Course of exfoliation and simplex glaucoma after primary trabeculectomy.
(25/3147)
AIM: To study the course of exfoliation and simplex glaucoma with respect to intraocular pressure (IOP) regulation and visual field survival after primary trabeculectomy. METHODS: Postoperative IOP regulation and complications were analysed prospectively in 95 patients. Mean follow up was 46 months. Visual field survival was studied by high pass resolution perimetry (HRP) in a subsample of 28 patients. RESULTS: Medical treatment was reinstated in 42% of exfoliation and in 36% of simplex glaucoma. In these patients, mean medicine free survival time, last untreated IOP, and mean IOP at the end of follow up were similar for both glaucoma types. Among patients with controlled postoperative IOP without added medication, mean IOP at the end of follow up was significantly lower in exfoliation glaucoma. Visual field deterioration and the pattern of complications were similar for both glaucoma types. CONCLUSION: The effect of trabeculectomy on IOP regulation was good in both types of glaucoma, and somewhat better in exfoliation glaucoma. The magnitude of IOP lowering could not separate patients with continued visual field deterioration from those in whom visual fields remained stable. Visual field preservation was similar for both glaucoma types. (+info)
"Cyclodiode": results of a standard protocol.
(26/3147)
AIMS: To analyse the results of intraocular pressure (IOP) reduction in refractory glaucoma following diode laser cyclophotocoagulation with a repeatable standard protocol. METHODS: 58 eyes of 53 patients were followed for 6-37 months (mean 19 months) after initial cyclodiode treatment. RESULTS: Mean (SD) pretreatment IOP for the 58 eyes was 33.0 mm Hg (10.7) reducing at final index visit to 16.7 mm Hg (7.8) (p < 0.0001). The mean antiglaucoma medication score per eye was significantly reduced from 2.4 (0.8) to 1.4 (1.0) at last index visit (p < 0.0001) with 91% of patients able to stop oral acetazolamide. 45% of eyes required more than one treatment and the overall mean per eye was 1.6 (range 1-5). Of eyes with visual acuity 6/60 or better pretreatment, 12 (32%) lost more than two lines of Snellen acuity and two eyes with poorer acuity initially dropped to NPL. Poor visual outcome was associated with the presence of diabetic retinopathy. Hypotony (IOP < 5 mm Hg) was noted in two eyes at the last index visit although neither had specific signs of the same. No phthisis was seen. CONCLUSION: The simple treatment protocol, repeated if necessary, appears relatively safe and effective at lowering IOP in eyes with refractory glaucoma. (+info)
Measurement of retinal nerve fibre layer by scanning laser polarimetry and high pass resolution perimetry in normal tension glaucoma with relatively high or low intraocular pressure.
(27/3147)
AIMS: To determine whether any differences may exist in the relation between the neural capacity as determined by high pass resolution perimetry and the thickness of the retinal nerve fibre layer (RNFL) in patients having normal tension glaucoma (NTG) with a relatively high intraocular pressure (IOP) between 16 and 21 mm Hg (HNTG) v those with a lower IOP below 15 mm Hg (LNTG). METHODS: Scanning laser polarimetry and high pass resolution perimetry were performed in 20 eyes of 20 patients with HNTG and 21 eyes of 21 patients with LNTG. The correlation between total and regional thickness of the peripapillary RNFL and the corresponding total and regional neural capacity with linear regression analysis were evaluated. RESULTS: Overall, although the total RNFL thickness was not significantly correlated with the total neural capacity, the RNFL thickness in each of the superior and inferior quadrants was significantly correlated with the corresponding regional neural capacity (r = 0.44, p = 0.0045; r = 0.39, p = 0.0126 for each). The RNFL thickness in each of the superior and inferior quadrants in the HNTG group was significantly correlated with the corresponding regional neural capacity (r = 0.52, p = 0.0196; r = 0.49, p = 0.0286 for each). No significant correlation between neural capacity and the RNFL thickness was observed either globally or regionally in the LNTG group. CONCLUSION: The degree of the correlation between neural capacity as determined by high pass resolution perimetry and thickness of the RNFL as measured by scanning laser polarimetry appeared to differ in NTG patients with an IOP higher than 15 mm Hg v those with a lower IOP. (+info)
Glaucoma patients demonstrate faulty autoregulation of ocular blood flow during posture change.
(28/3147)
BACKGROUND/AIMS: Autoregulation of blood flow during posture change is important to ensure consistent organ circulation. The purpose of this study was to compare the change in retrobulbar ocular blood flow in glaucoma patients with normal subjects during supine and upright posture. METHODS: 20 open angle glaucoma patients and 20 normal subjects, similar in age and sex distribution, were evaluated. Blood pressure, intraocular pressure, and retrobulbar blood velocity were tested after 30 minutes of sitting and again after 30 minutes of lying. Retrobulbar haemodynamic measures of peak systolic velocity (PSV), end diastolic velocity (EDV), and resistance index (RI) were obtained in the ophthalmic and central retinal arteries using colour Doppler imaging (CDI). RESULTS: When changing from the upright to supine posture, normal subjects demonstrated a significant increase in OA EDV (p = 0.016) and significant decrease in OA RI (p = 0.0006) and CRA RI (p = 0.016). Glaucoma patients demonstrated similar changes in OA measures of EDV (p = 0.02) and RI (p = 0.04), but no change in CRA measures. CONCLUSION: Glaucoma patients exhibit faulty autoregulation of central retinal artery blood flow during posture change. (+info)
Risk factors for failures of trabeculectomies performed without antimetabolites.
