Impact of Dry Eye on Prolonged Reading.

SIGNIFICANCE: Patients with dry eye frequently report difficulty with reading. However, the impact of dry eye on reading has not been studied in detail. This study shows the unfavorable effect of dry eye on reading speed and offers mechanisms that may be responsible. PURPOSE: The purpose of this study was to evaluate the impact of dry eye signs as well as symptoms on both short-duration out-loud and prolonged silent reading. METHODS: This study included 116 patients with clinically significant dry eye, 39 patients with dry eye symptoms only, and 31 controls, 50 years or older. After the Ocular Surface Disease Index (OSDI) questionnaire, objective testing of dry eye (tear film stability studies, Schirmer's test, and ocular surface staining) was performed. Total OSDI score and two subscores (vision related and discomfort related) were calculated. A short-duration out-loud reading test and a 30-minute sustained silent reading test were performed. Reading speed for each test was calculated as words per minute (wpm) and compared across the three groups. RESULTS: Patients with clinically significant dry eye read slower than controls measured with sustained silent reading test (240 vs. 272 wpm, P = .04), but not with short-duration out-loud reading test (146 vs. 153 wpm, P = .47). Patients with dry eye symptoms only did not have slower reading speed measured using either reading test as compared with controls. However, vision-related OSDI subscore independently was associated with slower reading speed (P = .02). Multivariable regression models demonstrated that each 1-point (between 0 and 6) increase in corneal staining score led to a 10-wpm decrease in sustained silent reading speed (P = .01). CONCLUSIONS: This study demonstrates a significant negative impact of dry eye (particularly presence of corneal staining) on prolonged reading. Prolonged reading task may serve as an objective clinically relevant test to measure the impact of dry eye on vision-related quality of life.

Validation of an Objective Measure of Dry Eye Severity.

PURPOSE: We evaluated the validity of a single dry eye severity measure estimated using Rasch analysis from a battery of clinical tests and patient symptoms. METHODS: This study included 203 dry eye patients and 51 controls. Administered tests included the Ocular Surface Disease Index (OSDI), tear osmolarity, Schirmer's test, noninvasive break-up time, and ocular surface staining. Each of the 12 OSDI questions and each clinical test was defined to be a separate indicator to estimate a single dry eye severity measure from Rasch analysis. Measures of severity were estimated for each subject (person measures) and measures of sensitivity to severity were estimated for each sign and symptom (indicator measures). RESULTS: The average severity measure for dry eye patients was significantly greater than the average severity measure for controls (-0.39 vs. -1.2, P < 0.001). The distribution of indicator measures was well matched to the distribution of person measures. No indicator carried >10% of the total information about dry eye severity carried by all indicators together. However, the most informative indicators were corneal and conjunctival staining. CONCLUSIONS: Our study indicated that there is no single "best" dry eye test. Clinical tests and symptoms should be used in combination to estimate a single dry eye severity measure. TRANSLATIONAL RELEVANCE: There is no single "gold standard" testing method for dry eye that correlates with the severity of disease. We propose that Rasch analysis can be used to calculate an objective dry eye severity score from a battery of clinical indicators.

Effects of Prolonged Reading on Dry Eye.

PURPOSE: To demonstrate the effects of prolonged silent reading on tear film and ocular surface parameters. DESIGN: Prospective, observational clinical study. PARTICIPANTS: A total of 177 patients with dry eye and 34 normal controls aged 50 years and older. METHODS: After evaluating symptoms using the Ocular Surface Disease Index (OSDI) questionnaire, the following tests were performed in consecutive order: automated noninvasive tear break-up time (TBUT), surface asymmetry and regularity indices, Schirmer's testing without anesthesia, corneal staining using fluorescein, and conjunctival staining using lissamine green. The participants were then asked to read a 30-minute validated passage silently. The tests were repeated after the reading task. MAIN OUTCOME MEASURES: Changes in tear film and ocular surface parameters after reading. RESULTS: All parameters, with the exception of surface asymmetry index, worsened after the reading task in patients with dry eye and in controls. The worsening reached a statistical significance for corneal and conjunctival staining in the dry eye group (P < 0.001) and for corneal staining in the control group (P < 0.01). At baseline, OSDI scores correlated only with corneal and conjunctival staining scores (r = 0.19, P = 0.006 and r = 0.27, P < 0.001). Among postreading measurements, baseline OSDI scores correlated with TBUT (r = -0.15, P = 0.03) in addition to corneal and conjunctival staining (r = 0.25, P < 0.001 and r = 0.22, P = 0.001). Changes in TBUT and Schirmer's test correlated significantly with their respective baseline values (r = -0.61, P < 0.001 and r = -0.44, P < 0.001), indicating that the more unstable the tear film and the lower the aqueous tear secretion, the worse they became after the prolonged reading task. Worsening in corneal staining directly correlated with the baseline conjunctival staining (r = 0.17, P = 0.02) and surface regularity index (r = 0.21, P = 0.01). CONCLUSIONS: Evaluating tear film and ocular surface parameters at rest may miss clinical findings brought about by common everyday tasks such as reading, leading to discordance between patient-reported symptoms and clinician-observed signs. Quantifying dry eye after visually straining activities such as prolonged silent reading may help better understand patient symptomatology.

