EVALUATION OF RETINAL NERVE FIBER LAYER DAMAGE IN ACUTE PRIMARY ANGLE CLOSURE BY CONFOCAL SCANNING LASER OPHTHALMOSCOPY

Pham Thi Thuy Tien MD., Nguyen Thi Ngoc Lien MD., Truong Thu Le Ha MD.

Glaucoma Department, Eye Hospital Ho Chi Minh City, Vietnam.

Purpose: To measure the loss of retinal nerve fiber layers (RNFL) of attacked eyes of acute primary angle closure (APAC) with their fellow eyes by using confocal scanning laser ophthalmoscopy (HRT).

Methods: A prospective, comparative, image diagnostic study was done to patients with a single unilateral attack of APAC. The suffered eyes were performed trabeculectomy and the fellow eyes were treated with laser peripheral iridotomy. Confocal scanning laser ophthalmoscopy was carried out at 6 month post-operation. The various parameters between the attacked and the fellow eyes (control group) were compared using the Student t-test.

Results: Twenty nine patients including 8 male and 21 female with the mean age 57.97 ± 5.97 (years) were recruited. The duration of the APAC ranged from 4 to 120 hours (mean, 47.50 ± 30.50 hours). The mean presenting IOP during the acute attack was 37.09 ± 6.30 mmHg. The rim volume, the height variation contour and the average of RNFL demonstrated a statistically significant difference between two groups. The retinal nerve fiber layers at temporal and inferior temporal sectors tended to loss more than those at nasal and inferior nasal sectors.

Conclusion: No matter how long the duration of attack of APAC lasted, the optic disc and RNFL damage were detected quantitatively by HRT. Severe RNFL loss was documented in eyes that underwent a single APAC with duration of attack up longer than 24 hours.
Key words: acute primary angle closure, retinal nerve fiber layers, scanning laser ophthalmoscopy, Heidelberg Retinal Tomograph (HRT).