Date Published: January 23, 2017
Publisher: Public Library of Science
Author(s): Kunho Bae, Kyuyeon Cho, Se Woong Kang, Sang Jin Kim, Jong Min Kim, Simon J. Clark.
To explore the pathogenesis of peripheral reticular pigmentary degeneration (PRPD) and its clinical significance.
This cross-sectional, observational study (conducted between January 2010 and May 2015) enrolled 441 eyes of 229 subjects, including 35 eyes with PRPD and 406 eyes without PRPD, which was identified by ultra-wide-field fluorescein angiography (UWFA). The distribution and angiographic circulation time of PRPD were assessed by UWFA. The frequencies of systemic and ophthalmologic comorbidities were compared between groups. Univariate and multivariate generalized estimation equation methods were used to determine the risk factors for PRPD.
The patients with PRPD had a mean age of 75.7 ± 8.5 years (range, 59–93 years), whereas the patients without PRPD had a mean age of 60.1 ± 14.9 years (range, 9–92 years). All eyes with PRPD manifested the lesion in the superior nasal periphery with or without circumferential extension. Among those, only 16 eyes (45.7%) in the PRPD group showed distinctive features in the same location on fundus photographs. There was significant choroidal filling delay in the PRPD group when compared with the control group (1.42±1.22 vs. -0.02±1.05 seconds, P < 0.001). Multivariate regression analysis revealed that older age (P < 0.001), stroke (P = 0.018), ischemic optic neuropathy (P < 0.001), and age-related macular degeneration (P = 0.022) were significantly associated with PRPD. UWFA may enhance the diagnostic sensitivity of PRPD. Choroidal vascular insufficiency with compromised systemic circulation in the elderly was related to the manifestation of PRPD. These results help to better understand the pathophysiology of PRPD. Co-existence of systemic and ophthalmic circulatory disorders should be considered in patients with PRPD.
Peripheral reticular pigmentary degeneration (PRPD) is an uncommon, distinct, and clinically significant fundus change, although its nomenclature has changed with increased understanding of the disease [1–5]. PRPD is characterized by a reticular pigmentation that forms a polygonal, netlike arrangement of hyperpigmented lines forming geometric patterns in the peripheral fundus. Although preceding reports noted the major ophthalmologic features of PRPD, understanding of its pathogenesis and clinical importance remains incomplete. This is, in part, because further research on PRPD was limited by available visualization techniques for a considerable period of time.
This was a cross-sectional observational study of PRPD. All investigations adhered to the tenets of the Declaration of Helsinki. This study was approved by the institutional review board of the Samsung Medical Center Patient records were anonymized and de-identified prior to analysis.
A total of 481 eyes of 254 patients were assessed with UWFA. Among the participants, 29 eyes of 16 patients were excluded because of prior pan-retinal photocoagulation, 7 eyes of 5 patients were excluded because of media opacity, and 4 eyes of 4 patients were excluded because of blindness. Thus, 35 eyes of 20 patients (9 males and 11 females) with PRPD and 406 eyes of 209 patients (109 males and 100 females) without PRPD were ultimately included in this study (S1 Data).
In this study, bilateral continuous circumferential pigmentary changes in the peripheral retina were identified by UWFA and denominated as PRPD. PRPD has been described under several appellations such as reticular pigmentary degeneration, senile reticular pigmentary degeneration, reticular degeneration of the pigment epithelium, senile peripheral pigmentary degeneration or peripheral reticular pigmentary change [1–5]. Although postmortem studies have reported a considerable incidence of PRPD in Caucasians , yet there has been no report of PRPD in an Asian population. There could be interracial differences in its prevalence. However, the dissimilarity of detection sensitivity related to the fundus pigmentation could also be another explanation. About half of the cases of PRPD diagnosed by UWFA showed no clearly distinguishable reticular pigmentary changes on ultra-wide-field color photography. The result implies that UWFA is a sensitive measure to identify PRPD, at least, in pigmented people.