Visual field loss following vitreous surgery
J. B. Kerrison, J. A. Haller, M. Elman and N. R. Miller
Wilmer Ophthalmological Institute, Baltimore, Md., USA.
OBJECTIVE: To assess possible causes of visual field loss following
vitreous surgery. DESIGN: Charts of 8 patients prospectively identified,
who developed visual field loss following vitreous surgery, were reviewed
to characterize this newly recognized syndrome and assess possible causes.
RESULTS: Two patients had preexisting chronic open-angle glaucoma and 1 had
ocular hypertension. Indications for surgery included 4 eyes with macular
holes, 1 eye with epiretinal membrane, 2 eyes with rhegmatogenous retinal
detachment, and 1 eye with retinal detachment and giant retinal tear. All
patients received retrobulbar anesthesia. Seven of 8 patients had fluid/gas
exchange with installation of long-acting bubbles. In 1 patient with a
macular hole, a small hemorrhage was noted along a vessel coming off the
nerve superotemporally while attempting to engage the posterior cortical
vitreous intraoperatively. This patient developed an inferior visual field
defect. No intraocular pressure (IOP) measurements greater than 26 mm Hg
were recorded in any eye perioperatively. Visual field defects included 4
eyes with inferotemporal defects, 2 eyes with inferior altitudinal defects,
1 eye with a cecocentral scotoma, and 1 eye with a superonasal defect. Only
1 patient had worsened visual acuity. A relative afferent pupillary defect
was observed in 4 eyes and disc pallor in 5 eyes. CONCLUSIONS: Central or
peripheral visual field loss can now be recognized as a possible
complication of vitreous surgery. In some cases, a relative afferent
pupillary defect and optic disc pallor are present, suggesting that the
optic nerve is the site of injury. Possible mechanisms include ischemia due
to elevated IOP or fluctuations in IOP, optic nerve damage from retrobulbar
injection, direct intraoperative mechanical trauma to the optic nerve,
indirect injury from vigorous suction near the optic nerve leading to
shearing of peripapillary axons or vessels, or a combination of these.
Certain optic nerves may be more susceptible to injury because of
preexisting compromise from glaucoma or vascular disease.
