Ocular hemodynamics in pseudoexfoliation syndrome and pseudoexfoliation glaucoma

OBJECTIVE: To evaluate orbital blood flow velocities by using color Doppler imaging in patients with pseudoexfoliation syndrome and pseudoexfoliation glaucoma. DESIGN: Prospective, comparative case series. PARTICIPANTS: Twenty-eight patients with pseudoexfoliation syndrome (n = 14) or pseudoexfoliation glaucoma (n = 14) and 14 healthy control participants were included. INTERVENTION: Color Doppler imaging was used with a 7.5-MHz probe. Evaluation of the ophthalmic, central retinal, short posterior nasal, and temporal ciliary arteries was performed, and peak systolic and end diastolic flow velocities were measured. Resistive indices were calculated. RESULTS: When compared with the control participants, patients with pseudoexfoliation syndrome showed statistically significant decreases in the mean peak systolic velocity of the central retinal artery (11.21 +/- 2.19 cm/second; P < 0.05), and end diastolic velocities of the central retinal artery (3.00 +/- 1.03 cm/second; P < 0.005), and short posterior temporal ciliary arteries (3.50 +/- 1.74 cm/second; P < 0.005), whereas mean resistive indices of the ophthalmic artery (0.75 +/- 0.06 cm/second; P < 0.005) and central retinal artery were found to have increased (0.70 +/- 0.05 cm/second; P < 0.01). Patients with pseudoexfoliation glaucoma, when compared with the control participants, showed statistically significant decreases in the mean peak systolic and end diastolic velocities and increased mean resistive indices in all vessels measured (P < 0.05). Compared with the patients with pseudoexfoliation syndrome, patients with pseudoexfoliation glaucoma showed statistically significant decreases in the mean peak systolic velocities of the ophthalmic artery (30.07 +/- 4.00 cm/second; P < 0.05) and short posterior nasal ciliary arteries (2.35 +/- 0.09 cm/second; P < 0.05), and in the mean end diastolic velocities of the ophthalmic artery (6.28 +/- 2.12 cm/second; P < 0.05), and short posterior nasal ciliary arteries (2.35 +/- 0.09 cm/second; P < 0.05). The differences in the mean resistive indices were not statistically significant between the patients with pseudoexfoliation syndrome and the ones with pseudoexfoliation glaucoma. CONCLUSIONS: The findings suggest that hemodynamic parameters in the retrobulbar vessels were altered in patients with pseudoexfoliation syndrome and pseudoexfoliation glaucoma; however, these alterations were more prominent in the latter group.     

超声乳化术治疗假性剥脱综合征白内障患者的疗效分析

目的：：评估在白内障超声乳化手术时使用适当的手术技巧及相应设备对假性剥脱综合征白内障患者的视力及术中、术后并发症的影响。方法：回顾性研究。选取53例67眼假性剥脱综合征白内障患者接受超声乳化及人工晶状体植入术。平均年龄71.68±9.96(53~89)岁,其中男性24例(45%),女性29例(55%),包括核性、皮质性及后囊下和成熟期的白内障。结果：核性白内障较其他类型更为常见(P=0.00)。术前平均最佳矫正视力为0.99±0.30(0.40~1.50) LogMAR,术后平均最佳矫正视力为0.32±0.31(0.00~1.00) LogMAR ( P=0.00)。运用虹膜牵拉器12眼(18%)。囊袋张力环植入15眼(22%),其中按计划植入8眼(12%),未计划7眼(10%)。后囊破裂4眼(6%),其中玻璃体脱出2眼(3%),并接受前段玻璃体切割术;且由于后囊破裂较大,此2眼(3%)转为白内障囊外摘除术。持续性角膜水肿4眼(6%),前房反应5眼(7%)。人工晶体脱位4眼(6%),仅1眼(1.5%)需复位。后囊混浊并接受Nd：YAG激光后囊切开术13眼(20%)。结论：假性剥脱综合征白内障患者术后视力良好,但术中及术后可能出现的并发症包括后囊破裂,玻璃体脱出,转为白内障囊外摘除术,持续性角膜水肿,前房反应及人工晶状体脱位。为避免并发症的发生,适当的手术技巧和相应设备的使用在手术时是必不可少的。     

Diurnal variation in central corneal thickness and intraocular pressure in eyes with pseudoexfoliation syndrome without glaucoma

Aim:

The aim was to ascertain if any differences exist in diurnal central corneal thickness (CCT) and intra-ocular pressure (IOP) between eyes with pseudoexfoliation (PXF) syndrome without glaucoma and eyes with no ocular pathology. A secondary aim was to determine whether there was a significant relationship between CCT and IOP.

Settings and Design:

This study was a prospective design conducted within a hospital setting.

