Neutrophil and eosinophil participation in atopic and vernal keratoconjunctivitis.

PURPOSE: A retrospective study was conducted at three centers to examine the participation of neutrophils and eosinophils in the inflammatory processes associated with atopic keratoconjunctivitis (AKC) and vernal keratoconjunctivitis (VKC). METHODS: Conjunctival specimens were obtained from four patients with AKC, six with VKC, and five normal subjects. Indirect immunofluorescent staining was used to localize neutrophil elastase (NE) and eosinophil granule major basic protein (MBP) in serial sections of all specimens. RESULTS: Specimens from both AKC and VKC patients revealed extracellular deposition of NE and MBP. Control specimens showed no or minimal extracellular NE, and no MBP. Statistical analysis demonstrated significantly greater extracellular MBP deposition in AKC specimens compared to controls (p = 0.009), and VKC specimens showed significantly greater staining for both extracellular MBP (p = 0.005) and NE (p = 0.006). CONCLUSIONS: These results suggest that neutrophils, in addition to eosinophils, play an active role in the pathogenesis of AKC and VKC as evidenced by the extracellular deposition of their specific granule proteins.

Effect of heparin-surface-modified intraocular lenses on postoperative inflammation after phacoemulsification: a randomized trial in a United States patient population. Heparin-Surface-Modified Lens Study Group.

OBJECTIVE: To compare postoperative inflammation occurring with heparin-surface-modified (HSM) versus non-HSM polymethyl methacrylate intraocular lenses (IOLs) after phacoemulsification. DESIGN: Randomized, double-masked, multicenter, parallel trial. PARTICIPANTS: A total of 367 patients, consisting of routine (n = 220), glaucoma (n = 58), and diabetes (n = 89) patients, from eight US medical centers. METHODS: Patients were observed for 1 year after phacoemulsification and lens implantation (week 1, months 1, 3, 6, 12). MAIN OUTCOME MEASURES: Primary measures of postoperative inflammation defined as the presence of giant cells on the lens surface via specular micrography and cellular deposits via slit-lamp examination. RESULTS: The cross-sectional analyses showed that consistently fewer routine patients with HSM lens implants had giant cells on the IOL than those with non-HSM lens implants across all follow-up visits. The statistical significance (P < 0.05) was observed at all visits except month 12 for routine patients. The diabetes patients also demonstrated the same giant cell difference, and the statistical significance was observed at all visits including month 12. A similar trend was also observed in the glaucoma patients, with statistical significance only at the 3-month visit. For cell deposits, significant differences in favor of the HSM lens (P < 0.05) were observed at 3 months among routine and diabetes patients, and at 3 and 6 months among glaucoma patients. A longitudinal data analysis using the generalized estimating equation approach indicated statistically significant treatment effect of HSM lenses in reducing inflammation in all patients except for cellular deposits in diabetes patients. In all patient groups, sight-threatening complications were not reported either more frequently or with more severity than normally expected for patients who have undergone cataract extraction and IOL implantation. CONCLUSIONS: The present study, the only one to have used phacoemulsification in virtually all patients (211/220 [96%] routine, 57/58 [98%] glaucoma, and 84/89 [94%] diabetes) is the largest to evaluate and compare concurrently routine, glaucoma, and diabetes patients. It is also the first US patient population study to document that heparin surface modification reduces postoperative inflammatory responses, as measured by specular micrography and slit-lamp examination, especially in the early postoperative period.

Cytokine modulation of human corneal epithelial cell ICAM-1 (CD54) expression.

