Suzanne de Bruijn

84 Chapter 2 Clinical evaluation Clinical data were collected from the medical records of two patients from Family A (A-II:1, A-II:2) and one patient from Family B (B-II:1). An overview of the clinical characteristics of the three affected individuals with damaging KIAA1549 variants at the most recent examination is provided in Table 1 and clinical images of patient A-II:2 and B-II:1 are shown in Figure 2 . All affected individuals were diagnosed with RP. They all initially experienced night blindness, followed by a gradual decline of their visual fields and visual acuity. The age of onset varied from the first decade (patient A-II:1) to the fifth decade (patient B-II:1) and all patients were myopic. Cortical cataract was observed in patient A-II:1 (age 38), whereas patient A-II:2 underwent a cataract extraction at the age of 38 (right eye) and 52 years (left eye). Ophthalmoscopy revealed characteristic RP features in all three patients, including attenuated retinal vessels, waxy pallor of the optic disc, and bone spicule pigmentation ( Figure 2A , 2D ). In addition, nummular deep pigmentations were visible in the mid-periphery. SD-OCT imaging in patient A-II:2 showed profound atrophy of the outer retinal layers with preservation of the photoreceptors in the fovea. This patient was treated for Coats-like exudative vasculopathy related to her RP in the past. Fundus autofluorescense imaging in patient B-II:1 showed the characteristic hyperautofluorescent ring that represents the transition zone between intact and degenerated photoreceptor outer segments, corresponding with a preserved ellipsoid zone within the ring on SD-OCT, and loss of the ellipsoid zone external to the ring ( Figure 2E-F ).