1 NHS National Services Scotland. â Edinburgh, UK,. 2 National Medical Academy of Postgraduate Education named after P. L. Shupyк of the Ministry of Public ...
Т. 4, № 2(6) – 2016 р.
Архів офтальмології України
Sudi Patel 1, Larysa Tutchenko 2, Oleksiy Voytsekhivskyy 3 NHS National Services Scotland – Edinburgh, UK, 2 National Medical Academy of Postgraduate Education named after P. L. Shupyк of the Ministry of Public Health of Ukraine – Kyiv, Ukraine, 3 Kyiv City Clinical Ophthalmological Hospital “Eye Microsurgery Center” of the Ministry of Public Health of Ukraine 1
AN EVALUATION OF UNEXPECTED REFRACTIVE OUTCOMES FOLLOWING TORIC IOL IMPLANTATION FOR ASTIGMATISM: A SECTOR SUBTRACTION GRAPHICAL METHOD FOR CALCULATING THE EFFECTIVE ASTIGMATIC CORRECTION Aim. To present and test a simple graphical procedure for determining the actual effective astigmatic correction applied after implanting toric intra-ocular lenses using the planned and residual astigmatic corrections. Methods. Nineteen cases where a range of toric intra-ocular lenses were implanted were refracted by objective means one year post-op. Of the 19, 14 cases presented with residual astigmatism ≥0.25DC. Using the presented geometric expression, the actual effective astigmatic correction was calculated for each of the 14 cases. Results. The pre-op planned astigmatic corrections ranged from –1.50DC to –7.50DC. The re-sidual astigmatic values at one year did not exceed –1.75DC. Residual astigmatism resulted from a combination of IOL rotational misalignment (either clockwise or anti-clockwise) coupled with under or overcorrection. The mean (±s.d) rotational misalignment was 1.6° (±7.5°) ranging from 0 to 44°. A significant association between the actual effective cylinder power (y1), planned cylinder power (x1) and sine of planned cylinder axis (x2) was found as follows , y1 = 0.807x1 + 0.199x2 – 0.372 (F= 25.43, r= 0.907, p