To determine whether pro-inflammatory cytokines modulate intercellular adhesion molecule-1 (ICAM-1; CD54) expression on cultured primary human corneal epithelial cells (HCEs), confluent HCEs were treated with various concentrations of interferon-gamma(IFN-gamma), interleukin-1alpha(IL-1alpha), IL-1beta, IL-4, tumor necrosis factor-alpha (TNF-alpha), or combinations over time. ICAM-1 expression was measured by flow cytometry and/or a cell-based ELISA using a monoclonal mouse anti-human CD54 antibody. The apparent MW of ICAM-1 protein was determined by immunoprecipitation of biotinylated HCEs. RT-PCR was used to detect ICAM-1 RNA. The mature cell surface form of HCE ICAM-1 was approximately 110 kDa as determined by immunoprecipitation. IFN-gammaand TNF-alpha induced both dose- and time-dependent increases in ICAM-1 expression. An approximately 20-fold increase in ICAM-1 was seen at 50-100 U IFN-gamma ml-1. ICAM-1 specific mRNA accumulated approximately 4.5-fold after IFN-gammatreatment. TNF-alpha(100 U ml-1) induced a consistent approximately 6.0-fold increase in ICAM-1 expression. When IFN-gammaand TNF-alpha were mixed, at sub-optimal concentrations of each, a synergistic effect on ICAM-1 expression was not detected. Neither IL-4, IL-1alpha nor IL-1beta affected ICAM-1 expression in a consistent fashion. In summary, ICAM-1 was modulated on primary human corneal epithelial cells by the cytokines IFN-gamma and TNF-alpha in a dose- and time-dependent fashion. Cytokine modulation of corneal epithelial cell ICAM-1 during inflammation may contribute to corneal epithelial cell injury by aiding the attachment of inflammatory cells such as eosinophils which express the receptor for ICAM-1, the beta2 integrins (CD11a,b,c/CD18).

Ocular manifestations of immunologic and rheumatologic inflammatory disorders.

Our understanding of ocular manifestations in immunologic and rheumatologic inflammatory disorders has continued to expand over this past year. Studies that support the proposed immunologic pathogenesis of Vogt-Koyanagi-Harada disease are discussed. An article on the course of Behçet's disease is reviewed as well as another article discussing severe visual loss in patients with a familial occurrence of Behçet's disease. The prognostic factors for visual outcome in sarcoid uveitis are presented. An unusual case of giant cell arteritis and the most significant symptoms and diagnostic clues in helping make the diagnosis of giant cell arteritis are discussed.

Phototherapeutic keratectomy.

The US Food and Drug Administration recently approved the 193-nm excimer laser for the treatment of superficial corneal pathology and surface irregularities--a procedure called phototherapeutic keratectomy (PTK). Indications for PTK include corneal dystrophies, degenerations, and scars that impair corneal transparency, thus compromising visual acuity. In some cases, PTK may offer a better treatment modality than corneal transplant surgery. This article reviews the basic fundamentals of PTK, including indications for surgery, the surgical procedure, preoperative and postoperative patient evaluation and care, and possible complications.

Corneal topography after excimer laser photorefractive keratectomy for myopia.

BACKGROUND: This study was performed to assess and correlate the changes in central corneal power with the changes in manifest refraction after myopic photorefractive keratectomy (PRK) and to measure ablation zone centration. METHODS: Fourteen patients had computerized videokeratography and manifest refraction performed preoperatively, and than 1, 2, 3, 4, 6, and 12 months after photorefractive keratectomy. RESULTS: There was a significant association (r = -0.9; p < 0.0001) between changes in manifest refraction and changes in central corneal power at the 12-month postoperative examination; however, a mean difference of 1.1 D was seen between the two readings. The mean decentration of the ablation zone was 0.47 +/- 0.26 mm (range, 0.08 to 1.05 mm: 0 to 0.49 mm, six patients; 0.50 to 0.99 mm, seven patients; and 1.00 to 1.50 mm, one patient). CONCLUSIONS: Corneal power-as measured by videokeratography-is not an accurate predictor of manifest refraction, although the two parameters did demonstrate good correlation. Centration of ablations was comparable to previous studies.

Effects of eosinophil granule proteins on human corneal epithelial cell viability and morphology.

