97th DOG Annual Meeting 1999



J. Hayler, N. Wakili, A. Händel

The purpose of this retrospective clinical cross-sectional study was to investigate the impact of the approach during cataract surgery following filtering operation on the functional outcome.

Patients and Methods: We studied 100 eyes (52 right, 48 left) of 48 female and 52 male patients (age 72±9 years) in whom cataract surgery was performed 5.9±6.7 years after filtering operation (54% primary open angle glaucoma, 42% secondary open angle glaucoma in pseudoexfoliation syndrome, 4% other types of secondary glaucoma). 60 cataract extractions were done by phacoemulsification and 42 by manual expression of the nucleus. In 67% of eyes the approach during cataract surgery was via clear cornea (CC) (location of approach: 50 superior, 7 temporal superior, 8 temporal and 4 superior nasal) and in 33% the approach was via corneoscleral tunnel (CST) (location of approach: 11 superior, 11 superior temporal, 10 temporal and 1 superior nasal). Visual acuity and astigmatism were assessed at three different time points: before (3.5±3.3 days), early (7.2±5.4 days) and late (33±21 months) after cataract surgery.

Results: Comparing CC and CST the best corrected visual acuity improved from 0,25±0,17/0,25±0,17 (p=0,78) preoperatively to 0.38±0.25/0.45±0.28 (p=0.27) early postoperatively and 0.42±0.27/0.49±0.35 (p=0.56) late postoperatively. The refractive minus-cylinder (in diopters D) increased from 0.6±0.9 D/0.4±0.7 D (p=0.368) preoperatively to 3.3±2.9 D/1.7±1.8 D (p=0.009) early postoperatively and decreased especially in the CC group to 1.5±2.0 D/1.2±1.2 D (p=0.934) late postoperatively. The keratometric astigmatism (²Zeiss²) increased from 0.9±0.8 D/1.0±0.7 D (p=0.492) preoperatively to 4.8±3.0 D/2.6±2.0 D (p=0.001) early postoperatively and decreased again to 1.9±2.0 D/1.2±1.2 D (p=0.298) late postoperatively.

Conclusion: The surgical approach during cataract surgery after filtering operation seems to have no impact on the best-corrected visual acuity (neither early nor late). However, the clear cornea approach (in order to protect the filtering bleb) is associated with a significantly higher astigmatism early after surgery, which tends to decrease during the long term follow up.

Augenklinik mit Poliklinik der Universität Erlangen-Nürnberg, Schwabachanlage 6, D-91054 Erlangen