Exfoliation syndrome (XFS) is an age-related disease characterised by production and progressive accumulation of fibrillar extracellular material in many ocular tissues, mainly the anterior lens capsule and the pupillary margin. Presence of exfoliation material is known to be associated with an increased incidence of complications with cataract surgery.12 Fragile zonules are one of the important risk factors for zonular dehiscence and vitreous loss in these eyes.3
On the anterior lens capsule, exfoliation material is characteristically deposited in 3 zones:4 a homogenous central disc corresponding to the size of the undilated pupil, a granular peripheral zone near the lens equator and a clear intermediate zone separating the two. We have noted the presence of a central bulge in the anterior lens capsule suggestive of anterior lenticonus in some eyes with exfoliation that is associated with very fragile zonules and a high risk for zonular dialysis during cataract surgery. A MEDLINE search using a combination of the key words exfoliation, lens, lenticonus and pseudoexfoliation and a search of relevant articles describing lenticular changes in exfoliation syndrome listed in a recent comprehensive review article4 suggested that this feature has not been described earlier.
One hundred thirty four consecutive eyes with exfoliation and senile cataract undergoing cataract surgery at our hospital over a 6-month period from July 2002 to December 2002 were examined by slit lamp biomicroscopy prior to surgery to look for a characteristic bulge in the anterior capsule. Of these, 5 eyes (3.7%) were noted to have anterior "lenticonus". All 5 eyes had a central conical bulge in the anterior capsule associated with exfoliation material on the anterior lens capsule, pupillary border and the corneal endothelium (Figures 1 and 2). All 5 eyes did not dilate well with mydriatics and had dense nuclear cataract while one eye (20%) had phacodonesis. Clinical features and surgical complications in these eyes are described in Table 1. In contrast, among the 129 exfoliation eyes without "lenticonus" undergoing extracapsular cataract extraction during the same period, phacodonesis was present in 7 eyes (5.4%) and 22 eyes (17.1%) did not dilate well. The difference between incidences of phacodonesis was not statistically significant (p > 0.1 chi-square test) but the incidence of poor mydriasis was significantly greater in eyes with "lenticonus" (p < 0.001 chi-square test).
During cataract surgery, zonular dialysis or vitreous loss occurred in all 5 eyes (100%) indicating fragile zonules. The incidence of zonular dialysis was significantly lower (11 eyes, 8.8%; p < 0.001 chi-square test), in other 129 exfoliation eyes without lenticonus.
The cause for the central bulge in the anterior capsule in eyes with XFS is unclear. We believe that it represents either a thick central disc of heaped up exfoliation material or a genuine conical protrusion of the anterior capsule due to lax zonules. All these eyes had a very heavy exfoliation load as was evidenced by the poor pupillary dilatation and extensive deposits of exfoliation material. Although this feature has not been reported earlier, we have noted that it occurs in several eyes with heavy exfoliation.
Presence of exfoliation is an important risk factor for cataract surgery but all eyes with XFS do not have the same risk for complications during cataract surgery. One study5 has reported excellent results following cataract surgery in eyes with exfoliation while other studies26 have found significantly higher complication rates in such eyes. Probably, the severity of XFS influences the result of cataract surgery. Eyes with dense XFS are known to be associated with phacodonesis78 although this may not be clinically evident. Although clinically evident subluxation was seen in one of the eyes with lenticonus, all eyes had very fragile zonules which was evidenced by the occurrence of zonular dialysis in all these eyes during cataract surgery.
We believe that the finding of anterior "lenticonus" in eyes with exfoliation is important. This isolates eyes with heavy exfoliation load, which are very likely to have fragile zonules and are prone to intra-operative complications.
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