this multi-center study. Comprehensive ophthalmologic assessment including refraction and keratometry were obtained at the time of the long-term VA examination and compared to the patients' postoperative military records.

RESULTS

Eighty patients (160 eyes) enrolled in this study. At the time of treatment, patients were 21-52 years of age. Long-term post-operative data was available from 4 to 17 years post-operatively. Fifteen percent of the treatment types were LASIK and 85% PRK. At the time of their military post-operative exam (range 3-14 months, mean 4 months), 82% of patients had uncorrected visual acuity (UCVA) of 20/20 or better, and their average manifest refraction was -0.08 D (SD ± 0.48 D). At the time of the long-term ophthalmological exam at the VA medical centers (range 4-11 years, mean of 8.2 years), 49% of patients had an UCVA of 20/20 or better and an average manifest refraction was -0.64 D (SD ± 0.69 D).

CONCLUSION

This is the first long-term study evaluating refractive surgery outcomes up to 17 years in a military population. Our study demonstrates safety after refractive surgery in the military with less than 0.1D increase in myopia per year and strong keratometric stability. Other changes in the eye may be the likely cause for this observed mild refractive shift.

Ocular Adverse Events following Use of Immune Checkpoint Inhibitors for Metastatic Malignancies

PURPOSE

To report the clinical features, severity, and management of ocular immune-related adverse events (irAEs) in the setting of immune checkpoint inhibitor therapy for metastatic malignancies.

METHODS

Retrospective chart review at three tertiary ophthalmology clinics. Electronic medical records were reviewed between 2000 and 2017 for patients with new ocular symptoms while undergoing checkpoint inhibition therapy.

RESULTS

Eleven patients were identified. Ocular irAEs ranged from keratoconjunctivitis sicca to Vogt-Koyanagi-Harada-like findings. Average timing of irAEs from starting checkpoint inhibitor therapy was 15.7 weeks. Ocular inflammation was successfully controlled with corticosteroids in most cases, however three patients discontinue treatment as a result of ocular inflammation with decreased visual acuity, two discontinued due to progression of metastatic disease, and one discontinued due to severe systemic irAEs.

CONCLUSION

We found a wide spectrum of ocular irAEs associated with immune checkpoint inhibitors. In most cases, ocular AEs did not limit ongoing cancer treatment.

Eleven Years of Cataract Surgery in Veterans Without Pre-existing Ocular Comorbidities

Introduction

In 2017, over 75,000 cataract surgeries were performed within the Veterans Health Administration System (VHA). Previous reports of outcomes of cataract surgery in veterans include patients with pre-existing ocular disease, which can affect vision. To exclude the confounding factor of pre-existing ocular comorbidities, we investigated the long-term visual outcomes and complications associated with small incision cataract surgery performed on veterans without any pre-existing eye disease.

Materials and Methods

Institutional Review Board approved cohort study with detailed retrospective chart review of all phacoemulsification (small incision) cataract surgeries performed at the Veterans Affairs Medical Center in Washington D.C. over 11 years, including all pre-and postoperative visits until postoperative month 12.

Results

A total of 1,513 consecutive surgical cases without any pre-existing ocular disease except the cataract were included. Vision improved significantly after cataract surgery compared to the preoperative best-corrected visual acuity (BCVA) (p = 0.0001) and remained stable over the first intra- and postoperative year. All eyes without complicated surgery and 99.1% of eyes with complications achieved 20/40 or better final vision postoperatively. The most common intra-and postoperative complications were vitreous loss (3.1%) and cystoid macular edema (CME; 1.4%). Patients with complications achieved final mean BCVA of 0.04 (20/22, vitreous loss) and 0.06 (20/23, CME) mean logMAR (Snellen).

Conclusion

Analysis of 11 years of small incision cataract surgery in eyes without pre-existing ocular disease within the VHA showed significant improvement in vision and stability 12 months after uncomplicated and complicated surgery in veterans.

