Corneoscleral limbus in glaucoma patients: in vivo confocal microscopy and immunocytological study.
OBJECTIVE
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 = 0.041; P = 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.
Ophthalmology Unit, Department of Neurological, Neuropsychological, Morphological and Movement Sciences, University of Verona, Verona, Italy.
Rodolfo
R
Mastropasqua
Ophthalmology Clinic, Department of Medicine and Aging Science, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy.
Luca
L
Agnifili
Ophthalmology Clinic, Department of Medicine and Aging Science, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy.
Vincenzo
V
Fasanella
Excellence Eye Research Center, CeSI, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy.
Claudia
C
Curcio
Ophthalmology Clinic, Department of Medicine and Aging Science, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy.
Lorenza
L
Brescia
Ophthalmology Clinic, Department of Medicine and Aging Science, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy.
Manuela
M
Lanzini
Department of Specialist, Diagnostics and Experimental Medicine (DIMES), Ophthalmology Service, University of Bologna, Bologna, Italy.
Michela
M
Fresina
Ophthalmology Clinic, Department of Medicine and Aging Science, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy.
Leonardo
L
Mastropasqua
Ophthalmology Unit, Department of Neurological, Neuropsychological, Morphological and Movement Sciences, University of Verona, Verona, Italy.
Giorgio
G
Marchini
D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D002452:Cell Count; D003713:Dendritic Cells / Q000473:pathology; D019573:Epithelium, Corneal / Q000378:metabolism; D005260:Female; D005901:Glaucoma / Q000188:drug therapy / Q000473:pathology*; D006684:HLA-DR Antigens / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D015850:Interleukin-6 / Q000378:metabolism; D016850:Limbus Corneae / Q000378:metabolism / Q000473:pathology*; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D012590:Sclera / Q000378:metabolism / Q000473:pathology*
D000959:Antihypertensive Agents; D015415:Biomarkers; D006684:HLA-DR Antigens; D015850:Interleukin-6
corneoscleral limbus; glaucoma therapy; impression cytology; in vivo laser scanning confocal microscopy; ocular surface; primary open angle glaucoma