Atopic ocular surface disease: implications on tear function and ocular surface mucins.
OBJECTIVE
To describe tear function, mucin alterations, and ocular surface disorder in patients with atopic diseases.


METHODS
Subjects underwent corneal sensitivity measurements, Schirmer test, tear film break-up time (BUT) assay, and fluorescein and rose Bengal staining of the ocular surface. Conjunctival impression cytology and brush cytology were also conducted. Impression cytology samples underwent PAS and immunohistochemical staining for MUC5AC. Brush cytology specimens underwent evaluation for inflammatory cell expression and RT-PCR for MUC5AC mRNA expression. Differences related to tear function and ocular surface examination parameters among patients with and without corneal ulceration and healthy control subjects were studied.


RESULTS
Mean corneal sensitivity and BUT values were significantly lower in atopic patients with corneal ulcers compared with patients without ulcers and controls (P<0.001). Brush cytology specimens from patients with corneal ulcers revealed significantly higher expression of inflammatory cells compared with patients without ulcers and controls (P<0.001). Impression cytology samples from eyes with corneal ulcers showed significant squamous metaplasia and reduction of goblet cell density compared with eyes without ulcers and control subjects. Specimens from eyes with corneal ulcers showed PAS (+) mucin pick up and did not stain positive for MUC5AC. MUC5AC mRNA expression was significantly lower in eyes with corneal ulcers compared with in eyes without ulcers and control subjects.


CONCLUSIONS
Ocular surface inflammation, tear film instability, and decreased conjunctival MUC5AC mRNA expression are important in the pathogenesis of noninfectious corneal shield ulcers in atopic ocular surface disease.
Dogru
Murat
M
Tokyo Dental College Ichikawa General Hospital, Department of Ophthalmology, Ichikawa, Japan. muratodooru@yahoo.com
Okada
Naoko
N
Asano-Kato
Naoko
N
Tanaka
Mari
M
Igarashi
Ayako
A
Takano
Yoji
Y
Fukagawa
Kazumi
K
Shimazaki
Jun
J
Tsubota
Kazuo
K
Fujishima
Hiroshi
H
D003320:Corneal Ulcer / Q000209:etiology; D009877:Endophthalmitis / Q000209:etiology / Q000503:physiopathology; D005123:Eye / Q000378:metabolism*; D005128:Eye Diseases / Q000150:complications / Q000378:metabolism*; D006801:Humans; D006967:Hypersensitivity / Q000150:complications / Q000378:metabolism*; D055271:Mucin 5AC; D009077:Mucins / Q000378:metabolism*; D013666:Tears / Q000378:metabolism*
C524678:MUC5AC protein, human; D055271:Mucin 5AC; D009077:Mucins