Abstract
Purpose:
Corneal nerve damage, particularly post-refractive surgery, can resultin hyper-excitability and subsequent chronic neuropathy, manifesting as severe corneal pain. The purpose of this study was to evaluate the use of 20% autologous serum tears (AST) in patients with chronic debilitating corneal pain, unresponsive to conventional therapy.
Methods:
Sixteen patients suffering from corneal neuropathy-induced corneal pain and no active clinical ocular surface disease were included. All patients were treated with 20% AST 8 times a day. Changes in pain severity (on a scale of 0 to 10, 10 being maximum), clinical signs and treatment were recorded. Laser in vivo confocal microscopy IVCM (HRT3/RCM) images of the central cornea were assessed by 2 masked observers for changes in the subbasal corneal nerve density and morphology before and after treatment, and compared to images of 12 age-matched controls.
Results:
Severity of corneal pain improved from 9.4±0.2 at baseline to 3.4±0.4 (p<0.001) following a duration 3.8±0.5 months of treatment with AST. Baseline IVCM showed significantly decreased density and altered morphology of subbasal nerve plexus in all parameters compared to controls (all p<0.01). Parallel to symptomatic improvement, significant improvement in the nerve plexus was noted post-treatment with AST, with the total nerve number and density improving to 15.1 ±1.6/frame and 17.3 ± 1.3 mm/mm2 from 10.5 ± 1.4 and 10.9± 1.2 at baseline. Similarly, post -treatment main nerve number and density (2.6 ± 0.2/frame and 6.7 ± 0.5 mm/mm2) and nerve branch number and density (12.9 ± 1.5/frame and 10.1 ± 0.9 mm/mm2) improved from baseline (1.9 ±0.2 and 4.5 ± 0.5) and (8.9 ± 1.2 and 6.5 ±0.8, respectively) (p=0.001). Morphologically the nerve beading and presence of neuromas decreased significantly from 37.5% and 75% of all patients to 6.25% and 68.75% (p<0.05). Additionally, reflectivity and tortuosity decreased from 2.9 ± 0.2 and 2.4 ± 0.2 to 2.4 ±0.2 and 2.2 ±0.2, respectively. However, these changes were not significant (p>0.05).
Conclusions:
IVCM demonstrates underlying alterations of the subbasal corneal nerve plexus in patients suffering from debilitating corneal neuralgia. AST, being rich in neurotrophic factors leads to corneal subbasal nerve regeneration and results in significant improvement in corneal pain in patients with corneal neuropathy.
Keywords: 479 cornea: clinical science •
550 imaging/image analysis: clinical •
678 refractive surgery