1. Bawazeer AM, Hodge WG, Lorimer B . Atopy and keratoconus: a multivariate analysis. Br J Ophthalmol 2000; 84: 834–836.
2. Family Health Service Register. Calderdale and Kirklees Health Authority, Patient Index Data Base. St Luke's House, Huddersfield, September 2000.
3. Kenyon RK, Hersh PS, Starck T, Fogle JA . Corneal dysgenesis, dystrophies and degenerations. In: Tasman W, Jaeger E (eds). Duane's Ophthalmology. Lippincott Williams & Wilkins: Baltimore, 1997; 4(16): 1–53.
4. Pearson AR, Soneji B, Sarvananthan N, Sandford-Smith JH . Does ethnic origin influence the incidence or severity of keratoconus? Eye 2000; 14(Part 4): 625–628.
5. Ihalainen A . Clinical and epidemiological features of keratoconus: genetic and external factors in the pathogenesis of the disease. Acta Ophthalmol 1986;178(Suppl): 5–64.