Materials and Methods:

The experimental group consisted of seven participants with bilateral PXF (14 eyes) and the control group comprised of 15 participants (30 eyes). Testing included CCT and IOP measured at four different times on one given day (8.00 a.m.; 11 a.m.; 2 p.m. and 5 p.m.).

Statistical Analysis:

The data were analyzed with the generalized linear latent mixed model.

Results:

PXF eyes displayed a significantly thinner overall mean CCT (520 μm) compared to controls (530 μm). Furthermore, a significant reduction in CCT and IOP occurred in the PXF group from 8 a.m. to 5 p.m. The mean overall IOP in PXF eyes was significantly lower than the control group. A significant association between IOP and CCT was also found in PXF eyes.

Conclusions:

Displaying a significantly thinner mean CCT highlights the importance of measuring CCT in an ophthalmic clinical setting as to avoid falsely underestimated IOP measurements in such a high-risk glaucoma population. Furthermore, a statistically significant correlation between IOP and CCT in PXF eyes suggests that the reduction in CCT that occurred in PXF eyes between 8 a.m. and 5 p.m. may be partly responsible for the reduction in IOP measurements.     

Iris neovascularisation in eyes with pseudoexfoliation syndrome.

The iris vascular bed of eyes with pseudoexfoliation syndrome has been studied with electron microscopy. Two of the eyes suffered from painful glaucoma, whereas the third showed normal intraocular pressure. The following changes were observed: (1) deposits of pseudoexfoliation material lying adjacent to the endothelial wall; (2) thin vessel basement membrane, sometimes even interrupted; (3) extreme reduction of vessel lumina through increased volume of the endothelial cells; (4) fenestration of the endothelial wall. It is suggested that the iris neovascularisation in eyes with pseudoexfoliation syndrome is due to an obstruction of iris vessels causing tissue hypoxia.     

Phacoemulsification in Indian eyes with pseudoexfoliation syndrome.

PURPOSE: To evaluate the intraoperative and postoperative behavior after phacoemulsification in Indian eyes with pseudoexfoliation syndrome. SETTING: Iladevi Cataract & Intraocular Lens Research Centre, Ahmedabad, India. METHOD: Ninety eyes were prospectively evaluated. Group 1 (cohort) comprised 45 consecutive eyes with pseudoexfoliation and coexisting cataract and Group 2 (control), 45 consecutive normal eyes with senile cataract only. Phacoemulsification was performed by a single surgeon using a step-by-step, chop in situ, and lateral separation technique. An AcrySof intraocular lens was implanted in the bag in all eyes. Intraoperative observations included pupil size after maximal mydriasis, phakodonesis, zonular dehiscence, grade of cataract, and capsule tear/rupture. Postoperatively, intraocular pressure (IOP), best corrected visual acuity, aqueous flare/cell response, and the presence of posterior synechias were evaluated at 1 day and 1 month. A chi-square test was used for statistical analyses. RESULTS: The mean pupil size was significantly smaller in Group 1 (P =.0000). No eye in either group had phakodonesis. Sixty percent of eyes in Group 1 and 31% in Group 2 had a hard cataract (P =.008). Endocapsular phacoemulsification was performed in 82% of eyes in Group 1 and 84% of eyes in Group 2. Intraoperative complications such as zonular or capsular dehiscence were not seen in any eye. Postoperatively, IOP and aqueous cell response were comparable between groups (P =.11 and P = 0.81, respectively). A significantly higher flare response was observed in Group 1 (P =.000). The visual outcome at 1 month was similar between groups. CONCLUSIONS: The intraoperative performance of Indian eyes with pseudoexfoliation was comparable to that in normal eyes. A good surgical outcome is ensured by using an appropriate surgical technique. Apart from a higher flare response, the postoperative outcomes in eyes with pseudoexfoliation were within normal limits, and the outcome at 1 month was satisfactory.     

Combined phacoemulsification and goniotrephination on eyes with primary open-angle glaucoma and classical pseudoexfoliation glaucoma

Background: Combined glaucoma and cataract operation has been demonstrated to be effective in controlling IOP and increasing visual acuity. Because of the differences between patients with primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXEG), for cataract and glaucoma surgery alone we evaluated the effects and complications for simultanous surgical management.     

