Abstract
Purpose :
We recently reported that pre-corneal tear-film (PCTF) breakup patterns (BUPs) can be classified into 5 definitive patterns (spot break: SB; area break: AB; line break: LB; dimple break: DB; random break: RB, Yokoi N, et al. Am J Ophthalmol 180:72–85, 2017) depending on the dynamic interaction between TF and corneal surface. The aim of this study was to classify the BUPs of pre-soft contact lens (SCL) TF (PSCLTF) based on the dynamic interaction between PSCLTF and SCL surface and to elucidate the possible impact of meniscus tear volume on the BUPs and the stability of the PSCLTF.
Methods :
This study involved 23 eyes of 23 SCL wearers (11 males and 12 females; mean age: 35.4±8.3 years). At pre and 30-minutes post SCL wear, the meniscus tear volume was assessed by measuring the tear meniscus radius (TMR, mm) at the central lower TM via the use of a video-meniscometer, BUPs of PCTF pre SCL wear and PSCLTF post SCL wear were assessed by use of a DR-1 video-interferometer (Kowa, Japan), and the stability of the PCTF and PSCLTF was assessed by non-invasive breakup time (NIBUT, seconds) of TF via the use of the video-interferometer.
Results :
In the 23 eyes, the BUPs of PCTF were 1 LB and 22 RB, yet the BUPs of PSCLTF were 5 LB, 5 DB, and 8 RB. Another BUP for PSCLTF was 5 cases in which the breakup appeared only in a very thin aqueous layer distributed on the SCL (newly coined as 'thin aqueous-layer break': TALB). Values for TMR and NIBUT (TMR; NIBUT) at pre and 30-minutes post SCL wear were (0.24±0.07; 6.8±2.5) and (0.17±0.04; 3.9±1.8), respectively; i.e. both values significantly decreased post SCL wear (p<0.0001). Values (TMR; NIBUT) of the different BUPs were (0.13±0.02; 3.1±0.4) in LB, (0.15±0.02; 2.7±0.6) in DB, (0.14±0.03; 3.0±0.6) in TALB, and (0.21±0.03; 5.8±2.2) in RB, respectively; i.e. the values were significantly greater in RB than in the other BUPs (p<0.05).
Conclusions :
Our findings suggest that the decrease of TMR post SCL wear is greatly associated with the BUPs and the stability of PSCLTF. Considering that RB (i.e., the BUP seen in normal eyes) and the other BUPs respectively occur post and pre complete establishment of TF, our findings also suggest that a greater TMR is vital to show RB with greater stability for PSCLTF.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.