Utility of Novel Autoantibodies in the Diagnosis of Sjögren's Syndrome Among Patients With Dry Eye.

PURPOSE: To investigate the value of 3 novel autoantibodies [salivary protein 1 (SP1), carbonic anhydrase 6 (CA6), and parotid secretory protein (PSP)] in differentiating Sjögren's syndrome (SS)-related dry eye from non-SS dry eye. METHODS: Forty-six dry eye patients with SS (SS dry eye), 14 dry eye patients without SS (non-SS dry eye), and 25 controls were included. The 2012 American College of Rheumatology classification criteria were used for the diagnosis of SS. After a detailed review of systems, the Ocular Surface Disease Index questionnaire, Schirmer test without anesthesia, tear film breakup time, and ocular surface staining were performed to assess dry eye. All participants underwent serological testing using a commercially available finger prick kit. RESULTS: Thirty-seven patients with SS (80.4%) had a positive traditional autoantibody and 28 (60.9%) had a positive novel autoantibody. Traditional autoantibodies were absent in all non-SS dry eye patients and controls. Novel autoantibodies were present in 7/14 (50%) non-SS dry eye patients and 4/25 (16%) controls. Among 3 novel autoantibodies, anti-CA6 was significantly more prevalent in the SS and non-SS dry eye groups than in controls (52.2% vs. 42.9% vs. 8.0%, P = 0.001). Dry eye patients with positive anti-CA6 alone were significantly younger than patients with only traditional autoantibodies. Anti-CA6 was associated with worse dry eye signs and symptoms. CONCLUSIONS: Anti-CA6 was the most prevalent novel autoantibody in patients with dry eye, and was associated with younger age and more severe disease. Longitudinal studies are needed to determine whether anti-CA6 is a marker for early SS or perhaps another form of an autoimmune dry eye disease.

Tear Osmolarity and Correlation With Ocular Surface Parameters in Patients With Dry Eye.

PURPOSE: To analyze the distribution of tear film osmolarity in patients with dry eye and its association with other ocular surface parameters. METHODS: Tear osmolarity and other quantitative dry eye parameters were obtained from patients with 1) clinically significant dry eye (significant symptoms and ocular surface staining, n = 131), 2) symptoms-only dry eye (significant symptoms but no significant ocular surface staining, n = 52), and 3) controls (no significant symptoms or staining, n = 42). RESULTS: Tear osmolarity varied significantly across groups (P = 0.01), with patients with clinically significant dry eye having the highest tear osmolarity (312.0 ± 16.9 mOsm/L), control patients having the lowest tear osmolarity (305.6 ± 9.7 mOsm/L), and patients with symptoms-only dry eye falling in between (307.4 ± 5.6 mOsm/L). Patients with clinically significant dry eye also tended to have a greater intereye difference in osmolarity (12.0 ± 13.4) than did the individuals with symptoms-only dry eye (9.1 ± 12.4) and controls (9.0 ± 7.4) (P = 0.06). In multivariable regression models, higher tear osmolarity was associated with higher Ocular Surface Disease Index, discomfort subscore (P = 0.02), and higher corneal and conjunctival staining scores (P < 0.01 for both). Worse eye tear osmolarity was not correlated with the corresponding tear film breakup time or Schirmer test (P > 0.05 for both). CONCLUSIONS: Individuals with symptomatic dry eye that is not yet clinically significant seem to have higher and more variable osmolarity measurements than controls, potentially indicating that changes in osmolarity precede clinical findings.