Retinal neurovascular coupling in patients with glaucoma and ocular hypertension and its association with the level of glaucomatous damage

Purpose

To analyze neurovascular coupling in the retina of untreated primary open-angle glaucoma (POAG) and ocular hypertension (OHT) patients.

Patients and methods

Maximal vessel dilation in response to flicker light was analyzed with Retinal Vessel Analyzer (RVA) in temporal superior/inferior arterioles and veins in 51 POAG patients, 46 OHT and 59 control subjects. RVA parameters were compared between groups, between contralateral POAG eyes, and correlated to intraocular pressure, visual field mean defect and retinal nerve fiber layer thickness.

Results

POAG eyes demonstrated generally smaller response of all vessels to flicker light than the other two groups (ANOVA p?=?0.026; mean arterial flicker response in percent of baseline, averaged superior and inferior was 3.48?±?2.22 % for controls , 2.35?±?2.06 % for POAG patients , and 2.97?±?2.35 % for OHT patients; corresponding values for venules were 3.88?±?1.98 %, 2.89?±?1.72 %, 3.45?±?2.77 %). There was no difference in flicker response between the eye with more and less advanced damage in each patient of the POAG group (ANOVA p?=?0.79). Correlation of flicker response to intraocular pressure (IOP) was borderline at best, correlations to the level of glaucomatous damage were not significant. Correlation of flicker response of superior and inferior vessels of the same eye was significant for the arteries (Pearson r?=?0.23, p?=?0.004), as well as venules (r?=?0.52, p?<?0.001).

Conclusion

General vessel response to flicker light was decreased in POAG patients, compared to normal controls and OHT patients. In contrast to significant correlation between the two contralateral eyes of the flicker response itself, only its borderline correlation to IOP was seen. There was no correlation to the level of damage, altogether indicating a systemic dysregulation phenomenon.

Grants

Swiss National Foundation Grant 3200B0-113685, Velux Stiftung Grant, Freie Akademische Gesellschaft (FAG) Grant, Pfizer Inc. Grant

Clinical trial registration reference number

ClinicalTrials.gov NCT00430209     

Retinal vessel diameter in normal-tension glaucoma patients with asymmetric progression

Purpose

To investigate the longitudinal changes in the central retinal vessel diameter in asymmetric progressive normal-tension glaucoma (NTG) patients.

Methods

This study included 27 patients with bilateral NTG without any systemic vascular disease who showed glaucomatous progression in one eye at the mean follow-up of 24.3 months (range, 18–29 months). Progression was determined by the development of new retinal nerve fiber layer (RNFL) defects or widening of pre-existing defects on red-free RNFL photographs. The central retinal arteriolar equivalent (CRAE) and the central retinal venular equivalent (CRVE) were measured at baseline and at the mean follow-up of 24.3 months. We classified the eyes of each patient as either progressed or stable eyes, and compared the differences and changes in the CRAE and CRVE.

Results

No significant inter-eye difference was observed at baseline in the mean CRAE (167.5?±?22.2 μm vs. 168.2?±?15.5 μm, p?=?0.809) and in the mean CRVE (276.3?±?18.2 μm vs. 281.6?±?21.9 μm, p?=?0.267) between the progressed and stable eyes. There were significant changes in CRAE in the progressed eyes between baseline and 2 years after baseline (from 167.5?±?22.2 μm to 146.9?±?18.0 μm, p?p?=?0.084).

Conclusions

In our series of NTG patients with asymmetric progression, central retinal artery diameter decreased over time in the progressed eyes, whereas no significant decrease in the central retinal artery diameter was seen in the stable eyes.     

Intraocular pressure correlates with optic nerve sheath diameter in patients with normal tension glaucoma

Purpose

1. Identify differences in optic nerve sheath diameter (ONSD) as an indirect measure of intracranial pressure (ICP) in glaucoma patients and a healthy population. 2. Identify variables that may correlate with ONSD in primary open-angle glaucoma (POAG) and normal tension glaucoma (NTG) patients.

Methods

Patients with NTG (n?=?46) and POAG (n?=?61), and healthy controls (n?=?42) underwent B-scan ultrasound measurement of ONSD by an observer masked to the patient diagnosis. Intraocular pressure (IOP) was measured in all groups, with additional central corneal thickness (CCT) and visual field defect measurements in glaucomatous patients. Only one eye per patient was selected. Kruskal–Wallis or Mann–Whitney were used to compare the different variables between the diagnostic groups. Spearman correlations were used to explore relationships among these variables.

