Abstract
Purpose: :
To evaluate ocular surface retention time of a lubricant eye drop in dry eye patients using fluorophotometry (Fluorotron Master; Ocumetrics, Inc).
Methods: :
This is a double masked, randomized, single eye crossover study design with 25 targeted confirmed dry eye patients. Patients are required to have 2 of the following at screening: composite symptom score ≥ 5 (modified Schein Questionnaire); NaFl TFBUT < 7 sec; NaFl corneal staining sum score ≥ 3 (NEI grid; 0-3/area, max 15 pts). Test eye is the eye with the most rapid TFBUT. The test (PG/PEG based tear) and control (saline) solutions were admixed with a fluorescein labeled dextran of ~ 70,000 MW (at 0.1% wt/vol) to reduce adsorption. At the study visits, baseline intrinsic corneal fluorescence is measured followed by instillation of one 25 µL drop of admixed solution per randomization in the test eye. Measures are taken as rapidly as possible in the initial 8 minutes, and then every 2 minutes thereafter until baseline signal is regained. The return to baseline is defined as the time when the first of 3 consecutive fluorescent values that are within 2 standard deviations of intrinsic corneal fluorescence is noted. All visits for each subject are performed on the same ½ day a minimum of 24 hrs apart.
Results: :
Preliminary results show a statistical difference (p=0.0376) in mean retention time of solution A (mean = 28.91 min + 15.3) vs solution B (mean = 19.29 min + 8.9). No adverse events or safety issues were noted with either admixed solution. Mean age of study patients = 50 yrs + 9.6.
Conclusions: :
This study was designed to determine if there is a difference in ocular surface retention between the two test solutions. The artificial tear test solution was formulated as a viscoelastic droppable gel to demonstrate that additional pre-corneal retention can be provided when compared to a saline control. Follow-up studies will compare various marketed tear retention times using this technique.
Clinical Trial: :
www.clinicaltrials.gov NCT00673855
Keywords: cornea: tears/tear film/dry eye