Abstract
Purpose :
Choroideremia is an X-linked retinal dystrophy characterized by progressive chorioretinal atrophy. Recently, a novel observation of focal scleral excavations, termed “scleral pits,” was reported in patients with choroideremia (van Schuppen et al., 2017). This study aims to characterize the frequency of scleral pits and correlate their presence with measures of disease severity.
Methods :
This was a retrospective chart review of consecutive patients with molecularly confirmed choroideremia seen at the University of Iowa. Age, gender, visual acuity, and genotype were recorded for each patient. Clinical testing, including Goldmann visual fields, color fundus photographs, and optical coherence tomography were reviewed, and the presence of scleral pits on color fundus photographs determined by two independent graders. For patients with longitudinal data, the patient’s vision and age at the earliest visit where a scleral pit was seen were also recorded.
Results :
Sixty eyes from 30 patients, including 9 disease-manifesting female carriers, were analyzed. Scleral pits were seen bilaterally in 7 out of 21 (33%) male patients and in none of the female carriers. Patients with scleral pits were noted to be older at the time of earliest pit visualization than those without pits (mean age 44.3 versus 34.0 years, respectively). Additionally, patients with scleral pits were noted to have worse vision on average (logMAR 0.749; Snellen 20/112) than those without pits (logMAR 0.383; Snellen 20/48). In patients with scleral pits, 6 out of 7 patients had Goldmann visual fields available, with one patient unable to perform fields due to light perception vision. Eyes with scleral pits had more severe visual field loss, with absence of the I2e isopter in 58.3% of eyes (7/12) and less than 20 degree central field to the V4e in 83.3% of eyes (10/12), compared to 21.9% (7/32 eyes) and 31.3% (10/32 eyes) respectively for those without visible pits. Notably, in 2 patients, the formation and progression of scleral pits were observed with serial fundus photography.
Conclusions :
Scleral pits are relatively common in patients with choroideremia. These pits likely represent degeneration at areas of focal scleral weakness (e.g. the insertion of the long posterior ciliary arteries) and are seen in eyes with more severe disease. Further study is needed to evaluate possible genotype-phenotype correlations for this peculiar fundus finding.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.