Abstract
Purpose: :
Bilateral diffuse uveal melanocytic proliferation (BDUMP) is a rare paraneoplastic syndrome whose choroidal histopathology has been well-characterized; however, the effects on the adjacent retina have not been well-described. The purpose of this study is to evaluate changes in the photoreceptors, horizontal cells, bipolar cells, and amacrine cells in a patient with bilateral diffuse uveal melanocytic proliferation.
Methods: :
The retina and choroid of a patient with BDUMP and a normal control were processed for immunohistochemistry and confocal microscopy. Cell-specific antibodies were used to the following proteins: recoverin (photoreceptors and cone on-bipolar cells), PNA (cone outer segments and pedicles), protein kinase C (rod bipolar cells), TRPM1 (rod and cone on-bipolar cells), calbindin D (horizontal cells), calretinin (amacrine cells), and SV2 and Vglut (synaptic vesicles).
Results: :
The patient with BDUMP had a complete loss of calbindin-D immunoreactivity in the inner retina. Positive staining, comparable to controls, was obtained with all other antibodies.
Conclusions: :
BDUMP is associated with an absence of calbindin D immunoreactivity in the retina, indicating a selective effect of this disease on horizontal cells, including a possible loss of horizontal cells. Horizontal cell loss may contribute to the decreased vision in patients with BDUMP.
Keywords: pathology: human • retina: distal (photoreceptors, horizontal cells, bipolar cells) • melanocytes