Page 180 - Characterization of genetic neurodevelopmental disorders at adult age, with a focus on 22q11.2 deletion syndrome - Emma Boersma

Chapter 6
Figure 1. Fundoscopic retinal images of the right eye.
A) Fundus photograph illustrating a high degree of tortuosity; calculated as arc length divided by
chord length, averaged over all vessels. B) The white arrow depicts the region for measurements of
the central retinal artery and central retinal vein equivalents calculated with the revised Knudtson‐
Parr‐Hubbard formula,22 using the region between 0.5 (inner orange circle; dashed line) and 2.0
(outer blue circle; dashed line) disc diameters from the disc margin (inner blue circle; solid line).
subsections. The global RNFL thickness represents the average thickness
of the six subsections. For measurements of the macula, the early
treatment diabetic retinopathy study grid was used, which consists of 3
concentric circles with diameters of 1, 3 and 6 mm.26 The inner and outer
rings (parafoveal and perifoveal, respectively) were each divided into four
quadrants: superior, inferior, temporal, and nasal. For OCT analyses, the left
eye was used because right eye measurements failed in two adults with
22q11.2DS.
Statistical analysis
Independent samples T-tests were used to compare continuous variables
and Fisher’s exact tests to compare categorical variables between groups.
Pearson correlations were used to test for any effects of age on retinal
vascular parameters and retinal layer thickness. Two-tailed p-values <0.05
were considered statistically significant. All analyses were performed
using the Statistical Package for Social Sciences (SPSS), version 25 (Inc.,
Chicago, IL).
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