Abstract
Including posterior corneal astigmatism (PCA) into consideration may increase the accuracy of astigmatism correction after corneal refractive surgery. In the present study we aim to investigate the distribution pattern of PCA in a large number of myopic patients from multiple ophthalmic centers. There were 7829 eyes retrospectively included in the study. Pentacam data of the eyes were retrieved from the machine and only results with image quality labelled with ‘OK’ were included. Distribution of PCA was slightly positively skewed (Skewness = 0.419, Kurtosis = 0.435, KS P < 0.0001). Mean PCA was 0.34 ± 0.14 D (range: 0.00 D-0.99 D). PCA was ≥ 0.25 D in 74.91% of the eyes and was ≥ 0.50 D in 11.61% of the eyes. In 97.55% of the eyes the steep meridian of PCA was vertical (SMV). PCA magnitude was significantly higher in eyes with SMV PCA (P < 0.0001) or high manifest astigmatism (MA, P < 0.0001). There was a significant correlation between anterior corneal astigmatism (ACA) magnitude and PCA magnitude in all of the eyes (r = 0.704, P < 0.0001). There was also a trend of decreasing frequency and magnitude of SMV PCA with aging (both P < 0.0001). In conclusion, PCA is present in myopic patients having corneal refractive surgery and PCA magnitude is increased with higher MA or ACA. Consideration of the impact of PCA on laser astigmatism correction may be necessary.
Highlights
Including posterior corneal astigmatism (PCA) into consideration may increase the accuracy of astigmatism correction after corneal refractive surgery
There was a significant correlation between anterior corneal astigmatism (ACA) magnitude and PCA magnitude in all of the eyes (Fig. 2; r = 0.704, P < 0.0001)
In the present multicenter study, we demonstrated the distribution pattern of PCA in myopic patients from different parts of mainland China (GZ from the south, Shenyang Aier Eye Hospital (SY) from the northeast, Chengdu Aier Eye Hospital (CD) from the southwest, Wuhan Aier Eye Hospital (WH) and HK from the central)
Summary
Including posterior corneal astigmatism (PCA) into consideration may increase the accuracy of astigmatism correction after corneal refractive surgery. In corneal laser surgery such as laser in situ keratomileusis (LASIK), correction of corneal astigmatism is often performed based on the ACA3 This method is not entirely unproblematic if the patients have a significant ocular residual astigmatism (ORA) of which PCA is one of the major c omponents[4]. It is of clinical importance to investigate the PCA distribution in patients having corneal refractive surgery Another scenario where PCA may need to be taken into consideration is astigmatism correction by cataract surgery. We aim to investigate the distribution pattern of PCA in Chinese myopic patients having corneal refractive surgery by pooling together the data from multiple ophthalmic centers
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
