This 85YO female presented with recent vision loss in her right eye. Vision was 20/200 OD and 20/40 OS.
Fundus photography of her right eye shows granular foveal pigmentary changes with a few faint, medium-sized drusen in her left eye.
Swept-source OCT OD shows a shallow, irregular elevation of the foveal RPE with visible Bruch’s membrane. Some cuticular drusen are noted bilaterally. Although the choroid itself is not thickened, large choroidal vessels are seen bilaterally, and choroidal en face imaging shows abnormal, dilated superior anastomotic vortex vessels that drain the entirety of each macula.
Learning Points:
Pachychoroid, meaning “thick” choroid, is secondary to large dilated Haller vessels. Increased oncotic pressure from these dilated vessels can cause RPE dysfunction, serous detachment, and macular neovascularization (MNV).
Our patient has pachychoroid despite having a ‘normal’ choroidal thickness on B-scan OCT. The choroidal thickness depends on numerous factors, including the patient’s age and refractive error. A high myope’s choroid should be quite thin, but if it appears as a ‘normal’ thickness, it is thick for that eye.
We also often see pachychoroid disease in elderly patients whose choroid is abnormally thickened for their age, but appears ‘normally’ thick when not accounting for this.
Originally described by Pang and Freund (Retina 2015;35:1-9), pachychoroid neovasculopathy is a variation of type 1 MNV (located below the RPE). About one-fifth of patients diagnosed with neovascular AMD actually have pachychoroid neovasculopathy (Farvardin et al, Int J Retina Vitreous 2022;8:78), and about one-third of eyes will progress to polypoidal choroidal vasculopathy by 5 years (Siedlecki et al, Ophthalmology Retina 20222;6:807-813).
Although our 85YO patient also has macular drusen, the summation of her findings most likely points to pachychoroid disease as the cause of her MNV. Anti-VEGF therapy was begun.
