Abstract
Purpose :
Keratoconus is a type of corneal ectasia which induces progressive thinning and steepening of the cornea. It has a wide range of severity, from infra-clinical disease to severe corneal scarring. Keratoconus is usually bilateral, but often asymmetric in terms of severity. Our purpose is to identify risk factors associated with asymmetry in keratoconus severity.
Methods :
This single-center observational study included patients with a confirmed diagnosis of keratoconus from the outpatient ophthalmology clinic of the Metz-Thionville Regional Hospital. Patients were questioned about their personal history of atopy, family history of keratoconus, age at diagnosis, hand dominance, sleeping position, eye-rubbing habits and screen time. They underwent slit-lamp examination, anterior-segment OCT and corneal Scheimpflug topography. Keratoconus severity was graded using the Amsler-Krumeich classification and the Sandali OCT classification. Patients with asymmetric keratoconus (difference higher than 1 in Krumeich stage between both eyes) were grouped according to the side of their most affected eye, namely "right" and "left", and compared with patients with "symmetrical" keratoconus (no difference in Krumeich stage between both eyes). Multinomial uni- and multivariate regression analysis was performed.
Results :
Our study included 121 patients for analysis, with 81 males (67%) and a median age of 28 years old. 89 (74%) had bilateral keratoconus, and 32 patients had unilateral keratoconus either in their left eye (21; 17%) or right eye (11; 9%). 23 patients (19%) had family history of keratoconus and 59 (49%) had personal history of atopy. 35 patients had "symmetrical" keratoconus, whilst 50 had a more severe disease in their left eye and 36 in their right eye. Our results show that right hand dominance was positively associated with having asymmetric keratoconus with a higher severity on the right eye, compared to patients with bilateral symmetrical keratoconus (OR > 999; [>999; >999], p < 0.001). No association was found between sleeping positions and keratoconus asymmetry.
Conclusions :
The laterality of hand dominance is associated with the side of the most severely affected eye in patients with asymmetrical keratoconus. Our results further corroborate the role of eye-rubbing in keratoconus. Further studies with a larger population will be needed to confirm our results.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.