Combining corneal hysteresis with central corneal thickness and intraocular pressure for glaucoma risk assessment

Purpose

To determine whether adjusting corneal hysteresis (CH) values for central corneal thickness (CCT) and intraocular pressure (IOP) improves its capability to differentiate primary open-angle glaucoma (POAG) from ocular hypertension (OH).

Methods

This prospective, observational, cross-sectional study included 169 eyes of 169 subjects with a diagnosis of POAG (n=81) or OH (n=88). We utilized the Ocular Response Analyzer (ORA), Pascal Dynamic Contour Tonometer (DCT), Goldmann applanation tonometer (GAT), and ORA ultrasound pachymeter to obtain CH, IOP, and CCT values. Correlational, regression, and t-test analyses were conducted before and after the sample was divided into low, intermediate, and thick CCT subgroups.

Results

In the full sample, CH and CCT were moderately correlated (r=0.44, P<0.001). Although both were related to diagnosis in univariate regression analysis, only CH was independently related to glaucoma diagnosis in multivariate analysis. After the sample was divided into CCT tertiles, CH was significantly lower in POAG vs OH eyes within all three CCT subgroups, and CH was the only multivariate variable that differentiated POAG from OH in each CCT subgroup. Moreover, the relationship between CH and diagnosis was more robust within the CCT subgroups compared with the full sample, suggesting that integrating CCT into CH interpretation is beneficial. Adjusting CH for IOP did not aid diagnostic precision in this study.

Conclusion

Our findings suggest that combining CH and CCT for glaucoma risk assessment improves diagnostic capability compared to using either factor alone. Conversely, adjusting CH for IOP provided no clear clinical benefit in this study.     

Comparison of trabeculectomy and Ex-PRESS implantation in fellow eyes of the same patient: a prospective, randomised study

Purpose

To compare intraocular pressure (IOP) over time after standard trabeculectomy vsEx-PRESS implantation in patients with bilateral primary open-angle glaucoma (POAG).

Design

Prospective, randomised study.

Patients and methods

This study included adult patients with bilateral POAG necessitating surgery. Each patient underwent trabeculectomy in one eye and Ex-PRESS implantation under a scleral flap in the other eye according to randomised contralateral allocations. Efficacy was assessed by IOP values and success rates (IOP threshold and/or need for topical glaucoma medication) during 30 months. Statistical analysis included Generalised Estimate Equation and Cox Survival models, and paired t-tests.

Results

Thirty eyes of 15 patients were studied for a mean of 23.6 months (SD, ±6.9). At the last follow-up visit, mean pre-operative IOP decreased from 31.1 (±14.2) to 16.2 (±1.5) mm Hg after trabeculectomy, and from 28.1 (±9.0) to 15.7 (±1.8) mm Hg after Ex-PRESS implantation (P=0.001). The mean number of anti-glaucoma medicines prescribed at the last follow-up decreased from 3.7 pre-operatively (both groups) to 0.9 after trabeculectomy vs0.3 after Ex-PRESS implantation (P=0.001). Complete success rates (5P=0.0024). Postoperative complications were more frequent after trabeculectomy (33%) compared with Ex-PRESS (20%), with four trabeculectomy eyes (27%) needing postoperative interventions, compared with none with Ex-PRESS.

Conclusions

Trabeculectomy and Ex-PRESS implantation provided similar IOP control, but the Ex-PRESS group had a lower rate of complications, fewer postoperative interventions, and needed less glaucoma medications.     

Prevalence and risk factors for primary open-angle glaucoma in a rural northeast China population: a population-based survey in Bin County, Harbin

Purpose

To estimate the prevalence and associated risk factors of primary open-angle glaucoma (POAG) in a rural population in northeast China.

Methods

A population-based survey was conducted within Bin County, Harbin of northeast China. Glaucoma was diagnosed using International Society of Geographical and Epidemiological Ophthalmology criteria. All the subjects underwent a complete ophthalmic examination.

Results

A total of 4956 (86.0%) of 5762 subjects aged 40 years or older were examined. The mean intraocular pressure (IOP) of right eyes was 14.0 (95% confidence interval (CI), 13.9 to 14.1) mm Hg. The prevalence of POAG was 0.71% (35/4956, 95% CI, 0.47 to 0.93). In these POAG subjects, 17 (48.6%) had elevated IOP >21 mm Hg in either eye, 3 (8.8%) participants had been treated by laser trabeculoplasty or trabeculectomy and were known to have POAG. Vision impairment to varying degrees was present in 20 subjects (58.8%) with 1 subject blind in both eyes and 8 subjects blind in one eye. On multivariate analysis, age, family history of glaucoma, systemic hypertension, and IOP were regarded as significant independent risk factors.