(29/3147)
AIMS: To assess the risk profile for the failure of trabeculectomies in a large group of patients who were selected to be operated on without the use of antimetabolites. This was done in an effort to find subgroups of patients who may not need antimetabolites for primary procedures. METHODS: Consecutive patients scheduled for routine trabeculectomies were operated during a 4 year period and were followed up for at least 6 months postoperatively. Patients were regularly examined in the glaucoma unit and by their local ophthalmologists. Pre- and postoperative data were evaluated and success rates determined. RESULTS: 709 eyes of 566 patients were operated on; 534 eyes of 534 patients (94.4%) were finally evaluated. The mean follow up was 27.9 (SD 13.6) months with a range of 6-62 months. Success rates for complete surgical success ranged from 59% in the best group with pigmentary dispersion syndrome to 0% in the worst group with neovascular glaucoma. Success rates of patients with POAG, pseudoexfoliation, chronic angle closure, pigmentary dispersion syndrome, and dysgenetic glaucoma were similar. Failure rates ranged from 11% in the best group (pseudoexfoliation) to 80% in the worst group (neovascular glaucoma). Failure rates were high in complicated forms of glaucoma such as traumatic (30%), buphthalmus (40%), and uveitic (50%). For repeat trabeculectomies, the failure rate was 49% (20 of 41 eyes). The mean time until failure ranged from 2.7 months (traumatic) to 15.5 months (pigmentary dispersion syndrome) and was 4.9 months for repeat trabeculectomies. CONCLUSION: Trabeculectomy performed in selected groups of patients has a favourable outcome without the use of antimetabolites. It may be possible to avoid antimetabolites in these groups of patients for primary procedures. (+info)
Pressure-dependent changes in nuclei and the process origins of the endothelial cells lining Schlemm's canal.
(30/3147)
Monkeys eyes were fixed with glutaraldehyde in vivo at positive intraocular pressure of 35 or 25 mm Hg and compared with eyes fixed without a positive pressure gradient, with the use of light microscopy and transmission and scanning electron microscopy. The entire endothelial lining of the inner wall of Schlemm's canal ballooned or distended toward the external wall of the canal at positive intraocular pressure. Characteristic nuclear shapes were identified and appeared to result from the increased pressure forcing the lining away from the meshwork opposed by a restraining or anchoring effect of cytoplasmic processes attached to the subendothelial cells and trabecular meshwork. Without positive intraocular pressure endothelial cell nuclei were rounded, with many folds and notches in the nuclear membrane and were not deformed by their cytoplasmic processes. These findings suggest that the cells may be capable of elastic recoil or contraction. (+info)
Peripheral endothelial dysfunction in normal pressure glaucoma.
(31/3147)
PURPOSE: To assess vascular endothelial function in patients with normal pressure glaucoma using forearm blood flow responses to intra-arterial infusions of endothelial-dependent and -independent vasoactive agents. METHODS: Eight patients with newly diagnosed and untreated normal pressure glaucoma and eight healthy age- and sex-matched control volunteers underwent measurement of forearm blood flow using venous occlusion plethysmography. Blood flow was assessed in response to incremental doses of sodium nitroprusside (an endothelial-independent vasodilator), acetylcholine (an endothelial-dependent vasodilator) and the vasoconstrictor N(G)-monomethyl-L-arginine (an inhibitor of nitric oxide synthase). RESULTS: Sodium nitroprusside caused a dose-related increase in forearm blood flow in patients and controls. Glaucoma patients appeared to have an increased vasodilatory response, but this was not significant (P = 0.23). Acetylcholine also induced vasodilatation in both groups, but the response was significantly reduced in the glaucoma group (P = 0.04). N(G)-monomethyl-L-arginine induced a similar degree of vasoconstriction in both groups (P = 0.76). CONCLUSIONS: This study has shown an impairment of peripheral endothelium-mediated vasodilatation in normal pressure glaucoma. These findings would support the concept of a generalized vascular endothelial dysfunction in patients with this condition. (+info)
Visual function correlates with nerve fiber layer thickness in eyes affected by ocular hypertension.
(32/3147)
PURPOSE: To test whether the high variability observed when measuring pattern electroretinogram (PERG), visual evoked potentials (VEP), and spatial contrast sensitivity (SCS) in eyes with ocular hypertension is associated with variation in nerve fiber layer thickness, as measured by optical coherence tomography (OCT). METHODS: The study involved 32 untreated eyes (32 patients; age range, 29-64 years) showing a normal whiteon-white 24/2 Humphrey (San Leandro, CA) perimetry, IOP between 23 and 28 mm Hg, best corrected acuity of 20/20 or better, and none of the following papillary signs on conventional color stereo slides: rim notch(es), peripapillary splinter hemorrhages, or increased vertical-to-horizontal cup-to-disc ratio. On recruitment, each eye underwent SCS testing, OCT, PERG, and VEP recordings. Linear regression (Pearson's test) or Spearman's rank regression was adopted for the analysis of the data. RESULTS: The 95% confidence limits of the electrophysiological data were: PERG P50 latency, 59.3 to 63 msec; PERG P50 to N95 amplitude, 0.74 to 1.15 cmV; VEP P100 latency, 113 to 118 msec; VEP N75 to P100 amplitude, 3.81 to 4.90 micromV. The 360 degrees nerve fiber layer thickness overall (NFLO) ranged between 113 and 169 microm (145+/-16 microm; mean+/-SD) and significantly correlated with PERG P50 to N95 amplitude (r: 0.518; P = 0.002), PERG P50 latency (r: -0.470; P = 0.007), VEP N75 to P100 amplitude (r: 0.460; P = 0.008), VEP P100 latency (r = -0.422; P = 0.016) and SCS at 3 cyc/deg (r: -0.358; P = 0.044). CONCLUSIONS: The variability of PERG, VEP, and SCS testing observed in eyes with ocular hypertension is associated with differences in NFL thickness (the thinner the layer, the worse the visual function). (+info)