THE EFFECT OF PROSTAGLANDIN ANALOGUE USE ON THE CORNEOSCLERAL BIOMECHANICAL PROPERTIES

PURPOSE: To analyze the corneoscleral biomechanics changes in patients with latanoprost instillations compared to local beta-blockers therapy by means of bidirectional applanation tonometry.

METHODS: The study included 2 groups of patients with newly diagnosed primary open-angle glaucoma: the Main group comprised 320 patients (320 eyes), the Control group — 200 (200 eyes). To assess the fibrous tunic viscoelastic properties the patients underwent bidirectional applanation tonometry using Ocular Response Analyzer (ORA, «Reichert»,USA).

Patients of the Main group received hypotensive latanoprost 0.005% (Prolatan, «Sentiss») instillations once daily in the evening, while the Control group received timolol maleate 0.5% solution twice daily with a 12-hour interval. Corneoscleral biomechanics was monitored prior to instillations administration and 6 months after to assess the dynamics and the treatment effect. The study included only one eye of each patient.

RESULTS: Patients of the Main group treated with latanoprost 0.005% showed an average IOP decrease by 33% with an equal change in both parameters measured with bidirectional applanation tonometry. Corneal resistance factor (CRF) decrease was accompanied by corneal hysteresis (CH) increase, equaling the parameters, which in turn indicated the fibrous tunic normal condition recovery. Similar changes in biomechanical parameters in the control group were expressed to a lesser degree leaving a discrepancy between CRF and CH levels.

CONCLUSION: The fibrous tunic of the eye showed no significant changes during latanoprost therapy. Biomechanical parameters dynamics measured by bidirectional corneal applanation was mostly related to IOP decrease. The effect of latanoprost on cornea and sclera was more pronounced, which can possibly be attributed to the difference in hypotensive efficacy between latanoprost and timolol maleate.

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