Abstract
Purpose :
Approximately 20% of keratoconus patients have a familial history of the disease, and they may belong to a particular keratoconus group. This study aims to describe patients with a familial history of keratoconus and the number of affected members and surgical treatments already performed, both in the patients and their relatives.
Methods :
A spontaneous series of keratoconus subjects with a familial history of keratoconus were included in this study. Demographic, clinical and tomographic data (mean and maximum keratometry, and thinnest corneal thickness), by the use of Pentacam, best-corrected visual acuity (BCVA), spherical equivalent (SE) refractometry of the right eyes (RE), and data from affected family members (number of family members and their surgical history of corneal transplantation). Continuous data were described as median (interquartile ranges).
Results :
Fifty-six patients were included from April to October 2019. The mean age at first attendance was 18.7(14.7-23.4), and the self-reported age at diagnosis was 17 (14-20) years. Twenty-nine (52%) were male. Right eye log mar BCVA was 0.4(0.3-0.6), and SE refractometry was -3.50(-6.50—2.25). Keratometric values showed Km of 49.60(47.05-53.25), Kmax of 59.80 (53.35-63.55), and thinnest pachymetry of 452.5 (420.5-470) and 64% of them had Kmax greater than 55 D. Seven patients (12.5%) were submitted to corneal transplantation. The most frequent clinical findings were palpebral laxity in 23 (41%), itching in 37 (66%), rhinitis in 18 (32%), asthma in 8 (14%), and obesity in 7 (12.5%). There were 109 self-related affected family members, 52 (48%) were first degree, 18 (16%) were second degree, and 39 (36%) were third-degree relatives. Twelve relatives (11%) had been corneal transplanted for keratoconus. Twelve (21%) patients with keratoconus in this series had three or more relatives with keratoconus.
Conclusions :
This study shows that there are approximately 2.0 self-related relatives for each patient with a familial history of keratoconus. The clinical findings show that atopy seems to play a critical whole even in patients with familial history. A group of patients with familial history has an autosomal dominant pattern of inheritance with variable expressivity in some families.
This is a 2020 ARVO Annual Meeting abstract.