Reversal of retinal ganglion cell dysfunction after surgical reduction of intraocular pressure

Ophthalmology. 2010 Dec;117(12):2329-36. doi: 10.1016/j.ophtha.2010.08.049. Epub 2010 Oct 8.


Purpose: The pattern electroretinogram optimized for glaucoma screening (PERGLA) is a noninvasive method of objectively measuring retinal ganglion cell (RGC) function. This study was undertaken to quantify the RGC response to intraocular pressure (IOP) reduction after glaucoma surgery.

Design: Prospective cohort study.

Participants: Forty-seven eyes of 47 patients with uncontrolled IOP or progressive glaucomatous optic neuropathy receiving maximal medical therapy requiring trabeculectomy or aqueous drainage device implantation who met eligibility criteria.

Methods: Eyes with visual acuity less than 20/30, corneal or retinal pathologic features, or unreliable standard automated perimetry (SAP) results were excluded. All patients underwent complete ocular examination, arterial blood pressure, SAP, and PERGLA at 2 sessions before surgery and at 3 months after surgery. Mean ocular perfusion pressure (MOPP) was calculated. Each measure of PERGLA amplitude and phase was an average of 600 artifact-free signal registrations.

Main outcome measures: Intraocular pressure and PERGLA amplitude and phase.

Results: Forty-seven eyes of 47 patients (mean age ± standard deviation [SD], 69.9 ± 11.3 years) were enrolled. Thirty-four eyes (72%) underwent trabeculectomy with antifibrosis therapy; 13 eyes (28%) underwent glaucoma drainage implant surgery. Mean ± SD postoperative IOP (10.4 ± 4.6 mmHg) was significantly (P< 0.001) reduced compared with that before surgery (19.7 ± 8.6 mmHg). Mean ± SD postoperative PERGLA amplitude (0.46 ± 0.22 μV) was significantly (P = 0.001) increased compared with preoperative PERGLA amplitude (0.37 ± 0.18 μV). Mean ± SD postoperative PERGLA phase (1.72 ± 0.20 π-radian) was significantly (P = 0.01) reduced compared with preoperative PERGLA phase (1.81 ± 0.22 π-radian). Mean ± SD postoperative MOPP (53.1 ± 6.4 mmHg) was significantly (P < 0.001) increased compared with mean ± SD preoperative MOPP (45.8 ± 10.1 mmHg). No correlation (P > 0.05) was identified between change in PERGLA amplitude and change in IOP or MOPP.

Conclusions: Reversal of RGC dysfunction occurs after surgical reduction of IOP and may be quantified using PERGLA.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Blood Pressure / physiology
  • Electroretinography
  • Female
  • Glaucoma / physiopathology
  • Glaucoma / surgery*
  • Glaucoma Drainage Implants*
  • Humans
  • Intraocular Pressure / physiology*
  • Male
  • Optic Nerve Diseases / physiopathology
  • Optic Nerve Diseases / surgery*
  • Prospective Studies
  • Retinal Ganglion Cells / physiology*
  • Tonometry, Ocular
  • Trabeculectomy*
  • Visual Acuity / physiology