The frequency of ocular symptoms during spectacle and daily soft and rigidcontact lens wear

Purpose: Ocular discomfort is the primary reason for discontinuation of con tact lens wear. The purpose of the study was to:quantify and compare the fr equency of ocular symptoms experienced by spectacle wearers and wearers of soft and rigid daily contact lenses. Methods: We analyzed the results of an ocular symptom survey of prospective volunteers for contact lens clinical trials during the period 1989 to 1995. Questions pertaining to lens-wear ex perience and ocular symptoms were answered by 883 untrained individuals wit hout active ocular disease. The sample included 664 spectacle wearers, 171 soft contact lens (SCL) wearers, and 48 rigid gas-permeable (RGP) lens wear ers. The frequencies of 10 ocular symptoms were compared for each group. Sp earman's Rank Correlation was used to test for correlations between symptom s. The chi(2) test was used to determine differences between subject groups , adjusted for multiple comparisons. Results: There were no significant dif ferences in the frequency of ocular symptoms between the soft contact lens (SCL) and RGP wearers. The most common symptom was ocular tiredness (27%). None of the symptoms were highly correlated, indicating that they are somew hat different "sensations." Despite ocular discomfort being the primary rea son for discontinuation of lens wear, contact lens weavers experienced the same type and severity of symptoms as spectacle wearers. Thus (in order of frequency of occurrence), tiredness, itchiness, watering, pain, aching, exc essive blinking, and burning had similar rates of occurrence for all three groups. The two major distinguishing symptoms were dryness and redness, whi ch were reported far more frequently and with greater severity in both cont act lens groups (p < 0.001). Grittiness was also reported more with RGP wea rers than with spectacle wearers (p < 0.001). Conclusions: Contact lenses d isturb the ocular environment, as evidenced by responses of increased ocula r dryness, redness, and grittiness. Despite fundamental differences in SCL' s and RGP contact lenses, both groups of contact lens wearers surveyed expe rienced a similar type and frequency of ocular symptoms.