Macular SD-OCT Outcome Measures: Comparison of Local Structure-Function Relationships and Dynamic Range
Miraftabi A, Amini N, Morales E, et al Invest Ophthalmol Vis Sci. 2016;57:4815-4823
Study Summary
Spectral domain optical coherence tomography (SD-OCT) has been a beneficial instrument for detecting and monitoring glaucoma. To date, the retinal nerve fiber layer (RNFL) measurement concentric to the optic nerve has been the most commonly used parameter in this process.
More recently, however, it has been suggested that macular measurements provide accurate diagnosis of glaucoma, although their utility in monitoring progression has yet to be established. In addition, the thickness measurement of individual or combined layers that best correlates with function, as determined by visual field evaluation, is also currently unknown.
Miraftabi and colleagues tested the hypothesis that the macular ganglion cell layer (GCL) has a stronger structure/function relationship and extends the useful range of macular measurements, compared with combined macular inner layer or full thickness. They analyzed 98 glaucomatous eyes and eight normal eyes with SD-OCT volume scans and 10-2 visual fields. Inner plexiform layer (IPL), GCL, macular RNFL, ganglion cell/inner plexiform layer (GCIPL), ganglion cell complex (GCC), and full thickness measurements were calculated.
The main outcome measures were local structure/function relationships between macular superpixels and corresponding sensitivities on 10-2 fields, dynamic range of measurements (the difference between the smallest and largest observed thickness values for macular SD-OCT thickness parameters), and the change point (total deviation value where macular parameters reached measurement floor).