Conclusions

POAG is a disease of serious consequence and of low diagnosis and treatment rates in rural northeast China. Age, family history of glaucoma, systemic hypertension, and IOP remain as significant independent risk factors for POAG.     

Peripheral lamina cribrosa depth in primary open-angle glaucoma: a swept-source optical coherence tomography study of lamina cribrosa

Purpose

To investigate peripheral lamina cribrosa depth (PLCD) and its vertical-horizontal difference in eyes with primary open-angle glaucoma (POAG).

Methods

Patients with POAG (n=90 eyes) and age-matched healthy individuals (n=90 eyes) underwent swept-source optical coherence tomography (SS-OCT) scans centered at the optic discs. The PLCD was defined as the vertical distance between the most peripheral visible end of anterior lamina cribrosa (LC) surface and the reference plane connecting the Bruch''s membrane openings. The PLCD in each quadrant region and the vertical-horizontal PLCD difference were compared between the POAG and healthy eyes. The clinical factors associated with increased PLCD were evaluated.

Results

The PLCD was significantly larger in the POAG eyes than the control eyes at the horizontal (P=0.034) and vertical (P=0.001) meridians. The vertical PLCD was significantly larger than the horizontal PLCD, both in the POAG eyes (P<0.001) and in the control eyes (P=0.003). However, the vertical-horizontal PLCD difference was significantly larger in the POAG eyes (47±60 μm) than in the control eyes (18±54 μm, P=0.001). Multivariate regression showed a significant association of male gender (P=0.005), increased baseline IOP (P=0.043), and decreased MD of VF (P=0.025) with increased PLCD.

Conclusions

The peripheral LC was displaced more posteriorly in the POAG eyes compared with the age-matched healthy eyes. In the POAG eyes, the peripheral LC was displaced more posteriorly at the vertical meridian than at the horizontal meridian. The peripheral LC in the vertical meridian might have increased IOP-related strain (deformation) compared with horizontal meridian in glaucomatous eyes.     

Bleb needling outcomes for failed trabeculectomy blebs in Asian eyes:a 2-year follow up

AIM:To describe the outcomes of bleb needling in primary glaucoma in an Asian tertiary eye centre over a 2y period. To compare the success rates between primary angle-closure glaucoma (PACG) and primary open angle glaucoma (POAG). Lastly, to identify factors associated with success of bleb needling.METHODS:This was a retrospective review of 227 patients who underwent bleb needling between June 2009 and June 2011 in Singapore National Eye Centre. The 5-fluorouracil (5-FU) augmented bleb needling was performed either at the slit lamp or in the operating theatre. Repeat bleb needlings were performed as necessary. Complete success was defined as maintenance of intraocular pressure (IOP) ≥6 mm Hg and ≤21 mm Hg, in the absence of further surgery or use of antiglaucoma medication. Qualified success met the above criteria with or without use of antiglaucoma medications.RESULTS:One hundred and seventy-five eyes completed the two-year follow up. Sixty-nine percent of participants had POAG and 31% had PACG. The mean interval between filtering surgery and bleb needling was 299.9±616.4d for POAG and 167.1±272.2d for PACG. Mean needling attempts were 1.9±1.4 and 2±1.6 for POAG and PACG respectively. In general, there was a statistically significant reduction of IOP ranging from 21.9% to 26.8% from month 1 through to month 24. The complete success rates at month 6 were 70.0% for POAG and 65.7% for PACG. At month 12, this decreased to 62.2% for POAG and PACG and at month 24, 57.9% for POAG and 63.0% for PACG respectively. The qualified success rates at month 6 for POAG and PACG were 23.8% and 29.9% respectively, 32.2% and 29.2% at month 12, and 34.7% and 29.6% at month 24. The success rates between POAG and PACG were not significantly different (P>0.05 for complete and qualified success at months 6, 12 and 24). An increased number of needlings and higher pre-needling IOP were associated with failure.CONCLUSION:The5-FU augmented bleb needling within one year of trabeculectomy in Asian eyes can provide clinically significant IOP lowering of more than 20% for 2y. POAG and PACG had similar complete success rates (58% and 63% respectively). Factors associated with greater risk of procedure failure included increased number of needlings and higher pre-needling IOP. Asian eyes have a greater propensity for scarring but bleb needling, if performed in a timely manner can rescue bleb function.     

