Abstract
Purpose: :
To describe neural retinal morphologic changes that occur in exudative AMD as measured by ocular coherence tomography (OCT, Zeiss). We also demonstrate changes in these findings that occur following anti– VEGF treatment with Macugen (pegaptanib, Eyetech) and Avastin (bevacizumab, Genentech).
Methods: :
This is a retrospective case series of 19 eyes of 19 patients, aged 66 to 92, who presented to The George Washington University ophthalmology clinic with exudative AMD from November 2003 to November 2005. Patients were included in the study if they had evidence of exudative changes/subretinal fluid on clinical exam confirmed with OCT and subfoveal CNV with leakage on fluorescein angiography (FA). Patients lacking OCT and those with long standing lesions (>6 months) or subretinal fibrosis were excluded. Foveal and maximal retinal thickness were measured on cross sectional OCT scans which were further evaluated for cystic lesions and retinal pigment epithelial detachments (RPED). For patients receiving treatment (n=8) with intravitreal Macugen 0.3mg/0.1ml or Avastin 1.0mg/0.04ml, OCT scans were reviewed and maximum retinal thickness measured before and after treatment.
Results: :
17 eyes showed predominately occult subfoveal CNV while 2 eyes showed predominately classic CNV as evaluated by FA. On initial OCT, 16 (84%) eyes had increased retinal thickness when compared with normal retina (>250 microns) with a mean maximum thickness of 334 microns (SD 71), 6 (32%) eyes had retinal cystic edema, and 7 (37%) eyes had a large RPED. OCT scans taken before and after treatment were evaluated for 10 injections (7 eyes) of intravitreal Avastin. There was statistically significant (p=0.026, Student T–test) reduction of retinal thickening after treatment with Avastin, with a mean pretreatment retinal thickness of 353 microns (SD 58) and post–treatment thickness (1–8 weeks after treatment) of 308 microns (SD 27), a 13% reduction. 1 of 2 eyes with cystic lesions showed a decrease in such lesions at 8 weeks. 2 of 4 eyes with RPED had collapse of RPED by 6 weeks. No significant difference in retinal thickness (p=0.50) was seen with Macugen treatment (n=4 injections in 3 eyes).
Conclusions: :
This is the first description of neural retinal thickening and retinal cystic changes that occur in exudative AMD as measured by OCT. Significant reduction in these pathlogies as well as in RPED following treatment with Avastin suggests that these processes are VEGF dependent. These results imply that anti–VEGF therapy may be important in the rehabilitation of vision in eyes with exudative AMD.
Keywords: age-related macular degeneration • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retina