Recovery of visual field and acuity after removal of epiretinal and inner limiting membranes.
BACKGROUND
Visual acuity serves as only a rough gauge of macular function. The aim therefore was to ascertain whether central an assessment of the central visual field afforded a closer insight into visual function after removal of epiretinal membranes and Infracyanine-Green- or Trypan-Blue-assisted peeling of the inner limiting membrane.


METHODS
Fourty-three patients undergoing pars-plana vitrectomy for the removal of epimacular membranes and dye-assisted peeling of the inner limiting membrane using either Infracyanine Green (n = 29; group 1) or Trypan Blue (n = 14; group 2) were monitored prospectively for 12 months. Preoperatively, and 1, 6 and 12 months postoperatively, distance and reading visual acuities were evaluated; the central visual field was assessed by automated static perimetry.


RESULTS
Twelve months after surgery, distance and reading visual acuities had improved in both groups, but to a significant degree only in Trypan-Blue-treated eyes. The difference between the two groups was not significant. Likewise at this juncture, the mean size of the visual-field defect remained unchanged in Trypan-Blue-treated eyes (preoperative: 4.3 (SD 2.1) dB; 12 months: 4.0 (2.1) dB (p = 0.15)), but had increased in Infracyanine-Green-treated ones (from 5.3 (3.7) dB to 8.0 (5.2) dB (p = 0.027)).


CONCLUSIONS
Unlike visual acuity, the central visual field had deteriorated in Infracyanine-Green-treated eyes but not in Trypan-Blue-treated eyes 12 months after surgery. Hence, as a predictor of functional outcome, testing of the central visual field may be a more sensitive gauge than visual acuity. Furthermore, Infracyanine Green may have a chronic and potentially clinically relevant effect on the macula which is not reflected in the visual acuity.
Garweg
J G
JG
Clinic for Vitreoretinal Disease, Swiss Eye Institute, Bremgartenstr. 119, CH-3012 Bern, Switzerland. justus.garweg@swiss-eye-institute.com
Bergstein
D
D
Windisch
B
B
Koerner
F
F
Halberstadt
M
M
D000368:Aged; D004396:Coloring Agents / Q000009:adverse effects; D019773:Epiretinal Membrane / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007208:Indocyanine Green / Q000009:adverse effects / Q000031:analogs & derivatives; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome; D014343:Trypan Blue / Q000009:adverse effects; D014786:Vision Disorders / Q000139:chemically induced / Q000503:physiopathology; D014792:Visual Acuity / Q000187:drug effects; D058609:Visual Field Tests; D014794:Visual Fields / Q000187:drug effects; D014821:Vitrectomy / Q000379:methods
D004396:Coloring Agents; C116320:Infracyanine green; D014343:Trypan Blue; D007208:Indocyanine Green