TJ-CEO
2008 , Vol 3 , Num 4
The Mid-Peripheral Lens Thickness in Astigmatism
1Texas Üniversitesi, Southwestern Tıp Merkezi, Göz Hastalıkları Bölümü, Dallas - Texas, ABD, Uzm. Dr.2Ankara Üniversitesi Tip Fakültesi Göz Hastalıkları A.D., Ankara, Doç. Dr.
3Ankara Üniversitesi Tip Fakültesi Göz Hastalıkları A.D., Ankara, Prof. Dr. Purpose: To investigate the relationship between astigmatism and mid-peripheral lens thickness.
Materials and Methods: Twenty-six eyes of 19 subjects (10 men, 9 women) with astigmatism (>3.00 D) were included into this prospective study. The mean age of the subjects was 28.8±5.9 years (range: 16 to 39 years). The lens thicknesses of all eyes were evaluated with rotating Scheimpflug imaging system (Pentacam, Oculus GmBH, Germany). The lens thickness measurements were made on lines paralel to the antero-posterior axis from the center of the lens to the mid-periphery with 1 mm intervals. The lens thickness measurements obtained on the steep axis were compared to those obtained on the flat axis.
Results: In 26 eyes, the mean spherical equivalent was -0.53±2.83 D (range: -4.63 D-5.38 D), the mean cylinder was 4.28±0.90 (range: 3.00-6.50) D. The mean keratometry was 43.9±0.7 (range: 42.6-45.2) D and 40.6±0.7 (range: 39.3-42.2) D on the steep and flat axes, respectively. The mean corneal astigmatism was 3.3±0.5 D (range: 2.8-4.9 D) and the mean lenticular astigmatism was 0.78±0.76 D (range: 0.11-1.36 D). No significant difference was observed between the mid-peripheral lens thicknesses on steep and flat axes (p>0.05). There was no significant correlation between the difference in lens thickness on the steep and flat axes and the difference in keratometry on the steep and flat axes (p>0.05), cylindric refraction, and lenticular astigmatism.
Conclusion: There is no significant relationship between astigmatism and mid-peripheral lens thickness. Keywords : Astigmatism, lens, corneal topography, refraction