Chronic visual dysfunction after blast-induced mild traumatic brain injury

The purpose of this study was to investigate the long-term visual dysfunction in patients after blast-induced mild traumatic brain injury (mbTBI) using a retrospective case series of 31 patients with mbTBI (>12 mo prior) without eye injuries. Time since mbTBI was 50.5 +/- 19.8 mo. Age at the time of injury was 30.0 +/- 8.3 yr. Mean corrected visual acuity was 20/20. Of the patients, 71% (n = 22) experienced loss of consciousness; 68% (n = 15) of patients in this subgroup were dismounted during the blast injury. Overall, 68% (n = 21) of patients had visual complaints. The most common complaints were photophobia (55%) and difficulty with reading (32%). Of all patients, 25% were diagnosed with convergence insufficiency and 23% had accommodative insufficiency. Patients with more than one mbTBI had a higher rate of visual complaints (87.5%). Asymptomatic patients had a significantly longer time (62.5 +/- 6.2 mo) since the mbTBI than symptomatic patients (42.0 +/- 16.4 mo, p < 0.004). Long-term visual dysfunction after mbTBI is common even years after injury despite excellent distance visual acuity and is more frequent if more than one incidence of mbTBI occurred. We recommend obtaining a careful medical history, evaluation of symptoms, and binocular vision assessment during routine eye examinations in this prepresbyopic patient population.

Visual Dysfunction in Combat-related Mild Traumatic Brain Injury—A Review

Approximately half of all military personnel who have served in the conflicts in Iraq and Afghanistan are reported to have some degree of combat-related mild traumatic brain injury (TBI). Although in civilian concussion injuries symptoms typically resolve within several weeks, blast-induced mild TBI may be accompanied by prolonged symptoms and afferent and efferent visual dysfunction. Most commonly near vision problems and photophobia are the presenting symptoms. A complete eye exam including vision testing, oculomotor function, and near tasking, is highly recommended after blast-induced mild TBI to detect and improve symptoms in this young patient population. A review of the current literature is presented.

Flap-off epi-LASIK versus automated epithelial brush in PRK: a prospective comparison study of pain and reepithelialization times

PURPOSE

To compare the effect of flap-off epi-LASIK versus automated brush epithelial removal on pain and wound healing in low myopic photorefractive keratectomy (PRK).

METHODS

In this prospective intraindividual study 60 patients received surface ablation in each eye. Epithelial removal was performed by an automated brush technique in one eye (brush group) and epi-LASIK with flap removal (flap-off group) in the fellow eye. The epithelial defect size was measured daily after surgery until both eyes were reepithelialized. Postoperative pain on a scale from 0 to 6 and topical and oral analgesic medication use was recorded until the bandage contact lens was removed.

RESULTS

The flap-off group had significantly less postoperative pain on days 1 (P=.0003), 2 (P=.0001), 3 (P<.0001), and 4 (P<.0001) compared to the brush group. However, the average difference in pain scores between groups was only 0.33 points out of 6. No difference was noted in the normalized overall percentage rate of healing over the first 4 days in the flap-off group (5.41±1.39%/hour) compared to the brush group (5.42±1.94%/hour) (P=.97).

CONCLUSIONS

The flap-off group showed a statistically but not clinically significant advantage over the brush group in pain scores. However, no difference was noted in the percentage rate of epithelial healing time between the two groups.

The molecular refractive function of lens γ-Crystallins

γ-Crystallins constitute the major protein component in the nucleus of the vertebrate eye lens. Present at very high concentrations, they exhibit extreme solubility and thermodynamic stability to prevent scattering of light and formation of cataracts. However, functions beyond this structural role have remained mostly unclear. Here, we calculate molecular refractive index increments of crystallins. We show that all lens γ-crystallins have evolved a significantly elevated molecular refractive index increment, which is far above those of most proteins, including nonlens members of the βγ-crystallin family from different species. The same trait has evolved in parallel in crystallins of different phyla, including S-crystallins of cephalopods. A high refractive index increment can lower the crystallin concentration required to achieve a suitable refractive power of the lens and thereby reduce their propensity to aggregate and form cataracts. To produce a significant increase in the refractive index increment, a substantial global shift in amino acid composition is required, which can naturally explain the highly unusual amino acid composition of γ-crystallins and their functional homologues. This function provides a new perspective for interpreting their molecular structure.

