Factors influencing poor visual outcome in patients treated with photodynamic therapy for choroidal neovascularization secondary to age-related macular degeneration.

BACKGROUND

This study evaluated patients with choroidal neovascular membranes secondary to age-related macular degeneration for factors that may predict the visual outcome after photodynamic therapy.

METHODS

A retrospective review of 172 eyes of 172 consecutive patients who received photodynamic therapy for predominantly classic with and without occult, minimally classic and occult choroidal neovascular membranes secondary to macular degeneration in private practice from June 2000 to September 2004 was undertaken. All eyes had a baseline vision of 6/12 to 6/60. Classification of lesion composition, retreatment and follow up adhered to published photodynamic therapy guidelines. The primary outcomes measured were effects of patient age, baseline visual acuity, lesion composition and lesion size on final visual acuity and loss of less than 15 letters of logMAR at 12 months.

RESULTS

All eyes were followed up for 12 months. Baseline mean logMAR visual acuity was logMAR 0.64. Using multivariate logistic regression, loss of logMAR vision at 12 months was independently associated with increasing age (P=0.004), better baseline vision (P=0.009) and increasing lesion size (P=0.035). However, there was no association with lesion composition (P=0.16). At 12 months the loss of 15 letters or less was found in 101 (59.7%; 95% confidence interval: 51.0-66.2%) of all patients.

CONCLUSIONS

This study found no statistically significant association between lesion composition defined on fluorescein angiography and loss of visual acuity compared with previous studies. Factors associated with an increased rate of loss of 15 letters were increasing age of the patient, increasing lesion size and better baseline logMAR vision.