Topographic indications of emerging keratoconus in teenage New Zealanders

Gamble, Greg D.; Boyce, Nicola K.; Owens, Helen; Bjornholdt, Melissa C; Keung, Lynnell

Abstract

PURPOSE: To screen a population of teenagers for emerging topographic signs of keratoconus (KC), with particular reference to ethnicity. METHODS: Corneal topography, visual acuity, and an environmental risk factor analysis were included in a screening program designed to identify early indications of potential KC in teenagers. Two schools from central North Island, New Zealand, were invited to participate: one with predominantly Maori/Polynesian students and the other with students of mainly European descent. RESULTS: A total of 198 Maori/Polynesian, 16.8 ± 1.05 years of age, and 243 European students, 16.2 ± 1.3 years of age, participated in the study. Corneal topography suggestive strongly of KC was evident in 3 Maori/Polynesian [1.2%; 95% confidence interval (CI): 0.3-4.3] and no European students (0%; 95% CI, 0%-1.5%). Anomalous corneal topography reminiscent of emerging KC in at least 1 eye were found in 19% (95% CI, 15.6%-22.9%). A significant difference (P = 0.0014) in the percentage of suspected KC was found between European students (12.9%; 95% CI, 9.2%-17.9%) and Maori/Polynesian students (26.9%; 95% CI, 21.0%-33.7%). In multivariate analyses, the significant independent predictors of probable or suspected KC included being Maori/Polynesian [odds ratio (OR) = 2.1; 95% CI, 1.25-3.54; P = 0.0052], increasing age (OR = 1.4; 95% CI, 1.10-1.80; P = 0.0067), and a history of hayfever (OR = 2.0; 95% CI, 1.16-3.59; P = 0.013). Topographical indicators that were associated significantly with suspected KC included central keratometry (P < 0.0001), astigmatism (P = 0.014), and inferior-superior asymmetry (P < 0.0001). CONCLUSIONS: Although only a longitudinal study will determine the proportion of true KC candidates, these data provide evidence of ethnicity-related differences in corneal topography in teenage New Zealanders. © 2007 Lippincott Williams & Wilkins, Inc.

• Journal Article Type: Article
• Acceptance Date: Nov 18, 2006
• Publication Date: Apr 1, 2007
• Deposit Date: Jul 31, 2018
• Journal: Cornea
• Print ISSN: 0277-3740
• Electronic ISSN: 1536-4798
• Publisher: Lippincott, Williams & Wilkins
• Peer Reviewed: Peer Reviewed
• Volume: 26
• Issue: 3
• Pages: 312-318
• DOI: https://doi.org/10.1097/ICO.0b013e31802f8d87
• Public URL: https://uwe-repository.worktribe.com/output/1028566
• Publisher URL: http://dx.doi.org/10.1097/ICO.0b013e31802f8d87
• Contract Date: Jul 31, 2018