The role of macromolecular crowding in the evolution of lens crystallins with high molecular refractive index

Crystallins are present in the lens at extremely high concentrations in order to provide transparency and generate a high refractive power of the lens. The crystallin families prevalent in the highest density lens tissues are γ-crystallins in vertebrates and S-crystallins in cephalopods. As shown elsewhere, in parallel evolution, both have evolved molecular refractive index increments 5-10% above those of most proteins. Although this is a small increase, it is statistically very significant and can be achieved only by very unusual amino acid compositions. In contrast, such a molecular adaptation to aid in the refractive function of the lens did not occur in crystallins that are preferentially located in lower density lens tissues, such as vertebrate α-crystallin and taxon-specific crystallins. In the current work, we apply a model of non-interacting hard spheres to examine the thermodynamic contributions of volume exclusion at lenticular protein concentrations. We show that the small concentration decrease afforded by the higher molecular refractive index increment of crystallins can amplify nonlinearly to produce order of magnitude differences in chemical activities, and lead to reduced osmotic pressure and the reduced propensity for protein aggregation. Quantitatively, this amplification sets in only at protein concentrations as high as those found in hard lenses or the nucleus of soft lenses, in good correspondence to the observed crystallin properties in different tissues and different species. This suggests that volume exclusion effects provide the evolutionary driving force for the unusual refractive properties and the unusual amino acid compositions of γ-crystallins and S-crystallins.

Peripheral interstitial keratitis: a novel manifestation of ocular mastocytosis

PURPOSE

To report a case of peripheral interstitial keratitis in a patient with mastocytosis.

METHODS

Clinical case description and immunohistologic examination of biopsied ocular tissue.

RESULTS

A 22-year-old woman with biopsy-proven urticaria pigmentosa, a subset of mastocytosis, presented with an active peripheral interstitial keratitis with vascularization associated with foreign body sensation and itching. Biomicroscopy of the cornea showed deep corneal inflammatory infiltrates and midstromal vascularization adjacent to a region of superior bulbar conjunctiva, which was mildly chemotic and inflamed. Topical mast cell stabilizers and a short course of topical steroids produced dramatic resolution of the lesion. Biopsy of the erythematous conjunctiva adjacent to the area of corneal inflammation showed the presence of mast cells.

CONCLUSION

This is the first case of corneal inflammatory infiltration in a patient with mastocytosis. Therapy for this condition consists of a combination of topical mast cell stabilizers, topical steroids, and systemic antihistaminic therapy.

Chronic recurrent varicella-zoster virus keratitis confirmed by polymerase chain reaction testing

PURPOSE

To report a case of chronic recurrent varicella virus epithelial keratitis in a child.

DESIGN

Case report.

METHODS

Clinical examination and polymerase chain reaction analysis of corneal epithelium.

RESULTS

A 10-year-old healthy child developed chronic recurrent varicella virus keratitis with pseudodendrites after recovering from systemic varicella. Analysis of the debrided pseudodendrites was repeatedly positive for VZV DNA and negative for HSV DNA. Treatment with oral acyclovir and topical corticosteroid drops was effective in eliminating the pseudodendrites; however, recurrences occurred once the medications were discontinued.

CONCLUSIONS

Varicella virus epithelial keratitis in children can be a recurrent chronic condition requiring prolonged treatment.