Combined phacoemulsification and goniotrephination on eyes with primary open-angle glaucoma and classical pseudoexfoliation glaucoma

BACKGROUND: Combined glaucoma and cataract operation has been demonstrated to be effective in controlling IOP and increasing visual acuity. Because of the differences between patients with primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXEG), for cataract and glaucoma surgery alone we evaluated the effects and complications for simultanous surgical management. PATIENTS AND METHODS: In a retrospective study 103 patients were examined who underwent a combined phacoemulsification and goniotrephination between January 1993 and January 1997 and had no surgery before (110 eyes with POWG, 22 eyes with PXEG). RESULTS: The average age in the POAG group (75.1 +/- 8.7 years) was significantly less than in the PXEG group (79.3 +/- 5.9 years) (P < 0.05). The mean preoperative IOP in PXEG (31.8 +/- 10.3 mmHG) was significantly higher than in POAG (25.0 +/- 6.4 mmHg) (P < 0.0005). Due to the combined surgery the mean intraocular pressure decreased in both groups < 10 mmHg (days 1 and 7). PXEG had a significantly higher IOP at day 3 than POAG (12.3 +/- 8.4 mmHg versus 8.5 +/- 5.7 mmHg) (P < 0.05) and developed after combined operation IOP peaks > 25 mmHg into a significantly higher level (P < 0.05). Moreover, zonulolysis, rupture of the posterior capsule, vitreous loss and persistence of inflammatory response occurred more often in PXEG, but there was no significant difference compared to POAG. CONCLUSION: PXEG has an higher incidence of typical problems of phacoemulsification, a temporary increase of IOP and prolonged inflammation after combined cataract and glaucoma surgery than POAG, but there is a similar risk compared to a single procedure.     

Pathophysiologic changes in the optic nerves of eyes with primary open angle and pseudoexfoliation glaucoma

PURPOSE: To determine whether differences in the optic nerve occur in eyes with primary versus secondary open-angle glaucoma. METHODS: Optic nerves obtained at autopsy from 36 eyes with primary open-angle glaucoma (POAG) and 15 with pseudoexfoliation glaucoma (PEXG) were studied quantitatively and qualitatively. Axon counts, fibrosis, capillary number and density, and arteriosclerotic changes were assessed in the postlaminar optic nerve and compared to normal age-matched autopsy eyes. Changes in composition of extracellular matrix components were evaluated by immunohistochemistry and electron microscopy. RESULTS: Marked differences were found between POAG and PEXG. Axon loss in eyes with POAG but not in PEXG was associated with increasing connective tissue in the septa and surrounding the central retinal vessels, including increased amounts of type IV and VI collagen. The total number of capillaries decreased with the loss of axons in both POAG and PEXG. POAG nerves, however, had a decrease in the density of capillaries, whereas in PEXG the capillary density did not change with axon loss. Arteriosclerotic changes were more common in glaucomatous eyes than in age-matched control eyes. CONCLUSIONS: The difference in morphology of the optic nerves between POAG and PEXG indicates that in eyes with POAG, elevated IOP cannot be the only pathogenetic factor in glaucomatous optic neuropathy. Additional factors, inducing fibrosis and loss of capillaries, seem to be involved. Such additional factors may also contribute to the clinical finding in POAG that nerves can become damaged without elevation of intraocular pressure.     

Homocysteine and nitric oxide levels in plasma of patients with pseudoexfoliation syndrome,pseudoexfoliation glaucoma,and primary open-angle glaucoma

Purpose To evaluate plasma total homocysteine (tHcy) and nitric oxide (NO) marker levels in patients with pseudoexfoliation syndrome (PXS), pseudoexfoliation glaucoma (PXG), primary open-angle glaucoma (POAG), and normal controls.Methods This cross-sectional, prospective study involved 19 patients with POAG, 18 with PXS, 22 with PXG, and 20 control subjects. Fasting tHcy levels of all study participants were determined using a fluorescence polarization immunoassay method. Quantitation of total nitrate was based on the Griess reaction, in which a chromophore with a strong absorbance at 545 nm is formed by reaction of nitrite with a mixture of naphthylethylenediamine and sulphanilamide.Results The mean plasma homocysteine level was statistically significantly elevated in the PXS (p=0.033) and the PXG (p=0.023) groups but not in the POAG group (p=0.996) when compared with the control group. Multiple logistic regression analyses comparing the various patient groups with the single control group indicated that elevation in plasma homocysteine concentration was a significant risk factor for PXS (odds ratio per 1 mol/l increase in homocysteine concentration=2.05, 95% CI=1.19–3.52) and PXG (odds ratio per 1 mol/l increase in homocysteine concentration=1.36, 95% CI=1.00–1.85) but was not a significant risk factor for POAG (odds ratio per 1 mol/l increase in homocysteine concentration=0.99, 95% CI=0.78–1.26). NO markers levels were found to be slightly higher in PXS and PXG patients than control and POAG patients but the differences were not statistically significant (p=0.151). Multiple logistic regression analyses comparing the various patient groups with the single control group indicated that elevation in NO marker concentration was not a significant risk factor for PXS (odds ratio per 1 mol/l increase in NO concentration=1.00, 95% CI=0.99–1.01), PXG (odds ratio per 1 mol/l increase in NO concentration=1.00, 95% CI=0.99–1.00) and POAG (odds ratio per 1 mol/l increase in NO concentration=0.99, 95% CI=0.99–1.00). No statistically significant correlations were observed between plasma tHcy and NO markers in study groups (p>0.05).Conclusion Elevated levels of homocysteine in pseudoexfoliation patients with and without glaucoma may partly explain the increased risk of vascular disease among patients with pseudoexfoliation. No significant difference was found in plasma NO markers among the POAG, PXS, PXG, and the control subjects.     