Clinical Characteristics of Glaucomatous Subjects Treated with Refractive Corneal Ablation Surgery

Purpose

To evaluate the clinical characteristics of newly diagnosed glaucomatous subjects who had a history of refractive corneal ablation surgery (RCAS).

Methods

Sixty-eight glaucomatous subjects who had a history of RCAS and 68 age- and visual field (VF) mean deviation-matched glaucomatous subjects with no history of RCAS were included. Intraocular pressure (IOP), central corneal thickness (CCT), VF, and retinal nerve fiber layer thickness determined by optical coherence tomography were assessed. Parameters were compared between patients with and without a history of RCAS. Between-eye comparisons in the same participant (more advanced vs. less-advanced eye, in terms of glaucoma severity) were performed in the RCAS group.

Results

With similar levels of glaucoma severity, those with a history of RCAS showed significantly lower baseline IOP and a thinner CCT than the eyes of individuals without a RCAS history (13.6 vs. 18.7 mmHg, 490.5 vs. 551.7 µm, all p < 0.001). However, the extent of IOP reduction after anti-glaucoma medication did not significantly differ between the two groups (17% vs. 24.3%, p = 0.144). In the between-eye comparisons of individual participants in the RCAS group, the more advanced eyes were more myopic than the less-advanced eyes (-1.84 vs. -0.58 diopter, p = 0.003).

Conclusions

Eyes with a history of RCAS showed a similar level of IOP reduction as eyes without such a history after anti-glaucoma medication. Our finding that the more advanced eyes were more myopic than the less-advanced eyes in the same participant may suggest an association between glaucoma severity and myopic regression.     

Diurnal intraocular pressure fluctuation and its risk factors in angle-closure and open-angle glaucoma

Purpose

To evaluate intraocular pressure (IOP) fluctuation during office hours and its predictive factors in untreated primary angle-closure suspects (PACS); post-iridotomy primary angle closure (PAC) and primary angle-closure glaucoma (PACG) eyes with or without IOP-lowering medication(s) as appropriate and medically treated primary open-angle glaucoma (POAG) eyes.

Methods

One-hundred seventeen eyes (29 PACS, 30 PAC, 28 PACG, and 30 POAG) of 117 patients were included in this cross-sectional study. The subjects underwent hourly IOP measurements with Goldmann tonometer from 0800 to 1700 hours. Subjects with PAC and PACG had laser peripheral iridotomy at least 2 weeks prior to the inclusion. SD of office-hour IOP readings was the main outcome measure.

Results

IOP fluctuation differed between the groups (P=0.01; Kruskal–Wallis Test). Post hoc Mann–Whitney U-tests showed significantly less IOP fluctuation in PACS compared with PACG (P<0.01). Peak office-hour IOP was observed in the morning in untreated subjects and in the early afternoon in treated subjects. A stepwise linear regression model identified the presence of peripheral anterior synechiae (PAS), thickness of lens, large vertical cup-to-disc ratio (VCDR), and PAC category as significant predictive factors associated with office-hour IOP fluctuation.

Conclusions

Diurnal IOP fluctuation in asymptomatic PACSs was less than that in treated PACG subjects and was at least comparable to that in treated PAC and POAG subjects. The greater the amount of PAS, the thicker the lens, the larger the VCDR, the greater was the IOP fluctuation during office hours.     

Comparison of surgical outcomes after phacotrabeculectomy in primary angle-closure glaucoma versus primary open-angle glaucoma

Purpose:

To compare postoperative outcomes and assess factors associated with intraocular pressure (IOP) reduction after phacotrabeculectomy in patients with primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG).

Methods:

This is a retrospective study of patients who underwent phacotrabeculectomy between 2010 and 2013. Factors including age, gender, visual field (VF), the number of glaucoma medications used, biometric changes, IOP, and surgical success rates were compared between groups.

