Test-retest variability of frequency-doubling perimetry and conventional perimetry in glaucoma patients and normal subjects.
(1/1514)
PURPOSE: To compare the test-retest variability characteristics of frequency-doubling perimetry, a new perimetric test, with those of conventional perimetry in glaucoma patients and normal control subjects. METHODS: The study sample contained 64 patients and 47 normal subjects aged 66.16+/-11.86 and 64.26+/-7.99 years (mean +/- SD), respectively. All subjects underwent frequency-doubling perimetry (using the threshold mode) and conventional perimetry (using program 30-2 of the Humphrey Field Analyzer; Humphrey Instruments, San Leandro, CA) in one randomly selected eye. Each test was repeated at 1-week intervals for five tests with each technique over 4 weeks. Empirical 5th and 95th percentiles of the distribution of threshold deviations at retest were determined for all combinations of single tests and mean of two tests, stratified by threshold deviation. The influence of visual field eccentricity and overall visual field loss on variability also were examined. RESULTS: Mean test time with frequency-doubling perimetry in patients and normal control subjects was 5.90 and 5.25 minutes, respectively, and with conventional perimetry was 17.20 and 14.01 minutes, respectively. In patients, there was a significant correlation between the results of the two techniques, in the full field and in quadrants, whereas in normal subjects there was no such correlation. In patients, the retest variability of conventional perimetry in locations with 20-dB loss was 120% (single tests) and 127% (mean tests) higher compared with that in locations with 0-dB loss. Comparative figures for frequency-doubling perimetry were 40% and 47%, respectively. Variability also increased more with threshold deviation in normal subjects tested with conventional perimetry. In both patients and normal subjects, variability increased with visual field eccentricity in conventional perimetry, but not in frequency-doubling perimetry. Both techniques showed an increase in variability with overall visual field damage. CONCLUSIONS: Frequency-doubling perimetry has different test-retest variability characteristics than conventional perimetry and may have potential for monitoring glaucomatous field damage. (+info)
Management of phacolytic glaucoma: experience of 135 cases.
(2/1514)
We retrospectively analyzed 135 eyes with phacolytic glaucoma. A trabeculectomy was added to standard cataract surgery if symptoms endured for more than seven days, or if preoperative control of intraocular pressure (IOP) with maximal medical treatment was inadequate. In the early postoperative period, IOP was significantly lower in the combined surgery group (89 eyes) compared to the cataract surgery group (46 eyes) (p < 0.001). At 6 months there was no difference in IOP or visual acuity between the two groups. There were no serious complications related to trabeculectomy. It is reasonable to conclude that in eyes with a long duration of phacolytic glaucoma, addition of a trabeculectomy to cataract surgery is safe, prevents postoperative rise in intraocular pressure and decreases the need for systemic hypotensive medications. A randomized trial is on to further address this question. (+info)
Asymmetry in optic disc parameters: the Blue Mountains Eye Study.
(3/1514)
PURPOSE: To examine asymmetry in vertical optic disc parameters among subjects classified as normal, as having ocular hypertension (OH), and as having open-angle glaucoma (OAG) in a population-based sample. METHODS: The Blue Mountains Eye Study examined 3654 people aged 49 to 97 years, including 2929 normal subjects, 118 with OH, and 79 with OAG in the groups of interest for the asymmetry study. Optic disc parameters were measured in a masked manner from stereo optic disc photographs. RESULTS: Vertical disc diameter asymmetry (the absolute value of left minus right disc diameters) was similar among normal, OH, and OAG groups (median, 0.07-0.08 mm). Vertical cup- disc ratio asymmetry was higher in patients with OAG (median, 0.11) than in normal subjects (median, 0.06; P < 0.0001) and in those with OH (median, 0.05; P < 0.0001) but was similar between normal subjects and patients with OH (P = 0.17). A cup- disc ratio asymmetry of 0.2 or more was found in 24% of patients with OAG, compared with 1% of patients with OH and 6% of normal subjects. Corresponding rates for cup- disc ratio asymmetry of 0.3 or more in these three groups were 10%, 0%, and 1%, respectively. Using multiple linear regression, cup-disc ratio asymmetry was associated with disc diameter asymmetry and intraocular pressure asymmetry. However, these two factors explained only 3% of the variability of cup- disc ratio asymmetry and 20% of cup diameter asymmetry. CONCLUSIONS: Despite differences between the OAG group and either the OH or normal groups, asymmetry alone was not useful in identifying patients with OAG. At all levels of asymmetry, subjects were more likely to be classified as normal than with OH or OAG. (+info)
Deep sclerectomy with collagen implant: medium term results.
(4/1514)
AIMS: To study prospectively the success rate and complications of deep sclerectomy with collagen implant (DSCI), a new non-penetrating filtration procedure. METHODS: Non-randomised prospective trial involving consecutive patients. 100 eyes of 100 patients with medically uncontrolled primary and secondary open angle glaucoma. A superficial scleral flap was raised and a deep sclerectomy was performed in the scleral bed. Schlemm's canal was opened and dissection of the cornea was performed up to Descemet's membrane, at which point aqueous percolated through the remaining trabeculo-Descemet's membrane. A collagen implant was sutured radially in the scleral bed. Visual acuity, intraocular pressure (IOP) measurements, and slit lamp examinations were performed before surgery and after surgery at 1 and 7 days, and 1, 3, 6, 9, 12, 18, 24, 30, and 36 months. RESULTS: The mean follow up period was 17.8 (SD 8.7) months. The mean preoperative IOP was 27.8 (8.6) mm Hg; the mean postoperative IOP was 5.7 (4.0) at day 1, 11.2 (4.6) at month 1, 14.0 (3.5) at month 12, and 13.0 (3.8) at month 36. Complete success rate, defined as an IOP lower than 21 mm Hg without medication, was 44.6% at 36 months. Qualified success rate, defined as an IOP lower than 21 mm Hg with medication, was 97.7% at 36 months. Early postoperative complications included hyphaema in seven patients, would leak in 10 patients, and subtle choroidal detachment in 11 patients. Goniopuncture was performed in 41 of the patients, and 5-fluorouracil injections were made in 23 patients; cataract progression occurred in seven patients. When comparing the different types of open angle glaucoma, no difference was found in terms of reduction in IOP, number of patients requiring antiglaucoma medications, or success rate. CONCLUSIONS: Deep sclerectomy with collagen implant appears to provide reasonable control of IOP at medium term follow up, with few immediate postoperative complications. (+info)
Immediate intraocular pressure response to selective laser trabeculoplasty.
