Learning effect of Humphrey Matrix frequency doubling technology perimetry in patients with open-angle glaucoma.

PURPOSE: To evaluate the learning effect of frequency doubling technology (FDT) perimetry using the Humphrey Matrix perimeter in patients with open-angle glaucoma with no perimetric experience. METHODS: One eye each of 30 glaucoma patients who had no history of visual field testing underwent 3 Matrix tests using 24-2 program with full-threshold strategy. The parameters investigated to detect learning effect were test duration, reliability indexes, mean deviation (MD), pattern standard deviation (PSD), and the number of points with a p of <5% and <1% in the total and pattern deviation maps. RESULTS: MD showed a larger defect at the first test (-13.64 +/- 1.63 dB) than at the second (-12.68 +/- 1.45 dB) and third (-11.69 +/- 1.48 dB) tests (p<0.05). A statistically significant reduction (p<0.05) in the number of points with a p <5% and <1% in the total deviation map was observed when repeating the examination. The values of test duration, PSD, fixation losses, false-positive rate, false-negative rate, and number of points with a p <5% and <1% in the pattern deviation map were not changed significantly (p>0.05). CONCLUSIONS: Humphrey Matrix FDT perimetry showed a statistically significant learning effect on MD and the number of significantly depressed points of the total deviation map in glaucoma patients with no perimetric experience. It is probably necessary to obtain at least 3 repetitions to rule out the presence of a learning effect in such patients before providing useful results.

Use of ivermectin in the treatment of orbital myiasis caused by Cochliomyia hominivorax.

Orbital myiasis cases by dipterous fly larvae are rarely reported. A case of massive orbital myiasis caused by Cochliomyia hominivorax resulting in complete loss of the globe is described. Oral ivermectin was used successfully to eliminate the larvae prior to enucleation, making the mechanical removal of larvae an unnecessary procedure.