Optimizing the Detection of Preperimetric Glaucoma by Combining Structural and Functional Tests

PURPOSE. We evaluated the performance of low contrast achromatic (LLA) multifocal visual evoked potentials (mfVEP) in preperimetric glaucoma and compared its diagnostic performance to other early diagnostic tests. We identified the clinically most useful tests and combinations in preperimetric glaucoma. METHODS. We studied 59 patients with at least one glaucomatous disc, with normal, reliable visual fields in that eye, and 17 normal controls. All participants underwent complete ophthalmic examination including Humphrey visual fields (HVF), short wavelength automated perimetry (SWAP), frequency doubling perimetry (FDT Matrix), Spectralis optical coherence tomography (OCT), Heidelberg retinal tomography (HRT 3), and color stereoscopic optic disc photographs. We recorded mfVEPs using LLA stimulation. RESULTS. We studied 85 eyes of 59 patients (64.89 +/- 8.15 years) and 34 eyes of 17 controls (64.28 +/- 13.06 years; P = 0.64). Heidelberg retinal tomography and LLA mfVEP demonstrated the best sensitivities (50.6% and 51.8%, respectively) in identifying preperimetric glaucoma, and were not significantly different from each other. Both tests had significantly better sensitivity than all other tests (P < 0.0001). Of the eyes, 76.5% were identified by the combination of (any one of) LLA mfVEP and HRT. Sensitivity of the combination was significantly better than any of the individual tests (P < 0.05 for all pairs), or any other combinations of tests, with better negative than positive predictive value. CONCLUSIONS. The LLA mfVEP test identified approximately 50.6% eyes with preperimetric glaucoma, which was significantly higher than other perimetric methods, and similar to HRT. The combination of LLA mfVEP and HRT had exceptionally high sensitivity of 76.5% for preperimetric glaucoma.