Correlation between retinal thickness analysis, visual field changes and optic nerve cupping in glaucoma and suspects

Asrani S., Challa P., Lee P., Herndon L. and Allingham R.

Duke University Eye Center, Durham, NC, USA

Retinal thickness losses at the posterior pole have been demonstrated in patients with glaucoma.  Visual field changes in glaucoma often appear late in the disease process.  Glaucomatous changes in the optic nerve frequently precede visual field changes.  Inter-subject variability in the appearance of the optic nerve makes the diagnosis of glaucoma in early cases challenging.

The Retinal Thickness Analyzer (Talia Technology, Ltd., Israel) was used to obtain retinal thickness maps in 87 eyes (50 persons, mean age 56 y) either suspected or diagnosed with glaucoma.  Humphrey visual field test was performed on every patient along with stereo-photography of the optic nerve head.  Two masked glaucoma specialists were asked to grade the level of severity of glaucoma using each of the above three parameters.  Retinal thickness losses strongly correlated with optic nerve head changes and both correlated poorly with the visual field.  Conclusion: Retinal thickness measurements allow earlier diagnosis of glaucoma and early identification of level of severity of glaucoma than the conventional techniques.  Retinal thickness may be a sensitive technique to monitor changes over time in glaucomatous eyes as it provides another objective measure of neural loss besides the optic nerve head.