Factors affecting signal strength in spectral-domain optical coherence tomography.

We found that older age, poorer BCVA, greater degree of myopia and presence of cortical and posterior subcapsular cataracts were associated with reduced signal strength in Cirrus SD-OCT. Our findings provide information on the barriers to obtaining good image quality when using SD-OCT, and allow clinicians to potentially identify individuals who are more likely to have unreliable OCT measurements.