Characteristics of 244 patients with keratoconus seen in an optometric contact lens practice

Abstract

Background:The purpose of this study was to describe the characteristics of keratoconic patients seen in a specialised contact lens practice from a general population with a high prevalence of the disease. Methods: Patients attending a contact lens practice for management of keratoconus were asked to complete a questionnaire. Data were collected on demographic characteristics, general health, family history, eye rubbing, allergy, asthma, eczema, education level, history of keratoplasty and smoking. Results: Two hundred and forty-four patients completed the questionnaire. There was a male bias (54.5 per cent). The majority of the patients (78.7 per cent) wore contact lenses, of whom 67.7 per cent wore hard, 13 per cent soft and 4.2 per cent scleral contact lenses. Some of the patients (21.3 per cent) had undergone corneal graft surgery. Eighteen per cent had an associated systemic disease, the most common of which was type 2 diabetes, although this disease was less prevalent, but not significantly, in the keratoconic sample than in the general population (p = 0.19). The prevalence of eye rubbing (65.6 per cent) was similar to other studies. Compared to the general population, asthma (13.2 per cent) was slightly, but not significantly, less prevalent (p = 0.17), eczema (6.6 per cent) was significantly less (p < 0.001) and allergy (34.4 per cent) was more prevalent (p < 0.001). A high proportion of patients reported a family history of the disease (27.9 per cent) and most were better educated than the general population. Conclusion:The results of this survey concur with those of other studies with regard to most known characteristics of keratoconus; however, the proportion of asthma and eczema tended to be less than in other surveys and may be linked to the environmental influence of a hot and sunny country. The high prevalence of positive family history of the disease in this cohort suggests a genetic influence.

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).…”

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. [40][41][42] The association of eye rubbing was shown to be higher (91.8%) in a cohort of 49 children, deemed secondary to either atopy or induced ametropia.…”

Keratoconus: How Best to Treat it?

“…5,6 Charu Khurana: Which kind of CLs do you recommend in your keratoconus patients and how is the planning and prescription done ? Sudhank Bharti: In mild KC I recommend gas permeable hard contact lenses.…”