Results

ONSD was not significantly different between healthy, NTG and POAG patients (6.09?±?0.78, 6.03?±?0.69, and 5.71?±?0.83 respectively; p?=?0.08). Visual field damage and CCT were not correlated with ONSD in either of the glaucoma groups (POAG, p?=?0.31 and 0.44; NTG, p?=?0.48 and 0.90 respectively). However, ONSD did correlate with IOP in NTG patients (r?=?0.53, p?<?0.001), while it did not in POAG patients and healthy controls (p?=?0.86, p?=?0.46 respectively). Patient’s age did not relate to ONSD in any of the groups (p?>?0.25 in all groups).

Conclusions

Indirect measurements of ICP by ultrasound assessment of the ONSD may provide further insights into the retrolaminar pressure component in glaucoma. The correlation of ONSD with IOP solely in NTG patients suggests that the translaminar pressure gradient may be of particular importance in this type of glaucoma.     

Clinical correlates to the goniodysgensis among juvenile-onset primary open-angle glaucoma patients

Objectives

To evaluate gonioscopic features and relate them to clinical characteristics in eyes with juvenile-onset primary open-angle glaucoma (JOAG).

Methods

Goniophotographs of unrelated JOAG patients, presenting between 10–40 years of age, were evaluated and compared with 60 healthy subjects in the same age group. Age of onset, family history of glaucoma, highest untreated IOP and visual field defect (mean deviation) were analyzed and correlated with the gonioscopic features among JOAG patients.

Results

Of 126 patients included in the study, 44 (34 %) had a normal open angle (group 1), while 82 (66 %) had developmental anomalies (group 2). Developmental anomalies of the angle were classified as: high iris insertion with or without prominent iris processes (n?=?42), a featureless angle (n?=?30), and those with prominent iris processes alone (n?=?10). There was no difference in age of onset (group 1, 30.5?±?7 years and group 2, 26.3?±?9.6 years) (p?=?0.07) or the untreated IOP at presentation (group 1; 36?±?12.5 mmHg and group 2, 38.8?±?12.3 mmHg; p?=?0.37) between the groups. However, those with angle anomalies presented with a greater visual field defect (MD ?23.5?±?10.5 vs ?14.8?±?13 dB; p?=?0.02) compared to those with normal appearing angle.

Conclusions

While two thirds of JOAG patients present with developmental anomalies of the angle, one third have normal appearing angles. High insertion of the iris is the most common form of gonio dysgenesis observed. Those with angle dysgenesis are more likely to present with severe disease.     

Novel use of 3T MRI in assessment of optic nerve volume in glaucoma

Purpose

To measure optic nerve (ON) volume using 3 T magnetic resonance imaging (MRI), to correlate ON volume with retinal nerve fiber layer (RNFL) thickness, and to determine the viability of MRI as an objective tool in distinguishing glaucoma severity.

Methods

In this cross-sectional study, 30 severe glaucoma patients, 30 mild glaucoma patients and 30 age-matched controls were recruited. All subjects underwent standard automated perimetry, RNFL analysis and 3 T MRI examinations. Glaucoma patients were classified according to the Hodapp–Anderson–Parish classification. Pearson’s correlation coefficient was used to correlate ON volume with RNFL, and receiver operating curve (ROC) analysis was performed to determine the sensitivity and specificity of ON volume in detecting glaucoma severity.

Results

Optic nerve volume was significantly lower in both the left and right eyes of the severe glaucoma group (168.70?±?46.28 mm³; 167.40?±?45.36 mm³) than in the mild glaucoma group (264.03?±?78.53 mm³; 264.76?±?78.88 mm³) and the control group (297.80?±?71.45 mm³; 296.56?±?71.02 mm³). Moderate correlation was observed between: RNFL thickness and ON volume (r?=?0.51, p <0.001), and in mean deviation of visual field and optic nerve volume (r?=?0.60, p?<?0.001). ON volume below 236 mm³ was 96 % sensitive and 80 % specific for the detection of severe glaucoma.

Conclusions

MRI measured optic nerve volume is a reliable method of assessing glaucomatous damage beyond the optic nerve head. A value of 236 mm³ and below can be used to define severe glaucoma.     

Ranibizumab as adjuvant in the treatment of rubeosis iridis and neovascular glaucoma—results from a prospective interventional case series

Background

To evaluate the capability of adjuvant intraocular ranibizumab (Lucentis®) injections in the treatment of rubeosis and intraocular pressure in patients with rubeosis and neovascular glaucoma.

Methods

Ten eyes with rubeosis (R) and ten eyes with neovascular glaucoma (NVG) received Lucentis® injections (ranibizumab 0.5 mg/0.05 ml) in this prospective, monocenter, 12-months, interventional case series. The primary efficacy outcome measure was the change of degree of iris rubeosis as documented by iris fluorescein angiography measured after 12 months. Secondary outcomes were intraocular pressure (IOP), best-corrected visual acuity (BCVA, logMAR), numbers of additional interventions or antiglaucoma medications administered after injection, the gonioscopic status of the anterior chamber angle, and central retinal thickness.

