Fan Zhang1,2, Jian Zhang3, Wei Li4, Lin Zhou5, Di Feng6, Haixia Zhang7,8, Wei Fang2, Ran Sun2, Zhicheng Liu7,8. 1. Department of Ophthalmology, Qingdao Women and Children Hospital, Qingdao University, Qingdao, China. 2. Department of Ophthalmology, Xuanwu Hospital, Capital Medical University, Beijing, China. 3. Department of Ophthalmology, Xuanwu Hospital, Capital Medical University, Beijing, China, drzhangjian@vip.163.com. 4. Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida, USA. 5. Department of Ophthalmology, First Hospital of Tsinghua University, Beijing, China. 6. School of Instrumentation Science and Optoelectronics Engineering, Beihang University, Beijing, China. 7. Biomechanics, School of Biomedical Engineering, Capital Medical University, Beijing, China. 8. Biomechanics, Beijing Key Laboratory of Basic Research on Biomechanics in Clinical University, Beijing, China.
Abstract
PURPOSE: To evaluate which ocular axis, the corneal topographic axis (CTA), pupillary axis (PA) or line of sight (LOS), for measuring the tilt and decentration of intraocular lens (IOL) is most relevant to correct distance visual acuity (CDVA). METHODS: A Scheimpflug device (Pentacam HR) was prospectively used to determine the tilt and decentration of IOLs in vivo 3 months after cataract surgery. A new method was developed to reliably measure PA and LOS. We further evaluated CTA and then used Spearman correlation coefficient and linear regression to assess the correlation between CDVA and IOL displacement based on the data of three different ocular axes. RESULTS: Forty-six eyes from 46 patients were evaluated. The majority of decentration and tilt of IOL with reference to CTA, PA and LOS were towards the subtemporal direction. We found that the horizontal meridian data measured using CTA and PA were statistically significantly different (p = 0.011 for tilt; p = 0.005 for decentration). The correlation between CDVA and the distance of decentration temporally (r = -0.344, p = 0.035) and inferiorly (r = -0.336, p = 0.042) of the IOL with regard to CTA was significant. PA and LOS measurements had no correlation with any indices. CONCLUSION: Assessment of tilt and decentration of the IOL with reference to different ocular axes was markedly different. IOL tilt and decentration measured by CTA were significantly correlated with CDVA.
PURPOSE: To evaluate which ocular axis, the corneal topographic axis (CTA), pupillary axis (PA) or line of sight (LOS), for measuring the tilt and decentration of intraocular lens (IOL) is most relevant to correct distance visual acuity (CDVA). METHODS: A Scheimpflug device (Pentacam HR) was prospectively used to determine the tilt and decentration of IOLs in vivo 3 months after cataract surgery. A new method was developed to reliably measure PA and LOS. We further evaluated CTA and then used Spearman correlation coefficient and linear regression to assess the correlation between CDVA and IOL displacement based on the data of three different ocular axes. RESULTS: Forty-six eyes from 46 patients were evaluated. The majority of decentration and tilt of IOL with reference to CTA, PA and LOS were towards the subtemporal direction. We found that the horizontal meridian data measured using CTA and PA were statistically significantly different (p = 0.011 for tilt; p = 0.005 for decentration). The correlation between CDVA and the distance of decentration temporally (r = -0.344, p = 0.035) and inferiorly (r = -0.336, p = 0.042) of the IOL with regard to CTA was significant. PA and LOS measurements had no correlation with any indices. CONCLUSION: Assessment of tilt and decentration of the IOL with reference to different ocular axes was markedly different. IOL tilt and decentration measured by CTA were significantly correlated with CDVA.