Data from: Changes in corneal biomechanical properties after long-term topical prostaglandin therapy

Objective: To compare corneal biomechanical properties, measured by a
newly developed tonometer (Corneal Visualization Scheimpflug
Technology?Corvis ST), in untreated primary open angle glaucoma (POAG)
patients?POAG patients with long-term topical prostaglandin analog (PGA)
therapy and in normal controls. Further is to investigate the potential
effects of PGA on corneal biomechanics. Methods: In this case-control
study, 35 consecutive medication naïve eyes with POAG, 34 POAG eyes with
at least 2 years treatment by PGA and 19 normal eyes were included.
Intraocular pressure (IOP), central corneal thickness (CCT) and corneal
biomechanical parameters, including deformation amplitude (DA),
applanation time (AT1 and AT2), applanation length (AL1 and AL2),
applanation velocity (AV1 and AV2), and peak distance and radius were
measured using Corvis ST. Axial length and corneal curvature were measured
with partial coherence interferometry (IOLMaster, Zeiss, Germany). General
linear model analysis was performed to investigate the corneal
biomechanical property changes among the normal controls, newly diagnosed
POAG patients and POAG patients with long-term PGA treatment, and among
the subgroups of different types of PGA treatment, including bimatoprost,
latanoprost and travoprost. Furthermore, pairwise comparisons using
Bonferroni correction for least squares means were employed. Results: AT1
(p<0.0001), AV1 (p<0.0001), AT2 (p=0.0001), AV2
(p<0.0001) and DA (p=0.0004) in newly diagnosed glaucoma patients
were significantly different from those in normal subjects and in patients
underwent at least 2 years topical PGA therapy after adjusting for age and
gender. After adjusting for age, gender, IOP, CCT, axial length and
corneal curvature, a significant difference was detected for DA between
glaucoma patients without PGA treatment and patients with long-term PGA
therapy (p=0.0387). Furthermore, there were no statistical significant
differences in all of the corneal biomechanical parameters among the 3
types of PGA therapy subgroups, namely bimatoprost, latanoprost and
travoprost. Conclusions: Significant changes in corneal deformation
parameters were found among untreated POAG patients, POAG patients with
long-term topical PGA therapy and normal controls. Long-term topical PGA
treatment might have a direct effect on corneal biomechanical properties
in addition to the indirect effect owing to the PGA-induced IOP reduction
and CCT decrease on corneal dynamic properties.