Is visual field evaluation using multiple correlations and linear regressions useful? An evaluation of Delphi perimetry.

BACKGROUND: Delphi perimetry is a method of visual field examination which produces a statistical estimation of the visual field by testing only four critical points of the central visual field. This study was performed to evaluate this technique for the detection of glaucomatous field loss. METHOD: Patients with glaucoma and ocular hypertension underwent Delphi perimetry and Humphrey visual field analysis (HVFA) program 24-2. The visual field results of both examination were compared. RESULTS: Of 262 eyes from 199 patients, 120 eyes showed glaucomatous defects by HVFA and 142 were normal. Delphi perimetry showed abnormal visual fields in 107 eyes, 13 of which were false-positive results as Humphrey visual fields were normal. Delphi classified 155 fields as normal, of which 26 were false negatives as Humphrey visual fields showed glaucomatous defects. Therefore, the sensitivity of Delphi perimetry for the detection of glaucomatous visual field defect was 78% and the specificity was 91%. In the 26 false-negative eyes, the most common defect missed was an isolated paracentral scotoma or an early nasal step. Furthermore, 27 of the 94 glaucomatous eyes classified as abnormal by Delphi had defects estimated by Delphi perimetry that corresponded poorly to the field loss demonstrated by Humphrey visual field analysis. Therefore, qualitative sensitivity and specificity of Delphi perimetry for producing an accurate representation of the location, extent and defect depth of glaucomatous visual field loss would be 48.8% and 72% respectively. CONCLUSION: In this study Delphi perimetry failed to give an accurate statistical estimation of the visual field in an unacceptably high number of cases; therefore, it cannot be recommended for clinical use.

Long-term intraocular pressure control after cataract extraction with trabeculectomy: phacoemulsification versus extracapsular technique.

PURPOSE: To compare long-term intraocular pressure (IOP) control after extracapsular cataract extraction and intraocular lens (IOL) implantation combined with trabeculectomy (ECCE + TRAB) with that after phacotrabeculectomy and IOL implantation. SETTING: Glaucoma Unit, Royal Liverpool University Hospital, Liverpool, England. METHOD: This retrospective study comprised 32 eyes having ECCE + TRAB and 31 eyes having phacotrabeculectomy with a mean follow-up of 37.5 and 41.0 months, respectively. The need for pressure-lowering medication was recorded. Kaplan-Meier curves were created for each group. RESULTS: At every measurement after 3 weeks of follow-up, significantly fewer eyes in the phacotrabeculectomy group required IOP-lowering medication (P = .04). CONCLUSIONS: After both ECCE + TRAB and phacotrabeculectomy, IOP control was achieved in significantly more eyes on fewer pressure-lowering medications than preoperatively. Phacotrabeculectomy with IOL implantation led to better unaided long-term postoperative IOP control than ECCE + TRAB with IOL implantation.

A full-thickness scleral graft for the surgical management of a late filtration bleb leak.

BACKGROUND AND OBJECTIVES: Late bleb leak may follow months to years after filtration surgery. This article describes the surgical repair of eight leaking blebs using a full-thickness scleral graft and analyzes the efficacy of the procedure and its effect on intraocular pressure (IOP) control. PATIENTS AND METHODS: The indications for surgical bleb revision were hypotony maculopathy (2 eyes), endophthalmitis (2 eyes), bleb infection (2 eyes), and chronic epiphora and blurring of vision (2 eyes). All eyes were treated surgically through bleb excision and repair of the scleral defect with a full-thickness scleral graft. Conjunctival closure was performed either by its advancement to the limbus or by free conjunctival autograft. Follow-up ranged from 4 months to 7 years. RESULTS: Surgery stopped the leak in all cases, and hypotony was relieved without loss of long-term IOP control. However, early postoperative IOP rises (> 30 mm Hg) occurred in 2 eyes and a pressure-lowering medication was necessary to achieve long-term IOP control (IOP < 22 mm Hg) in 3 eyes. CONCLUSIONS: The technique described is an effective procedure for the treatment of late bleb leaks and is especially useful for the treatment of leaks found in association with full-thickness scleral defects. IOP spikes in the early postoperative period may occur, but long-term IOP control can be expected without the need for further filtration surgery.

Silicone versus poly(methyl methacrylate) lenses in combined phacoemulsification and trabeculectomy.

