Objective  Classifying the conjunctiva of normal and dry eye patients by conjunctival impression cytology with acridine orange fluorescent staining(CICAO) in Nelson's method. To statistically analyze the correlation between the Nelson's grade and dry eye patients' symptoms and signs.
Methods  From June 2010 to January 2011, 152 patients (303 eyes) suffering from dry eye and 60 normal subjects (120 eyes) were selected. Dry eye patients' complaints were recorded.The Schirmer I test (SIT)，break-up time (BUT), fluorescein staining of the cornea(FL) and Rose Bengal staining(RB) were examined ,meanwhile CICAO was done. All the patients were diagnosed according to the International Dry Eye Work Shop's(DEWS) principle of dry eye's grading. A fragment of 3mm×5mm (pore size: 0.22μm) nitrocellulose filter paper was compressed on the nasal conjunctiva of lower eyelid for 3 or 4 seconds them transferred the conjunctival epithelium specimens to a glass slide, dropped into the 0.01% acridine orange salt solution and stained for at least 3 minutes. Finally, specimens were observed under a fluorescence microscopy and recorded. The Spearman rank correlation test was used in statistical analysis on not only the relation between the grade of CICAO with the subjective symptoms of dry eye,but also the correlation between CICAO grade with the clinical signs. Moreover, the statistical analysis also done between the grade of CICAO and the diagnosis level according to the DEWS guide.
Result  There were 52 males (104 eyes) and 100 female patients (199 eyes) in dry eye group, with mean age was 55.7 ± 15.6 years. And the normal group's mean age was 53.1 ± 9.2 years,which consisted of 24males(48 eyes) and 36 females (72 eyes).The correlation between the grade of CICAO with subjective symptoms including dryness, tearing and soreness had a significant statistical association, the Spearman Correlation coefficients were 0.337, -0.278, 0.395,respectively P<0.05.The correlation coefficients between CICAO with RB, SIT, BUT and FL values were 0.757 ,-0.668 ,-0.549 ,and 0.428( P=0.000<0.01 ).The correlation coefficients between CICAO and the level of diagnosis on the basis of DEWS guide were 0.762(P<0.01).
Conclusion  The symptom of dry eye patients is complicated,and it has poor correlation with the clinical examinations. The conjunctival pathological damage in dry eye patients is earlier and more serious than the cornea's.The CICAO can determine the pathological changes of ocular surface especially in dry eye patients and provide a direct experimental evidence for the clinical diagnosis of dry eye. It has a high level corresponding relationship between CICAO and DEWS diagnosis level. Therefore, in accordance with the grade of CICAO, the severity level of dry eye's diagnosis is emerged, and then grading treatment has a reliable supporting evidence. Key Words: conjunctival impression cytology, dry eye, association, symptoms and signs