[Comparison of the accuracy of intraocular pressure measurement by Goldmann applanation tonometer and Keeler noncontact tonometer]

Glaucoma is one of the leading causes of blindness, and its major risk factor is elevated intraocular pressure. Intraocular pressure measurement is a major examination in patients with glaucoma for diagnosis and treatment follow-up. This study was carried out with the purpose of comparing the accuracy of two types of conventional tonometers for measuring intraocular pressure. In this descriptive cross-sectional study, after complete ophthalmologic examinations, intraocular pressure was measured in 142 patients [284 eyes], two times at 5-minute intervals using both Goldmann and Keeler tonometers. The obtained results were analyzed with paired t-test and Pearson's correlation test. Mean intraocular pressure in subjects that were in normal pressure range [<21mmHg] was obtained 14.03 +/- 2.35mmHg with Goldmann tonometer, and 14.28 +/- 3.05mmHg with Keeler tonometer. The mean difference of the two methods was 0.25 +/- 0.70 [p=0.015] and the correlation coefficient between two methods was calculated 0.83 [p<0.0001]. Mean intraocular pressure in high intraocular pressure range [>/= 21mmHg] was obtained 26.16 +/- 5.1mmHg with Goldmann tonometer, and 26.92 +/- 5.58mmHg with Keeler tonometer. The mean difference of the two methods was 0.76 +/- 0.44 [p=0.003], and correlation coefficient between two methods was calculated 0.97 [p<0.0001]. Based on the results of this study, both used tonometry methods had acceptable accuracy in normal intraocular pressure range, but in high-risk cases such as glaucoma, Goldmann applanation tonometer is preferred as the gold standard

Opposite clear corneal incisions versus steep meridian incision phacoemulsification for correction of pre-existing astigmatism

To compare the efficacy of adding an opposite clear corneal incision [OCCI] on the steep meridian versus performing surgery on the steep meridian alone during phacoemulsification in reducing pre-existing corneal astigmatism. This randomized clinical trial was performed on 120 eyes with corneal astigmatism of > 1D undergoing phacoemulsification. Incisions were made based on the type of astigmatism as follows: superior or superior + OCCI for with-the-rule and temporal or temporal + OCCI for against-the-rule astigmatism. Patients were followed with refraction, keratometry and topography. Statistical analysis was performed using one- and two-way ANOVA and Tukey-a test. Mean corneal astigmatism was 1.82 +/- 0.86 D in the superior + OCCI group and 1.74 +/- 0.86 D in the temporal + OCCI group preoperatively which decreased to 1.31 +/- 0.59 [P=0.013] and 1.19 +/- 0.64 [P=0.009] postoperatively respectively. No significant change occurred in the amount of astigmatism in any of the two single incision groups. Paired OCCI on the steep axis is a useful technique to correct mild to moderate pre-existing astigmatism with no need for particular skill or additional instruments