Abstract
Purpose: :
To evaluate the visual outcome of photodynamic therapy (PDT) in patients with neovascular age-related macular degeneration (AMD) in routine clinical practice
Methods: :
A retrospective review of neovascular AMD patients treated with PDT between October 1999 and January 2007 in Lions Eye Institute in West Australia was conducted. Snellen visual acuities were converted to logMAR units for all calculations. The primary outcome measure was change in visual acuity. We defined effective response to treatment as vision improved or unchanged or deteriorated by less than 3 lines (0.3 logMAR units) and final visual acuity ≥6/60. We defined poor response to treatment as visual acuity deteriorated 3 or more lines (≥0.3 logMAR units) or legal blindness (<6/60) at the final visit
Results: :
A total of 323eyes (291patients) received mean 3.4 PDT treatments and were followed up for at least 6 months with a mean of 28 months. At final visit, 16.7% (54eyes) experienced improved vision, 7.1% (23eyes) were unchanged, and 76.2% (246eyes) had deteriorated. With our definition of response, 29.4% (95 eyes) had an effective response after PDT treatment, while 70.6% (228eyes) had a poor response, of which 56.3% (182 eyes) ended up legally blind in the treated eye. No correlation was found between lesion characteristics and treatment responses, except for subretinal scar tissue. The prevalence of subretinal scar tissue in the poor response group was 53.7% (117 eyes), compared with 21.5% (20 eyes) in the effective response group (p<0.001). Patients who received more than three treatments had a higher proportion of eyes (57.7% of 82eyes) forming subretinal scar tissue, compared with only 25.0% (11eyes) and 35.2% (44 eyes) with one treatment or 2 to 3 treatments respectively (p<0.001). As the number of treatment sessions increased, the proportion of effective responses decreased. With one treatment, 40.4% (19eyes) got an effective response. With two to three treatments, the effective response rate decreased to 32.6% (42 eyes). When treatment was applied four to 8 times only 23.1% (34 eyes) had an effective response (p=0.046)
Conclusions: :
The efficacy of PDT treatment for neovascular AMD is low. Most patients requiring multiple treatment sessions had a poor outcome. More than three PDT treatments added substantial cost with little benefit. Formation of scar tissue was a bad prognostic factor for visual outcome
Keywords: age-related macular degeneration • photodynamic therapy • clinical (human) or epidemiologic studies: outcomes/complications