Sir,

Intravitreal triamcinolone (IVT) is increasingly frequently used for a variety of retinal disorders, such as refractory diabetic oedema, cystoid macular oedema following vein occlusions, and in the treatment of occult sub-retinal neovascular membranes. We report a case of inadvertent injection of triamcinolone into the crystalline lens and the observation of the lens for the subsequent year.

Case report

An 82-year old phakic, diabetic man had persistent, bilateral, chronic macular oedema. Despite two macular grid laser treatments to each eye, the best-corrected visual acuity remained at 6/60 right and left. He underwent right IVT, performed by a surgeon with previous experience of intravitreal injections. It was recorded as having been performed in aseptic conditions with a needle insertion site 3 mm posterior to the superotemporal limbus. Routine examination 1 h post-procedure revealed a needle puncture site in the superotemporal aspect of the posterior lens capsule and multiple collections of triamcinolone throughout one lamellar plane of the posterior lens substance. Figures 1 and 2 show the lens at 2 months and 5 months post-procedure. At the time of these photos, the visual acuities were Snellen 3/60, and count fingers, respectively. The triamcinolone granules remained almost unchanged for almost a year before gradually dispersing. A posterior subcapsular cataract first developed at 7 months post-procedure. However, even at 11 months (Figure 4), the lens was not densely cataractous and there was still a needle track opacity visible. Although the cataract has progressed, he has not undergone cataract extraction as the intraocular pressure rose to 42 mm Hg at 6 months post-procedure, and has proved difficult to control, making surgery high risk. The view of the macula is poor but the chronic oedema does not appear to have improved.

Figure 1
figure 1

2 months post injection.

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Figure 2
figure 2

5 months post injection.

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Comment

Our current technique for intravitreal injection is based on recently published guidelines1 and in summary is as follows: after appropriate local anaesthetic, the surgical field is cleaned with povidone iodine and a speculum is inserted to keep the site clear of eyelashes. Calipers are used to mark a point 4 mm posterior to the limbus. A bleb of local anaesthetic is created at this site. The triamcinolone is injected at this point through a 27-gauge needle aiming towards the optic nerve. In the above case, a combination of a slightly anterior injection site (3 mm from the limbus) and misdirection of the needle is likely to be responsible for the complication.

Perforation of the lens usually causes a rapidly forming, localized or generalized lens opacity, sometimes forming along the track of the penetration.2 In our case, the injection site was visible, as were the triamcinolone granules in a lenticular plane and two tracks along which they travelled. However, the lens did not opacify until 7 months post-procedure.

We have illustrated above the association between steroid and cataract and breech of the lens capsule and cataract. We were therefore surprised that this patient did not develop cataract sooner. Intravitreal triamcinolone is being administered increasingly frequently for an ever increasing list of conditions. This uncommon complication of the procedure shows that this is not a risk-free procedure. It illustrates the importance of careful technique in the hands of experienced surgeons and the need for careful supervision for trainee surgeons.