Visual Loss and Glaucoma
Visual Loss and Glaucoma
Although visual field loss from glaucoma typically spares fixation and visual acuity is preserved, patients with marked visual field defects or those that are dense around fixation are at risk to lose central vision. Historically this risk has been thought to be particularly high in patients undergoing filtration surgery. Spikes in intraocular pressure (IOP) related to the perioperative period have been thought to cause damage to the remaining nerve fibers serving central vision.
Law SK, Nguyen AM, Coleman AL, Caprioli J Arch Ophthalmol. 2007;125:1044-1050
The authors of this study reviewed the records of patients undergoing trabeculectomy with severe visual field defects preoperatively from 1998 to 2005 to determine the rate of central visual loss (defined as 20/200 or worse, a 4-line loss of visual acuity, or counting fingers or less if the initial visual acuity was worse than 20/200). Of 117 patients undergoing filtration surgery, 7 (6%) developed decreased central vision. The causes were hypotony maculopathy (N = 3), elevated IOP (N = 2), posterior subcapsular cataract (N = 1), and inflammation (N = 1). The mean visual acuity was statistically decreased when comparing preoperative with postoperative measures. Patients who developed severe loss of visual acuity had higher mean IOPs and higher rates of surgical complications compared with those who did not lose central vision.
The authors of this study found that decreased central vision may uncommonly occur after filtration surgery; however, an unexpected finding was that this decrease in vision occurred more often from specific causes, rather than from progression of the glaucomatous optic atrophy. Although this rate of central visual loss in patients with advanced visual field defects is of concern, it is lower than that reported in some other studies. This is an important finding and somewhat reassuring for clinicians performing or contemplating filtration surgery on their patients with advanced glaucoma.
Abstract
Introduction
Although visual field loss from glaucoma typically spares fixation and visual acuity is preserved, patients with marked visual field defects or those that are dense around fixation are at risk to lose central vision. Historically this risk has been thought to be particularly high in patients undergoing filtration surgery. Spikes in intraocular pressure (IOP) related to the perioperative period have been thought to cause damage to the remaining nerve fibers serving central vision.
Severe Loss of Central Vision in Patients With Advanced Glaucoma Undergoing Trabeculectomy
Law SK, Nguyen AM, Coleman AL, Caprioli J Arch Ophthalmol. 2007;125:1044-1050
Summary
The authors of this study reviewed the records of patients undergoing trabeculectomy with severe visual field defects preoperatively from 1998 to 2005 to determine the rate of central visual loss (defined as 20/200 or worse, a 4-line loss of visual acuity, or counting fingers or less if the initial visual acuity was worse than 20/200). Of 117 patients undergoing filtration surgery, 7 (6%) developed decreased central vision. The causes were hypotony maculopathy (N = 3), elevated IOP (N = 2), posterior subcapsular cataract (N = 1), and inflammation (N = 1). The mean visual acuity was statistically decreased when comparing preoperative with postoperative measures. Patients who developed severe loss of visual acuity had higher mean IOPs and higher rates of surgical complications compared with those who did not lose central vision.
Comment
The authors of this study found that decreased central vision may uncommonly occur after filtration surgery; however, an unexpected finding was that this decrease in vision occurred more often from specific causes, rather than from progression of the glaucomatous optic atrophy. Although this rate of central visual loss in patients with advanced visual field defects is of concern, it is lower than that reported in some other studies. This is an important finding and somewhat reassuring for clinicians performing or contemplating filtration surgery on their patients with advanced glaucoma.
Abstract
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