Effect of three months of soft contact lens wear on conjunctival cytology

BACKGROUND

The purpose of this study was to investigate the effect of three months of soft contact lens wear on conjunctival goblet cell density and epithelial cell morphology.

METHODS

This was a longitudinal clinical trial. Conjunctival impression cytology was performed on the superior palpebral conjunctiva in fifty-four eyes of twenty-seven neophyte contact lens wearers before and after three months of contact lens wear. Goblet cell density was determined by optical microscopy and epithelial cell morphology was classified according to the Tseng classification. Changes in goblet cell density as well as epithelial cell grading were determined. The effects of lens material and wearing modality on cytological changes were also investigated.

RESULTS

Goblet cell density reduced significantly by 85 ± 151 cells/mm(2) (p < 0.001) after three months of contact lens wear. Reduction in goblet cell density was associated with lens materials; it was higher in conventional hydrogel lenses in comparison to silicone-hydrogel lenses (p = 0.008). The highest reduction in goblet cell density was found with Nelfilcon A lens wear (p = 0.002) and the lowest with Comfilcon A lens wear (p = 0.414). There was no statistically significant difference in grading of epithelial metaplasia before and after three months of contact lens wear (p = 0.075). Age was not correlated with the reduction in goblet cell density (r = -0.196, p = 0.160) but it was associated with the change in epithelial cell morphology (p = 0.036).

CONCLUSION

Three months of soft contact lens wear statistically significantly reduced goblet cell density; however, no significant changes were found in the grading of epithelial metaplasia. Contact lenses with lower oxygen permeability, higher Young modulus and higher thickness highly affected the conjunctival cytology.

Contact lens wear and the goblet cells of the human conjunctiva-A review

PURPOSE

To review the reported effects of contact lens wear on the goblet cells of the human conjunctiva.

METHODS

A literature search was undertaken to identify reports on the conjunctival health after contact lens wear, principally as assessed using the conjunctival impression cytology (CIC) technique in which cells are examined ex vivo, after fixation and staining. Details of technique, data on duration of contact lens wear and then CIC outcome in terms of goblet cell density (GCD) were extracted.

RESULTS

Of 24 reports identified, 22 examined the bulbar conjunctiva and 2 examined the tarsal conjunctiva. A decrease in GCD was considered, directly or indirectly, to be a consequence of contact lens wear in 18 of the studies, but there was no obvious overall relationship between duration of lens wear and the GCD changes. Conversely, four reports indicated an increase in GCD or goblet cell-related mucins. Two reports concluded that there was no change in goblet cells or their mucin, a result however that is consistent with a recent conclusion that no statistically significant change in GCD was detectable in contact lens wearers assessed by in vivo imaging of the human conjunctiva by confocal microscopy.

CONCLUSIONS

The majority of published studies have concluded that contact lens wear results in a decrease in goblet cells in the conjunctiva. While there are reports that draw a very different conclusion, it should be noted that there has been limited consistency in technique or the method of reporting the results across the various studies.

Therapeutic contact lenses and eyedrops--is there a problem?

Numerous authors have investigated the interactions of contact lenses with their care solutions. Many reported hypersensitivity and toxicity reactions induced by the preservative in the care solution, especially with soft contact lenses. In medical contact lens practice the concurrent use of eyedrops in a patient wearing therapeutic contact lenses is a contentious issue. The usual practice is to prescribe unpreserved drops. In reviewing the literature, we found no evidence of complications using preserved eyedrops with such contact lenses in situ. The reluctance to prescribe preserved topical medication could stem from the evidence relating to contact lens care solutions.

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.

Effects of soft contact lenses on conjunctival surface

PURPOSE

To examine the effects of soft contact lenses on tear breakup time (TBUT), basal Schirmer test result, and the conjunctival surface in patients wearing contact lenses.

METHODS

In this study, conjunctival cytologic changes, TBUT, and Schirmer test function alterations of soft contact lens wearers were evaluated by impression cytology. The study included 100 eyes of 50 soft contact lens wearers who were followed up in the Department of Ophthalmology of Dicle University and 80 eyes of 40 subjects as a control group. After TBUT and basal Schirmer test, conjunctival surface epithelial morphology was investigated using impression cytology. After the materials were appropriately stained, they were evaluated according to the Nelson grading scale.

RESULTS

Contact lens wearers were divided into three groups according to the duration of contact lens wear. When these groups were evaluated according to the Nelson grading method, 21% of cases were grade 0; 32% were grade 1; and 28% were grade 3. There were statistically significant differences in epithelial cell morphology, goblet cell density, snakelike chromatin changes, TBUT, and basal Schirmer test result between the control and study groups.

CONCLUSIONS

We suggest that TBUT and Schirmer test result be carefully monitored in contact lens wearers. Impression cytology may be used as a safe, simple, and noninvasive method in the diagnosis of ocular surface alternations in patients with contact lens intolerance.

Conjunctival impression cytology in contact lens wearers

The upper tarsal conjunctiva is in constant friction with the surface of the contact lens. The conjunctival surfaces of 80 soft and gas-permeable contact lens wearers (40 each) and 20 controls were studied using biomicroscopy and impression cytology. A filter dissolution technique was used to process the conjunctival imprints. Biomicroscopic and cytologic grading of the conjunctivae was performed using four-tier grading systems. Impression cytology is a non-invasive, painless procedure. The altered technique of processing yielded better cellularity and excellent cellular detail. On biomicroscopy and cytology, all controls showed Grade 1 appearances. Soft lens wearers who were symptomatic were found to have a significant increase in both biomicroscopic and cytologic grades, when compared with their asymptomatic counterparts. No correlation was found between duration of lens use and biomicroscopic or cytologic grades. All changes were found to be more severe in soft lens wearers.

Clinicopathological correlation of hard contact lens related changes in tarsal conjunctiva by impression cytology

Eighty contact lens wearing eyes and 20 non-contact lens wearing eyes are investigated for biomicroscopic changes and impression cytology. Symptomatic contact lens wearing eyes demonstrate significantly more prevalent and severe papillary conjunctival changes than in asymptomatic contact lens wearing eyes. Impression cytological changes demonstrate squamous metaplasia and goblet cell loss which is seen to increase with increasing duration of lens wear.