Figure 3. Goldmann-Weeker dark adaptation curves at the age 16 and 22 in a female carrier of RPGR ORF15 X-linked retinitis pigmentosa. The rod sensitivity after 30-min dark adaptation is similar at age 16 and age 22. The threshold value is about 2.6 for both curves. However, there is a delay of 3–5 min in the blue curve performed at age 22. This delay occurs about 10 min after the dark adaptation and lasts for about 7 min. Furthermore, at age 16, the dark adaptation final threshold is reached after 14 min, compared to 17 min at age 22. This may indicate a progressive delay in the rod activation kinetics.