Effects of ionizing radiation on human conjunctival epithelial cells: a clinical and cytologic study

Goblet cells of the normal human bulbar conjunctiva and their assessment by impression cytology sampling

Goblet cells of the conjunctiva are the main source of mucus for the ocular surface. The objectives of this review are to consider the goblet cells as assessed by various histological, cytological and electron microscopy methods, and to assess the consistency of published reports (over more than 25 years) of goblet cell density (GCD) from impression cytology specimens from nominally healthy human subjects. Reported GCD values have been notably variable, with a range from 24 to 2226 cells/mm² for average values. Data analysis suggests that a high density of goblet cells should be expected for the healthy human conjunctiva, with a tendency toward higher values in samples taken from normally covered locations (inferior and superior bulbar conjunctiva) of the open eye (at 973 +/- 789 cells/ mm²) than in samples taken from exposed (interpalpebral) locations (at 427 +/- 376 cells/mm²). No obvious change in GCD was found with respect to age, perhaps because the variability of the data did not allow detection of any age-related decline in GCD. Analyses of published data from 33 other sources indicated a trend for GCD to be lower than normal across a spectrum of ocular surface diseases.

Impression cytology of the ocular surface: a review

PURPOSE

To historically review the technique of impression cytology as a minimally invasive diagnostic tool for ocular surface pathology.

METHODS

A comprehensive review of published literature cited in PubMed since the first description of impression cytology in 1977 up to date has been undertaken.

RESULTS

A wide range of processing methods have been adapted to the technique of impression cytology (from conjunctiva, cornea or limbus): regular light microscopy with different stainings, transmission and scanning electron microscopy, immunofluorescence, immunocytochemistry, polymerase chain reaction analysis, immunoblotting analyses, or flow cytometry. At present, it is widely used as a non-invasive alternative to the full-thickness biopsy for the obtention of epithelial cells from the ocular surface.

CONCLUSIONS

Impression cytology represents a non- or minimally invasive biopsy of the ocular surface epithelium with no side effects or contraindications. It has demonstrated to be a useful diagnostic aid for a wide variety of processes involving the ocular surface. In addition, and mainly during the last decade, its use as a research tool has experienced an enormous growth and has greatly contributed to the understanding of ocular surface pathology.

Treatment of conjunctival squamous cell carcinoma with topical 5-fluorouracil

AIM

To evaluate the efficacy of topical 5-fluorouracil (5-FU) alone, without concurrent surgery or radiotherapy, for the treatment of conjunctival squamous cell carcinoma.

METHODS

Eight patients affected by conjunctival squamous cell carcinoma (three recurrent cases, three incompletely excised, and two untreated cases) were treated with 1% 5-FU eye drops. Topical 1% 5-FU was administered four times daily for 4 weeks (one course). Clinical examination (biomicroscopy and photography) and morphological evaluation of conjunctival cytological specimens were used to monitor the efficacy of local chemotherapy, side effects, and recurrences.

RESULTS

All patients showed clinical regression of conjunctival carcinoma after topical 1% 5-FU treatment. Neoplastic conjunctiva was completely replaced by normal epithelium within 3 months. Mean follow up was 27 months. One patient needed two courses of local chemotherapy for recurrent disease. An acute transient toxic keratoconjunctivitis was observed in all treated cases; it was easily controlled with topical therapy. No long term side effects were found.

CONCLUSIONS

Topical 1% 5-FU is effective in the treatment of recurrent, incompletely excised, and selected untreated conjunctival squamous cell carcinomas. Topical 1% 5-FU has no major complications. This study suggests that topical conjunctival chemotherapy with 1% 5-FU may be useful, at least as adjunctive therapy, in the treatment of conjunctival squamous cell carcinoma.