Estimated incidence of pseudoexfoliation syndrome and pseudoexfoliation glaucoma in Olmsted County,Minnesota

PURPOSE: To determine the incidence of newly diagnosed pseudoexfoliation syndrome and pseudoexfoliation glaucoma in residents of Olmsted County, Minnesota from 1976 to 1991. MATERIALS AND METHODS: The database of the Rochester Epidemiology Project was used to identify all patients residing in Olmsted County who were newly diagnosed with pseudoexfoliation syndrome from 1976 to 1991. The criterion used to diagnose pseudoexfoliation syndrome was the presence of pseudoexfoliation material on 1 or more anterior segment structures. Criteria used to diagnose pseudoexfoliation glaucoma were diagnosis of pseudoexfoliation syndrome with evidence of glaucomatous changes or ocular hypertension receiving therapy. The overall age and sex-adjusted annual incidences of pseudoexfoliation syndrome and pseudoexfoliation glaucoma, adjusted to the 1990 US white population, were determined with differences across age and sex using Poisson regression. RESULTS: Pseudoexfoliation syndrome was diagnosed in 290 patients (mean age, 73 +/- 10 years). Two hundred twenty-one (76%) were female. The overall age and sex-adjusted annual incidence of pseudoexfoliation syndrome was 25.9 per 100,000. The age-adjusted incidence was higher in females than in males (32.7 vs 16.9 per 100,000; P<0.001). Pseudoexfoliation syndrome diagnoses increased with age, from 2.8 per 100,000 in persons 40 to 49 years to 205.7 per 100,000 in persons > or =80 years (P<0.001). Thirty-five patients were excluded from pseudoexfoliation glaucoma diagnosis. Of the remaining 255 patients, 113 (44%) were diagnosed with pseudoexfoliation glaucoma during the study period (mean age, 76 +/- 10 years), 84 (74%) of whom were female. The overall age- and sex-adjusted annual incidence of pseudoexfoliation glaucoma was 9.9 per 100,000. The age-adjusted incidence was higher in females than in males (11.7 vs 7.2 per 100,000; P < 0.001). Pseudoexfoliation glaucoma was increasingly diagnosed with age, rising from 0.6 per 100,000 in persons 40 to 49 years to 114.3 per 100,000 in persons > or =80 years, (P<0.001). CONCLUSIONS: In a defined population, the estimated overall age- and sex-adjusted annual incidence of pseudoexfoliation syndrome was 25.9 per 100,000 population, while the estimated overall age- and sex-adjusted annual incidence of pseudoexfoliation glaucoma was 9.9 per 100,000 population. The incidence of both diseases was higher in females and increased with advancing age.     

Corneal curvature and central corneal thickness in eyes with pseudoexfoliation syndrome

BACKGROUND: Previous studies have reported different central corneal thickness (CCT) values in eyes with pseudoexfoliation syndrome (PXS). There has been no report about corneal curvature (CC) in PXS eyes. The aim of this study was to investigate the CCT together with the CC in PXS eyes with and without glaucoma. METHODS: The CC (simulated keratometry 1 [SimK1], SimK2, and mean K) and CCT were prospectively studied by rotating a Scheimpflug camera in 72 PXS eyes and comparing them with 65 normal eyes. RESULTS: In all PXS eyes, the mean K was significantly steeper than in control eyes (44.1 [SD 1.5] diopters (D) vs. 43.2 [SD 2.0] D, p = 0.04). When PXS eyes were subcategorized, the mean K was significantly steeper in both normotensive PXS eyes (44.6 [SD 1.6] D) and pseudoexfoliation glaucoma (PEXG) eyes (44.0 [SD 1.2] D) than normal eyes (43.2 [SD 2.0] D) (p = 0.001 and 0.02, respectively). In all PXS eyes, the mean CCT (546.4 [SD 39.6] microm) was not significantly different than the control eyes (542.9 [SD 32.2] microm) (p = 0.56). When PXS eyes were subcategorized, however, the CCT was significantly thinner in normotensive PXS eyes and significantly thicker in PEXG eyes. INTERPRETATION: It appears that PEXG eyes have a significantly steeper CC and higher CCT than normal eyes. This could be of clinical significance because overestimation of true intraocular pressure may then occur in these eyes.