The effect of artificial tear administration on visual field testing in patients with glaucoma and dry eye.

AIM: To examine the effects of artificial tear administration on perimetry of primary open-angle glaucoma patients with dry eye. METHODS: A total of 40 patients with primary open-angle glaucoma experienced in automated perimetry with symptoms of dry eye were enrolled in this study. After their pretest visit, they were instructed to use artificial tear four times a day in both eyes for 1 week. After 1 week, patients had visual field testing. Test taking time, reliability parameters (false-positive and false-negative errors) visual field indices and number of depressed points at different probability levels (P<5%, P<2%, P<1%, P<0.5%) in both total and pattern deviation plots were compared using paired Ttest. RESULTS: We found significant improvement in reliability parameters (false-positive errors from 2.4+/-2.1 to 2.1+/-1.9, P=0.02; and false-negative errors from 7.3+/-6.4 to 4.8+/-3.6, P=0.01) and visual field indices (MD increased from 5.97+/-5.61 to 4.57+/-4.53, P=0.001; PSD from 4.67+/-2.95 to 4.13+/-2.77, P=0.04 and SF decreased from 2.24+/-1.23 to 1.83+/-0.77, P=0.04) in the second testing after artificial tear administration. Test time significantly increased from 11.66+/-2.55 min to 14.26+/-1.36, P=0.001. The number of depressed points at probability levels P<1% (P=0.03) and P<0.5% (P=0.04) at total deviation plot and P<2% (P=0.02) and P<0.5% (P=0.009) in pattern deviation plot decreased significantly. CONCLUSION: Artificial tear administration in glaucomatous patients with dry eye seems to improve significantly reliability parameters and visual field indices.

Assessment of spatial-contrast function and short-wavelength sensitivity deficits in patients with migraine.

AIMS: To study spatial-contrast function and short-wavelength sensitivity deficits in a migraine population with a disease duration of 30 years or less. MATERIALS AND METHODS: In this prospective, cross-sectional study, we evaluated 28 subjects with migraine headache and 15 nonheadache healthy controls. Visual fields were evaluated using the Humphrey Field Analyzer 750i and the 30-2, blue and yellow threshold programme. Contrast sensitivity (CS) was measured at 1.5, 3, 6, 12, and 18 cpd spatial frequencies, using the Functional Acuity Contrast Test (F.A.C.T.). The results of the visual field parameters (mean defect (MD) and pattern standard defect (PSD)) and CS were compared with 15 age-equivalent normal subjects. RESULTS: Short-wavelength amplitude perimetry (SWAP) parameters and CS scores at all spatial frequencies were significantly altered in the migraine patients when compared with the control subjects. Visual field parameters correlated significantly with contrast sensitivity scores: positively for MD (r=0.39, P=0.01; r=0.43, P=0.005; r=0.56, P=0.0001; r=0.45, P=0.003; r=0.48, P=0.0001) and negatively for PSD (r=-0.45, P=0.003; r=-0.45, P=0.003; r=-0.51, P=0.001; r=-0.53, P=0.0001; and r=-0.67, P=0.0001) at all (1.5, 3, 6,12, and 18 cpd) spatial frequencies, respectively. Migraine duration correlated negatively with MD (r=-0.42, P=0.04) and positively with PSD (r=0.42, P=0.03). CONCLUSION: Migraineurs had significantly altered visual field and contrast function at all spatial frequencies to the normal population. These defects share some features with early stages of glaucoma and may relate a possibility for a common vascular disease pathogenesis in these two conditions.

Evaluation of two Humphrey perimetry programs: full threshold and SITA standard testing strategy for learning effect.

PURPOSE: To compare learning effect of Swedish interactive threshold algorithm (SITA) standard strategy with full threshold testing. METHODS: Thirty-nine medical students with no experience in visual field testing had full threshold (FT) and SITA standard for either right or left eyes. They were chosen in such a way that 20 (Group I) had FT for right and SITA for left eyes and 19 (Group II) had SITA standard for right and FT for left eyes. It was designed to have both strategies on same person whereby eliminating inter-individual variability. Visual field testing was repeated in the same week of the first test on the same subject with the same strategy that was chosen for that eye. RESULTS: The authors found an improvement in mean deviation (MD) and pattern standard deviation (PSD) of first and second testings correspondingly for FT (MD from -3.04 to -2.55; PSD from -2.60 to -2.29) and SITA standard (MD from -2.86 to -2.20; PSD from 2.25 to 2.10) and changes were statistically significant (p<0.05). To analyze learning effect of visual field testings, we calculated percentage change in MD and PSD for full threshold and SITA standard strategy. The percentage changes in visual field parameters were significantly lower in SITA standard strategy testing for MD (p=0.02) and PSD (p=0.01). CONCLUSIONS: This study shows that a learning effect is present for both strategies and SITA standard may have a reduced learning effect compared to FT.