Abstract
Purpose: :
To relieve differences in the corneal sub-basal nerve plexus between HIV+ and HIV- patients, using corneal confocal microscopy. Nerve Fibre Lenght (NFL) was assumed as an index to evaluate the compromise of the peripheral nervous system.
Methods: :
We scanned the cornea from both eyes of 20 HIV+ patients and 20 HIV- patients and collected images of the nerve plexus contained in the Bowman’s layer.Corneal confocal laser scanning microscopy was performed using a Rodstock Cornea Module attached to a Heidelberg Retina Tomograph II.2 images per eye were analyzed, using a custom software program, to determine NFL (total nerve lenght [µm] within a confocal image [area = 160000 µm²]).Inclusion criteria were HIV seropositivity, being on highly active antiretroviral therapy (HAART), age 25-65 years, CD4+ T lymphocytes < 500/ microL. Exclusion criteria were diabetes, neuropathies other then DSP, chronic renal failure, Sjogren’s sindrome, connective disorders, corneal pathology, previous eye surgery.
Results: :
Corneal Nerve Fibre Lengh (µm/µm2) was reduced in HIV+ patients (0.0194, SD=0.047) compared with HIV- patients (0.0236, SD=0.034).NFL was significantly different among the two groups (0.042, 95% CI of mean 0.024-0.060, p<0.001, t test).
Conclusions: :
The results suggest that HIV+ patients show alterations in corneal innervations consisting in Nerve Fibre Lenght reduction.All HIV+patients in our study had a reduced NFL, even if only 3 of them had clinical diagnosis of DSP, confirmed by electromyography.Corneal confocal microscopy is a rapid, non-invasive in vivo clinical examinationtechnique, that could act as a surrogate measure of distal neuropathy in HIV+ patients.Further prospective clinical studies are needed to evaluate a larger number of patients and a long-term follow up.
Keywords: nerve fiber layer • microscopy: confocal/tunneling • AIDS/HIV