Abstract
Purpose: :
To investigate the efficacy of preservative-free cromolyn sodium 4%-chlorpheniramine maleate 0.2% (Visuglican®) eye drops in reducing signs, symptoms and tear levels of neuropeptides after Conjunctival Allergen Challenge (CAC) in allergic patients.
Methods: :
Fourteen asymptomatic patients (2F, 12M; mean age:30±9yrs) with allergic conjunctivitis and 9 age and sex-matched controls were included in the study. After a wash-out period of 7 days, patients were challenged in one eye with increasing doses of the sensitizing allergen to reach a 2+ score of conjunctival hyperaemia (threshold dose). Patients were then treated twice-daily with Visuglican® eye-drops and challenged with allergen challenge. Conjunctival signs (hyperemia, chemosis and secretion) and symptoms (itching, photophobia and tearing) were scored from 0 to 3 (0= absent; 1= mild; 2= moderate; 3= severe) at baseline and 15 minutes after CAC. Tear samples were collected before and after CAC, and tear levels of Substance P, CGRP, VIP, NPY were measured by ELISA. Mann-Whitney U test and paired sample T-test were used to compare signs, symptoms and neuropeptides’ tear levels.
Results: :
All the allergic patients but not the healthy subjects showed a positive conjunctival reaction following CAC. Visuglican® eye drop treatment significantly reduced ocular signs (hyperemia 1.1±0.7 vs. 0.2±0.6, p<0.05) and symptoms (itching 1.7±0.5 vs. 0.7±0.6; p<0.05) when compared to healthy subjects. Levels of neuropeptides were significantly reduced in tears of allergic patients when pre-treated with Visuglican® (Substance P: 3.7±1.5 vs. 5.6±1.3 µg/mL; p=0.041; CGRP: 5.5±2 vs. 6.9±2.7µg/mL, p=0.025; VIP: 4±0.8 vs. 4.9±1.5µg/mL, p=0.045; NPY: 32±27 vs. 39±31µg/mL, p<0.05).
Conclusions: :
Our data confirm the efficacy of preservative-free cromolyn sodium 4%-chlorpheniramine maleate 0.2% (Visuglican®) eye drops in the treatment of allergic patients challenged with a sensitizing allergen. Visuglican® eye drops are also effective in inhibiting the neurogenic allergic inflammation induced by neuropeptides.
Keywords: neuropeptides • conjunctivitis • inflammation