Tear evaluation of subjects wearing rigid gas permeable contact lens for six months: the Asian context

OBJECTIVE: Asians are known to have different tear characteristics compared to Caucasians that may affect contact lens wear. There are scanty research studies that have evaluated tears during continuous wear contact lens in Asia. The present study aims to evaluate changes in tears in subjects wearing continuous wear rigid gas permeable contact lens (CWRGP) for 6 months.
MATERIALS AND METHODS: Thirty five neophyte subjects (21 females, 14 females) were recruited for this study. Subjects were fitted with CWRGP lenses with Dk of 163 on both eyes. Tear was evaluated using Phenol red thread test (PRT), tear break up time (TBUT) test and tear meniscus height (TMH) measurement. Non parametric and parametric analyses were used to compare the parameters.
RESULTS: Values at baseline (BL) and six months (6M) were as follow: PRT, BL=19.10 ± 3.86 mm, 6M= 21.02 ± 4.27 mm, TBUT, BL= 8.58 ± 4.90 sec, 6M=8.08 ± 5.32 sec, TMH, BL= 0.38 ± 0.12 mm, 6M= 0.34 ± 0.07 mm. Statistical analysis showed significant difference in tear volume for PRT only at 6 months (p=0.007).
CONCLUSION: Our analysis showed minimal change in the tear characteristics after six months of CWRGP lens wear, which indicated low impact of CWRGP contact lens on tears characteristics of Asian eyes. However, careful monitoring is required to prevent development of adverse events during contact lens wear.