Case Study of the Month - November 2023
Karen is a 53-year-old Caucasian woman who presents with a 6-month history of “hundreds of floaters,” decreased vision, and nyctalopia. Examination confirms poor dark adaptation, moderate vitreous cell, mild disc edema, and cystoid macular edema. Her VA and IOP are normal. A photograph of the patient's fundus is shown. Testing for which of the following human leukocyte antigens is most likely to prove informative? Also consider what the other ophthalmic diseases the other HLAs are associated with.
A: HLA B51
B: HLA A29
C: HLA B27
D: HLA B5
The correct answer is HLA-A29. The findings in this case are consistent with a diagnosis of birdshot chorioretinopathy (BSCR). BSCR is an idiopathic posterior uveitis that is more common 3 in Caucasian women, and typically presents in the sixth decade of life. Early symptoms include floaters from mild vitritis as well as decreased vision from cystoid macular edema. Chronic disease is associated with nyctalopia and decreased color vision. The fundus photograph above is typical for the disease with numerous roughly 300 micron hypopigmented spots scattered throughout the fundus. Optical coherence tomography is important to document CME, and can be used to follow vitreous cell in the infrared image. Fluorescein angiography reveals the chorioretinitis with early hypofluorescence and late staining in the location of the spots, as well as optic nerve inflammation. BSCR has a strong association with the human leukocyte antigen HLA-A29 (96% of patients are carriers). Patients can be managed with systemic corticosteroids (prednisone) once infectious etiologies are ruled out, but it is often preferable to treat locally with intravitreal corticosteroids such as Ozurdex. With good control, patients can do well for a very long time.
Figure. Color fundus photograph of a patient with BSCR revealing multiple hypopigmented spots. The SDOCT reveals no CME, but shows loss of detail in the ellipsoid zone of the outer retina as well as shadowing from vitreous opacities. Late frame fluorescein angiography reveals staining of the hypopigmented spots as well as leakage of both optic nerves.
Best wishes, and until next time,
Nikolas London, MD, FACS
President and Director of Research, Retina Consultants San Diego
Chief of Ophthalmology, Scripps Memorial Hospital La Jolla