Results

In the R group, 3.6 injections and in the NVG group 2.3 injections of Lucentis® were administered. Additional treatments were photocoagulation (n?=?19), cyclodestructive procedures (n?=?9), cryopexy (n?=?3), and vitrectomy (n?=?1). The mean stage of rubeosis was 3.4?±?0.7 in the R group and 3.6?±?0.8 in the NVG group at baseline. At month 12, the rubeosis was almost resolved in the R group (0.1?±?0.3, p?<?0.001), and decreased significantly in the NVG group (0.7?±?1.1, p?<?0.001). In the NVG subgroup, mean IOP was 41.4?±?13.4 mmHg at baseline, which decreased rapidly (18.2?±?12.3, day-14, p?=?0.005) and stabilized during the follow-up (15.6?±?2.0 mmHg, p?<?0.05). BCVA improved significantly in both groups (p?<?0.05, at month 12).

Conclusions

Injection of 0.5 mg ranibizumab appears to be beneficial as an adjuvant treatment in neovascular glaucoma and rubeosis due to its anti-angiogenic properties and its ability to prevent establishment or progression of anterior chamber angle obstruction. Conventional therapeutic procedures addressing the retinal ischemia are still required in a stage-wise treatment approach.     

High-frequency electric welding: a novel method for improved immediate chorioretinal adhesion in vitreoretinal surgery

Purpose

To evaluate high-frequency electric welding (HFEW) as a novel technique for retinopexy with improved immediate chorioretinal adhesion

Methods

In a prospective, randomized, experimental study, we examined 104 eyes of 52 rabbits randomly assigned to either standard 810 nm endolaser retinopexy, alternating current 14–16 V or 18–20 V HFEW retinopexy. A full-thickness fragment of eye wall tissue containing the retinopexy was isolated 1 h, 3 days, 1 week, or 1 month respectively after the intervention, and fixed to an analytical electronic scale. A nylon suture passed through the retina was elevated by a biomechanical force elongation tester. The reduction in weight at the time of retinopexy rupture was registered as a measure for retinopexy adhesion strength.

Results

One hour post-exposure, adhesive strengths were significantly higher in both HFEW groups than in controls (212?±?26.6 mg and 122?±?16 mg vs 104?±?10 mg; p?=?0.0001 and p?=?0.024 respectively) while laser retinopexy did not significantly change adhesive strength (114?±?14.0 mg, p?=?0.149). Subsequent adhesive strengths were significantly increased for all retinopexy techniques: 3 days post-op 14–16 V HFEW 224?±?30.0 mg (p?=?0.001), 18–20 V HFEW 128?±?15.6 (p?=?0.001), laser 131?±?12.7 mg (p?=?0.0007); at 1 week 14–16 HFEW 235?±?24.7 mg, 18–20 V HFEW 213?±?22.4 mg, laser 188?±?18.7 mg (all p?≤?0.001); 1 month post-op 14–16 V HFEW 275?±?32.0 mg, 18–20 V HFEW 283?±?31.0 mg, laser 276?±?21.7 mg, rspectively (all p?≤? 0.0001).

Conclusion

HFEW represents a novel technique for retinopexy during vitreoretinal surgery. It allows firm chorioretinal adhesion immediately after exposure. In non-vitrectomized eyes, using 14–16 V is particularly effective.     

Combined clear cornea phacoemulsification in the treatment of pseudoexfoliative glaucoma associated with cataract: significance of trabecular aspiration and ab interno trabeculectomy

Background

In the present study, the effectiveness of combined cataract surgery and ab interno trabeculectomy (Trabectome) in exfoliation glaucoma (PEX) was compared with combined cataract surgery and trabecular aspiration.

Methods

In this retrospective comparative cohort outcome study, 27 consecutive patients (mean age 73.41 years?±?10.78) in group 1 suffering from visually significant cataract and PEX glaucoma (mean preoperative IOP 23.41 mmHg?±?5.86) were treated with phacoemulsification combined with Trabectome; and 28 consecutive patients (73.83 years?±?8.94) were treated with phacoemulsification combined with trabecular aspiration (mean preoperative IOP 22.22 mmHg?±?6.33). The intraocular pressure (IOP) and the number of antiglaucoma eyedrops before and after surgery were evaluated.

