Adverse ocular outcomes in the management of allergic conjunctivitis and the efficacy of a herbal intervention

Allergic conjunctivitis (AC) is on the rise and pharmacological intervention is the mainstay of its treatment. However, reports on adverse ocular effects have been observed in the use of orthodox medicines in managing AC. This study, therefore, sought to investigate the outcomes of conventional anti-allergic medications use and the efficacy of a herbal intervention in management of AC. A cross-sectional study was first conducted to determine the prevalence, prescription pattern and ocular complications in AC management, followed by a retrospective cohort study to determine the underlying cause of the commonest ocular complication observed in the management of AC by reviewing medical records of cases of AC diagnosed from January to December 2010. The results indicated a high prevalence 9.1% of AC, with the acute forms of AC accounting for 82.5% of the total AC cases. The commonest prescribed medications were topical steroids 69.7% (1198) mainly prescribed for atopic keratoconjunctivitis (P = 0.002), and systemic antihistamines 48% (839) for the acute types of AC (P ≤ 0.001). Dry eyes was the commonest disorder (5.2%) found accompanying AC, and the use of systemic antihistamines in managing AC was the most significant risk factor (OR: 2.79; P ≤ 0.001) to this condition after adjusting for patient‘s age and occupation. Anecdotal reports suggests P. stratiotes, a traditional medicinal plant, is potent in managing allergies. There is, therefore, the need to confirm or otherwise the efficacy of this herb in treating AC since conventional orthodox treatment is ineffective and/or associated with adverse ocular effects. Ovalbumin-sensitized ICR mice were pretreated with different doses (10, 50 and 100 mg/kg) of an aqueous leaf extract of P. stratiotes (ALPS) 1h before v multiple topical challenges in eyes by instillation of ovalbumin to induce AC. ALPS significantly and dose-dependently lowered (P ≤ 0.05-0.001) ocular signs of AC (including conjunctival redness, lid edema, tearing and lid scratching), serum ovalbumin-specific IgE, and mast cell infiltrations and degranulations in ocular tissue of mice. Managing AC with conventional orthodox drugs results in decreased tear secretion and stability (i.e. dry eyes). It was hence important to evaluate the effect of P. stratiotes on tear secretion and tear film stability. Phenol red thread test and fluoresceine tear breakup time, for the assessment of tear secretion and tear film stability respectively, were performed before and after oral administration of ALPS for 7 consecutive days. No significant change (P > 0.05) in tear secretion and tear film stability was found following treatment with ALPS, while mice treated with prednisolone and cetirizine showed significant decline in tear secretion and/or stability (P ≤ 0.05- 0.001). AC is a prevalent eye disorder in Ghana and caution should be exercised in the use of systemic antihistamines as it could precipitate dry eyes. ALPS exhibited potent anti-allergic activity and did not affect tear secretion and tear film stability; hence may be useful in managing AC in humans.

Source: KNUST