PURPOSE: There is mounting evidence that eosinophil granule proteins may cause tissue injury during allergic inflammation of the eye. Therefore, the authors investigated the in vitro effects of human eosinophil major basic protein (MBP), eosinophil cationic protein (ECP), eosinophil peroxidase (EPO), and eosinophil-derived neurotoxin (EDN) on cultured human corneal epithelial cell viability and morphology. METHODS: Confluent primary human corneal epithelial cell cultures were exposed to each of the four human eosinophil cationic granule proteins at concentrations ranging from 0 to 100 micrograms/ml (0, 12.5, 25, 50, and 100 micrograms/ml) for up to 48 hours in serum-free media. Morphologic changes were assessed by light microscopy at 1, 6, 24, and 48 hours; cell viability was measured using the MTT cell viability assay at 24 hours. RESULTS: Cells treated with MBP and ECP induced a dose-dependent gradual increase in morphologic changes; in contrast, EPO and EDN induced minimal changes in cell morphology. At 24 hours, both MBP and ECP induced statistically significant (P < 0.05) decreases in cell viability at a concentration of 100 micrograms/ml; EPO induced a significant (P < 0.05) decrease in cell viability at all concentrations tested, and EDN showed no significant reduction of cell viability at any of the concentrations tested. CONCLUSIONS: The current study suggests that the human eosinophil granule proteins MBP and ECP affect human corneal epithelial cell viability and morphology in vitro, whereas the protein EPO affects cell viability only. EDN had no significant effect on cell viability or morphology. Hence, MBP, ECP, and EPO perturb the corneal epithelium differentially and may contribute to keratopathy associated with severe ocular allergy.

ICAM-1 expression in corneal epithelium of a patient with vernal keratoconjunctivitis: case report.

Recent reports have demonstrated the expression of intercellular adhesion molecule-1 (ICAM-1; CD54) on the epithelium in various allergic diseases and inflammatory conditions, including the bronchial epithelium of patients with allergic asthma, conjunctival epithelium of allergic patients after allergen-specific challenge, and corneal epithelium of rejected corneal allografts. We investigated the presence of ICAM-1 expression on the corneal epithelium from a patient with vernal keratoconjunctivitis (VKC). Immunohistochemical staining of the diseased cornea demonstrated abundant ICAM-1 expression on the corneal epithelium. Immunoreactive ICAM-1 appeared to localize primarily to the cells of the basal and middle layers of the corneal epithelium. No staining was detected on the ocular surface epithelium. The normal, healthy cornea demonstrated no significant ICAM-1 expression on any of the epithelial layers, similar to that previously reported. To the best of our knowledge, this is the first report of ICAM-1 expression on the corneal epithelium from a patient with VKC.

Ocular manifestations of immunological and rheumatological inflammatory disorders.

Our understanding of ocular manifestations in immunological and rheumatological inflammatory disorders has continued to expand over the past year. A report on the characteristics of ocular disease in children with Behçet's disease is presented. Two reports of Vogt-Koyanagi-Harada syndrome in 4-year-old children are discussed, and the uncommon complication of macular edema in this syndrome is highlighted. An article reporting the presence of Epstein-Barr virus DNA in the vitreous of a patient with Vogt-Koyanagi-Harada syndrome is reviewed. Radiologic imaging patterns of orbital disease in Wegener's granulomatosis are presented. Unusual manifestations of sarcoidosis, systemic lupus erythematosus, and Wegener's granulomatosis are also reported.

Central and peripheral endothelial cell changes after excimer laser photorefractive keratectomy for myopia.

OBJECTIVE: To investigate changes in the human corneal endothelium after photorefractive keratectomy for treatment of myopia. DESIGN: Specular microscopy of the central, paracentral, and peripheral zones of the corneas of 14 patients (12 of whom were previous contact lens wearers) was performed preoperatively and at 1, 2, 3, 6, and 12 months after photorefractive keratectomy. The corneal endothelial cell density, coefficient of variation (CV) of the endothelial cell area, and percentage of hexagonal cells were assessed at each examination. RESULTS: The central endothelial cell density was increased by 7% during the first 3 postoperative months (P < .05). In contrast, the peripheral cell density declined steadily by 6.9% during the first year (P < .01). The CV of the cell area was decreased in all 3 zones, whereas the percentage of hexagonal cells was increased in the central and paracentral zones (P < .05). CONCLUSIONS: We observed statistically significant changes in the central and peripheral endothelial cell densities and morphological features that could have resulted from photorefractive keratectomy; however, these changes also may have been explained by the discontinuation of contact lens wear. If such changes are contact lens-related, they could mask the effects of laser-induced damage to the central zone of the endothelium.

Acceleration of corneal wound healing in diabetic rats by the antioxidant trolox.

