Abstract
Purpose :
To study superficial and deep retinal capillary plexus integrity using optical coherence tomography angiography (OCTA) in patients with chronic uveitis and macular thinning as seen on spectral domain optical coherence tomography (OCT).
Methods :
All patients with chronic uveitis and macular thinning less than or equal to 270 microns on OCT (central retinal thickness, CRT) were included in the study between January 1 & October 31, 2017. Clinical characteristics and patient demographics were recorded for all patients. The foveal avascular zone (FAZ) was measured in the deep (DCP) and superficial retinal capillary plexuses (SCP) on OCTA for all patients in both eyes, ImageJ was used to calculate the area of the FAZ in pixels2. Statistical analysis using simple linear regression was performed to test the association of CRT on OCT with area of FAZ on OCTA in the deep and superficial retinal capillary plexuses and with visual acuity (Snellen and logarithm of minimum angle of resolution [logMAR]). In separate models, CRT was the independent variable with logMAR, DCP and SCP as the dependent variables.
Results :
A total of 32 eyes from 17 patients were included in the study. Snellen visual acuity ranged from 20/15 to 20/200, average logMAR 0.2631 (standard deviation [SD] 0.26). Average central retinal thickness was 198 microns (SD 33 microns, range 120-270 microns), average DCP area was 11449 pixels2 (SD 8164 pixels2, range 1607 to 39370 pixels2), and average SCP area was 21947 pixels2 (SD 13652 pixels2, range 4812 to 71130 pixels2). Linear regression analysis showed that central retinal thickness is inversely associated with both logMAR visual acuity (p = 0.0046) and SCP area (p = 0.0197), but not with DCP area (p = 0.7112).
Conclusions :
Patients with chronic uveitis and thinner maculas on OCT tend to have loss of vision with increased FAZ area at the level of the superficial capillary plexus on OCTA, which does not correlate with changes at the deep capillary plexus on OCTA. Further follow-up studies are warranted to verify if findings apply to patients with other diagnoses.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.