Results:

There were 27 PACG and 34 POAG patients. The PACG group had a greater mean IOP reduction after phacotrabeculectomy compared to the POAG group (5.5 ± 7.9 mmHg versus 2.0 ± 4.2 mmHg; p = 0.03). However, the final mean IOP was similar between the two groups (PACG: 12.2 ± 4.8 mmHg, POAG: 12.3 ± 3.1 mmHg; p = 0.92). Phacotrabeculectomy resulted in a mean decrease in axial length (AL) of 0.16 ± 0.15 mm in PACG and 0.16 ± 0.11 mm in POAG (p = 0.96), and an increase in anterior chamber depth (ACD) of 1.41 ± 0.91 mm in PACG, and 0.87 ± 0.86 mm in POAG (p = 0.04). At 2 years follow-up, the cumulative success rate of phacotrabeculectomy was 74% in PACG and 62% in POAG. Multivariate analysis found that early glaucoma stage, greater postoperative increase in ACD, and high preoperative IOP were factors associated with greater IOP reduction.

Conclusion:

Postoperative success rates and mean IOP on the final visit after phacotrabeculectomy were similar between the PACG and POAG groups. Factors associated with IOP reduction were greater postoperative increase in ACD, and high preoperative IOP.     

Oxygen saturation measurements of the retinal vasculature in treated asymmetrical primary open-angle glaucoma using hyperspectral imaging

Purpose

To determine whether there are differences in retinal vascular oxygen saturation measurements, estimated using a hyperspectral fundus camera, between normal eyes and treated eyes of subjects with asymmetrical primary open-angle glaucoma (POAG).

Methods

A noninvasive hyperspectral fundus camera was used to acquire spectral images of the retina at wavelengths between 556 and 650 nm in 2-nm increments. In total, 14 normal eyes and both eyes of 11 treated POAG subjects were imaged and analyzed using algorithms that use the spectral variation of the optical densities of blood vessels to estimate the oxygen saturation of blood within the retinal vasculature. In the treated POAG group, each of the eyes were categorized, based on the mean deviation of the Humphrey visual-field analyzer result, as either more-advanced or less-advanced, glaucomatous eyes. Unpaired t-tests (two-tailed) with Welch''s correction were used to compare the mean oxygen saturation between the normal subjects and the treated POAG subgroups.

Results

In less-advanced and more-advanced-treated POAG eyes, mean retinal venular oxygen saturations (48.2±21.6% and 42.6±18.8%, respectively) were significantly higher than in normal eyes (27.9±9.9% P=0.03 and 0.01, respectively). Arteriolar oxygen saturation was not significantly different between normal eyes and treated POAG eyes.

Conclusions

The increased oxygen saturation of the retinal venules in advanced-treated POAG eyes may indicate reduced metabolic consumption of oxygen in the inner retinal tissues.     

Spectral domain optical coherence tomography cross-sectional image of optic nerve head during intraocular pressure elevation

AIM: To analyze changes of the optic nerve head (ONH) and peripapillary region during intraocular pressure (IOP) elevation in patients using spectral domain optical coherence tomography (SD-OCT).METHODS: Both an optic disc 200×200 cube scan and a high-definition 5-line raster scan were obtained from open angle glaucoma patients presented with monocular elevation of IOP (≥30 mm Hg) using SD-OCT. Additional baseline characteristics included age, gender, diagnosis, best-corrected visual acuity, refractive error, findings of slit lamp biomicroscopy, findings of dilated stereoscopic examination of the ONH and fundus, IOP, pachymetry findings, and the results of visual field.RESULTS: The 24 patients were selected and divided into two groups:group 1 patients had no history of IOP elevation or glaucoma (n=14), and group 2 patients did have history of IOP elevation or glaucoma (n=10). In each patient, the study eye with elevated IOP was classified into group H (high), and the fellow eye was classified into group L (low). The mean deviation (MD) differed significantly between groups H and L when all eyes were considered (P=0.047) and in group 2 (P=0.042), not in group 1 (P=0.893). Retinal nerve fiber layer (RNFL) average thickness (P=0.050), rim area (P=0.015), vertical cup/disc ratio (P=0.011), cup volume (P=0.028), inferior quadrant RNFL thickness (P=0.017), and clock-hour (1, 5, and 6) RNFL thicknesses (P=0.050, 0.012, and 0.018, respectively), cup depth (P=0.008), central prelaminar layer thickness (P=0.023), mid-inferior prelaminar layer thickness (P=0.023), and nasal retinal slope (P=0.034) were significantly different between the eyes with groups H and L.CONCLUSION:RNFL average thickness, rim area, vertical cup/disc ratio, cup volume, inferior quadrant RNFL thickness, and clock-hour (1, 5, and 6) RNFL thicknesses significantly changed during acute IOP elevation.     

