Plica semilunaris temporal ectopia: evidence of primary nasal pterygia traction.

PURPOSE: 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.

External ophthalmomyiasis caused by Dermatobia hominis. A retrospective study of nine cases and a review of the literature.

PURPOSE: To report nine cases of external ophthalmomyiasis caused by Dermatobia hominis. METHODS: Retrospective, non-comparative, interventional case series. Participants consisted of patients (n = 9) presenting at Cayenne Hospital between 1968 and 2003. The location and number of larvae, the larval stage, and the medical and surgical procedures applied were studied in each case. RESULTS: Seven patients had palpebral myiasis (including one with three larvae) and two had conjunctival myiasis. Every patient had palpebral oedema. The larval respiratory pore was located on the palpebral skin or free margin or on the conjunctiva. Movements were present within the lesion in at least three patients. Petroleum ointment or ivermectine solution was used in at least four patients to smother or kill the larvae. Extraction under local anaesthesia was possible in six patients, while three required general anaesthesia. CONCLUSION: Several larvae may be present in a patient. Topical ivermectine may help to kill the larvae before extraction is attempted.