Size of Cells Collected from Normal Human Subjects Using Contact Lens Cytology

Laurent, John; Wilson, Graeme

doi:10.1097/00006324-199705000-00023

Cited by 10 publications

(17 citation statements)

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“…The size frequency profile of cells shed in non-contact lens wearing eyes is consistent with previous observations,15 as is the finding that 70% of the cells recovered using this technique are non-viable 24. Cell shedding has been attributed to two distinct mechanisms in the rabbit cornea—namely, terminal differentiation and apoptosis 25.…”

Section: Discussionsupporting

confidence: 89%

“…In contrast, 3 months of extended wear of low oxygen permeable lenses results in a significant increase in cell diameter of 8% compared with both non-wearers and wearers of highly oxygen permeable lenses. Longest cell diameter has been previously shown to correlate highly with cell area15 16 and based on their published regression, a cell size of 42 (SD 7) μm would be expected to have an area of 891 μm 2 . This calculated increase in area is similar to a previous report showing increased cell area (820 (99) μm 2 ) after 3 months of extended wear with weekly disposable lenses 10.…”

Section: Discussionmentioning

confidence: 99%

“…In the present study, apoptotic cells were not visible morphologically, and there were no statistically significant differences in cell size between viable and non-viable cells. However, the presence of a second peak at 27 μm (Fig 1) may suggest that apoptotic cells form part of the shed cell population15 and that more specific staining or immunohistochemical labelling techniques are required to confirm whether apoptosis is occurring and whether contact lens wear modulates this.…”

Section: Discussionmentioning

confidence: 99%

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Short term wear of high Dk soft contact lenses does not alter corneal epithelial cell size or viability

Stapleton

Kasses²,

Bolis³

et al. 2001

British Journal of Ophthalmology

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Background/aims-Current contact lenses (CLs) when worn on an extended wear basis cause corneal epithelial alterations. The aim of this study was to evaluate changes in corneal epithelial cell morphology and physiology following short term (3 months) wear of highly oxygen permeable CLs and to compare this with disposable CLs. Methods-Subjects were wearers of highly oxygen permeable CLs (n=11, wearing CLs on a 30 night schedule), disposable CL users (n=6, wearing CLs on a 6 night schedule), and non-CL wearers (n=20). Mean CL wear experience was 3 months. Epithelial cells were harvested using corneal cytology and were stained using acridine orange and ethidium bromide. Epithelial cell size and viability were determined. Results-The majority of epithelial cells recovered were non-viable (71%), and the mean longest cell diameter was 38 (SD 8) µm. Disposable CLs caused an increase in cell size (42 (7) µm) compared with both non-wear (39 (7) µm, p=0.01) and wear of highly oxygen permeable CLs (37 (10) µm, p=0.0049). There was no diVerence in cell viability between groups. Conclusions-Extended wear of disposable CLs caused an 8% increase in cell diameter in harvested corneal epithelial cells following 3 months of CL wear. Cells harvested following 3 months' wear of highly oxygen permeable CLs were indistinguishable from those recovered from non-CL wearers. (Br J Ophthalmol 2001;85:143-146) Long term overnight contact lens (CL) wear causes profound changes in corneal epithelial metabolism and physiology. In animal studies these eVects manifest as increased corneal epithelial fragility, due to epithelial oedema and loss of desmosomal contacts between cells, 1 and reduced epithelial adhesion, due to a reduction in the number of hemidesmosomes in the basement membrane adhesion complex.2 3 Lens related metabolic changes have manifested as impaired mitosis with lactate accumulation in the anterior chamber. 4 Studies in humans have demonstrated epithelial thinning and reduced oxygen uptake rate with long term extended lens wear. 5 More recently, overnight lens wear has been shown to impair epithelial barrier function, measured by an increase in permeability to sodium fluorescein. 6 Direct evaluation of corneal epithelial cell alterations has been possible using specular and confocal microscopy. Morphological changes following extended wear of hydrogel lenses have included increased corneal epithelial cell size on specular microscopy, 7 8 which has been attributed to a prolonged residence time of mature cells on the surface epithelium. Short term wear of disposable hydrogel lenses on a 6 night extended wear schedule has been shown to increase superficial cell area by 28% 9 and this eVect appears to be proportional to the duration of continuous wear. 10Both morphological and metabolic alterations associated with extended wear of hydrogel lenses have been primarily attributed to chronic hypoxia or corneal acidosis and, perhaps secondarily, to factors such as reduced tear exchange, mechanical eVects, and the impact of t...

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Section: Discussionsupporting

confidence: 89%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Short term wear of high Dk soft contact lenses does not alter corneal epithelial cell size or viability

Stapleton

Kasses²,

Bolis³

et al. 2001

British Journal of Ophthalmology

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“…In the present study, mean cell area of BC was measuring between 80 and 130 mm² and IC was between 130 and 160 mm². 26 our results support correlation between longest cell diameter and mean cell area. We have found that the mean cell size increases gradually from BC to SC layer (Fig.…”

Section: Discussionsupporting

confidence: 87%

Characteristic Quantities of Corneal Epithelial Structures in Confocal Laser Scanning Microscopic Volume Data Sets

Prakasam

Winter²,

Schwiede³

et al. 2013

Cornea

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“…These include use of the non-contact corneal irrigation chamber (NC-CIC) (Fullard and Wilson, 1986) and the contact lens cytology (CLC) approach, in which cells are collected from within a soft contact lens applied briefly to the cornea (Laurent and Wilson, 1997;Zhou et al, 2000). A further development is the Ocular Surface Cell Collection Apparatus (OSCCA), by which cells are collected after directing a stream of saline at the central cornea.…”

Section: Epithelial Turnover and Cell Sheddingmentioning

confidence: 99%