Anterior chamber configuration changes after cataract surgery in eyes with glaucoma

Purpose

To evaluate changes in anterior chamber depth (ACD) and angle width induced by phacoemulsification and intraocular lens (IOL) implantation in eyes with glaucoma, using anterior segment optical coherence tomography (AS-OCT).

Methods

Eleven eyes of 11 patients with angle-closure glaucoma (ACG) and 12 eyes of 12 patients with open-angle glaucoma (OAG) underwent phacoemulsification and IOL implantation. Using AS-OCT, ACD and angle parameters were measured before and 2 days after surgery. Change in intraocular pressure (IOP) and number of ocular hypotensive drugs were evaluated.

Results

After surgery, central ACD and angle parameters increased significantly in eyes with glaucoma (p < 0.05). Prior to surgery, mean central ACD in the ACG group was approximately 1.0 mm smaller than that in the OAG group (p < 0.001). Post surgery, mean ACD of the ACG group was still significantly smaller than that of the OAG group. No significant differences were found in angle parameters between the ACG and OAG groups. In the ACG group, postoperative IOP at the final visit was significantly lower than preoperative IOP (p = 0.018) and there was no significant change in the number of ocular hypotensive medications used, although clinically, patients required fewer medications. In the OAG group, the IOP and number of ocular hypotensive drugs were almost unchanged after surgery.

Conclusions

The ACD and angle width in eyes with glaucoma increased significantly after phacoemulsification and IOL implantation. Postoperative ACD significantly differed between the ACG and OAG groups, whereas angle parameters did not differ.     

Comparison of the Progression of High- and Low-tension Glaucoma as Determined by Two Different Criteria

Purpose

To investigate and compare the progression of medically treated primary open angle glaucoma according to the baseline intraocular pressure (IOP).

Methods

This study included a total of 345 eyes from 345 patients (mean follow-up period, 4.5 years). Eyes were classified into either conventional normal tension glaucoma (cNTG, ≤21 mmHg) or conventional high-tension glaucoma (cHTG, >21 mmHg) groups according to the conventional cut-off value of the IOP. Additionally, the median IOP (15 mmHg) was used to create two other groups (median NTG [mNTG] ≤15 mmHg and median HTG [mHTG] >15 mmHg). Using these values, 306, 39, 153, and 192 eyes were assigned to the cNTG, cHTG, mNTG, and mHTG groups, respectively. Glaucoma progression was determined either by optic disc/retinal nerve fiber layer photographs or serial visual field data.

Results

Mean reduction of IOP after medical treatment and of central corneal thickness was lower in the cNTG group, while the prevalence of disc hemorrhage and baseline visual field mean deviation did not differ between the cNTG and cHTG groups. A mean reduction in the IOP was observed after medical treatment, and central corneal thickness was lower in the mNTG group; disc hemorrhage was more frequent in the mNTG than in the mHTG group. Among the 345 analyzed eyes, 100 (29%) showed progression during the follow-up period. In the cHTG group, a higher baseline IOP (hazard ratio, 1.147; p = 0.024) was associated with glaucoma progression. Disc hemorrhage (hazard ratio, 15.533; p < 0.001) was also strongly associated with progression in the mNTG group.

Conclusions

Baseline IOP was a significant risk factor for glaucoma progression in cHTG patients (10% of our total participants), while disc hemorrhage showed the strongest association with progression in the mNTG group, indicating that a cut-off value other than the conventional 21 mmHg is required to define true low-tension glaucoma in populations where NTG predominates among all glaucoma patients.     

Comparison of retinal nerve fiber layer thickness between Stratus and Spectralis OCT

Purpose

To compare the peripapillary retinal nerve fiber layer (RNFL) thickness of normal patients and those with various glaucoma diseases by time domain (Stratus) and spectral domain (Spectralis) optical coherence tomography (OCT).

Methods

The RNFL thickness as measured by the Stratus and Spectral OCT was compared (paired t-test). The relationship and agreement of RNFL thickness between the two OCT modalities were evaluated by Pearson correlation, Bland-Altman plot, and area under the receiver operating characteristic curve.

Results

Two-hundred seventeen eyes of 217 patients, including twenty-four normal eyes, ninety-one glaucoma suspects, seventy-six normal tension glaucoma cases, and twenty-six primary open angle glaucoma cases (POAG) were analyzed. The peripapillary RNFL thicknesses as measured by Stratus OCT were significantly greater than those measured by Spectralis OCT. However, in quadrant comparisons, the temporal RNFL thickness obtained using Stratus OCT were significantly less than those obtained using Spectralis OCT. Correlations between RNFL parameters were strong (Pearson correlation coefficient for mean RNFL thickness = 0.88); a high degree of correlation was found in the POAG group. Bland-Altman plotting demonstrated that agreement in the temporal quadrant was greater than any other quadrant.

