Page 162 - Demo

Chapter 5160DiscussionThe results of our study indicate that ocular findings are frequently present in patients with 22q11.2DS. We report on ocular findings in the largest cohort of 22q11.2DS patients to date. Importantly, VA was (near) normal in almost all patients. Severe visual impairment was reported for two children, one with Peters’ anomaly and one with keratoconus, posterior subcapsular cataract and tapetoretinal degeneration with a suspected second genetic hit. It is important to detect visual impairment because of its impact on language and communication development and for its negative effect on psychiatric illness such as depression or anxiety.18, 19 Patients with intellectual disabilities and visual impairment may have an atypical presentation, such as self-injurious behavior or functional deterioration.20 Also, fatigue and headaches are common in 22q11.2DS,21 and may be caused by visual impairment in some cases. When measuring VA of patients with 22q11.2DS, cognitive abilities should be taken into account. We found a high prevalence of moderate to severe hyperopia, especially in children with 22q11.2DS aged six years and older, compared to children and adults in the general population and also children with intellectual disabilities.22-24 Studies in the general population have shown that emmetropisation takes place during early development resulting in a reduction and stabilization of refractive errors in early teenage years,25, 26 which was not the case in our cohort. A possible reason for the high prevalence of hyperopia may be that the axial length of the eye is too short relative to the refractive power of the lens or cornea because of a delay in growth. Also, lag in accommodation has been found in children with severe hyperopia in the general population and may have contributed to the high prevalence of moderate to severe hyperopia in our study.27 In addition, the prevalence of astigmatism in children and adults with 22q11.2DS was much higher compared to the general population and compared to adults with intellectual disabilities.23, 28 Also, in our cross-sectional study, high astigmatism was more frequently present compared to previous studies in 22q11.2DS. This may be explained by a higher inclusion rate of adults in our study, in whom astigmatism was found more often. Against-the-rule