Association between atopic keratoconjunctivitis and the risk of keratoconus.


Weng SF(1)(2)(3), Jan RL(4)(5), Wang JJ(6)(7)(8), Tseng SH(9)(10), Chang YS(5)(10).
Author information:
(1)Department of Healthcare Administration and Medical Informatics, College of Health Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan.
(2)Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
(3)Center for Medical informatics and Statistics, Office of R&D, Kaohsiung Medical University, Kaohsiung, Taiwan.
(4)Department of Pediatrics, Chi Mei Medical Center, Liouying, Tainan, Taiwan.
(5)Graduate Institute of Medical Science, College of Health Science, Chang Jung Christian University, Tainan, Taiwan.
(6)Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan.
(7)Department of Anesthesiology, Chi Mei Medical Center, Tainan, Taiwan.
(8)AI Biomed Center, Southern Taiwan University of Science and Technology, Tainan, Taiwan.
(9)Department of Ophthalmology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
(10)Department of Ophthalmology, Chi Mei Medical Center, Tainan, Taiwan.


PURPOSE: To investigate the risk of keratoconus (KCN) in patients with atopic keratoconjunctivitis (AKC). METHODS: This nationwide, retrospective, matched cohort study included 186 202 newly diagnosed AKC patients who were identified by the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), code 372.05, and selected from the Taiwan National Health Insurance Research Database. The age- and sex-matched control group included 186 202 non-AKC patients selected from the Taiwan Longitudinal Health Insurance Database 2000. Patient information was collected between 1 January 2004 and 31 December 2011, and both groups of patients were tracked from the index date until December 2013. The incidence and risk of KCN (ICD-9-CM, code 371.6) were compared between the groups. A Cox proportional hazard regression analysis was performed to obtain the adjusted hazard ratio (HR) for KCN. The cumulative KCN incidence rate was calculated with the Kaplan-Meier analysis. RESULTS: In total, 62 AKC patients and 26 controls developed KCN during the follow-up period. The incidence rate of KCN was 2.49 times (95% confidence interval [CI] = 1.57-3.93; p < 0.0001) higher in AKC patients than in controls. After adjusting for potential confounders, AKC patients were 2.25 times more likely to develop KCN than controls (adjusted HR, 2.25; 95% CI = 1.41-3.58; p < 0.05). CONCLUSION: Atopic keratoconjunctivitis (AKC) patients had an increased risk of developing KCN. Therefore, AKC patients should be advised of this risk.