The Correlation of Routine Tear Function Tests and Conjunctival Impression Cytology in Dry Eye Syndrome

Abstract

Purpose:To establish the strength of the association between routine tear function tests and conjunctival impression cytology (CIC) and to determine whether they simulate the morphological and cytological changes that occur on the ocular surface in dry eye. What are the sensitivity, specificity and positive predictive values of these tests when CIC is considered the gold standard? Methods: The tear film profile included tear film break up time (TBUT), Schirmer's-1, Rose Bengal scores (RBS), and impression cytology. CIC samples were obtained from the inferior bulbar conjunctiva and stained with periodic acid-Schiff and counter stained with hematoxylin and eosin. Results: The mean Schirmer's value was 11.66 ± 5.90 in patients and 17.17 ± 2.97 in controls (p < 0.001). The mean TBUT in participants was 8.88 ± 3.54 and 13.53 ± 2.12 in controls (p < 0.001). Patients had a mean goblet cell density (GCD) of 490 ± 213, while the value for controls was 1,462 ± 661 (p < 0.001). Abnormal CIC was observed in 46.7% cases of dry eye and in 32.8% of controls. The correlation coefficient (L) for Schirmer's was 0.2 and 0.24 for participants and controls, respectively, while TBUT values were 0.26 and 0.38, RBS were 0.5 and 0.5, and GCD was 0.8 and 0.6 in cases and controls, respectively. Conclusions: GCD, RBS, and TBUT were better predictors of morphological and cytological changes in the conjunctiva than Schirmer's in dry eye syndrome. The sensitivity of tear function tests in diagnosing dry eye was TBUT > Schirmer's > RBS, and the specificity was Schirmer's > TBUT > RBS in decreasing order when CIC was considered the gold standard.

Impression cytology as diagnostic tool in horses with and without ocular surface disease

“…ICS collects the most superficial layers of the ocular surface due to the adhering property of the sampling device [4]. ICS is now widely used in human ophthalmology to examine the healthy ocular surface [5] and to assess conjunctival and corneal alterations in contact lens wearers [6][7][8] Examination of eyes with ocular surface neoplasia [9,10] and keratoconjunctivitis sicca [11,12] are other indications for ICS. A major advantage of ICS is the arrangement of harvested cells in their natural layout; thus enabling clinical pathologists to examine an exact copy of the area of interest.…”

Goblet cell density association with tear function and ocular surface physiology

“…Contrary to what was found in the present study, Zuazo et al [22] found GCD of 497 cells/mm 2 in normal subjects and 310 cells/mm 2 in subjects with dry eyes, and Torricelli et al [4] found GCD of 521 cells/mm 2 in bulbar conjunctiva of normal subjects. Similarly, in a recent study conducted in India, Kumar et al [23] found GCD of 1462 cells/mm 2 in normal eyes. The lower GCD obtained in this study may be due to the fact that no pressure was applied during impression cytology process unlike those authors [4,23].…”

“…Similarly, in a recent study conducted in India, Kumar et al [23] found GCD of 1462 cells/mm 2 in normal eyes. The lower GCD obtained in this study may be due to the fact that no pressure was applied during impression cytology process unlike those authors [4,23]. In that way, only superficial layer(s) were removed and goblet cells in the deep layer may not be collected in the sample.…”

Dry Eye Status Based on the Schirmer Test and Tear Film Break Up Time Results Following Use of Soft Contact Lens in Kerala

“…No contact lens induced dry eye studies from India were available for comparison. However dry eye studies done by Shah S et al (14 ) in Gujarat and Gupta N et al (15) in Delhi have found a greater prevalence of dry eye in females. Dry eye studies by Chia EM et al (16) have shown that females are 1.5 -2 times more likely to report dry eye symptoms compared to males.…”