Konieczka Katarzyna, Koch Simone, Hauenstein Daniela, Chackathayil Thomas Navin, Binggeli Tatjana, Schoetzau Andreas, Flammer Josef
Department of Ophthalmology, University of Basel, Basel, Switzerland.
Augen Zentrum Prof Fankhauser, Bern, Switzerland.
Transl Vis Sci Technol. 2019 Jun 21;8(3):47. doi: 10.1167/tvst.8.3.47. eCollection 2019 May.
The aim of this study was to investigate the effects of the glaucoma drugs latanoprost, brimonidine, and the combination of both on the central corneal temperature (CT) of healthy subjects by means of infrared thermography. Changes of the central CT may reflect changes of ocular blood flow.
Before application and during 2 hours after the application of latanoprost, brimonidine, or the combination of both in one eye, the CT in both eyes of 40 healthy subjects was measured repeatedly.
Brimonidine reduced CT by approximately 0.5°C. This effect was statistically significant ( < 0.0001). Latanoprost, however, had a very small and insignificant influence ( = 0.47). Accordingly, the combination of brimonidine and latanoprost also reduced CT up to 0.5°C, and this effect was statistically significant ( < 0.0001).
Brimonidine, but not latanoprost, had a significant effect on central CT. This cooling effect of brimonidine is most probably due to a drug-induced reduction of blood circulation in the ciliary body and iris and to a certain extent also to a reduction of blood flow in the fundus of the eye.
This study shows evidence that thermography of the cornea provides indirect information on the influence of drugs on the blood flow to the anterior segment of the patient's eye.
本研究旨在通过红外热成像技术，调查青光眼药物拉坦前列素、溴莫尼定以及二者联合用药对健康受试者中央角膜温度（CT）的影响。中央角膜温度的变化可能反映眼部血流的变化。
对40名健康受试者的双眼进行测量，在单眼应用拉坦前列素、溴莫尼定或二者联合用药前及用药后2小时内，反复测量双眼的角膜温度。
溴莫尼定使角膜温度降低约0.5°C。这一效应具有统计学意义（<0.0001）。然而，拉坦前列素的影响非常小且无统计学意义（=0.47）。因此，溴莫尼定与拉坦前列素联合用药也可使角膜温度降低达0.5°C，且这一效应具有统计学意义（<0.0001）。
溴莫尼定而非拉坦前列素对中央角膜温度有显著影响。溴莫尼定的这种降温效应很可能是由于药物引起睫状体和虹膜血液循环减少，在一定程度上也归因于眼底血流减少。
本研究表明，角膜热成像可为药物对患者眼前节血流的影响提供间接信息。
