Clinical Study
Eye (2007) 21, 614–623. doi:10.1038/sj.eye.6702286; published online 24 February 2006
Quantitative analysis of corneal microstructure in keratoconus utilising in vivo confocal microscopy
K H Weed1, C J MacEwen1, A Cox1 and C N J McGhee2
- 1Ophthalmology Department, Ninewells Hospital and Medical School, Dundee, Scotland, UK
- 2Department of Ophthalmology, University of Auckland, Auckland, New Zealand
Correspondence: KH Weed, Ophthalmology Department, Ninewells Hospital and Medical School, Dundee, Scotland DD1 9SY, UK. Tel: +44 1382 632 348; Fax: +44 1382 660 130; E-mail: k.h.weed@dundee.ac.uk
Received 16 June 2005; Accepted 6 January 2006; Published online 24 February 2006.
Abstract
Purpose
To establish and quantify the in vivoconfocal microscopic features of moderate to advanced keratoconus.
Methods
Nineteen keratoconus subjects were catergorised using Orbscan-derived corneal apex power and pachymetry as exhibiting moderate (n=7) and advanced (n=12) keratoconus. Control subjects included 23 noncontact lens wearers (Group A) and 15 contact lens wearers (Group B). All subjects underwent Confoscan slit scanning in vivoconfocal microscopy.
Results
Compared with Group A (4912
434 cells/mm2), basal epithelial density was significantly lower in both moderate (4592414 cells/mm2, P<0.05) and advanced keratoconus (4530596 cells/mm2, P=0.01). In comparison to Group A (761118 cells/mm2), anterior stroma keratocyte density was significantly greater in both moderate keratoconus (883111 cells/mm2, P=0.001) and advanced keratoconus (952122 cells/mm2, P<0.001). Compared to Group A (50480 cells/mm2) posterior stroma keratocyte density was also significantly greater in advanced keratoconus (59997 cells/mm2, P<0.001) and posterior stromal keratocyte density appeared to increase with increasing severity of keratoconus (P<0.05). However, comparing control Groups A and B, contact lens wear per se, was associated with significantly reduced (P=0.000) keratocyte density in the anterior stroma (60966 cells/mm2) and demonstrated a trend (P=0.056) in the posterior stroma (47063 cells/mm2). Keratoconic corneas (42972 
m) were significantly thinner than control Groups A (50877 mm) and B (49580 m). The presence of keratoconus did not affect the endothelial cell density (P=0.54).
Conclusion
In vivoconfocal microscopy can provide insight into the microstructural changes that occur in keratoconus.
Keywords:
in vivo confocal microscopy, keratoconus, cornea, contact lens
