Plica semilunaris temporal ectopia: evidence of primary nasal pterygia traction.
OBJECTIVE
To study whether plica semilunaris (PS) temporal ectopia is associated with primary nasal pterygia and whether such hypothetical ectopia is linked to with-the-rule astigmatism so that a discussion of the clinical and surgical implications of such possible findings might take place.


METHODS
Cross-section observational study of 208 consecutive eyes of 152 cases and 169 eyes of 109 control subjects enrolled for 6 months. Four PS position grades were designed. Grade 1 features a grossly vertical PS position. Grades 2 and 3 involve temporal displacement and an abnormal PS tilt. Grade 4 involves PS obliteration with possible associated temporal caruncle dragging. Pterygium corneal encroachment, pterygium fleshiness, and manifest refraction were recorded.


RESULTS
PS position was significantly displaced temporally in pterygium-affected eyes (P = 2 x 10(-4)). Corneal encroachment (P = 2.1 x 10(-5)), pterygium fleshiness (P = 2.7 x 10(-5)), and age (P = 1.3 x 10(-2)) were positively correlated with PS position grades > 1. The presence of with-the-rule astigmatism was significantly linked to PS position grades > 1 (P = 0.01).


CONCLUSIONS
Primary nasal pterygia result in PS temporal ectopia, and PS position grades (more than grade 1) are linked to the presence of with-the-rule astigmatism. These findings are consistent with the exertion of tractional forces at both pterygium ends. In eye abduction, medial canthus structures (PS, caruncule) may be dragged temporally. Thus, pterygium-related corneal traction may not always significantly increase in eye abduction. PS temporal ectopia may influence the decision to remove PS during pterygium surgical excision.
Ophthalmology Department, Cayenne Hospital, Rue des Flamboyants, Cayenne, French Guiana. edenion@wanadoo.fr
Eric
E
Denion
Antoine
A
Chambaz
Pierre-Henri
PH
Dalens
Jean
J
Petitbon
Max
M
Gérard
D000368:Aged; D001251:Astigmatism / Q000209:etiology*; D003286:Contracture / Q000209:etiology*; D003315:Cornea / Q000002:abnormalities*; D019781:Corneal Topography; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011625:Pterygium / Q000150:complications*