Is Consanguinity a Risk Factor for Keratoconus?

Abstract

This study supports the hypothesis that consanguinity is a significant risk factor for KC and provides strong support for a genetic contribution to the disease. Wearing sunglasses in this environment is beneficial, and the study confirmed that eye rubbing, allergy, and education are also significantly associated with KC after adjusting for other predictors.

Effect of Allergic Diseases on Keratoconus Severity

“…In contrast to our findings, there are other studies in the Middle East which did not find a significant association between asthma and eczema with KC. 20,21 In Sharma et al 28 study the prevalence of VKC and AC was significantly lower than in our findings (10.8% and 1.7%, respectively). Shneor et al 20 evaluated 244 KC patients attending a contact lens clinic and reported that asthma and eczema were significantly less prevalent, whereas allergy was significantly more prevalent in KC patients in comparison with the general population (p<0.001).…”

“…[7][8][9]13,15,[19][20][21][22][23] Several studies have found a significantly higher prevalence of allergic diseases in KC patients in comparison with normal control subjects 13,15,19-21 but some case-control studies 8 did not. These conflicting results may be due to different definitions of allergy and different classification of allergic diseases.…”

“…[5][6][7]13,15,19,22,23 The percentage of the allergy, asthma, and eczema in various studies is demonstrated in Table 4. 13,15,[19][20][21][22][23][24][25][26][27] In a recent study by Merdler et al, 6 who investigated various allergic diseases, a statistically significant difference was found between 807 KC patients and the general population regarding asthma, allergic rhinitis, and the combination of VKC/AC/chronic blepharitis, but no significant association was found between urticaria, eczema, angioedema, history of anaphylaxis, and allergy to hymenoptera. Nemet et al 13 evaluated the relationship between KC and immune disorders in 426 patients and 1704 controls, and revealed that asthma and environmental allergy were significantly associated with KC (p<0.05).…”

Keratoconus: an inflammatory disorder?

“…On the other hand, consanguinity have been associated with a higher risk of development of keratoconus. 39,49 Recently, Kriszt et al 50 performed a segregation analysis of 60 unrelated sporadic keratoconus families and suggested that this type of keratoconus is a complex non-Mendelian disease. However, genetics does not seem to be the only factor in keratoconus, and as many researchers have suggested it is very probable that the vast majority of cases are the result of patients exhibiting genetic predisposition triggered by environmental factors.…”

Eye Rubbing and Keratoconus: A Literature Review

“…38 Another paper surveyed 240 patients with known keratoconus and showed 65.6% had a history of eye rubbing when questioned. 39 Similar incidences of eye rubbing in cohorts of keratoconus patients have been shown in other studies.…”