Several corneal complications have been reported in patients with long standing diabetes, but their exact pathogenesis is not well understood. It has been observed that the rate of epithelial wound healing in diabetic rats is delayed compared to those in normal animals. Here we present the effect of the free radial scavenger, Trolox, a water soluble vitamin E analogue, on epithelial wound healing in diabetic rat cornea. Three groups of rats were included: 1) normal, 2) diabetic, 3) diabetic + Trolox. After 3 months, rats were sacrificed and corneas removed. Standard 3 mm diameter corneal epithelial defects were made and residual epithelial defects were measured after 18 hours at 37 degrees C in a sterile cell culture incubator. Wound healing data measured in mm2 was used for statistical analysis. There were significantly larger (p < 0.05) epithelial defects in diabetic corneas as compared to control. Treatment with Trolox antioxidant in diabetic rats produced a significantly smaller (p < 0.05) epithelial defect than that of untreated diabetic rats. These studies suggest the involvement of free radicals in the delay of corneal epithelial wound healing in diabetes.

Ocular manifestations of immunological and rheumatological inflammatory disorders.

Further exploration of ocular manifestations in systemic immunologic and inflammatory disease continues to yield new information regarding the genetic associations, diagnosis, and treatment of these disorders. The use of color Doppler ultrasound to diagnose giant cell arteritis is reported to be of diagnostic promise. The prognosis of scleritis associated with systemic immunologic and inflammatory disease is recently highlighted in two articles. The treatment of scleritis and uveitis associated with inflammatory bowel disease is reviewed. Two reports of Vogt-Koyanagi-Harada syndrome in monozygotic twins provide further understanding of the genetic factors involved in this disease. Unusual presentations of sarcoidosis and Wegener's granulomatosis are also reported.

The eye and the eosinophil.

Recent work has highlighted the eosinophil's role as an effector cell in a wide array of disease entities, including parasitic infections and allergic and nonallergic diseases. The eosinophil is filled with granules containing toxic cationic proteins, capable of harming tissue when released to the extracellular space. In the eye, toxic eosinophil cationic granule proteins have been encountered in conjunctiva, cornea, tears, and contact lenses of patients suffering from ocular allergy, suggesting an effector role for the eosinophil in the ophthalmic manifestations of atopy. Laboratory investigations indicate that eosinophil granule major basic protein, the principal eosinophil granule protein, may adversely influence corneal epithelium, and promote corneal ulceration in the severest forms of ocular allergy. Further, the eosinophil may play a contributory pathophysiologic role in some nonallergic ophthalmic diseases such as Wegener's granulomatosis, orbital pseudo-tumor, and histiocytosis X. The eosinophil's morphologic, immunologic, and biochemical characteristics will be reviewed and its role in certain ophthalmic diseases thoroughly examined.

Ocular manifestations of immunologic and rheumatologic inflammatory disorders.

Exciting new discoveries into the pathophysiological mechanisms of immunologic and inflammatory ocular disease continue. The genetic locus for susceptibility to Behçet's disease and Sjögrens syndrome has been further characterized. Important guidelines for serial slit-lamp examinations for the early detection of iridocyclitis in juvenile rheumatoid arthritis is suggested. In ocular allergy, further investigation of the interaction between mast cell and eosinophil sheds more light on the pathophysiological mechanism of vernal keratoconjunctivitis and vernal corneal ulcers. Unusual manifestations of Behçet's disease, sarcoidosis, scleritis, and Wegener's granulomatosis are reported. A possible pathophysiological mechanism for lacrimal gland destruction in Sjögrens syndrome is presented.

Eosinophil granule major basic protein inhibition of corneal epithelial wound healing.

PURPOSE: Human eosinophil major basic protein (MBP) was studied in an established organ culture model for rat corneal epithelial wound healing to elucidate further the role of the protein in vernal keratopathy. METHODS: Epithelial migration rates were tested for five MBP concentrations (10, 25, 50, 100, and 200 micrograms/ml MBP). RESULTS: Significantly less epithelial migration than control (P < 0.05) was observed in all tested groups. Histologic examination revealed abnormally heaped-up leading epithelial edges in all test groups compared to the normal tapered edges in all controls. Immunofluorescence disclosed MBP deposition on deepithelialized cornea. CONCLUSIONS: These results suggest that MBP may contribute to vernal corneal ulcerations by inhibiting corneal epithelial migration.

Eosinophil granule major basic protein deposition in corneal ulcers associated with vernal keratoconjunctivitis.

