Table 2. Ophthalmologic features of a cohort of 26 individuals with CDD who underwent neurological and ophthalmological evaluations in the CDKL5 clinic at Boston Children’s Hospital.

cpd = cycles per degree; IQR = interquartile range; PL= preferential looking; sVEP = sweep visual evoked potential; y = year

Ophthalmologic clinical characteristics	N(%) or Median [IQR]
Ophthalmologic findings
Diagnosis of cerebral visual impairment, >2 years of age	21/21 (100.0%)
Structural eye abnormalities	0/26 (0.0%)
Nystagmus	10/26 (28.4%)
Strabismus	24/26 (92.3%)
Age at testing and number of visits
Age (y) at first visual acuity assessment (N=24)	1.3 y [0.9, 2.3]
Age (y) at most recent visual acuity assessment (N=24)	3.0 y [1.0, 8.2]
Number of visits with assessment of visual acuity (N=26)	3 [2, 8]
PL acuity testing attempted	24/26 (92.3%)
Patients with measureable PL acuity, N (%)	20/24 (83.3%)
Patients with PL test performed, no response, N (%)	4/24 (16.7%)
Best PL acuity 2 years or older (N=16), median [IQR]	4.6 cpd [1.7, 6.9]
sVEP acuity testing attempted	13/26 (50%)
Patients with measureable VEP acuity, N (%)	13/13 (100%)
Best VEP acuity 2 years or older (N=8), median [IQR]	12.2 cpd [7.1, 16.6]