AUTHOR=Yang Kaili , Fan Qi , Xu Liyan , Gu Yuwei , Pang Chenjiu , Ren Shengwei 

TITLE=Accuracy of tomographic and biomechanical parameters in detecting unilateral post-LASIK keratoectasia and fellow eyes

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=Volume 11 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2023.1181117

DOI=10.3389/fbioe.2023.1181117

ISSN=2296-4185

ABSTRACT=Background: Patients with unilateral post-LASIK keratectasia (KE) have clinical ectasia in one eye but not in the fellow eye. As serious complications, these cases are rarely reported but are worth investigating. This study aimed to explore the characteristics of unilateral KE and the accuracy of corneal tomographic and biomechanical parameters to detect KE and distinguish fellow eyes from control eyes. 
Methods: The study analyzed 23 KE eyes, 23 KE fellow eyes, and 48 normal eyes from age- and sex-matched patients who had undergone LASIK. Kruskal-Wallis test and further paired comparisons were performed to compare the clinical measurements of the three groups. The receiver operating characteristic curve was used to evaluate the ability to distinguish KE and fellow eyes from the control eyes. Binary logistic regression with the forward stepwise method was performed to produce a combined index, and the Delong test was used to compare the discriminability difference of the parameters.
Results: Males accounted for 69.6% of patients with unilateral KE. The duration between corneal surgery and the onset of ectasia ranged from 4 months to 18 years, with a median time of 10 years. KE fellow eye had a higher posterior evaluation(PE) value compared to the control eyes(5 vs. 2, P = 0.035). Diagnostic tests showed that PE, posterior radius of curvature (3 mm), anterior evaluation(FE), and Corvis biomechanical index–laser vision correction(CBI-LVC) were sensitive indicators for distinguishing KE in the control eyes. The ability of PE to detect KE fellow eye from control eye was 0.745 (0.628, 0.841), with 73.91% sensitivity and 68.75% specificity at a cut off value of 3. The ability of a combined index, constructed using PE and FE, to distinguish fellow eyes of KE from controls was 0.831(0.723, 0.909), which was higher than that of PE and FE individually(P < 0.05).
Conclusion: The fellow eyes of patients with unilateral KE had significantly higher PE values than control eyes, and a combination of PE and FE enhanced this differentiation in a Chinese population. More attention should be paid to the long-term follow-up of patients after LASIK and to be wary of the occurrence of early KE.