David A Ammar1, Malik Y Kahook. 1. Rocky Mountain Lions Eye Institute, Department of Ophthalmology, University of Colorado Denver, Aurora, 80045, USA.
Abstract
INTRODUCTION: The purpose of this study was to determine the effects of two commercially available combination topical ophthalmic medications on human ocular surface cells in vitro. METHODS: Tissue culture plates (96-well) containing immortalized human corneal and conjunctival epithelial cells were divided into five groups. The test solutions examined were: timolol 0.5%+brimonidine 0.2%, containing 0.0050% benzalkonium chloride (BAK); timolol 0.5%+dorzolamide 2%, containing 0.0075% BAK; and preservative-free artificial tears. Balanced salt solution (BSS) was used as the live control, and a fixative solution containing 70% methanol and 0.2% saponin was used as the dead control. Cells were exposed to 100 microL of test or control solution for 25 minutes at 37 degrees C and 5% carbon dioxide (CO(2)). A live cell assay was used to measure the toxicity of combination treatments compared with BSS controls. RESULTS: Exposure to timolol 0.5%+brimonidine 0.2% resulted in a significantly higher percentage of living conjunctival cells (48%+/-12%) as compared with timolol 0.5%+dorzolamide 2% (10%+/-5%, P<0.00001). In corneal cells, testing revealed 12%+/-3% live cells after timolol 0.5%+brimonidine 0.2% exposure compared with 2%+/-3% after timolol 0.5%+dorzolamide 2% (P<0.001). CONCLUSIONS: Both combination medications demonstrated a significant reduction in the percentage of live corneal and conjunctival epithelial cells compared with control. However, cell cultures exposed to timolol 0.5%+dorzolamide 2% had significantly fewer live cells compared with cell cultures exposed to timolol 0.5%+brimonidine 0.2%. Further studies are needed to better understand the clinical significance of these findings in patients using these medications for chronic treatment of glaucoma and ocular hypertension.
INTRODUCTION: The purpose of this study was to determine the effects of two commercially available combination topical ophthalmic medications on human ocular surface cells in vitro. METHODS: Tissue culture plates (96-well) containing immortalized humancorneal and conjunctival epithelial cells were divided into five groups. The test solutions examined were: timolol 0.5%+brimonidine 0.2%, containing 0.0050% benzalkonium chloride (BAK); timolol 0.5%+dorzolamide 2%, containing 0.0075% BAK; and preservative-free artificial tears. Balanced salt solution (BSS) was used as the live control, and a fixative solution containing 70% methanol and 0.2% saponin was used as the dead control. Cells were exposed to 100 microL of test or control solution for 25 minutes at 37 degrees C and 5% carbon dioxide (CO(2)). A live cell assay was used to measure the toxicity of combination treatments compared with BSS controls. RESULTS: Exposure to timolol 0.5%+brimonidine 0.2% resulted in a significantly higher percentage of living conjunctival cells (48%+/-12%) as compared with timolol 0.5%+dorzolamide 2% (10%+/-5%, P<0.00001). In corneal cells, testing revealed 12%+/-3% live cells after timolol 0.5%+brimonidine 0.2% exposure compared with 2%+/-3% after timolol 0.5%+dorzolamide 2% (P<0.001). CONCLUSIONS: Both combination medications demonstrated a significant reduction in the percentage of live corneal and conjunctival epithelial cells compared with control. However, cell cultures exposed to timolol 0.5%+dorzolamide 2% had significantly fewer live cells compared with cell cultures exposed to timolol 0.5%+brimonidine 0.2%. Further studies are needed to better understand the clinical significance of these findings in patients using these medications for chronic treatment of glaucoma and ocular hypertension.
Authors: Regina Cele Silveira Seixas; Marcos Balbino; Alberto Basile Neto; Amanda de Alcantara Almeida Costa; Marcelo Lopes da Silva Jordão; Heloisa Helena Abil Russ Journal: Clin Ophthalmol Date: 2020-12-16
Authors: Ruti Sella; Yamit Cohen-Tayar; Takako Noguchi; Emma N Finburgh; Rebecca R Lian; Anser A Abbas; Dominic F Hakim; Jennifer J Bu; Jiagang Zhao; Peter Shaw; Irit Bahar; Natalie A Afshari Journal: Transl Vis Sci Technol Date: 2022-09-01 Impact factor: 3.048