TY - JOUR T1 - Visual prognostic value of the pattern electroretinogram in chiasmal compression JF - British Journal of Ophthalmology JO - Br J Ophthalmol SP - 1024 LP - 1026 DO - 10.1136/bjo.84.9.1024 VL - 84 IS - 9 AU - Dipak N Parmar AU - Ajit Sofat AU - Richard Bowman AU - John R Bartlett AU - Graham E Holder Y1 - 2000/09/01 UR - http://bjo.bmj.com/content/84/9/1024.abstract N2 - BACKGROUND/AIMS The visual loss associated with compression of the optic chiasm by pituitary tumours may be transient or permanent, possibly related to the extent of irreversible retrograde degeneration to the retinal ganglion cells. The pattern electroretinogram (PERG) N95 component is thought to rise in relation to retinal ganglion cell function and hence may be a potential prognostic indicator for visual function following decompressive surgery. METHODS The notes and electrodiagnostic records of 72 eyes from 36 patients with chiasmal compression were retrospectively analysed. RESULTS The postoperative change in visual field was found to be associated with the PERG N95:P50 ratio (p=0.01). Improvement in visual field was shown by a greater proportion of eyes with a normal N95:P50 ratio (65%) than with an abnormal ratio (27%). No change in visual field occurred in 26% of the eyes with a normal N95:P50 ratio compared with 67% of those with an abnormal ratio. Only 8% of eyes showed a worsening of visual field following surgery, in similar proportions for eyes with normal and abnormal N95:P50 ratios. There was no significant relationship with visual acuity. CONCLUSION The PERG is a useful visual prognostic indicator in the preoperative assessment of chiasmal compression. ER -