Influence of cataract surgery with implantation of different intraocular lenses on scanning laser tomography and polarimetry.

PURPOSE: To describe the influence of cataract surgery with implantation of different intraocular lenses on scanning laser tomography (SLT) and scanning laser polarimetry (SLP) and to measure the birefringent properties of intraocular lenses in a laboratory setting.

DESIGN

Prospective cohort study.

METHODS

The influence of phacoemulsification cataract surgery with intraocular lens implantation (56 polymethylmethacrylate [PMMA; 31 Pharmacia/Upjohn 811 B and 25 Domilens Flex 60]; 25 hydroxyethylmethacrylate/methylmethacrylate (HEMA/MMA) [Technomed, Memory Lens]; 32 silicone [Allergan Si40]; 25 acrylic [Storz Hydroview]) on SLP and SLT measurements was evaluated preoperatively and 3 to 4 weeks postoperatively in 138 eyes of otherwise healthy patients. Lens opacities were classified according to the Lens Opacities Classification System III (LOCS III). Imaging was performed with TopSS and GDx (Laser Diagnostic Technologies, San Diego, California, USA) for SLT and SLP, respectively. Additionally, birefringent properties of intraocular lenses were measured in a laboratory setting.

RESULTS

Our results show that imaging with SLT and SLP is possible with lens opacity-induced visual acuity reductions down to 0.2 and 0.16, respectively. There were no significant differences in the topographic parameters assessed before and after cataract surgery with SLT. However, standard deviations between three within-session single measurements were smaller postoperatively. Nerve fiber layer patterns were similar before and after cataract surgery with SLP, whereas certain total nerve fiber layer thickness values were significantly higher postoperatively. As a consequence, "the number" is significantly lower in the Domilens Flex 60 group (P =.01) and in the Storz Hydroview group (P =.02), and with a tendency also in the other groups as well. Measurements with a high-resolution optical bench revealed no birefringent properties of the implanted lenses.

CONCLUSIONS

Our results indicate that after cataract surgery with intraocular lens implantation some SLP values are altered significantly, whereas SLT parameters are not influenced. These findings are of clinical interest, especially in the follow-up of glaucoma patients.