Sir,

Cataract surgery has advanced owing to increasing biocompatibility of newer materials. Complications involving the clarity of intraocular lenses (IOLs) exist in literature and include most of the IOL types.1, 2, 3 We present a unique case of IOL opacification reminiscent of a congenital lamellar cataract.

Case report

An 81-year-old woman presented with 6-month history of cloudy vision in her left eye (LE). Her best-corrected visual acuity (BCVA) was 6/9 (RE) and 6/18 (LE). She underwent uneventful bilateral phacoemulsification 8 years previously with a foldable hydrophilic acrylic IOL (HA60-OUV, Suncoast Ophthalmics, Clearwater, FL, USA) in the LE. No information was available regarding the right IOL.

On examination, there was bilateral posterior capsular opacification. The LE was treated with YAG-laser capsulotomy, improving BCVA to 6/9. RE received no treatment. Central opacification in the lens optic reminiscent of lamellar cataract was subsequently observed in the LE (Figures 1a and b). The patient remained asymptomatic, maintained good near vision (N5) and normal contrast sensitivity. All other clinical findings were unremarkable.

Figure 1
figure 1

(a) and (b) Pseudophakic lamellar opacification. Note the central location of the opacity with the surrounding pulverulent-like changes, best seen in retroillumination.

Full size image

Comment

The SC60-OUV intraocular lens produced by Medical Developmental Research is a hydrophilic acrylic lens composed of poly-(2-hydroxyethyl methacrylate-(HEMA)) and PMMA with a polymerisable ultraviolet absorber. Distribution reached Europe with various commercial names including Suncoast as in our case. Production ceased in 2000 following reports of IOL opacification.4, 5, 6, 7 The majority of the reported cases of IOL opacification required surgical replacement. However, this was not necessary in our case.

Studies consider varying degenerative theories. Werner et al6 describe calcified granular deposits in hydrophilic acrylic IOLs deep in the lens optic with clear zone under the surface of the IOL, similar to our case. Werner et al7 also found calcium/phosphate deposits with element silicon and silicon compounds in extracted hydrophilic lenses. Moosavi et al4 suggested slow degradation of the polymer matrix and swelling of incompletely polymerized material in the optic core resulting in damage to the HEMA component of the IOL.

Most reports describe diffuse opacities leading to visual deterioration.5, 6 In our case, dense lens opacification occupied a concentric zone of the IOL, surrounded by dust-like satellite opacities in the outer zone, leaving a clear zone under the surface. This gave a unique appearance akin to paediatric lamellar cataract but no visual compromise 8 years after surgery, compared with reports of symptomatic IOL opacification occurring 6–24 months postoperatively.4, 5, 6

Late-onset IOL opacification can occur. Long-term follow-up is advisable before any conclusions are drawn regarding biocompatibility of hydrophilic acrylic IOLs.