Results

Examinations were performed prior to surgery, 1 day, 6 weeks, 3 months, 6 months, and 1 year after surgery. In both groups there was a statistically significant decrease in postoperative IOP during the whole follow-up period. Comparing the two groups, there was a statistically significant lower IOP in the Trabectome group 1 day (p?=?0.019), 6 months (p?=?0.025), and 1 year (p?=?0.019) after surgery. Between the two groups, there was no statistically significant difference in the number of antiglaucoma eyedrops at any time.

Conclusions

Both procedures have the ability to significantly lower the postoperative IOP during the first year. However, clear cornea phacoemulsification combined with Trabectome seems to be more effective in IOP reduction in cases of PEX glaucoma associated with cataract.     

The effect of photodynamic therapy on macular sensitivity in eyes with acute central serous chorioretinopathy

Background

To evaluate the effect of half-fluence rate indocyanine green angiography (ICGA)-guided verteporfin photodynamic therapy (PDT) on macular sensitivity (MS) in eyes with acute symptomatic central serous chorioretinopathy (CSC).

Methods

Single-center consecutive case series by retrospective chart review. Sixteen eyes of 16 patients with acute CSC of 3 months duration or less, treated with half-fluence (25 mJ/cm²) ICGA-guided verteporfin PDT were reviewed. At baseline and after 1, 3, and 6 months, all patients underwent MS testing of the central 20 °, MS testing of the retinal area covered by the PDT laser spot (MSLS), and evaluation of fixation stability (FS) for the central two degrees with the MP-1 microperimeter (Nidek, Vigonza, Italy).

Results

Macular sensitivity improved from 16.4?±?3.0 dB at baseline (n?=?16) to 18.2?±?2.4 dB (p?<?0.001) at 1 month (n?=?16). At the 3-month (n?=?13) and 6-month (n?=?12) follow-up, MS stabilized at 19.5?±?0.9 dB (p?=?0.21) and 19.0?±?1.3 dB (p?=?0.74), without changes when compared to respective precedent follow-up. Mean MSLS improved from 12.9?±?5.4 dB at baseline to 16.4?±?4.9 dB (p?<?0.001) after 1 month. At the 3- and 6-month follow-up, MSLS was 19.1?±?1.2 dB (p?=?0.1) and 18.9?±?1.9 dB (p?=?0.8) respectively. Mean FS at the central 2 ° was 78.8?±?30.4 % before treatment and 81.8?±?29.5 % (p?=?0.7), 81.9?±?27.5 % (p?=?0.7) and 83.6?±?17.1 % (p?=?0.5) respectively 1, 3 and 6 months after treatment.

Conclusion

Half-fluence (25 mJ/cm²) PDT significantly increased mean MS of central 20 ° and mean MSLS, in eyes with acute symptomatic CSC. Fixation stability was stable at baseline and throughout 6 months of follow-up.     

Comparison of ganglion cell and retinal nerve fiber layer thickness in primary open-angle glaucoma and normal tension glaucoma with spectral-domain OCT

Background

The aim of this study was to evaluate the macular thickness (MT), ganglion cell complex (GCC), and circum-papillary retinal nerve fiber layer (RNFL) thickness in primary open-angle glaucoma (POAG) and normal tension glaucoma (NTG) with spectral domain optical coherence tomography (SD-OCT).

Methods

A total of 169 subjects were enrolled: 52 normal subjects, 61 with POAG, and 56 with NTG. Spectral-domain optical coherence tomography (SD-OCT) was used to analyze MT, GCC, and RNFL thickness. To compare the discrimination capabilities between the MT, GCC, and RNFL thickness measurements, we analyzed the areas under the receiver operating characteristic (ROC) curves (AUCs). The relationships between GCC and RNFL measurement and also the relationships of the groups, with age, gender, GCC, and RNFL thickness were assessed.

Results

Normal subjects showed the thickest superior and inferior GCC, followed by in order NTG and POAG (p?<?0.05). While there was a statistically difference in MT value of the normal subjects and the glaucoma patients (p?<?0.05), MT value did not differ between POAG and NTG (p?<?0.05). RNFL thickness parameters were significantly greater in normal subjects, followed in order by the NTG, and POAG (p?<?0.05). Between the normal and entire glaucoma groups, all GCC and RNFL parameters showed the similar discrimination power. RNFL thickness parameters correlated significantly with all GCC thickness (p?<?0.05). Superior RNFL thickness was the only independent variable between the POAG and NTG patients (odds ratio (OR) 0.942, p?=?0.004, 95 %CI 0.905–0.981).

Conclusions

SD-OCT evaluation results suggest higher GCC and RNFL parameters for NTG than POAG.     

