Abstract
Purpose :
Corneal dendritic cells, visible as dendritiform cells (DCs) by in vivo confocal microscopy (IVCM), have a role in corneal immune surveillance. An increased size of DCs has been considered to be an indicator for their activation, which has been associated with progression and severity of inflammatory corneal diseases. Neurotrophic keratopathy (NK) is a neurodegenerative disease that affects corneal nerves. However, the role of inflammation and DC alterations have not been assessed in NK to date. Thus, we aim to determine corneal DC density and size by IVCM in patients with NK and to correlate results to corneal nerve density and clinical signs.
Methods :
This retrospective, cross-sectional, case-control study included patients with NK stage 1 (n=16) and NK stage 2 (n=2) who had not received systemic immunosuppressive treatment or topical steroids within the past month. Three representative IVCM images were graded for nerve and DC density/size. Sex- and age-matched reference controls were selected from a database of healthy subjects for comparison. Clinical signs were recorded from the clinical charts and correlated with IVCM parameters.
Results :
The NK group (n=18, age 59.2±20.3yrs; 22.2% male) and control group (n=14, age: 47.0±8.2yrs, 28.6% male) did not differ in age or sex (p>0.05 for both). DC density (cells/mm2) and DC size (µ2) [median (range)] were higher in the NK group 81.25 (2.08-479.19) and 179.06 (63.86-300.67) vs. controls 18.13 (4.38-136.25) (p<0.001), and 77.50 (48.9-263.10) (p=0.002), respectively. Total nerve density [median (range) in mm/mm2] was lower in NK group [2.55 (0.00-12.55)] vs. controls [17.85 (12.76-26.87), (p<0.001)]. DC density and size were significantly inversely correlated with total nerve density (ρ=-0.361, p=0.042), and (ρ=-0.565, p<0.001), respectively. Further, DC Density and DC size were significantly and inversely correlated with corneal sensation [(ρ=-0.62, p<0.001), and (ρ=-0.53, p=0.004), respectively], and correlated with corneal fluorescein staining [(ρ=0.45, p=0.022), and (ρ=0.40, p=0.041), respectively].
Conclusions :
Increased DC density and DC size in patients with NK stages 1 and 2 correlate with decreased corneal nerve density, decreased corneal sensation, and increased corneal fluorescein staining, suggesting that inflammation may play a role in the pathogenesis of this disease.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.