The Epidemiology of Keratoconus in New Zealand – The ARK Study Part I – Update 2015

Akilesh Gokul

Meeting:  2015 RANZCO


Date:      -

Session Title: Uveitis/Genetics/Epidemiology Rapid Fire

Session Time:      -

Purpose: To investigate the epidemiologic, demographic and clinical characteristics of patients with keratoconus managed by optometrists in New Zealand (NZ)/Aotearoa.

Method: The ARK study: Part I, consists of a prospective, longitudinal, nationwide, survey of optometrists in NZ/Aotearoa. Participating optometrists (N=100) agreed to complete the survey protocol for every patient with keratoconus that underwent a consultation in a 2-year period (2014-2016). Data requested for each patient includes: date of birth, gender, self-reported ethnicity, new or existing diagnosis, types of refractive correction employed, uncorrected (UVA) and best corrected visual acuity (BCVA). Data collected at 18 months (up to June 2015) has been analysed.

Results: N=549 patients. The mean age was 37.7 ± 15.7 years (59.4% male) and 81.8% had an existing diagnosis. The distribution of cases across NZ was skewed toward Auckland (28.2%), Wellington (29.0%) and Bay of Plenty (23.9%). Self-reported ethnicities were predominantly; NZ European (54.2%), M_ori (24.2%), and Pacific Island Nations (11.5%), which are disproportionate compared to the 2013 NZ Census data (74.0%, 14.9%, and 7.4% respectively). Most eyes were managed with contact lenses (28.2% rigid, 15.2% Semi-scleral, 7.6% hybrid). The mean UVA was 6/49 and BCVA was 6/9.

Conclusion: Preliminary results indicate that the number of patients with keratoconus managed by community optometrists in New Zealand likely exceeds 550 over the entirety of the study period. There appears to be an ethnic predilection with M_ori and Pacific Island Nations ethnicities over represented relative to their overall population proportions.