A comparison between Goldmann applanation tonometry and dynamic contour tonometry after photorefractive keratectomy

Background

The intraocular pressure (IOP) could be measured by both Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT). Although these two methods have been discussed widely after laser-assisted sub-epithelial keratectomy (LASIK), there is little data in the cases undergoing photorefractive keratectomy (PRK). We aimed to compare the changes of IOP measurements obtained by GAT and DCT after PRK for myopia/myopic astigmatism.

Methods

This prospective study enrolled 77 candidates (154 eyes) for PRK to correct myopia or myopic astigmatism and 30 matched patients (30 eyes) with myopia or myopic astigmatism who served as controls. Changes of the IOP measurements (ΔIOP) obtained by GAT and DCT before and at 6 months after PRK in the operated eyes, and at baseline and 6 months later in the controls, were documented. Changes of the central corneal thickness (ΔCCT) were determined in the same fashion.

Results

The mean IOP readings obtained by DCT were comparable before and at 6 months after procedure (18.34 ± 3.03 mmHg and 17.87 ± 2.61 mmHg respectively, p?=?0.41); whereas the mean IOP reading obtained by GAT decreased significantly 6 months postoperatively (17.92 ± 3.63 mmHg and 16.25 ± 2.66 mmHg, p?<?0.001). A significant correlation was present between the ΔIOP obtained by GAT and ΔCCT (r?=?0.61, p?<?0.001). Similar correlation was not significant between the DCT-obtained ΔIOP and the ΔCCT (r?=?0.07, p?=?0.44). The mean ΔIOP obtained by GAT was significantly higher in the operated eyes than in the controls (?1.54?±?1.45 vs 0.07?±?0.44 mmHg, p?=?0.02). The mean DCT-obtained ΔIOP was just marginally insignificant between the operated and nonoperated eyes (?0.63?±?0.59 vs 0.02?±?0.38 mmHg respectively; p?=?0.09).

Conclusions

The authors recommend DCT after PRK in the cases with myopia or myopic astigmatism     

Baseline thickness of macular ganglion cell complex predicts progression of visual field loss

Background

Previous studies reported that the thickness of the macular ganglion cell complex (mGCC) showed good diagnostic ability for detecting glaucoma. However, its impact on the progression of visual field loss in primary open angle glaucoma (POAG) is unknown. The purpose of this study was to assess whether baseline mGCC thickness is associated with the progression of visual field loss in POAG.

Methods

Fifty-six patients with POAG were included in the study. All patients were followed for more than 2 years after baseline optical coherence tomography (OCT) measurements. They had at least five reliable Humphrey visual field tests with 30–2 Swedish Interactive Threshold Algorithm standard tests during the follow-up period. The subjects were divided into two groups according to the slope of the mean deviation (MD): the fast progression group (MD slope < ?0.4 dB/y) and the slow progression group (MD slope ≥ ?0.4 dB/y). Factors compared between the groups were as follows: age, baseline intraocular pressure (IOP), mean IOP during the follow-up, refraction, baseline MD, pattern standard deviation (PSD), and baseline OCT measurements.

Results

There were no significant differences between the two groups in age, baseline IOP, mean IOP during the follow-up, refraction, baseline MD or PSD, average thickness of retinal nerve fiber layer (RNFL), or disc parameters. However, the baseline mGCC thickness (average and inferior hemifield) was significantly thinner in the fast progression group than in the slow progression group (74.0?±?7.2 μm vs. 80.3?±?8.6 μm; 68.0?±?6.6 μm vs. 78.2?±?11.6 μm, respectively). Moreover, global loss volume and focal loss volume, which are parameters of mGCC, showed significantly higher rates in the fast progression group than in the slow progression group. In multivariate analysis, only mGCC thickness of the inferior hemifield was associated with disease progression (P?=?0.007).

Conclusions

Baseline mGCC thickness can be predictive of progressive visual field loss in patients with POAG.     

The effect of cataract surgery on blue–yellow and standard-pattern visual-evoked potentials

Purpose

Blue–yellow visual-evoked potentials (BY-VEPs) may be used for diagnostics of functional ganglion cell damage in glaucoma and other ocular diseases. In this study we investigated the impact of lenticular opacities on BY- and standard pattern reversal VEPs by examining patients before and after cataract surgery.

Methods

Eighteen patients with moderate cataract were included in a prospective study. Transient on/off isoluminant blue–yellow 2° checks were used for short-wavelength stimulation (BY-VEP), transient large 1° (M1) and small 0.25° (M2) black-white checks for standard pattern reversal VEPs. VEPs were acquired before (24?±?30 days) and after cataract surgery (14?±?16 days). The contralateral eye was used as a control.

