Biometric risk factors for acute glaucoma attack

PURPOSE. To assess the prognostic significance of the LAF coefficient (Lens thickness/Axial length factor) as a risk factor for acute glaucoma attack in anatomically short eyes of Europeans.

METHODS. Group 1 consisted of 24 patients (48 eyes) with axial hyperopia. Group 2 included 24 patients (48 eyes) with primary closure of the anterior chamber angle. Group 3 — 17 patients (34 eyes) with initial stage of primary angleclosure glaucoma. Group 4 — 35 patients (35 eyes) with an acute attack of glaucoma. The studied groups did not differ in age (p=0.97) and gender (p=0.28). Lens thickness and axial length (AL) were measured by A-scan with calculation of the LAF coefficient.

RESULTS. The LAF coefficient in group 4 (acute attack) was statistically significantly higher than in the other three groups. The best separation of groups 1 and 4 was seen in LAF coefficient compared to lens thickness and AL with sensitivity, specificity and the area under the curve (AUC) of 89%, 83% and 0.9, respectively. LAF coefficient values greater than 2.332 in patients with short AL are objectively associated with high risk of acute attack of glaucoma. The average value of the LAF coefficient (2.528) observed in group 4 (acute attack of glaucoma) significantly exceeds these parameters in works of other authors, which may be associated with morphometric structural features of the eyes of Europeans compared to the eyes of Asians.

CONCLUSION. The LAF coefficient provides better separation of group 1 and 4 in comparison with lens thickness and, especially, axial length. LAF coefficient values greater than 2.332 in eyes with short AL objectively indicate high risk of acute attack of glaucoma, as evidenced by high sensitivity, specificity, and AUC.

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