Outcomes of bleb excision and conjunctival advancement for leaking or hypotonous eyes after glaucoma filtering surgery.

AIM: To determine outcomes of bleb excision and conjunctival advancement for leaking or hypotonous eyes after glaucoma filtering surgery. METHODS: In a retrospective case series the medical records of all patients who underwent bleb excision and conjunctival advancement surgery for bleb leaks or hypotony (defined as IOP less than 6 mm Hg, associated with reduced vision) at the Jules Stein Eye Institute and the Yale University Eye Center between January 1993 and June 2002 were reviewed. Only patients with more than 6 months of follow up were included. Complete success was defined as resolution of the pre-existing leak or hypotony, with maintenance of IOP > or =6 and < or =21 mm Hg, in the absence of further glaucoma surgery and without any glaucoma medication. Qualified success met the above criteria with or without the use of glaucoma medications. Success rates were analysed with Kaplan-Meier survival curves. RESULTS: 49 eyes were included in the study; 13 eyes had overt bleb leaks, 27 eyes had hypotony. Nineteen patients underwent resuturing of sclera and/or placement of a pericardial graft in addition to bleb excision and conjunctival advancement. Mean preoperative IOP increased from 3.2 (SD 2.4) mm Hg (range 0-10 mm Hg) to 13.8 (4.8) mm Hg (range 6-29 mm Hg) at last follow up (p<0.0001). Mean preoperative visual acuity improved from 0.6 (0.3) logMAR (range 0-2) to 0.3 (0.3) logMAR (range 0-2) at final follow up (p<0.0001). 16 eyes (40%) were classified as complete success and 17 additional eyes achieved qualified success, for a total of 33 eyes (83%) achieving at least qualified success. There was no significant difference in the rate of complete success (p = 0.95) or qualified success (p = 0.88) between the group of patients who underwent bleb excision and conjunctival advancement alone versus those who also had resuturing of sclera and/or placement of a pericardial graft. Failures included three eyes that had persistent hypotony without leak, requiring additional bleb revision, and four with uncontrolled IOP, two of whom underwent additional glaucoma surgery. CONCLUSION: Bleb excision with conjunctival advancement is a successful procedure for bleb repair. This technique provides successful resolution of leaks and hypotony, maintains glaucoma control with or without medication, and preserves vision with minimal postoperative complications in a majority of eyes.

Relationship between visual field testing and scanning laser polarimetry in patients with a large cup-to-disk ratio.

PURPOSE: To determine the relationship between quantitative nerve fiber layer measurements and visual field testing in patients with large cup-to-disk ratios. METHODS: Seventy-six patients with vertical cup-to-disk ratios by contour of at least 0.8 on stereoscopic photographs and 50 normal subjects were included. One eye was randomly selected for study. All patients underwent standard achromatic automated perimetry, short-wavelength automated perimetry, and retinal nerve fiber layer measurements with scanning laser polarimetry. Analysis of variance was used to evaluate differences between the subject groups. Significance of pairwise comparisons was determined using the Tukey-Kramer multiple comparison test. RESULTS: Statistically significant differences in nerve fiber layer measurements between patients with large cup-to-disk ratios and both abnormal standard achromatic automated perimetry and short-wavelength automated perimetry (n = 22) and patients with large cup-to-disk ratios and both normal standard achromatic automated perimetry and short-wavelength automated perimetry (n = 42) were found for superior nasal ratio, maximum modulation, ellipse modulation, and the linear discriminant function (Tukey-Kramer less than.05). There was no significant difference in patients with abnormal short-wavelength automated perimetry only (n = 9) as compared with patients with both normal standard achromatic automated perimetry and short-wavelength automated perimetry and patients with both abnormal standard achromatic automated perimetry and short-wavelength automated perimetry. Statistically significant differences between the normal subjects and patients with large cup-to-disk ratios and both abnormal standard achromatic automated perimetry and short-wavelength automated perimetry were found for all retinal nerve fiber layer parameters, with the exception of symmetry, superior ratio, and inferior ratio. CONCLUSION: Our results show considerable overlap in nerve fiber layer measurements in eyes with large cup-to-disk ratio and abnormal visual fields as compared with eyes with large cup-to-disk ratios and normal visual fields. This may limit the clinical usefulness of scanning laser polarimetry for detection of early glaucoma in patients with large cup-to-disk ratios. Longitudinal studies are needed to determine if patients with large cup-to-disk ratios with normal standard achromatic automated perimetry and abnormal short-wavelength automated perimetry subsequently develop standard achromatic automated perimetry defects and if scanning laser polarimetry can concurrently detect progression of nerve fiber layer damage.