Main

Sir,

True exfoliation or lamellar delamination of the lens capsule is a rare disorder characterised by thickening of the lens capsule with marked splitting of the superficial portion of the anterior lens capsule from the deeper layers, which then extends creating an unusual floating membrane structure in the anterior chamber.1, 2, 3 There are no reports of patients with this condition undergoing modern phacoemulsification cataract surgery.

We describe a case in which completion of a continuous curvilinear capsulorhexis (CCC) was permitted by the use of trypan blue vital staining and uncomplicated phacoemulsification was completed.

Case report

A 65-year-old gentleman was referred to the eye clinic for consideration of cataract surgery. He complained of a gradual reduction in visual acuity over several months. There was no past ophthalmic history of note and no known systemic illness. He was taking no medication.

On examination, his visual acuities (VA) were 6 / 18 right and 6 / 12 left. Slit-lamp examination of the anterior segments demonstrated a striking floating membrane arising from the anterior lens capsule in both eyes. Corresponding defects were present on the anterior capsule in each eye; however, no lens fibre oedema or uveitis to suggest a full-thickness capsular rupture (Figure 1). Moderately advanced nuclear sclerotic cataracts were present, worse in the right eye. Fundal examination was unremarkable.

Figure 1
figure 1

Preoperative slit-lamp photograph of right eye in retroillumination demonstrating capsular abnormalities.

Full size image

At the patients' request, he was listed for surgery with planned right phacoemulsification cataract extraction with intraocular lens (IOL) implantation. The patient was counselled and given a guarded prognosis owing to uncertainty surrounding the intraoperative behaviour of the capsular abnormality.

Trypan blue (Vision Blue) vital staining of the anterior lens capsule demonstrated that the capsular abnormalities were indeed not full thickness and permitted the completion of a clearly identifiable, 5 mm CCC. The operation was continued with caution, but the capsules behaviour was not unduly atypical. The lens nucleus was removed utilizing a phacochop technique and the lens cortex material aspirated with a Simcoe cannula. No complications ensued and a foldable IOL was implanted in the capsular bag.

At 2 weeks postoperatively, the best-corrected VA was 6 / 9 and the IOL well centred ‘in the bag’.

Discussion

True exfoliation of the lens capsule was first described in glassblowers in 1922. Infrared exposure was recognised as the aetiology. Other reported causes include iridocyclitis, metallic intraocular foreign bodies, trauma, and idiopathic.3, 4 We suggest that our case represents an idiopathic aetiology, as the history was noncontributory. It is interesting to note that some authors believe the condition to be underdetected and under-reported.5

This, to our knowledge, is the first report of phacoemulsification with IOL implantation in true exfoliation of the lens capsule. The capsular abnormalities are striking and in our case these raised some concern. It was not clear whether it would be possible to form a CCC or whether capsular strength would be sufficient to withstand the forces associated with phacoemulsification. Trypan blue staining of the capsule permitted the construction of a clearly identifiable CCC despite the pre-existing abnormalities. Intraoperatively, although care was taken to avoid capsular stress where possible, there was no suggestion of overt fragility.

We consider that trypan blue staining of the anterior lens capsule was vital in the management of this case. Although the capsular integrity appeared satisfactory, a guarded prognosis with regard to outcome would seem prudent in patients with true exfoliation of the lens capsule.