Is filtering surgery in glaucoma patients with advanced visual field loss associated with an increased risk of postoperative functional loss?

Background: We evaluated the prevalence of the loss of visual acuity due to loss of the central portion of the visual field and foveolar fixation in the first week after glaucoma filtering surgery. Patients and methods: We included 408 patients, in whom glaucoma filtering surgery was performed between January 1993 and April 1997 at the University Eye Clinic in Tubingen and who had completed 1-year follow-up examinations. The retrospective evaluation included preoperative, intraoperative and postoperative data. We excluded all patients who did not complete 1-year follow-up examinations (12+/-3 months),who have died during the 1-year follow-up,who had combined glaucoma and cataract surgery or in whom the Molteno implant procedure was performed. Results: A total of 404 patients (99.3%) did not suffer loss of the central visual field and foveolar fixation in the first week after glaucoma filtering surgery. In 11 cases, loss of visual acuity >2 dB was due to progressive lens opacification. One patient suffered from postoperative progression of his age-related maculopathy. In one patient (0.2%) progression of a preexisting relative central scotoma occurred immediately after the operation. Two patients (0.5%) suffered from loss of fixation and the central visual field immediately after glaucoma filtering surgery. Conclusions: Loss of the central visual field and central fixation immediately after glaucoma filtering surgery is a rare complication. Therefore,glaucoma filtering surgery can also be recommended for patients with advanced visual field defects.