Optical Coherence Tomography–based Correlation Between Choroidal Thickness and Drusen Load in Dry Age-Related Macular Degeneration

Abstract

Purpose-Spectral domain optical coherence tomography can be used to measure both choroidal thickness and drusen load. The authors conducted an exploratory study using spectral domain optical coherence tomography to determine if a correlation between choroidal thickness and drusen load exists in patients with dry age-related macular degeneration.Methods-Forty-four patients with dry age-related macular degeneration were recruited. The drusen area and volume were determined using the automated software algorithm of the spectral domain optical coherence tomography device, and choroidal thickness was measured using enhanced depth imaging. Correlations were determined using multivariable and univariable analyses.Results-The authors found an inverse correlation between choroidal thickness and drusen load (r = −0.35, P = 0.04). Drusen load was also correlated with visual acuity (r = 0.32, P = 0.04). A correlation between choroidal thickness and visual acuity was suggested (r = −0.22, P = 0.21).Conclusion-Spectral domain optical coherence tomography can be used to assess the correlation between drusen load and choroidal thickness, both of which show a relationship with visual acuity. The measurement of these outcomes may serve as important outcome parameters in routine clinical care and in clinical trials for patients with dry age-related macular degeneration. Age-related macular degeneration (AMD) is one of the leading causes of vision loss in people over the age of 50 in the developed world. The role of the choroid in the pathogenesis and progression of dry AMD through the formation and accumulation of drusen deserves further investigation. The choroid provides the only circulation for the retinal pigment epithelium (RPE) and outer retina. Therefore, it is the primary means of metabolic support for these tissues. 1 It has been shown that the choriocapillaris has unique features including high flow rate and low oxygen extraction that are mandatory to sustain normal photoreceptor metabolism. 3 Hence, the choroid's critical role of metabolic support for the retina and RPE suggests that this vascular layer may have a role in drusen development. In other words, RPE with poor metabolic support secondary to deficient choroidal supply may be more prone to developing drusen as they are unable to completely metabolize photoreceptor byproducts. 4,5 Spectral domain optical coherence tomography (SD-OCT) is a relatively new technology that allows detailed imaging within the retina, including the photoreceptor layer and RPE, as well as the choroid. 6 High-definition SD-OCT has previously been used to measure choroidal thickness in AMD. 7 It has been demonstrated that enhanced depth imaging (EDI) SD-OCT, which produces an inverted image from 100 scans to improve signal-to-noise ratio, can be used to visualize the choroid even better. [8][9][10][11] The new technology has lead to better understanding of the role of choroid in various macular diseases, including central serious chorioretinopathy, 9-11 high myopia, 12,13 Vogt-Koy...

Relationship of Central Choroidal Thickness With Age-Related Macular Degeneration Status

“…14 Ko and associates reported an inverse relation between drusen area and choroidal thickness, but after multivariate regression analysis including age and sex, drusen area was not found to be an independent predictor of choroidal thickness. 38 In contrast, our results differed from that of Lee and associates, who examined 176 eyes with non-neovascular AMD stratified based on AREDS classification of fundus findings, and found progressive choroidal thinning correlating with later stages of nonexudative AMD, even after age adjustment. 39 This cohort consisted of primarily East Asians, and the mean age of eyes classified as AREDS category 3 intermediate AMD was much younger than those reported in other studies (Table 4).…”

MRI of rod cell compartment-specific function in disease and treatment in vivo

“…Indeed, significant light-evoked expansion of choroidal thickness in mice was observed using ADC MRI (Berkowitz et al, 2015a). To assess sensitivity, it was noted that light-adapted choroidal thickness and its regulation are reduced with diabetes and age as has been reported in other studies using other methods (Dallinger et al, 1998;Fitzgerald et al, 2001;Ko et al, 2013). This Table 1 Anti-oxidant approaches so far examined that correct early diabetes-induced MRI retinal abnormalities.…”

Macular Ganglion Cell Complex and Retinal Nerve Fiber Layer Comparison in Different Stages of Age-Related Macular Degeneration

“…[2][3][4][5][6][7][8][9][10][11][12][13] On the other hand, there is scant information regarding the condition of the inner retina in the different stages of the disease. 14 Some authors have hypothesized that AMD might also affect the three innermost retinal layers, referred to collectively as the ganglion cell complex (GCC) -the inner plexiform layer (IPL), which contains the retinal ganglion cell dendrites; the ganglion cell layer (GCL), which is composed of ganglion cell bodies; and the retinal nerve fiber layer (RNFL), where the ganglion axons are located.…”