title: Comparison of the optical coherence tomographic features of choroidal neovascular membranes in pathological myopia versus age-related macular degeneration, using quantitative subanalysis.
abstract: OBJECTIVE
  To compare the retinal morphological characteristics of eyes with choroidal neovascularisation (CNV) secondary to pathological myopia versus eyes with CNV secondary to age-related macular degeneration (AMD), using quantitative optical coherence tomography (OCT) subanalysis.
  
  
  METHODS
  Twenty-one eyes of 21 patients newly diagnosed as having CNV secondary to pathological myopia, and 43 consecutive cases of eyes with newly diagnosed subfoveal CNV secondary to AMD were retrospectively collected. In all patients, StratusOCT images and fluorescein angiograms (FA) were available for analysis. StratusOCT images were analysed using custom software (termed "OCTOR"), which allowed calculation of the thickness/volume of the neurosensory retina, subretinal fluid (SRF), subretinal tissue (SRT) and pigment epithelial detachments (PEDs). FA images were used to calculate CNV leakage area and CNV lesion size for each eye.
  
  
  RESULTS
  The total volume of neurosensory retina in the pathological myopia group was significantly less than in the AMD group (7.10 (SD 0.50) mm3 vs 7.76 (0.93) mm3, p = 0.004). The total volume of SRF in the pathological myopia group was less than in the AMD group, but the difference was not statistically significant (0.33 (1.38) mm3 vs 0.55 (0.82) mm3, p = 0.434). The total volume of SRT in the pathological myopia group was less than in the AMD group, but the difference was not statistically significant (0.16 (0.15) mm3 vs 0.36 (0.60) mm3, p = 0.144). The total volume of PED in the pathological myopia group was markedly less than in the AMD group (0.01 (0.03) mm3 vs 1.09 (1.89) mm3, p<0.001). On FA, the total leakage of CNV in the AMD group was significantly greater than in the pathological myopia group (4.17 (3.29) DAs vs 0.53 (0.58) DAs, p<0.001).
  
  
  CONCLUSIONS
  CNV lesions in pathological myopia were associated with considerably less retinal oedema, SRF and SRT compared with CNV associated with AMD. PEDs were almost negligible in myopic lesions compared with AMD. These findings are consistent with previous clinical and angiographic descriptions of myopic CNV as relatively small lesions with modest exudation.
authors.affiliation: Doheny Image Reading Center, Doheny Eye Institute, Keck School of Medicine of the University of Southern California, 1450 San Pablo Street, DEI 3623, Los Angeles, CA 90033, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Keane
authors.forename: S
authors.initials: S
authors.lastname: Liakopoulos
authors.forename: K T
authors.initials: KT
authors.lastname: Chang
authors.forename: F M
authors.initials: FM
authors.lastname: Heussen
authors.forename: S C
authors.initials: SC
authors.lastname: Ongchin
authors.forename: A C
authors.initials: AC
authors.lastname: Walsh
authors.forename: S R
authors.initials: SR
authors.lastname: Sadda
mesh_terms: D000293:Adolescent; D000328:Adult; D020256:Choroidal Neovascularization / Q000209:etiology* / Q000473:pathology*; D005451:Fluorescein Angiography; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008268:Macular Degeneration / Q000150:complications*; D008875:Middle Aged; D047728:Myopia, Degenerative / Q000150:complications*; D010211:Papilledema / Q000209:etiology / Q000473:pathology; D010857:Pigment Epithelium of Eye / Q000473:pathology; D012160:Retina / Q000473:pathology; D012163:Retinal Detachment / Q000209:etiology / Q000473:pathology; D041623:Tomography, Optical Coherence / Q000379:methods