Abstract
Purpose:
The primary objective of this study is to assess the effect of prostaglandin analogue (PGA) eye drops on the course of thyroid associated orbitopathy (TAO). The atrophic effect of PGA topical eyedrops has recently been highlighted in the literature, with the proposed mechanism being an inhibition of pre-adipocyte differentiation. Because the primary pathogenesis of TAO involves the adipogenesis of orbital fibroblasts, it can be hypothesized that PGA’s may have an effect on the adipocyte dysregulation in TAO. This is the first study to compare the progression of external exam findings in TAO patients on PGA’s to TAO controls.
Methods:
An IRB approved retrospective study was performed on patients seen at Northwestern ophthalmology clinic for evaluation of TAO while simultaneously being treated with a PGA for intraocular pressure reduction over the past 10 years identified via the Enterprise Data Warehouse. These patients were then age and gender matched to a set of control patients also seen for evaluation of thyroid eye disease but not on any eye drop treatment. Known smokers were excluded from this study. Serial Hertel’s exophthalmometry measurements, lid crease position, palpebral fissure measurements, levator function, superior and inferior scleral show, MRD 1 and 2, and lagopthalmos were recorded for all patients in the study. The progression of these measurements in those on a PGA were compared to progression in age and gender matched controls, and results were statistically analyzed and represented in line graph form.
Results:
This study identified 10 patients seen for TAO and also happened to be on a PGA. When these 10 patients were analyzed and compared to their age and gender matched controls, it was found that progression of exophthalmometry and palpebral fissure size as well as increases in superior scleral show occurred at a slower rate in those patients on a PGA as compared to those not on therapy. This study depicts these differences with visual direct correlations in a series of graphs and external photographs.
Conclusions:
While it has been shown that PGA’s inhibit normal orbital adipogenesis, it has not yet been documented that they have any effect on the progression of adipogenesis in TAO. This study is the first to demonstrate that prostaglandin associated periorbitopathy may work to diminish the progression of thyroid associated adipocyte dysregulation.
Keywords: 631 orbit •
462 clinical (human) or epidemiologic studies: outcomes/complications •
526 eyelid