In vivo confocal microscopy of trachoma in relation to normal tarsal conjunctiva.
OBJECTIVE
To describe the in vivo confocal microscopy (IVCM) appearances of the tarsal conjunctiva in trachoma compared with the appearance of healthy conjunctiva and to develop grading systems for IVCM examination of the tarsal conjunctiva for use in future studies on trachoma and other conjunctival diseases.


METHODS
Prospective observational study.


METHODS
In vivo confocal microscopy examination was performed on 302 clinically normal adults, 16 clinically normal children, 750 adults with trachomatous conjunctival scarring, and 25 children with active trachoma.


METHODS
Clinical evaluation was performed with ×2.5 loupes, and IVCM examination of the upper tarsal conjunctiva was carried out with a Heidelberg Retina Tomograph 3 with the Rostock Cornea Module (Heidelberg Engineering GmbH, Dossenheim, Germany).


METHODS
In vivo confocal microscopy images were analyzed for cellular and tissue changes associated with trachomatous inflammation and scarring compared with healthy subjects.


RESULTS
Trachomatous subjects with follicular and papillary inflammation had an increased inflammatory cellular infiltrate, including dendritiform cells, discrete follicular and papillary structures, and cystic lacunae suggestive of tissue edema. Trachomatous conjunctival scarring was seen with IVCM as organization of the subepithelial connective tissue into bands/sheets. Grading systems for inflammatory changes and scarring were developed, with the system for scarring showing good interobserver agreement with an intraclass coefficient of 0.88.


CONCLUSIONS
In vivo confocal microscopy provides a powerful tool for examining the ocular surface. Numerous cellular and tissue changes were observed in subjects with trachoma, the first time IVCM has been applied to this disease. These changes both complement and add to previous histologic analyses. In vivo confocal microscopy promises to provide new insights into the pathogenesis of trachoma and other conjunctival diseases.
International Centre for Eye Health, Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom. victor.hu@lshtm.ac.uk
Victor H
VH
Hu
Patrick
P
Massae
Helen A
HA
Weiss
Ian A
IA
Cree
Paul
P
Courtright
David C W
DC
Mabey
Robin L
RL
Bailey
Matthew J
MJ
Burton
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003228:Conjunctiva / Q000033:anatomy & histology / Q000473:pathology*; D005143:Eyelids / Q000033:anatomy & histology / Q000473:pathology*; D006801:Humans; D018613:Microscopy, Confocal; D011446:Prospective Studies; D014141:Trachoma / Q000145:classification / Q000175:diagnosis* / Q000209:etiology; D055815:Young Adult