Results

Amplitude and latency of M1 and M2 peaks did not change significantly from before to after surgery. The amplitude of the BY-VEPs did not change significantly after cataract surgery (pre-surgery, ?7.42?±?3.43 μV, post-surgery, ?7.93?±?3.65 μV, p?=?0.42), yet the latency of the main negative peak showed a significant decrease (pre-surgery, 143.9?±?12.9 ms, post-surgery, 133.2?±?7.7 ms, p?=?0.0006). The BCVA improvement was significant from before to after cataract surgery (pre-surgery, 0.344?±?0.125 LogMAR, post-surgery, 0.224?±?0.179 LogMAR, p?=?0.013) yet not correlated to the absolute decrease in latency of the BY-VEP after surgery (r?=?0.309, p?=?0.22). No significant changes were found in the contralateral eye.

Conclusions

The BY-VEP is sensitive to lenticular opacities of the human lens, presumably due to the increased short-wavelength absorption in the aging eye. This fact should be considered when applying BY-VEPs for diagnostics.     

Clinical results of selective laser trabeculoplasty in silicone oil-induced secondary glaucoma

Background

To analyze the efficacy of selective laser trabeculoplasty (SLT) on silicone oil-induced secondary glaucoma in terms of intraocular pressure (IOP).

Patients and Methods

42 patients (42 eyes) with silicone oil-induced secondary glaucoma were selected, and SLT was performed with 360° of the trabecular meshwork. During the 12-month follow-up, the complications, IOP, and antiglaucoma medication usage were observed.

Results

The mean IOP decreased from 23.1?±?1.9 mmHg before treatment to 18.4?±?3.7 mmHg after treatment (p?<?0.05). Mean number of antiglaucoma medications used for IOP control also decreased from 2.17?±?1.21 to 1.25?±?0.89 (p?<?0.05). The 12-month success rate in the total sample was 59.5 %. The success rate was 60.7 % (17 eyes) and 57.1 % (eight eyes) for phakic and aphakic eyes, respectively (p?>?0.05)

Conclusions

SLT is a safe and effective option for the treatment of patients with silicone oil-induced secondary glaucoma.     

Ab interno gel implant in patients with primary open angle glaucoma and pseudoexfoliation glaucoma

Purpose

To compare efficacy and safety results of an ab interno gel implant in patients with pseudoexfoliation glaucoma (PXG) and primary open angle glaucoma (POAG).

Methods

Retrospective analysis of the medical records of 110 consecutive eyes with open angle glaucoma who had received a XEN45 gel implant between March 2014 and June 2015. Intraocular pressure course, number of glaucoma medications, the need for additional intervention (including needling) and complications were evaluated until 12?months postoperatively.

Results

Data of 67 eyes with POAG and 43 eyes with PXG were analyzed. At 12?months postoperatively, the mean IOP had significantly decreased by 54.0% from preoperatively 31.85?±?8.5?mmHg to 13.99?±?2.6?mmHg in the POAG group, (p?=?0.000; Wilcoxon test), and by 55.2% from 31.63?±?9.0?mmHg to 13.28?±?3.1?mmHg in the PXG group (p?=?0.000; Wilcoxon test). The mean number of anti-glaucoma medications had significantly decreased from 3.25?±?0.8 at baseline to 0.3?±?0.7 medications at 12?months postoperatively in POAG eyes (p?=?0.000; Wilcoxon test), and from 3.05?±?1.0 to 0.3?±?0.6 medications in PXG eyes (p?=?0.000; Wilcoxon test). Hypotony (IOP?≤?6?mmHg) was observed in 2 POAG eyes (3.0%) and in 5 PXG eyes (11.7%) at 1?month but normalized in all eyes at 12?months postoperatively. Severe complications were not observed. No statistically significant differences were found between PXG eyes and POAG eyes.

Conclusion

Our data indicate that the XEN45 gel implant provides significant and comparable reduction in IOP and anti-glaucoma medication during the one-year follow-up period in POAG as well as PXG eyes. This suggests that it may be a noteworthy alternative to traditional filtering procedures in patients with POAG and PXG respectively.

     

Retinal and optic nerve evaluation by optical coherence tomography in adults with obstructive sleep apnea–hypopnea syndrome (OSAHS)

Objective

To assess the peripapillary retinal nerve fiber layer (RNFL) thickness, optic nerve head (ONH) morphologic parameters, and macular thickness and volume in patients affected by obstructive sleep apnea–hypopnea syndrome (OSAHS).

Methods

This prospective, observational case-control study consisted of 96 eyes of 50 OSAHS patients (mean age of 50.9?±?12.4 years, best-corrected visual acuity ≥20/20, refractive error less than 3 spherocylindrical diopters, and intraocular pressure <21 mmHg) who were enrolled and compared with 64 eyes of 33 age-matched controls. Peripapillary RNFL thickness, ONH parameters, macular thickness and volume were measured by optical coherence tomography (OCT).

