Abstract
Purpose :
Recently, macrophage-like cells (MLC) have been visualized on the surface of the human retina using clinical optical coherence tomography (OCT) systems. Normal eyes demonstrate very few cells in the macula, while eyes with diabetes have been shown to have MLCs in the macula. We aimed to analyze these cells in the macula of syphilis patients before and after antibiotic treatment.
Methods :
We retrospectively analyzed OCT images of 5 patients (10 eyes) who were diagnosed with uveitis secondary to neurosyphilis. Patients were initially imaged for clinical purposes using the Cirrus HD-OCT (Carl Zeiss Meditic, Dublin, CA). All available patient OCT images were analyzed from initial diagnosis, during antibiotic treatment, and after antibiotic treatment. MLCs were visualized by segmenting slabs above the inner limiting membrane (ILM) using the en-face view of the macula on OCT cubes. For each image, slabs were taken at various distances from 3 μm to 25 μm above the ILM at various slab thicknesses (3 μm to 15 μm). A total of 12 different thickness and offset settings were analyzed for each image.
Results :
Prior to antibiotic therapy, all patients showed numerous MLCs on the retinal surface in the macula. After treatment, there was significant reduction and often complete resolution of these cells. In addition, using various thickness and offset settings to generate OCT slabs revealed varying levels of cells, vasculature artifacts, and background noise depending on the settings used. The ideal settings which minimized background signal and vasculature, while allowing clear visualization of the MLCs, were different for each patient and for each eye.
Conclusions :
Our study was able to visualize and characterize changes in MLCs throughout treatment using OCT, which has never been reported in patients with uveitis of any type. In addition, there is no current consensus on the optimal offset and thickness settings for generating OCT slabs that best isolate these cells. Previous literature has used various settings on different OCT systems to visualize these cells. Our analysis shows that the ideal offset and thickness of OCT slabs may be patient-specific when imaged using the Cirrus HD-OCT. Further research is needed to determine what setting would be most optimal for each patient.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.