CAT OCULAR HYPERTENSIVE MODEL MUSHROOM EXTRACT AND LATANOPROST

Abstract

Purpose : It has been stated that, ‘Mushrooms are manners and their water heals eye diseases’. Pleurotus tuberregium (PT), a specie of mushroom, has also been reported to lower dexamethasone induced ocular hypertension. We hypothesize that PT and latanoprost 0.005% might have opposite effects on the circadian intra-ocular pressure (IOP) cycle of dexamethasone-induced ocular hypertension in cats.

Methods : The research is experimental in design and divided into three phases. In phase one, the baseline diurnal IOP of 12 acclimatized cats were determined. In phase two, the cats were divided into two groups (X ((n= 8) and Y (n=4)). Group Y was left untreated, while group X was treated with 0.1% dexamethasone topically twice daily at 9am and 3pm for two weeks and then stopped. In phase three, group X was divided into two subgroups, X₁ and X₂ (n = 4 each). The right eyes (OD) of the cats in X₁ were treated with latanoprost 0.005% once daily at 4pm while the left eyes (OS) were left untreated. The OD of the cats in X₂ received aqueous extract of PT topically same time as X₁ while OS was left untreated. The IOP was measured at 3hr intervals for 24hrs. Measurement started after two weeks of treatment.

Results : Mean baseline IOP was 12.8mmHg with a peak of 14.8mmHg at 6am and a trough of 12.00mmHg at 12noon and midnight. Two weeks after commencement of treatment dexamethasone significantly increased the IOP of the cats in group X to a mean of 23.2mmHg in OD and 22.8mmHg in OS. Two weeks after the commencement of treatment both PT and latanoprost significantly (p<0.0001) reduced the ocular hypertension induced in OD of groups X₁ and X₂ to 15.6mmHg and 14.4mmHg respectively. Their mean dark phases (9pm to 3am) were 15.8mmHg and 14.2mmHg, while their mean light phases were 15.5mmHg and 14.6mmHg respectively. The untreated OS in groups X₁ and X₂ still maintained their ocular hypertension at 23.6mmHg and 23.9mmHg respectively. At the end of the experiment the control group Y had a mean IOP of 13.2mmHg.

Conclusions : Both PT and latanoprost lowered the dexamethasone-induced ocular hypertension significantly. While PT is more effective in the light phase latanoprost is more effective in the dark phase but the difference is not significant.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.