Adaptation of a surface plasmon resonance biosensor with microfluidics for use with small sample volumes and long contact times

The efficient delivery of sample to surface-immobilized sites is a key element in biosensing. For a surface plasmon resonance (SPR) biosensor, this has been addressed by constant flow through a microfluidic system with a sample injection loop (Sjölander, S.; Urbaniczky, C. Anal. Chem. 1991, 63, 2338-2345). The present study describes an alternative mode of sample delivery without constant unidirectional flow. It was implemented on a commercial Biacore X SPR biosensor equipped with a microfluidic cartridge, but with the fluidic handling performed by an externally computer-controlled syringe pump. We demonstrate that sample volumes as low as 2 microL can be reproducibly positioned to cover the sensor surfaces, manipulated in a serial fashion, efficiently mixed by applying an oscillatory flow pattern, and fully recovered. Compared to the traditional continuous unidirectional flow configuration, we found very similar kinetic responses at high analyte concentrations and slightly slower responses at low concentrations, most likely due to depletion of analyte from the small sample volumes due to surface binding. With the antibody-antigen systems tested, binding parameters were obtained that are generally within 10% of those from conventional experiments. In the new configuration, biosensor experiments can be conducted without the usual constraints in the surface contact time that are correlated with sample volume and mass transport rate. This can translate to improved detection limits for slow reactions and can facilitate kinetic and thermodynamic binding studies.

Systemic or mucosal administration of immunostimulatory DNA inhibits early and late phases of murine allergic conjunctivitis

Seasonal allergic conjunctivitis is one of the most common manifestations of allergic disease, affecting 15 % population in the United States annually. Short ragweed (RW) is a major cause of seasonal allergies. Immunostimulatory DNA sequences (ISS or CpG motifs) can inhibit an on-going Th2/allergic response and induce a de novo Th1 response. In this study, we investigated the ability of these ISS to modulate allergic responses in a RW-induced mouse model of seasonal allergic conjunctivitis. Systemic or mucosal administration of ISS oligonucleotide (ISS-ODN) after RW sensitization inhibited both the immediate hypersensitivity response and the late-phase cellular infiltration and induced a RW-specific Th1 response. ISS-ODN administration suppressed the rise of RW-specific IgE titers after repeated allergen challenge. Furthermore, ISS administration was more effective than dexamethasone in inhibiting the allergic response. Mechanistically, the ISS-induced immunomodulatory effects were abolished when mice were treated with anti-IL-12 neutralizing antibodies, suggesting a pivotal role for type 1 cytokines in the inhibition of both the immediate hypersensitivity and the late-phase cellular infiltration. Thus, ISS-ODN is a novel anti-inflammatory and immunomodulatory agent that significantly inhibits the allergic response and may provide an alternative to the current standard care of ocular allergy.

The role of IL-12 in the induction of late-phase cellular infiltration in a murine model of allergic conjunctivitis

BACKGROUND

The applied murine model of allergic conjunctivitis mimics human disease, and an immediate hypersensitivity reaction (IHR) and a late-phase cellular reaction typically develop in sensitized mice after topical challenge with the allergen.

OBJECTIVE

We investigated the role of IL-4, IFN-gamma, and IL-12 in the early and late phases of ocular allergy with use of cytokine knockout (KO) mice and neutralizing antibodies.

METHODS

Ragweed-sensitized wild-type or IL-4KO, IL-12KO, IFN-gamma KO, anti-IL-12 mAb-treated, recombinant murine IL-12-treated, and anti-IFN-gamma mAb-treated mice were challenged with the allergen 10 days after the immunization. IHR, cellular infiltration, lymphoproliferative response, and cytokine production from draining lymph nodes were recorded and compared among groups.

RESULTS

We show that IL-12KO mice and anti-IL-12 antibody-treated wild-type animals failed to have a cellular infiltration into the conjunctiva. Treatment with recombinant murine IL-12 also reduced the number of infiltrating PMNs but increased the percentage of mononuclear cells in the conjunctiva compared with controls. IFN-gamma KO mice had a significantly stronger IHR and prolonged infiltration into the conjunctiva after challenge with ragweed than controls.

CONCLUSION

Our data suggest that the presence of IL-12, although better known as a T(H)1-inducing cytokine, is important for the development and the regulation of the late-phase pathologic features in ocular allergy. Furthermore, IFN-gamma is a limiting factor in the late phase of allergy and thus may be important in preventing chronic allergic disease.

