Is Choroidal or Scleral Thickness Related to Myopic Macular Degeneration?
The relative contribution of mechanical and vascular factors to the pathogenesis of myopic macular degeneration (MMD) is unclear. To address this gap, we examined the association of choroidal thickness (CT) and scleral thickness (ST) with MMD.



Prospective, clinic-based case series of 62 eyes of 41 patients with high myopia (≤-6 diopters or axial length ≥26.5 mm). Swept-source optical coherence tomography (SSOCT) was performed to measure subfoveal CT and ST. Myopic macular degeneration was graded from fundus photographs according to the International Meta-Analysis for Pathologic Myopia (META-PM) classification. Presence of MMD was defined as META-PM category ≥ 2 and severe MMD was defined as category ≥ 3.



The distribution of MMD severity was 15 (24.2%) in category 1, 28 (45.2%) in category 2, 10 (16.1%) in category 3, and 9 (14.5%) in category 4. Correlation of MMD severity was strong for subfoveal CT (r = -0.70, P < 0.001) but weak for subfoveal ST (r = -0.31, P = 0.01). Subfoveal CT, but not ST, was independently associated with presence of MMD (age and gender adjusted odds ratio [OR] per 10 μm decrease in CT 1.41, P = 0.002), and subfoveal CT, but not subfoveal ST, was significantly thinner in eyes with severe MMD (≥ category 3) than in eyes with mild MMD (CT: 31.5 ± 40.5 μm versus 82.0 ± 57.1 μm, P < 0.001; ST: 261.6 ± 78.5 μm versus 297.0 ± 73.8 μm, P = 0.09).



We demonstrated significant thinning of the choroid with increasing MMD severity. In contrast, ST was weakly correlated with MMD. These data suggest progressive loss of choroid may be important in the pathogenesis of MMD.
Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 2Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, National University of Singapore, Singapore.
Chee Wai
CW
Wong
Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.
Val
V
Phua
Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 2Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, National University of Singapore, Singapore.
Shu Yen
SY
Lee
Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 2Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, National University of Singapore, Singapore.
Tien Yin
TY
Wong
Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 2Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, National University of Singapore, Singapore.
Chui Ming Gemmy
CM
Cheung
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058452:Axial Length, Eye / Q000473:pathology; D002829:Choroid / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008266:Macula Lutea / Q000473:pathology*; D008268:Macular Degeneration / Q000175:diagnosis* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D047728:Myopia, Degenerative / Q000150:complications* / Q000175:diagnosis; D011446:Prospective Studies; D012029:Refraction, Ocular; D012590:Sclera / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity