Association between keratoconus and atopy.

Abstract

SUMMARY Sixty-seven patients with keratoconus were classified according to atopic status. Keratoconus patients with and without atopy did not differ significantly with regard to sex, age of onset, or rate of keratoplasty, but patients with very high IgE levels were more prone to graft rejection. Atopy was less common in patients with unilateral keratoconus, and keratoconus occurred more frequently on the side of the dominant hand. There was a significantly lower frequency of HLA B7 in the keratoconus group than in the controls. No abnormalities of essential fatty acid metabolism were found in keratoconus patients with or without atopy. There was no social class bias in the group. The study included a brother and sister with keratoconus and atopy, and a non-atopic patient whose identical twin did not have keratoconus.

The Epidemiology and Etiology of Keratoconus

“…31,35 Conversely, reports of monozygotic twins who were discordant for keratoconus have been published. 33,46,47 This can be explained by epigenic, stochastic and environmental factors. In cases in which there was KC discordance in identical twins, eye rubbing and hormonal influences were suggested as possible environmental factors involved in the etiology of KC.…”

Keratoconus: an inflammatory disorder?

“…9,10 However, as many of the patients with ocular allergic diseases rub their eyes excessively, it remained unclear whether atopy itself or eye rubbing was the factor related to keratoconus. Harrison et al 6 found that in atopic keratoconus patients, the disease occurred more frequently on the side of the dominant hand. More recently, in 2000, Bawazeer et al 11 published their results of a case-control study, which showed in the univariate associations that there was an association between keratoconus and atopy, as well as eye rubbing and family history of keratoconus.…”

“…Association between atopy and keratoconus has been identified for more than 50 years, but multiple studies have shown conflicting results. [4][5][6][7][8] Higher levels of serum immunoglobulin E was found in 59% of keratoconus patients in studies performed around 30 years ago. 9,10 However, as many of the patients with ocular allergic diseases rub their eyes excessively, it remained unclear whether atopy itself or eye rubbing was the factor related to keratoconus.…”

Associação do sistema de histocompatibilidade humano com doenças oftalmológicas

“…A apoptose de ceratócitos, que ocorre com freqüência muito maior em córneas com ceratocone do que em córneas normais consiste em um reforço à possível influência genética sobre a doença (44) . O antígeno HLA-B7 é sugerido como marcador de proteção (45) . Ihalainen (1986) realizou a tipagem de antígenos HLA-A, -B e -C em famílias com múltiplos casos de ceratocone (46) .…”