Blocking ICAM-1 (CD54) and LFA-1 (CD11a) inhibits experimental allergic conjunctivitis

Cell adhesion molecules are critical for the homing and migration of leukocytes into inflamed tissues. We investigated the role of ICAM-1 and LFA-1 in a previously described experimental model of ragweed (Rw)-induced allergic conjunctivitis. SWR/J mice were treated intraperitoneally 6 and 1 h prior to topical challenge with Rw with injections of anti-ICAM-1 monoclonal antibody (mAb), anti-LFA-1 mAb, both anti-ICAM-1 and anti-LFA-mAbs, or rat IgG. Blocking ICAM-1 or LFA-1 reduced the clinical signs of allergic conjunctivitis. Treatment with anti-ICAM-1 or anti-LFA-1 mAbs also significantly inhibited cellular infiltration into the conjunctiva. The greatest inhibitory effect was achieved with the combination of antibodies against both cell adhesion molecules. Since antibodies against ICAM-1 and LFA-1 significantly inhibit the development of the clinical and histologic signs of allergic conjunctivitis, they may be useful for treating patients with ocular allergy.

A novel murine model of allergic conjunctivitis

Allergic conjunctivitis affects over 40 million patients per year in the United States. Here we present the first murine model that incorporates the clinical, cellular, and humoral parameters of allergic conjunctivitis, including a ragweed-induced Th2-type cytokine production by lymphocytes. SWR/J mice were immunized with short ragweed pollen in aluminum hydroxide. Ten days after immunization, allergic conjunctivitis was induced by one topical application of ragweed pollen onto the eye. Immediate response was characterized by chemosis, redness of the conjuctiva, and lid edema. Histopathology and immunohistochemistry showed dense conjunctival infiltration with polymorphonuclear leukocytes, macrophages, and CD4+ T lymphocytes. In addition, ragweed-specific IgG1 and IgE serum levels were significantly higher in immunized animals, and high levels of IL-4 and IL-5 were detected in supernatants from ragweed-activated lymphocytes. This reproducible model is a well-suited instrument for testing the pathophysiology and future therapies of allergic conjunctivitis.

Elevation of laser flare photometry in patients with cytomegalovirus retinitis and AIDS

PURPOSE

To investigate an alteration of the blood-ocular barriers by laser flare photometry in patients with acquired immunodeficiency syndrome (AIDS) diagnosed with cytomegalovirus retinitis.

METHODS

Serial laser flare photometry measurements from 31 eyes of 31 patients with AIDS and newly diagnosed cytomegalovirus retinitis were compared with measurements from 31 control patients with AIDS but without documented eye disease. Location and extent of retinitis, presence of visual symptoms, and CD4 lymphocyte counts were also compared with laser flare photometry readings.

RESULTS

Laser flare readings (mean +/- SE) were significantly higher in eyes with (13.0 +/- 1.5 photon counts per msec) than without cytomegalovirus retinitis (4.9 +/- 0.3 photon counts per msec) (P < .001). Lesions within the arcade vessels resulted in significantly higher laser flare photometry readings (17.3 +/- 2.5 photon counts per msec) compared with peripheral retinitis (9.8 +/- 1.5 photon counts per msec) (P = .01). A significant correlation was found between area of involvement of peripheral retinitis and laser flare photometry readings (P = .008). Readings in patients without cytomegalovirus retinitis increased significantly 10 months after the first measurement (9.5 +/- 1.9 photon counts per msec) (P = .04). Readings in patients with cytomegalovirus remained elevated 3 months after successful treatment of retinitis (12.3 +/- 2.3 photon counts per msec) (P = .6).

CONCLUSIONS

Laser flare photometry readings are significantly elevated in eyes with cytomegalovirus retinitis, suggesting a breakdown of the blood-ocular barriers. Increasing laser flare photometry readings over time in patients without known ocular disease suggests that HIV infection may cause progressive breakdown of the blood-ocular barrier.