Conclusions

Both OCT systems were highly correlated and demonstrated strong agreement. However, absolute measurements of peripapillary RNFL thickness differed between Stratus OCT and Spectralis OCT. Thus, measurements with these instruments should not be considered interchangeable. The temporal quadrant was the only sector where RNFL thickness as measured by Spectralis OCT was greater than by Stratus OCT; this demonstrated greater agreement than other sectors.     

Twenty-four hour efficacy with the dorzolamide/timolol-fixed combination compared with the brimonidine/timolol-fixed combination in primary open-angle glaucoma

Aim

The aim of this study is to compare the 24-hour efficacy of dorzolamide/timolol-fixed combination (DTFC) and brimonidine/timolol-fixed combination (BTFC) in primary open-angle glaucoma (POAG).

Methods

One eye each of 77 POAG patients was included in this prospective, observer-masked, crossover comparison. Following a 2-month timolol run-in period, patients had three intraocular pressure (IOP) measurements at 1000, 1200 and 1400 h while on timolol treatment. Patients showing at least a 20% IOP reduction on timolol were randomised to 3 months of therapy with DTFC or BTFC, and then were crossed over to the opposite therapy.

Results

Sixty POAG patients completed the study. The mean 24-hour IOP was significantly reduced with both the fixed combinations compared with the timolol-treated diurnal IOP (P<0.001). When the two fixed combinations were compared directly, DTFC demonstrated a lower mean 24-hour IOP level as compared with BTFC (mean difference: −0.7 mm Hg, 95% confidence interval (CI): (−1.0, −0.3), P<0.001). At two individual time points, DTFC significantly reduced IOP more than BTFC: at 1800 h (−1.0 mm Hg, 95% CI (−1.6,−0.5), P=0.001) and at 0200 (−0.9 mm Hg, 95% CI: (−1.4,−0.5), P=0.001). No significant difference existed for the other time points.

Conclusion

Both the fixed combinations significantly reduce 24-hour IOP in POAG. DTFC provided significantly better 24-hour efficacy.     

Outcomes of Ahmed valve surgery for refractory glaucoma in Dhahran, Saudi Arabia

AIM:To evaluate the outcomes of Ahmed glaucoma valve (AGV) implantation surgery for refractory glaucoma.METHODS:This one-armed historical cohort study was conducted in 2011. Refractory glaucoma was defined as eyes with an intraocular pressure (IOP) greater than 21 mm Hg with maximally tolerated glaucoma medications, failed surgeries, or both. For all eyes with refractory glaucoma that underwent AGV implantation, data were collected on IOP, the best corrected visual acuity (BCVA) and glaucoma medications preoperatively and 4, 6, 12, 24 and 56wk postoperatively. Logarithm values of IOP were calculated and compared.RESULTS: The study group was comprised of 30 patients (30 eyes, 16 males and 14 females) with refractory glaucoma. Mean preoperative IOP was 39.3±13.8 mm Hg. Postoperative mean IOP was 15.7±7.1 mm Hg, 19.6±12.8 mm Hg and 13.9±14.2 mm Hg at 12, 24 and 56wk respectively. BCVA was ≥ 6/60 in 11 eyes preoperatively, and five eyes had BCVA≥6/60 at 56wk postoperatively. Preoperatively, more than four medications were used to treat glaucoma in 21 eyes. At 12wk postoperatively, no medications were required to control IOP in 20 eyes. At 56wk postoperatively, at least one medication was required to control IOP in 10 eyes. Over the entire follow up period, four eyes were treated with yttrium aluminium garnet (YAG) laser and 14 eyes required a second surgery. The AGV was removed in four eyes.CONCLUSION: AGV implantation reduced IOP and the number of medications required to control refractory glaucoma. However, there was a higher risk of decreased vision. Long-term follow up and prompt intervention are recommended.     

Factors associated with topographic changes of the optic nerve head induced by acute intraocular pressure reduction in glaucoma patients

Purpose

To investigate factors associated with changes in optic nerve head (ONH) topography after acute intraocular pressure (IOP) reduction in patients with primary open-angle glaucoma (POAG).