An indirect immunofluorescence assay detected eosinophil granule major basic protein in the inflammatory debris covering deepithelialized cornea in two patients with vernal keratoconjunctivitis. A slight degree of non-specific fluorescence was present in the control autopsy corneas. High concentrations of the eosinophil granule major basic protein inhibit epithelial migration and protein synthesis, whereas low concentrations affect epithelial migration. The results suggest participation of eosinophil granule major basic protein in the ulcerative process.

Medical therapy for ocular allergy.

The ocular manifestations of allergy have traditionally been classified into four categories--namely, hay fever conjunctivitis, vernal keratoconjunctivitis, atopic keratoconjunctivitis, and contact lens-associated giant papillary conjunctivitis. Typically, hay fever conjunctivitis is characterized by mild conjunctival inflammation, whereas the other disorders may have severe inflammation and clinical manifestations. Potentially blinding corneal complications may result from vernal keratoconjunctivitis and atopic keratoconjunctivitis. Although hay fever conjunctivitis is clearly an immediate hypersensitivity reaction, the immunologic mechanisms that cause vernal keratoconjunctivitis, atopic keratoconjunctivitis, and giant papillary conjunctivitis are primarily unknown and speculative. Treatment of patients with ocular allergies is often challenging and may necessitate collaborative efforts of an ophthalmologist and an allergist. Herein we discuss conventional therapy and new, promising antiallergy drugs.

Structural and functional studies of the corneal endothelium in diabetes mellitus.

We performed specular microscopy, anterior segment ocular fluorophotometry, corneal pachymetry, and tonometry on 14 patients with chronic type I diabetes and nonproliferative retinopathy and on 14 age-matched control subjects. The eyes of patients with diabetes had an increased coefficient of variation of endothelial cell area, a decreased percentage of hexagonal endothelial cells, increased corneal autofluorescence, and increased intraocular pressure, which confirmed previous studies. There was no difference, however, in corneal thickness or endothelial permeability to fluorescein. Thus, we were unable to detect any abnormality in endothelial function in these diabetic corneas in the unstressed state, despite structurally abnormal endothelial cells.

Cold-induced corneal edema in patients with trigeminal nerve dysfunction.

Two previous cases of cold-induced corneal edema have been reported in patients with corneal anesthesia secondary to a trigeminal nerve disorder. We studied six patients with complete unilateral corneal anesthesia after trigeminal ablation. Subjects' eyes were exposed to 4 C air from a fan for one hour. We measured corneal thickness, corneal surface temperature, and endothelial permeability to fluorescein. During cold exposure, two of the six study eyes exhibited reversible corneal swelling (11% and 26% over baseline value). All anesthetic corneas were consistently colder (13.8 +/- 0.7 C) than the contralateral corneas (21.0 +/- 1.7 C, P = .001). Baseline endothelial permeability and aqueous humor flow rates were similar in both the study and control groups. After cold exposure, the study eyes had a significant transient increase in permeability compared to the controls (7.5 +/- 2.4 x 10(-4) cm/min vs 2.9 +/- 1.4 x 10(-4) cm/min, P = .007). Baseline endothelial photomicrographs also showed increased pleomorphism (fewer hexagonal cells) in the anesthetic corneas. These data suggest that sensory denervation of the eye influences ocular temperature regulation and corneal endothelial cell morphologic characteristics. Some anesthetic corneas are prone to cold-induced edema, which may result from excessive cooling.

Eosinophil and neutrophil degranulation in ophthalmic lesions of Wegener's granulomatosis.

Although eosinophils and neutrophils have been identified in orbital and corneoscleral tissues in some patients with Wegener's granulomatosis, their role in the pathogenesis of the disorder is not completely understood. Nine specimens from six patients with Wegener's granulomatosis and autopsy controls from patients without ophthalmic disease were evaluated with indirect immunofluorescence for eosinophil granule major basic protein and neutrophil elastase. Extracellular deposition of both major basic protein and elastase was identified in orbital tissues from all the patients with Wegener's granulomatosis. Two of the specimens were from enucleated eyes with corneoscleral disease; extracellular deposition of eosinophil major basic protein was identified in one eye, and extracellular neutrophil elastase was deposited in both eyes in lesional areas. None of the control tissues showed major basic protein or elastase deposition. These findings suggest that both eosinophils and neutrophils participate in the pathogenesis of the orbital and corneoscleral manifestations of Wegener's granulomatosis.