Effect of artificial tears on aqueous deficient dry eye, a dynamic optical study

Abstract Background: To investigate the change of dynamic optical quality in aqueous deficient dry eye (ADDE) patients after the use of artificial tears.Methods: Fifty-nine patients with ADDE and 31 healthy age- and sex-matched control subjects were included in this prospective case-control study. Clinical evaluation of the ocular surface included Ocular Surface Disease Index (OSDI), tear film break-up time (TBUT), lipid layer thickness (LLT), and Schirmer I testing. ADDE patients were divided into two groups, mild (31 patients) and severe (28 patients). The optical quality of the tear film was measured with the Optical Quality Analysis System (OQAS) using the mean objective scatter index (mean OSI), standard deviation of objective scatter index (SD-OSI) and modulation transfer function cut-off (MTF cut-off). After baseline examinations, one drop of artificial tears (ATs, carboxymethylcellulose ophthalmic solution, 0.5%) was instilled in both eyes, and optical quality parameters were measured again at 5- and 30-minutes following application of ATs.Results: At baseline, the mean OSI was higher in the ADDE group (0.95 ± 0.54) than in controls (0.54 ± 0.23, P<0.001). The SD-OSI was also significantly increased in ADDE patients (0.44 ± 0.71) compared to control subjects (0.12 ± 0.06, P=0.003). Five minutes after ATs instillation, mean OSI and SD-OSI decreased significantly in severe ADDE patients (P=0.044; P=0.018), was unchanged in mild ADDE patients, and increased in the control group (P=0.019; P<0.001). Thirty minutes after ATs instillation, no significant difference in optical quality parameters was observed for the three groups.Conclusion: The effect of ATs on optical quality in patients with ADDE may differ according to the severity of the disease. Measurement of optical quality might be a promising tool to evaluate the effects of various ATs and possibly individualize treatment in ADDE patients.