Corneoscleral Limbus in Glaucoma Patients: In Vivo Confocal Microscopy and Immunocytological Study

Abstract

Citation: Mastropasqua R, Agnifili L, Fasanella V, et al. Corneoscleral limbus in glaucoma patients: in vivo confocal microscopy and immunocytological study. Invest Ophthalmol Vis Sci. 2015;56:205056: -205856: . DOI:10.1167 PURPOSE. To investigate morphologic changes of the corneoscleral limbus in glaucoma patients using laser scanning confocal microscopy (LSCM) and impression cytology (IC). METHODS.Eighty patients with glaucoma and 20 with dry eye were enrolled; 20 healthy subjects served as controls. Patients underwent the Ocular Surface Disease Index (OSDI) questionnaire, tear film break-up time, corneal staining, Schirmer test I, and LSCM of the limbus. Laser scanning confocal microscopy evaluated the limbal transition epithelium (LTE) regularity, dendritic cell (DC) density, and palisades of Vogt (POV). Impression cytology was performed and samples stained with HLA-DR and IL6.RESULTS. Glaucomatous patients were divided into three groups: Group 1 (40 eyes): one drug; Group 2 (20): two drugs; and Group 3 (20): three or more drugs. Limbal transition epithelium regularity was worse, and DC density higher in Groups 2, 3, and dry eyes compared with Group 1 and controls (P < 0.01). Preserved drugs worsened LTE regularity and induced higher DC density compared with preservative-free (PF) drugs (P ¼ 0.041; P ¼ 0.004). Despite typical POV architecture was preserved, signs of inflammation were found in glaucoma groups. HLA-DR and IL-6 positivity were higher in Groups 2, 3, and dry eye compared with controls (P < 0.001), and in preserved versus PF drugs (P < 0.05; P < 0.001). Dendritic cell density and LTE regularity correlated with HLA-DR, IL-6, and OSDI score in glaucoma groups and dry eyes (P < 0.001).CONCLUSIONS. Laser scanning confocal microscopy and IC documented antiglaucoma therapy induced morphologic alterations of limbus, which may play a role in the glaucoma-related ocular surface disease. Further studies are required to determine if limbal changes affect stem cell viability.

The Growing Need for Validated Biomarkers and Endpoints for Dry Eye Clinical Research

“…While the wide range of percentages in DED samples could be attributed to differences in the patient groups (age, proportion of male to female, severity, and so forth), more striking is the variation in percentage of HLA-DR expressed in IC samples from normal subjects (with no history of ocular disease or clinical ophthalmic abnormality), a group where interstudy variation should be minimal. In this group, percentage of HLA-DR–positive cells has ranged from 1.95 ± 1.46 43 to 22.1 ± 19.1. 44 All of the above once again emphasizes the need for stricter quality control with collective standardization of procedures as well as demonstration of reliability and repeatability of each step, and a need for optimization of nonsubjective data analysis tools.…”

In Vivo Confocal Imaging of the Conjunctiva as a Predictive Tool for the Glaucoma Filtration Surgery Outcome

“…19 The definition and reference images of each confocal parameter were consistent with those reported in the literature. 3,10,[13][14][15][19][20][21][22][23]…”

“…To quantify the confocal image reflectivity of the deep stroma, we adopted a previously used arbitrary grading scale. 23 The SMR was calculated by determining the average gray value of the selected image using Image J software. This value corresponded to the sum of gray values of all pixels in the entire image divided by the number of pixels.…”

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“…The long-term use of anti-glaucoma medications produces several alterations of ocular surface components, with the most prominent changes involving the cornea, limbus, and conjunctiva (6)(7)(8)(9). The most common epithelial modifications of the conjunctiva are squamous metaplasia, cellular desquamation and keratinization, dendritic cell activation, conjunctiva-associated lymphoid tissue activation, involution, and goblet cell (GCs) loss (7,10,11).…”