[Effects of lens opacity on AccuMap multifocal objective perimetry in glaucoma].
OBJECTIVE
To investigate the effect of lens opacity on the performance of the multi-focal visual evoked potential (mfVEP) test in patients with glaucoma and its relationship with the Humphrey's automated static perimetry.


METHODS
This is a prospective, non-randomized study. Twenty-two patients were enrolled with moderate cataract and primary glaucoma scheduled for cataract surgery with or without glaucoma surgery. Humphrey visual field and mfVEP test were preformed before surgery and after 6 - 8 weeks of post-operation. Lens opacity was evaluated with slit lamp according to LOCS III (lens opacity classification system, version III) by the same ophthalmologist.


RESULTS
The improvement of AccuMap objective visual field was noted after lens removal in glaucoma patients. The amplitude of the AccuMap was significantly (P < 0.01) increased after cataract surgery compared to pre-operation (382.6 nV +/- 146.7 nV vs 308.0 nV +/- 96.6 nV). AccuMap severity index (ASI) was significantly (P < 0.001) decreased following lens removal compared with pre-operation (48.6 +/- 42.4 vs 90.0 +/- 54.8, P < 0.001). Latency was little changed before and after surgery (1207.5 ms +/- 67.7 ms, 1191.2 ms +/- 61.9 ms, respectively, P = 0.289). There were no correlations between the changes of amplitude and the degree of lens opacity (Spearman correction, P = 0.09). For Humphrey visual field, the mean deviation (MD) of pre- and post-operative was significantly (P < 0.001) affected by lens opacity (-12.2 +/- 7.8, -9.6 +/- 8.8, respectively, P < 0.001), but pattern standard deviation (PSD) had no such changes (6.5 +/- 3.2, 6.3 +/- 4.0, respectively, P = 0.748). There were well correlated between the ASI and the MD both pre- or post-operation (Pearson correction, P = 0.013, P < 0.001), and between the ASI changes and the MD changes after lens removal (Pearson correction, P = 0.017).


CONCLUSIONS
Lens opacity affects the AccuMap objective visual field in patients with glaucoma, especially the amplitude of the AccuMap. The ASI is sensitively correlated with the MD of Humphrey perimetry.
Cai
Yu
Y
Department of Ophthalmology, First Hospital of Peking University, Beijing 100034, China. cai-yuu@hotmail.com
Lim
Boon Ang
BA
Chi
Luu
L
Por
Yongming
Y
Oen
Francis
F
Yan
Xiao-ming
XM
Chew
Paul
P
Seah
Steve
S
D000368:Aged; D000369:Aged, 80 and over; D002386:Cataract / Q000503:physiopathology*; D005074:Evoked Potentials, Visual; D005260:Female; D005901:Glaucoma / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D058609:Visual Field Tests; D014794:Visual Fields