Abstract
Abstract: :
Purpose: The purpose of this study was to investigate the relationship between the duration and severity of ocular symptoms and corneal sensitivity in dry eye patients. Methods: Forty-one (41) subjects diagnosed with dry eye underwent examinations including a medical history, ocular symptom evaluation, slit-lamp biomicroscopy and corneal sensitivity measurement. Ocular discomfort was evaluated using a standardized 0-4 point scale (4 = worst possible score). Corneal sensitivity was determined with a Luneau Cochet Bonnet Aesthesiometer (model # 8305). Results: Subject eyes were grouped as having either Low Corneal Sensitivity (LCS) (defined as ≤ 4), n = 36 (mean = 2.51), or Normal Corneal Sensitivity (NCS) (defined as > 4), n = 46 (mean = 5.41). Mean age was 72.4 years in LCS eyes and 69.1 years in NCS eyes (p = 0.25). Mean duration of ocular symptoms associated with dry eye was 10 years in LCS eyes and 6.5 years in NCS eyes (p = 0.001). Mean ocular discomfort was 1.5 units in LCS eyes and 1.67 units in NCS eyes (p = 0.39). Conclusions: The data shows that the duration of dry eye symptoms correlates with corneal sensitivity. Surprisingly, regardless of their corneal sensitivity, these dry eye patients report similar ocular discomfort. This suggests that a dry eye symptom ‘zone’ of consistent, low-level discomfort, when not exposed to adverse environmental conditions, may exist. The mechanism which maintains dry eye patients within this ‘zone’ may be a proper balance of natural compensation (reflex tearing) and an alteration of blink rate.
Keywords: cornea: tears/tear film/dry eye • clinical (human) or epidemiologic studies: tre • cornea: clinical science