Cone implicit time as a predictor of visual outcome in macular hole surgery.
OBJECTIVE
To investigate whether preoperative retinal function measured by full-field ERG and multifocal ERG is correlated to postoperative visual acuity after macular hole surgery.


METHODS
Standard pars plana vitrectomy with removal of the internal limiting membrane (ILM) was performed on 19 consecutive patients undergoing macular hole surgery. Intraocular gas tamponade with a C2F6 gas-air mixture was employed, followed by a face-down position for at least 5 days. The patients were examined with the ETDRS chart, full-field ERG (Espion), multifocal ERG (Veris 6), and optical coherence tomography (OCT) preoperatively, and 6 weeks, 6 months, and 18 months after surgery.


RESULTS
The cone 30-Hz flicker implicit time in the full-field ERG reflecting retinal function was prolonged (p = 0.016) before surgery compared to aged-matched controls. After macula hole surgery, longstanding alteration of cone function reflected by mfERG and full-field ERG was verified 18 months after surgery. The prolonged cone 30-Hz flicker implicit time in the full-field ERG before surgery was significantly correlated to the ETDRS visual acuity 6 months postoperatively (p = 0.03).


CONCLUSIONS
Preoperative evaluation of retinal function with multifocal ERG and full-field ERG improves the understanding of the retinal recovery process after macular hole surgery. The cone implicit time in full-field 30-Hz flicker ERG could be a valid predictor of long-term visual outcome, which may be useful for selecting patients suitable for surgery.
Department of Ophthalmology, University of Lund, 221 85, Lund, Sweden, sten.andreasson@med.lu.se.
Sten
S
Andréasson
Fredrik
F
Ghosh
D000368:Aged; D004596:Electroretinography; D058450:Endotamponade; D005260:Female; D005466:Fluorocarbons; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016684:Prone Position; D011446:Prospective Studies; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D012167:Retinal Perforations / Q000503:physiopathology / Q000601:surgery*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology*; D014821:Vitrectomy
D005466:Fluorocarbons; C048381:perfluoroethane