Abstract
Purpose: :
To evaluate the ability of a confocal laser microscope non-contact lens prototype to detect structural alterations of the cornea, iris, and lens in the unaffected eye of patients with clinically unilateral exfoliation syndrome (XFS) and XFS suspects.
Methods: :
We enrolled 24 patients (12 unilateral XFS [24 eyes], 6 XFS suspects [10 eyes], and 6 age-matched control subjects [12 eyes]). XFS suspects had secondary signs (loss of pupillary pigment ruff, iris transillumination defects, increased TM pigment, pigment dispersion after dilation, pigment dotting of the iris) in one or both eyes without any evidence of exfoliation material (XFM). Controls displayed no evidence of XFM or any secondary signs. The cornea, iris, and lens were imaged using a non-contact lens prototype for the Rostock Cornea Module of the Heidelberg Retina Tomograph II (50x Nikon lens, estimated lateral/axial resolution 1-2 µm/ 10 µm, field of view: 500 x 500 µm, working distance 13.8 mm). All images were analyzed by two observers masked to the clinical findings.
Results: :
XFM on the anterior lens capsule was characterized by hyperreflectivity in the granular and central disc areas and hyporreflective spaces in the intermediate clear zones. Similar hyperreflective areas were noted in 4/12 unaffected eyes of unilateral XFS, but no suspect or control (p=0.001, Fisher-exact test) eyes. Corneal stromal and/or endothelial deposits (less than size of endothelial cell) were found in 12/24 XFS (8 affected and 4 unaffected), 1/10 XFS suspect, and no control eyes. Pleomorphic and irregular deposits likely represent XFM, as pigment granules usually appear round and regular in size. Cataractous lenses revealed hyperreflective lens fibers and cavitations (vacuoles) in all groups.
Conclusions: :
Non-contact in vivo confocal microscopy permits visualization of XFM and/or XFM-related changes in the cornea and lens in the unaffected eyes of patients with clinically unilateral XFS. This new technique may allow early detection of subclinical XFS.
Keywords: imaging/image analysis: clinical • anterior segment • microscopy: confocal/tunneling