A recent Ophthalmic Research study has introduced a new diagnostic approach for early primary open-angle glaucoma (POAG) by combining steady-state pattern electroretinogram (ssPERG) and optical coherence tomography (OCT) parameters. This innovative method significantly improves the early detection of retinal ganglion cell (RGC) dysfunction, potentially preventing irreversible vision loss caused by the disease.
Detecting glaucoma before noticeable vision impairment occurs is crucial, since significant RGC damage precedes VF changes. Traditional diagnostic methods like OCT provide structural analysis, while functional tests like ssPERG help to detect early RGC dysfunction. Employing these pre-existing modalities, the study evaluated whether combining the two methods could enhance diagnostic accuracy.
The retrospective cohort study included 135 eyes from 78 patients with early POAG and 57 healthy individuals. Researchers compared PERGratio, a measure derived from ssPERG, with various OCT and VF parameters, and found that: PERGratio alone had a high area under the receiver operating characteristic curve, marking it as one of the best functional indicators of early glaucoma; among OCT parameters, the 7 o’clock circumpapillary retinal nerve fiber layer (cpRNFL) thickness was effective at identifying early POAG; combining PERGratio with 7 o’clock cpRNFL thickness resulted in the highest diagnostic accuracy, outperforming all other combinations.
As with other previous glaucoma studies, the study supports the dysfunction-preceding-death hypothesis, which suggests that RGC dysfunction occurs before structural damage. Therefore, the combined index could act as a valuable tool for early glaucoma screening, helping ophthalmologists to detect the disease earlier before significant RGC loss and visual impairment occurs, improve their patient monitoring, and enhance diagnostic confidence by reducing reliance on subjective VF tests. However, the researchers do acknowledge challenges involved with implementing this combined modality into routine clinical practice due to the need for logistic regression calculations.
