Abstract
Purpose :
Topical eye drops, especially prostaglandin analogs, remain the cornerstone of treatment for glaucoma. It has been estimated that nearly 60% of medically treated patients with glaucoma reported ocular surface disease symptoms, including dry eye. We evaluated the effects of prostaglandin glaucoma eye drops, with or without preservatives, on immortalized human Meibomian gland epithelial cells (MGC) in vitro.
Methods :
MGCs (kindly provided by David Sullivan) were first expanded in serum-free medium and then differentiated in the presence of 10% serum for 1 week. The cells were exposed to different concentration of latanoprost 0.005% (preservative-free [PF]), latanoprost 0.0005% eye drop (0.002% Benzalkonium Chloride [BAK]), bimatoprost 0.01% (PF), LumiganTM 0.001% (0.005% BAK), travoprost 0.004% (PF), Travatan-Z TM 0.0004, and Zioptan TM 0.00015% for 3 days. Phosphate Buffered Saline (PBS) was used as the control. Apo-Tox-Glo TM and MTT assays were used to assess cytotoxicity and viability. LipidTOXTM staining was used to assess the neutral lipid accumulation inside the MGCs.
Results :
Viability, cytotoxicity and lipid content of MGCs after exposure to the chemical form of latanoprost, bimatoprost, and travoprost (without any preservatives or additives) were not significantly different from control (P >0.1 for all comparisons). Likewise, exposure to Travatan-Z TM and Zioptan TM (final concentration 1/10 of the original drops) did not have any noticeable effects on the cells. On the other hand, exposure to latanoprost (medication form) and LumiganTM eye drops (10x diluted from the original eye drops) increased cytotoxicity and decreased viability by almost 4 folds compared to the control (P <0.001). MGCs exposed to the corresponding BAK concentrations (present in the 10x dilution of latanoprost and LumiganTM), resulted in a similar level of cytotoxicity compared to latanoprost and LumiganTM eye drops (P >0.999).
Conclusions :
These studies demonstrate that the chemical form of prostaglandin glaucoma medications is not toxic to the MGCs in vitro and does not alter their lipid accumulation. The toxicity observed from these the drops is primarily due to BAK as a preservative.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.