Results

OSAHS patients showed a significant reduction of the nasal quadrant RNFL thickness (74.7?±?15.8 μm) compared with those values observed in control patients (81.1?±?16.6 μm, p?=?0.047, Student's t-test). No differences in peripapillary RNFL thickness were observed when dividing the OSAHS group in accordance with disease severity. Vertical integrated rim area (VIRA) (0.67?±?0.41 mm³ in OSAHS vs 0.55?±?0.29 mm³ in controls; p?=?0.043, Student's t-test), horizontal integrated rim width (HIRW) (1.87?±?0.31 mm² in OSAHS vs 1.8?±?0.25 mm² in controls; p?=?0.039, Student's t-test) and disc area (2.74?±?0.62 mm² in OSAHS vs 2.48?±?0.42 mm² in controls; p?=?0.002, Student's t-test) showed significant differences, all of them being higher in the OSAHS group. Severe OSAHS had significant higher disc area (2.8?±?0.7 mm²) than controls (2.5?±?0.4 mm²; p?=?0.016, ANOVA test). Temporal inner macular thickness was significantly higher in mild–moderate OSAHS patients (270?±?12 μm) than in severe OSAHS patients (260?±?19 μm; p?=?0.021, ANOVA test).

Conclusions

OSAHS patients showed decreased peripapillary nasal RNFL thickness, and increased ONH area and volume parameters when they were evaluated by OCT. These findings suggest that neuronal degeneration might be present in the retina of OSAHS patients, as previously observed in some neurodegenerative disorders     

Farbduplexsonographie der retrobulb?ren Gef??e und Hyperkapnie bei Normaldruckglaukom

Purpose

The aim of the study was to investigate retrobulbar flow velocities during hypercapnia in patients with normal tension glaucoma (NTG) without systemic vasospasm and jn controls.

Methods

A total of 16 NTG patients (mean age 58?±?14 years) and 16 control subjects (mean age 50?±?13 years, p?=?0.10) were enrolled in this study. Flow velocities, peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistive indices (RI) of the ophthalmic (OA) and central retinal arteries (CRA) were assessed using color Doppler imaging. Blood flow velocities were measured under normocapnic and hypercapnic conditions (increasing the end-tidal pCO₂ by 15%). Blood pressure, ventilation rate and oxygen saturation were monitored simultaneously.

Results

During hypercapnia, velocity responses of the PSV (p?=?0.044) and EDV (p?=?0.037) of the CRA were significantly different in NTG patients and healthy controls, showing a greater increase of flow velocities in control subjects. Flow velocities of the OA increased significantly in both groups (PSV p?=?0.039, EDV p?=?0.003) during hypercapnia. Blood pressure, oxygen saturation and intraocular pressure changed similarly in both study groups with carbon dioxide provocation.

Conclusions

Velocity response to hypercapnia was reduced in the CRA of NTG patients compared to controls. This may indicate a faulty vasodilatory response in NTG patients without vasospastic disease.     

Comparison of Spectralis-OCT, GDxVCC and GDxECC in assessing retinal nerve fiber layer (RNFL) in glaucomatous patients

Background

Glaucomatous optic neuropathy is characterized by a progressive loss of retinal ganglion cells (RGCs). The defects in the peripapillary retinal nerve fiber layer (RNFL) have been reported to be the earliest sign of glaucoma. We determined the agreement between RNFL thickness assessments from spectral-domain OCT (Spectarlis HRA?+?OCT; Heidelberg Engeneering, Heidelberg, Germany), scanning laser polarimetry (SLP) with variable cornea compensation (GDxVCC; Carl Zeiss Meditec, Dublin, CA, USA), and SLP with enhanced cornea compensation (GDxECC; Carl Zeiss Meditec, Dublin, CA, USA) in glaucomatous patients. Furthermore, we investigate the influence of typical scan score (TSS) on the results of GDx assessments.

Methods

The enrolled subjects were devided into different groups by modified HODAPP visual field criteria. The peripapillary RNFL thickness was assessed with the three devices . ANOVA test, Pearson and Spearman correlation coefficient, and Bland-Altman plots were used to analyse the RNFL thickness assessments.

