1. Conjunctival Impression Cytology in healthy volunteers
Diane Marinho, Andressa P. Stolz, Sergio Kwitko, Felipe K. Mallmann, Samuel Rymer
Ophthalmology Department - Hospital de Clínicas de Porto Alegre Federal University of Rio Grande do Sul - Porto Alegre - Brazil
The authors have no financial interest in the subject matter of this poster

2. Purpose
To determine conjunctival cytology findings in volunteers with no history of ocular disease and to correlate results with dry eye tests and frequency of symptoms.

3. Methods
Impression cytology (IC) of superior, inferior, nasal and temporal conjunctivae (Aragona’s scoring system)
Ocular surface evaluation clinical tests: Schirmer test (ST), tear film break-up time (TFBUT), Fluorescein staining (FS), Rose Bengal staining (RBS) and slit lamp examination
History and symptoms questionnaire

4. Results
78 eyes of 39 patients (77% female, 85% white) were examined. Mean age was 362 years (16-71)
Impression cytology : - grade A (normal):
71% superior
57% nasal
87% inferior
75% temporal
Snake-like chromatin in 15% of superior samples.
Clinical Tests:
Mean BUT was 13.6 seconds (70% ≥10 sec)
ST median was 19.2 mm (76% >6 mm),
RBS grade 0-3 in 87%
FS grade 0 in 75%
Slit lamp eyelid exam normal in 65%

5. Table 01. Scoring system for conjunctival impression cytology
Parameters
Normal
Borderline
Abnormal
Cellularity 1 2
Cell-to-cell contact
Nucleus/cytoplasm ratio
0 (1:2-3)
1 (1:4-5)
2 (1:≥ 6)
Nuclear chromatin
1 (≤ 1%)*
2 (> 1%)*
Goblet cell distribution
Keratinisation
2-3
Inflammatory cells -
Total Score
0-3
(class A)
4-6
(class B)
> 6
(class C)
*if snake-like chromatin

6. Figure 01. Illustrative impression cytology specimensB C D
A. Normal Cytology, B. Borderline Cytology, arrow indicating goblet cell, C. Abnormal Cytology (superior conjunctiva, PAS/HE/Papanicolaou OM 200x), D. 1-10% Snake-like chromatin containing sample, sign indicating a track of anomalous nuclear cells and E. > 10% Snake-like chromatin containing sample (superior conjunctiva, PAS/HE/Papanicolaou OM 400x). E

7. Results Nasal IC was associated with ST, TFBUT, RBS and symptoms.
Nasal IC score showed positive correlation with number of abnormal clinical tests (figure 3).
Temporal IC was associated with ST and symptoms.
Snake-like chromatin was associated with age, ST and IC nasal and superior findings.

8. Figure 02. IC data (valid specimens) for 6 combined clinical tests
*Linear-by-linear association S = superior; N = nasal; I = inferior; T = temporal.

9. Conclusions
Our study identified a prevalence of 57 – 81% of normal cytological findings in normal subjects
Impression cytology findings of exposed bulbar conjunctiva were more often altered
Despite a few associations among tests, there was no conclusive correlation among these tests, symptoms and IC results.

10. References
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Nelson JD. Impression cytology. Cornea 1988;7:71-81
Schein OD, Tielsch JM, Munoz B, Bandeen-Roche K, West S. Relation between signs and symptoms of dry eye in the elderly. A population-based perspective. Ophthalmology 1997;104:
Methodologies to diagnose and monitor dry eye disease: report of the Diagnostic Methodology Subcommittee of the International Dry Eye WorkShop (2007). Ocul Surf 2007;5:
Bjerrum KB. Snake-like chromatin in conjunctival cells of a population aged years from Copenhagen City. Acta Ophthalmol Scand 1998;76:294-8.
Paschides CA, Petroutsos G, Psilas K. Correlation of conjunctival impression cytology results with lacrimal function and age. Acta Ophthalmol (Copenh) 1991;69:422-5.