PURPOSE: To compare the outcome of phacotrabeculectomy with silicone or poly(methyl methacrylate) (PMMA) intraocular lens (IOL) implantation over the first year. SETTING: Glaucoma Unit, Royal Liverpool University Hospital, Liverpool, United Kingdom. METHOD: Two consecutive groups of 30 eyes each had phacotrabeculectomy with implantation of a foldable, plate-haptic silicone IOL (3.2 mm wide incision) or a PMMA IOL (5.2 mm wide incision) with a loosely or tightly sewn scleral flap, respectively. Early postoperative results and outcomes up to a mean of 1 year postoperatively in both groups were compared. RESULTS: In the early postoperative period, eyes in the silicone IOL group had a lower incidence of postoperative intraocular pressure (IOP) spikes (more than 30 mm Hg) than those in the PMMA IOL group (two and six cases, respectively) but also showed an increase (eight and three cases, respectively) in incidence of ocular hypotony (less than 8 mm Hg). There was also an increased incidence, although not statistically significant, of early postoperative complications in the silicone group; for example, fibrinous reaction in the anterior chamber (26.6 versus 10.0%; P = .18), shallow anterior chamber (16.6 versus 3.3%, P = .20), and choroidal detachment (16.6 versus 3.3%, P = .20). These complications, often associated with ocular hypotony, resolved quickly without serious sequelae. One year after surgery, IOP control (less than 22 mm Hg) was attained without medication in 80.0% in the silicone group and 76.7% in the PMMA group (P = 1.00), and corrected visual acuity of 20/40 or better was attained in 70.0% in the silicone group and 73.3% in the PMMA group (P = 1.00). CONCLUSION: The loosely sutured flap in the silicone group resulted in fewer early pressure spikes but at a cost of an increase in early postoperative hypotony with its associated complications. One year after surgery, there was no significant difference between the two groups in IOP control or visual acuity, showing that both procedures were effective in the surgical management of patients with cataract and glaucoma.

Pulsatile ocular blood flow in eyes with untreated choroidal melanoma.

PURPOSE: To investigate the effect of choroidal melanoma on pulsatile ocular blood flow (POBF). METHODS: Seventeen patients (10 men and 7 women) with unilateral untreated choroidal melanoma and 22 controls matched for age and sex were studied. Intraocular pressure (IOP), pulse amplitude (PA) and POBF were measured using the OBF Tonograph. In each patient, mean inter-ocular differences were analysed using the paired t-test. The correlation coefficient between tumour thickness and POBF was calculated. To assess the variation of this parameter, the coefficient of variation for three repeated readings was determined for healthy and affected eyes. RESULTS: In the control group, there was no significant difference between eyes in any parameter. In patients with melanoma, there was no significant difference in IOP and PA between affected and unaffected eyes. Mean POBF was significantly higher in affected eyes (1040 microliters min-1) than unaffected eyes (876 microliters min-1) (p = 0.003). There was no correlation between tumour thickness and absolute POBF (r = -0.24) or between tumour thickness and inter-ocular difference in POBF between affected and unaffected eyes (r = -0.17). Mean coefficient of variation of three repeated readings of POBF was 7.76% in healthy eyes and 8.97% in affected eyes. CONCLUSIONS: These findings suggest a high tumour blood flow or a global increase in choroidal blood flow in the presence of melanoma. POBF measurement may be useful in the clinical assessment of eyes with choroidal melanoma.

Apparent glaucomatous visual field defects caused by dermatochalasis.

We have studied the effects of dermatochalasis on Humphrey automated perimetry of the central 24 degrees visual field. Fifteen visual fields of 9 ocular hypertensive patients (18 eyes) were found to be incongruous with their apparently healthy optic discs. Examination revealed dermatochalasis, which was felt to be responsible for the field defects. This was confirmed by reversal of the defects on repeating the field test (programme 24-2) with the redundant upper lid skin taped up, or in 2 cases following blepharoplasty. The defects always involved the superior visual field. The deepest and largest defects were sited in the supero-temporal quadrant in 13 of the 15 affected fields and the supero-nasal quadrant in 2 fields. The most common pattern was a temporally skewed defect which reflected the tendency of the loose upper lid skin to be greater in extent temporally than nasally. In 7 fields the supero-temporal defect extended to fuse with the blind spot, mimicking a superior arcuate scotoma. Temporal extension of the field defects below the horizontal meridian occurred in 5 fields. In cases where visual field testing was repeated without taping up the lid inter-test fluctuation in scotoma size and depth was observed, although the position of scotomas when present within the visual field remained constant. We conclude that dermatochalasis has the potential to confound diagnostic automated visual field testing for glaucoma.