Accuracy of pattern deviation in estimating the glaucomatous damage in the central 10° visual field in eyes with...

The accuracy of pattern deviation (PD) in estimating the damage to the glaucomatous visual field (VF) in the central 10° in eyes with glaucoma and cataract is unclear.

This retrospective study includes 63 eyes of 52 glaucoma patients who successfully underwent cataract surgery or cataract surgery plus iStent implantation. Using the Humphrey Field Analyser 10-2 test, VF was measured within 6 months preoperatively and postoperatively (VF_pre and VF_post, respectively). The mean total deviation values in VF_post (mTD_post) indicates glaucomatous damage without cataract and the difference between this value and mean PD values in VF_pre (mPD_pre) was evaluated (εmPD). The effect of cataract was then evaluated as the difference between mTD_post and mTD_pre (ΔmTD), while the effects of mTD_post and ΔmTD on εmPD were also assessed. In addition, based on preoperative visual acuity (VA_pre) and VF_pre, the optimal model for predicting mTD_post was identified. The error of this method (εOptimalModel) was estimated as the difference against mTD_post, which was compared with εmPD.

Compared with mTD_pre, there was a significant improvement in mTD_post (p=0.028). A significant difference was observed between mPD_pre and mTD_post (p<0.001). Further, εmPD significantly increased with the increase of mTD_post or ΔmTD (p<0.001 and p=0.0444, respectively). The absolute εOptimalModel was significantly smaller than the absolute εmPD (p<0.001).

This study warns clinicians that PD of the central 10° VF might underestimate the glaucomatous VF damage with the progression of glaucoma and overestimate it as a cataract progresses.