Methods

Untreated POAG patients (IOP >21 mm Hg) were prospectively enrolled. Systemic and ocular information were collected, including central corneal thickness (CCT) and corneal hysteresis (CH). All patients underwent confocal scanning laser ophthalmoscopy and tonometry (Goldmann) before and 1 h after pharmacological IOP reduction. The mean of three measurements was considered for analysis. Changes in each ONH topographic parameter were assessed (one eye was randomly selected), and those that changed significantly were correlated with patient''s systemic and ocular characteristics.

Results

A total of 42 patients were included (mean age, 66.7±11.8 years). After a mean IOP reduction of 47.3±11.9%, significant changes were observed in cup area and volume, and in rim area and volume (P<0.01), but not in mean cup depth (P=0.80). Multiple regression analysis (controlling for baseline IOP and magnitude of IOP reduction) showed that CH (r²=0.17, P<0.01) and diabetes diagnosis (r²⩾0.21, P<0.01) were negatively correlated with the magnitude of changes in ONH parameters, whereas the cup-to-disc ratio was positively correlated (r²=0.30, P<0.01). Age, race, disc area, and CCT were not significant (P⩾0.12). Including all significant factors in a multivariable model, only the presence of diabetes remained significantly associated with all ONH parameters evaluated (P<0.01).

Conclusions

Different systemic and ocular factors, such as diabetes, CH, and the relative size of the cup, seem to be associated with the magnitude of changes in ONH topography after acute IOP reduction in POAG patients. These associations partially explain the ONH changes observed in these patients and suggest that other factors are possibly implicated in an individual susceptibility to IOP.     

Relationship between systemic hypertension,perfusion pressure and glaucoma: A comparative study in an adult Indian population

Aims:

To study the relationship between blood pressure (BP), intraocular pressure (IOP), mean ocular perfusion pressure (MOPP) and primary open angle glaucoma (POAG) in patients with hypertension and compare it to a control group of normotensives.

Design:

Cross-sectional observational study.

Materials and Methods:

A total of 108 subjects with primary hypertension and 100 age-matched controls without hypertension were enrolled for the study. IOP measurement using Noncontact Tonometer and dilated fundus evaluation using + 90 D lens were done for all cases. Single recording of BP was taken. Gonioscopy, Humphrey''s central visual fields, optical coherence tomography and pachymetry were done for all subjects with IOP > 21 mm Hg or C: D ratio ≥ 0.5 or asymmetry of > 0.2.

Statistical Analysis:

Univariate and multivariate multinomial regression models were used to determine the association between covariates and risk of glaucoma or glaucoma suspect.

Results:

There was no difference in the glaucoma status between subjects with and without hypertension. Subjects on antihypertensive medications were 1½ times more likely to have suspicious glaucoma (odds ratio [OR] =1.56] and nearly twice as likely to have POAG (OR = 1.85). In addition, we found a 31% and 12% reduction in risk of having POAG (95% confidence interval [CI] =13–45%, P = 0.001) and glaucoma suspect (95% CI = 2–21%, P = 0.03) respectively with every 1 mm Hg increment in MOPP.

Conclusion:

Subjects on antihypertensive medications are more likely to have either glaucoma or glaucoma suspect, and higher ocular perfusion pressure offers relative protection from glaucomatous damage.     

Comparison of ocular response analyzer parameters in primary open angle glaucoma and exfoliative glaucoma patients

Aim:

We sought to identify differences in the following measures of the ocular response analyser (ORA) between primary open angle glaucoma (POAG) and exfoliative glaucoma (EXG) patients: Corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPcc) and Goldmann-correlated intraocular pressure (IOPg). We also sought to relate these ORA measures with central corneal thickness (CCT).

Materials and Methods:

This cross-sectional study was conducted on a total of 162 individuals (46 EXG patients, 66 POAG patients and 50 healthy subjects without any ocular and systemic disease). ORA measurements were performed, and a minimum of three readings were obtained from each test subject. Groups were compared according to their ORA parameters.

Results:

The mean CH levels of the EXG, POAG and healthy subjects were 7.6 ± 2.1, 9.1 ± 1.9 and 9.6 ± 1.7 mmHg, respectively. CH was significantly lower in the EXG patients compared to the other groups (P < 0.001). The mean CRF levels of the EXG, POAG and healthy subjects were 9.0 ± 2.0, 10.1 ± 1.7 and 9.8 ± 1.8mmHg, respectively. CRF levels in the eyes of the EXG patients were significantly lower compared to those of either the POAG patients (P = 0.005) or the healthy subjects (P = 0.03), but there was no significant difference in CRF levels between the POAG patients and the healthy subjects (P = 0.59). There was a significant positive correlation between CH and CCT in the EXG patients and healthy subjects (P < 0.001), but this correlation was not present in the POAG patients (P = 0.70).

