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Topographic indications of emerging keratoconus in teenage New Zealanders

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


Greg D. Gamble

Nicola K. Boyce

Melissa C Bjornholdt

Lynnell Keung


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
Publication Date Apr 1, 2007
Journal Cornea
Print ISSN 0277-3740
Publisher Lippincott, Williams & Wilkins
Peer Reviewed Peer Reviewed
Volume 26
Issue 3
Pages 312-318
APA6 Citation Boyce, N. K., Bjornholdt, M. C., Gamble, G. D., Owens, H., Gamble, G. D., Bjornholdt, M. C., …Keung, L. (2007). Topographic indications of emerging keratoconus in teenage New Zealanders. Cornea, 26(3), 312-318.
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