Results

Ninety-two eyes from 92 glaucomatous subjects were analysed. These were divided into four groups: preperimetric glaucoma (n?=?26), mild glaucoma (n?=?18), moderate glaucoma (n?=?21), and severe glaucoma (n?=?27). For Spectralis-OCT, the average RNFL thickness (mean ± SD) was 99.25?±?26.31 μm, 80.52?±?16.63 μm, 71.59?±?21.15 μm, and 63.85?±?20.86 μm for preperimetric, mild, moderate, and severe glaucoma respectively. For GDxVCC, the corresponding assessments were 52.63?±?8.18 μm, 52.95?±?10.20 μm, 46.77?±?10.62 μm, and 49.70?±?13.34 μm. For GDxECC, the assessments were 49.35?±?6.52 μm, 45.92?±?7.21 μm, 42.19?±?8.00 μm, and 39.53?±?8.45 μm. All Spectralis-GDxVCC and Spectralis-GDxECC differences were statistically significant by ANOVA test. The differences between GDxVCC and GDxECC were statistically significant only for severe glaucoma. There was a highly significant correlation between Spectralis-OCT and GDxECC, as well as Spectralis-OCT and GDxVCC, in assessing the RNFL thickness. The best instrument agreement was found between GDxECC and Spectralis-OCT. The RNFL thickness assessed with Spectralis-OCT and GDxECC showed a better correlation to visual field defects than GDxVCC. Evaluating GDx assessments with typical retardation pattern GDxVCC and GDxECC showed very similar RNFL thickness results.

Conclusions

RNFL thickness assessments between GDxVCC, GDxECC, and Spectralis-OCT cannot be directly compared. The assessments are generally higher with Spectralis-OCT than with GDxVCC and GDxECC, because of differences in method of the devices. The atypical retardation pattern has a major impact on the RNFL thickness results of GDx devices. This must be taken into account when evaluating the assessed RNFL thickness results.     

Relationship of change in central corneal thickness to visual field progression in eyes with glaucoma

Background

To assess the relationship between baseline central corneal thickness (CCT) and/or ongoing CCT change over time with subsequent visual field progression.

Methods

One hundred sixty three eyes of 163 patients with medically treated glaucoma were followed up for 6.8?±?1.8 years. Exclusion criteria was laser or intraocular surgery. Baseline and follow up CCT, confocal scanning laser tomography and visual fields were performed. CCT and CCT change related to visual field progression using Glaucoma Progress Analysis were assessed. Multivariate logistic regression analysis for predictive factors of glaucoma progression was used to analyze data.

Results

Thinner baseline CCT was associated with more advanced damage at presentation, mean deviation (MD) (r?=?0.17, p?=?0.02) and neuroretinal rim area (NRR) (r?=?0.20, p?=?0.02). Progressing eyes had significantly thinner (p?=?0.01) baseline CCT compared to non-progressing eyes. The slope of visual field change was significantly greater (p?=?0.05) for thinner (<540 μm) as compared to thicker eyes. A small but significant CCT reduction (12.78?±?13.35 μm, p?<?0.0001) was noted in all eyes; however, there was no significant difference (p?=?0.95) in the amount of change between progressing and non-progressing eyes. CCT change did not correlate with MD or NRR change. A thinner CCT (Odds ratio?=?1.80, p?=?0.02), but not CCT change (Odds ratio?=?1.07, p?=?0.69), was a significant risk factor for glaucoma progression.

Conclusions

CCT correlates significantly with the amount of glaucomatous damage at presentation. Thinner corneas may be associated with increased risk of visual field progression. CCT reduced slightly over time in eyes with glaucoma; but the magnitude of this change was not related to visual field progression.     

The use of heterochromatic flicker photometry to determine macular pigment optical density in a healthy Australian population

Purpose

To establish the normal macular pigment density (MPOD) in a healthy adult Australian sample using heterochromatic flicker photometry (HFP).

Methods

Macular pigment density was measured using heterochromatic flicker photometry in a total of 201 subjects ranging in age from 21 to 84 years with healthy macula. Fifty-seven of the healthy subjects also completed a food-frequency dietary questionnaire. Best-corrected visual acuity (BCVA) was measured using logMAR, chart and macular morphological profiles were assessed using high-resolution integrated Fourier-domain optical coherence tomography (OCT).

Results

The average MPOD value was 0.41?±?0.20 (range 0.07–0.79). There was no statistically significant difference between values in the left and right eye, with good interocular agreement (0.41 vs 0.40, r?=?0.893, p?<?0.01). Age significantly predicted MPOD score (R ²?=?0.07, p?<?0.05). A subgroup analysis of patients who completed the dietary questionnaire revealed a close correlation between higher diet scores and higher MPOD (r?=?0.720 p?=?0.031). There was no effect of smoking, gender, or iris colour on MPOD values. There was no significant correlation between BCVA, macular OCT profiles, and MPOD.

Conclusion

Given that MPOD values are potentially affected by geographical variation, we have determined a mean MPOD value for healthy subjects in a population south of the equator, providing a reference point for future studies on Caucasian samples.