Irregular Astigmatism and Higher-Order Aberrations in Eyes With Dry Eye Disease

To report dry eye patients' functional visual acuity, which was measured after sustained eye opening for 10-20 seconds, as a simulation of visual function of daily acts of gazing, which is defined as looking at an object with involuntary blink suppression. Interventional clinical nonrandomized comparative trial. We measured ordinary best-corrected visual acuity and functional visual acuity in non-Sjögren's syndrome (non-SS, N = 10) and Sjögren's syndrome (SS, N = 12) patients and in normal controls (N = 8), prospectively. Surface regularity index (SRI) of corneal topography was also measured under routine circumstances and after sustained eye opening. Blink rates while gazing were measured during reading in another 28 dry eye patients and during driving in another 8 normal controls. Functional visual acuity did not change (1.27-1.16) in normal controls, but decreased significantly from 1.18-0.336 in non-SS patients (P = .0007) and from 1.15-0.228 (P < .00001) in SS patients. SRI after sustained eye opening increased in non-SS (P = .032) and SS patients (P = .0007), but not in the normal controls. Blink rates during reading (P < .001) and driving (P = .012) were significantly decreased from baseline blink rates. This study shows that the visual function of dry eye patients becomes abnormal with ocular surface irregularity when the eye is kept open for 10-20 seconds. Our data indicate impaired visual function in dry eye patients while gazing. Functional visual acuity may be important in daily activities.

The authors' clinical experience has suggested that there is a form of dry eye with only decreased tear break-up time, which is associated with allergic conjunctivitis. The current study was performed to verify this hypothesis. The authors recruited patients with two types of dry eye syndrome, those with only decreased tear break-up (BUT type) and those with positive vital staining (staining type). Individuals without any symptoms or signs served as controls. All subjects were compared regarding symptoms, Schirmer and tear clearance test results, conjunctival papillary formation, antigen-specific serum-IgE level (s-IgE), and goblet cell density of the palpebral conjunctiva. Antigen-induced allergic conjunctivitis was produced in guinea pigs, and histopathologic changes of the conjunctiva were examined. Patients with the BUT-type dry eye syndrome were younger and their symptoms were as severe as the staining type. The Schirmer and tear clearance test results were better, and the papillary formation and s-IgE were observed more than in the BUT type. The average goblet cell density in the BUT-type syndrome was 625.4 +/- 193.2/mm2, which was significantly less than 1005.6 +/- 294.5/mm2 in the controls (P < 0.01). The average goblet cell density was significantly decreased in the allergic animals (10.40 +/- 1.11/0.2 mm) compared with that of the controls (16.21 +/- 0.26/0.2 mm) or the anti-allergic drug-treated group (13.69 +/- 0.30/0.2 mm) (P < 0.01). These results support the authors' hypothesis that decreased break-up time is in part associated with the decreased goblet cell density caused by allergic conjunctivitis.