Conclusions:

In this study, CH and CRF were found to be significantly reduced in the eyes of EXG patients compared to both the POAG patients and healthy subjects. Reduced CH in EXG patients might result in decreased support of peripapillary scleral structure and increased damage to the optic nerve during IOP increase.     

Effects of caffeinated coffee consumption on intraocular pressure, ocular perfusion pressure, and ocular pulse amplitude: a randomized controlled trial

Purpose

To examine the effects of caffeinated coffee consumption on intraocular pressure (IOP), ocular perfusion pressure (OPP), and ocular pulse amplitude (OPA) in those with or at risk for primary open-angle glaucoma (POAG).

Methods

We conducted a prospective, double-masked, crossover, randomized controlled trial with 106 subjects: 22 with high tension POAG, 18 with normal tension POAG, 20 with ocular hypertension, 21 POAG suspects, and 25 healthy participants. Subjects ingested either 237 ml of caffeinated (182 mg caffeine) or decaffeinated (4 mg caffeine) coffee for the first visit and the alternate beverage for the second visit. Blood pressure (BP) and pascal dynamic contour tonometer measurements of IOP, OPA, and heart rate were measured before and at 60 and 90 min after coffee ingestion per visit. OPP was calculated from BP and IOP measurements. Results were analysed using paired t-tests. Multivariable models assessed determinants of IOP, OPP, and OPA changes.

Results

There were no significant differences in baseline IOP, OPP, and OPA between the caffeinated and decaffeinated visits. After caffeinated as compared with decaffeinated coffee ingestion, mean mm Hg changes (±SD) in IOP, OPP, and OPA were as follows: 0.99 (±1.52, P<0.0001), 1.57 (±6.40, P=0.0129), and 0.23 (±0.52, P<0.0001) at 60 min, respectively; and 1.06 (±1.67, P<0.0001), 1.26 (±6.23, P=0.0398), and 0.18 (±0.52, P=0.0006) at 90 min, respectively. Regression analyses revealed sporadic and inconsistent associations with IOP, OPP, and OPA changes.

Conclusion

Consuming one cup of caffeinated coffee (182 mg caffeine) statistically increases, but likely does not clinically impact, IOP and OPP in those with or at risk for POAG.     

Damage patterns of retinal nerve fiber layer in acute and chronic intraocular pressure elevation in primary angle closure glaucoma

AIM: To observe the differences of damage patterns of retinal nerve fiber layer (RNFL) between acute and chronic intraocular pressure (IOP) elevation in primary angle closure glaucoma (PACG) using optical coherence tomography (OCT). METHODS: Twenty-four patients (48 eyes) with unilateral acute PACG (APACG) attack in the 6 months after admission and 36 patients (64 eyes) with chronic PACG (CPACG) were included in this prospective study. For all cases, IOP has been controlled under 21mmHg after treatment. Using stratus OCT, the RNFL thickness was assessed in eyes with PACG within 3 days, 2 weeks, 1, 3 and 6 months after IOP was controlled. Repeated measures ANOVA was used to examine the changes of RNFL thickness at different time after IOP being controlled in both acute attack eyes and unaffected fellow eyes of APACG and eyes with CPACG. RESULTS: The mean RNFL thickness for the APACG- attacked eyes increased significantly within 3 days (121.49±23.84)μm after acute onset and then became thinner along with time [(107.22±24.72)μm at 2 weeks,(93.58±18.37)μm at 1 month, (84.10±19.89)μm at 3 months and (78.98±19.17)μm at 6 months]. In APACG-attacked eyes, there were significant differences of average RNFL thickness at 5 different times after IOP was controlled (P＜0.001). In the APACG unaffected fellow eyes and CPACG eyes, there were no significant differences in mean RNFL thickness at 5 different times(F=0.450, P=0.104 in APACG unaffected fellow eyes and F=1.558, P=0.200 in CPACG eyes). There was significant difference for interaction between time periods and groups (F=1.912, P=0.003). CONCLUSION: RNFL damage patterns are different under different IOP elevated courses. In APACG, RNFL was found to be swollen and thickening right after acute attack and then becomes thinning and atrophy along with the time, while RNFL was found to be diffused thinness in CPACG.