Discussion
cataract, conjunctival, postcataract dry, trauma
DRY EYE, AFTER CATARACT, CATARACT, CORNEA
Dexamethasone as topical treatment is routinely used after cataract surgery. BAC-containing eyedrops are one of the main factors contributing to iatrogenic postcataract dry eye diseaseWe found that the group receiving preserved dexamethasone eye drops had more conjunctival and corneal staining as well as foreign body sensation at 2 weeks after cataract surgery in comparison to patients receiving nonpreserved formulation. Another study assessed netylmicin/dexamethasone preservative-free and tobramycin/dexamethasone-preserved fixed combinations after cataract surgery and found no significant differences in ocular surface statusBenzalkonium chloride (BAC) induces tear film instability and ocular surface damageAnother possible explanation for the more pronounced staining and ocular discomfort in the preserved dexamethasone group is the effect of the suspension formula on the ocular surface. Suspensions contain microparticles of the active substance, which may cause microabrasions of the corneal epitheliumAdministration of dexamethasone sodium phosphate is subjected to a hydrolysis reaction catalysed by enzymes in the tear film and cornea, partly converting water-soluble phosphate into lipid-soluble dexamethasone alcohol, which theoretically penetrates the lipophilic corneal epithelium more easilyWe chose the 2-week time point for our assessments, presuming that at this time, all short-term ocular surface damage caused by the procedure itself (corneal cuts, iodine povidone irritation, speculum trauma) should be healed, leaving the postoperative eye drops as a main cause of any dry eye symptoms, with their peak intensity at that timeIn the paper by Kohli, an OSDI score > 33 was reported in 32% of patients 2 weeks after cataract surgeryPovidone iodine used before surgery for sterilization could possibly induce tear film instability and ocular surface damageTo the best of our knowledge, this is the first study to compare preservative-free and standard formulations of 0.1% dexamethasone in terms of dry eye signs and symptoms after standard cataract surgery. This study indicates and addresses possible postoperative complaints of the patients, such as foreign body sensation and treatment-related ocular surface impairment.