Epidemiology of Keratoconus in New Zealand: Aotearoa Research

Into Keratoconus Study Part I

Akilesh Gokul PhD Candidate1

Dr Stuti Misra PhD1; A/Prof Dipika V Patel MRCOphth1; Prof Charles NJ McGhee FRCOphth1

1. Department of Ophthalmology, Faculty of Medical and Health Sciences, University of Auckland, New Zealand National Eye Centre

World Cornea Congress VII 2015

The authors have no financial interests to disclose

The Aotearoa ARK Study: Part I• Purpose: To investigate the incidence,

prevalence, demographic and basic clinical characteristics of keratoconus in New Zealand/Aotearoa

• Prospective, longitudinal epidemiologic study focused on patients managed by optometrists

• Hypothesis: The incidence and prevalence of keratoconus in New Zealand is higher than reported internationally, particularly among Māori and Pacific Peoples

Epidemiology of Keratoconus

• Current prevalence estimates range from 6.8–2300 per 100, 0001-7

• Predominantly retrospective studies

• Mainly hospitals and other tertiary centres

• Variation in estimates due to location and population of interest

• First community based epidemiology study of keratoconus in NZ since Sabiston 19788

The ARK Study: Part I - Methods

• Nation-wide survey of optometrists in New Zealand

• Survey filled in for every patient with keratoconus in 2 year study period (2014-2016)• DOB• Gender• Ethnicity• Established or new diagnosis • Refractive correction• Uncorrected and Best corrected VA

• All patient data are anonymous

Preliminary Results: Age, Gender and New/Existing Diagnosis

• N = 446 patients

• Mean Age = 37.7 ± 15.7 years

• Gender: 58.3% 41.7%

• New/Existing: Existing 83.2% New 16.8%

Auckland 25.6%

Wellington 25.6%

Bay of Plenty 28.7%

Otago 4.3%

Manawatu-Wanganui 4.3%

Taranaki 1.1%

Canterbury 3.6%

Waikato 0.7%

Gisborne 3.4%

Nelson 2.9%

Distribution of Keratoconus Across New Zealand by Region

Distribution by Ethnicity

2013 New Zealand Census:

• New Zealand European 74%

• Māori 14.9%

• Pacific peoples 7.4%

New Zealand Eu-ropean56.2%

Māori24.0%

Pacific Island9.6%

Other4.8%

Indian3.4%

New Zealand European/Māori

2.1%

Types of Refractive Correction

RGP28.2%

Spectacles21.7%Semi-Scleral

15.2%

No Correction11.0%

Soft Contact Lens9.8%

Hybrid Contact Lens7.6%

Piggyback Contact Lens 6.5%

0.000

0.100

0.200

0.300

0.400

0.500

0.600

0.700

0.800

0.900

LogMAR

Unaided Vision and Visual Acuity

20/140

20/30

N = 655 eyes

Mean Unaided VA

N = 835 eyes

Mean Best Corrected VA

• Largest prospective, longitudinal study of epidemiology of keratoconus in NZ to date

• n = 446 patients (>450 per year)

• Relatively young population

• Male and existing diagnosis predominance

• Mostly Auckland, Bay of Plenty and Wellington

• Māori and Pacific ethnicities over represented

• Relatively poor uncorrected vision but good visual potential with refractive correction

The ARK Study: Part I - Preliminary Conclusions

References

1. Ljubic AD. Keratoconus and Its Prevalence in Macedonia. Macedonian Journal of Medical Sciences 2009 2(1):58-62.

2. Brookes NH, Niederer RL, Hickey D, McGhee CN, Sherwin T. Recurrence of keratoconic pathology in penetrating keratoplasty buttons originally transplanted for keratoconus. Cornea 2009;28(6):688-93.

3. Rabinowitz YS. Keratoconus. Surv Ophthalmol 1998;42(4):297-319.

4. Nielsen K, Hjortdal J, Aagaard Nohr E, Ehlers N. Incidence and prevalence of keratoconus in Denmark. Acta Ophthalmol Scand 2007;85(8):890-2.

5. Ziaei H, Jafarinasab MR, Javadi MA, et al. Epidemiology of keratoconus in an Iranian population. Cornea 2012;31(9):1044-7.

6. Kennedy RH, Bourne WM, Dyer JA. A 48-year clinical and epidemiologic study of keratoconus. Am J Ophthalmol 1986;101(3):267-73.

7. Jonas JB, Nangia V, Matin A, Kulkarni M, Bhojwani K. Prevalence and associations of keratoconus in rural maharashtra in central India: the central India eye and medical study. Am J Ophthalmol 2009;148(5):760-5.

8. Sabiston DW. The crazy cone. Australian Journal of Ophthalmology. 1978;6:43-45.

Acknowledgements

• Participating optometrists

• New Zealand Association of Optometrists

• Cornea & Contact Lens Society of New Zealand

• New Zealand National Eye Centre Supervisory Team