Abstract
Purpose :
To evaluate pre-lens tear film surface quality (TFSQ) using high speed videokeratoscopy (HSV) with two types of Si-Hy contact lenses (CL1: Somofilcon A, CL2: Sternfilcon A).
Methods :
Ten subjects (6F & 4M, aged 20-40) participated in the study. Assessment on day one included fluorescein tear film break up time (BUT), measuring meniscus height, assessing lid margins redness and roughness, meibomian glands, tarsal, and palpebral conjunctiva. Participants also completed the Ocular Surface Disease Index (OSDI) questionnaire and subjective assessment of CL comfort. On the second day each patient was randomly fitted with different types of CLs in each eye (masked for subjects and operators) and non-invasive assessment of TFSQ was evaluated before insertion, 20min after, and after 7h. The acquired recordings were then subjectively evaluated by two operators, noting morphological changes in Placido disk patterns in three score categories: adequate, satisfactory or inadequate, separately for five zones of the cornea. Further, non-invasive BUT (NIBUT) was estimated for each of the recording.
Results :
The differences between the scores of both eyes were recorded for bare eye condition and the results showed slightly better score for left eye especially in the central zone. Both lenses similarly decreased the quality of the tear film, except L2 in the superior zone. Although the decrease for both CLs was comparable, in absolute terms more adequate counts were found in the central zone of L2. Four patients indicated differences in lens comfort at the end of wear with three ranking L1 as less comfortable than L2. No association was found between subjective assessment of comfort and fluorescein BUT or scores of OSDI. NIBUT for baseline, morning and afternoon measurements ranged from 3.1-37.6s, 0-37.5s and 0-37.9s, respectively. Similarly, no association was found between those values and any other clinical parameter evaluated in the study.
Conclusions :
The dynamics of TFSQ on CL surface is different to that of a bare eye. The superior zone may be more related to comfort due to the lid while the central zone is related to quality of vision. In our study NIBUT estimates did not add information in terms of differences in quality of TF especially during CL wear. However, assessing TF using HSV could optimise CL wear in the future.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.