(5/1514)
BACKGROUND/AIMS: Selective laser trabeculoplasty targets the pigmented trabecular meshwork cells without damage to the trabecular meshwork architecture in vitro. A study was conducted in vivo of eight eyes with uncontrolled open angle glaucoma to ascertain the immediate intraocular response to selective laser trabeculoplasty. METHODS: The trabecular meshwork of each eye was treated 360 degrees with a frequency doubled Q-switched Nd:YAG laser. Intraocular pressure was measured 1, 2, 24 hours and 1, 4, 6 weeks after treatment. RESULTS: The average preoperative intraocular pressure was 26.6 (SD 7) mm Hg (range 18-37). Two hours and 6 weeks respectively after selective trabeculoplasty intraocular pressure was reduced in all the eyes treated with an average fall of 10.6 (5.2) mm Hg or 39.9%. A pressure spike of 10 mm Hg verified in one eye 1 hour after treatment. CONCLUSIONS: Selective laser trabeculoplasty decreased intraocular pressure by an amount similar to that achieved with standard trabeculoplasty. Additional study is needed to determine whether the beneficial effect is sustained over a longer period of follow up. (+info)
Effect of aging on optic nerve appearance: a longitudinal study.
(6/1514)
AIM: To determine whether aging causes detectable changes in the appearance of the optic disc. METHODS: A retrospective longitudinal study was performed with quantitative and qualitative evaluations of digitised stereoscopic optic disc photographs of 224 eyes of 224 subjects. There were three groups: 100 normal subjects from the Framingham Eye Study, 68 glaucomatous patients followed longitudinally, and 56 normal subjects and glaucoma patients who had separate sets of disc photos taken on the same day. A disc was considered qualitatively worse if two of three experienced observers agreed that it was worse. Quantitative progression was defined as a >10% decrease in rim/disc area ratio measured with computer assisted planimetry. RESULTS: With quantitative evaluation, normal eyes (mean follow up 13 years) and same day eyes displayed no statistically significant difference in change of rim/disc area ratios (p=0.095), nor in the number of discs that progressed-five of 100 (5%) v two of 56 (4%) respectively. Glaucomatous eyes (mean follow up 9 years) showed a quantitative loss of disc rim in 24 of 68 (35%), and differed significantly from the normal eyes both in the change of rim/disc area ratio (p<0.0005) and number of discs that progressed (p<0.0005). With qualitative evaluation, the number of progressive discs in the glaucomatous eyes (31%) differed significantly (p<0. 0005) from the normal eyes (3%) and the same day eyes (0%). CONCLUSIONS: Over a period of follow up appropriate for long term outcome studies in glaucoma, there was no quantitatively or qualitatively detectable neuroretinal rim loss in normal aging optic nerves with stereoscopic optic disc photographs. (+info)
Cataract, glaucoma and season of birth amongst patients born on the Indian subcontinent.
(7/1514)
The relation between the prevalence of open-angle glaucoma and of different types of cataract on the one hand and the patient's season of birth on the other was studied with special reference to natives of the Indian Subcontinent. Partial comparisons were made with results obtained on British-born patients. Both primary open-angle glaucoma (POAG) and the mixed nuclear/posterior-subcapsular type (NP) showed a statistically significant variation with the month of birth for the Asian patients, but only NP showed significant variation for the European patients in a month-by-month analysis. The Asian data are examined from the point of view of seasonal variations in maternal nutrition and of low birth-weight babies. (+info)
Glaucoma: diagnosis and management.
(8/1514)
Glaucoma is the third most prevalent cause of global blindness, accounting for over 5 million blind. It is common in Western Countries; the estimated prevalence of primary open angle glaucoma rises from a total prevalence of 1.1% to approximately 3% of our population as it ages. Ethnicity affects both the risk of developing glaucoma and the outcome. It is an expensive disease both to detect and to treat. Recent scientific advances include elucidation of the genetic mechanism behind the disease and the study of haemodynamic and biochemical co-factors in the development of glaucomatous optic neuropathy, particularly in relation to the pathogenesis of normal tension glaucoma. Several new types of topical medication have recently been developed for use in glaucoma; both the impact of these therapies and their cost effectiveness remain to be evaluated. There are widely differing regimes which effectively treat glaucoma; some ophthalmologists prefer early surgical intervention whilst others reserve surgery for relatively advanced disease. All methods of current treatment rely on the reduction of intra-ocular pressure; as yet there is no medication which has been definitively proven to be either neuroprotective or to influence favourably optic nerve perfusion. Despite this, most sufferers of glaucoma are able to lead lives of quality. Increased community awareness of glaucoma, and earlier detection of the condition, will doubtless result in decreased morbidity due to glaucoma. (+info)