Matched case-control comparison of surgical success after XEN45 Gel Stent and PRESERFLO MicroShunt implantation in a Caucasian population.

BACKGROUND: The aim of this study was to compare the outcome of implantation of a XEN45 Gel Stent with the outcome of implantation of a Preserflo MicroShunt in a matched-pair analysis in eyes being naïve to filtering surgery. METHODS: In this comparative, retrospective study, 50 eyes that had undergone XEN45 Gel Stent implantation were compared with 50 eyes after Preserflo implantation. Follow-up was at least 6 months, and surgical success was measured by criteria A (IOP < 21 mmHg, IOP reduction >20%, no repeat surgery); criteria B (IOP < 18 mmHg, IOP reduction >20%, no repeat surgery); and criteria C (IOP ≤15 mmHg, IOP reduction ≥40%, no repeat surgery). RESULTS: After a follow-up period of 12 months, mean IOP had decreased from preoperative 25.2 ± 4.8 mmHg in the XEN group to 14.5 ± 4.0 (n = 35) and from 25.3 ± 6.8 mmHg to 11.9 ± 2.9 (n = 41) in the Preserflo group, respectively. The IOP at the last follow-up of the two groups differed significantly (p < 0.01). The probability of surgical success did not differ concerning Criteria A and B, but surgical success was significantly higher in the Preserflo group for Criteria C (60%, p < 0.01). CONCLUSION: Both the Preserflo and XEN45 Gel Stent provide an effective and safe treatment option for advanced glaucoma and have a high potential to reduce intraocular pressure. Absolute IOP levels of <16 mmHg after 12 months were significantly more frequent in the Preserflo group.

Predictability of success for combined iStent inject trabecular bypass implantation with phacoemulsification in the subsequent eye.

BACKGROUND: To investigate in combined iStent inject implantation with phacoemulsification carried out bilaterally, whether intraocular pressure (IOP)-lowering effectiveness in the first eye has a predictive potential for the outcome of the second eye in primary open-angle glaucoma (POAG). METHODS: This retrospective study included 72 eyes from 36 participants, who underwent trabecular bypass implantation in combination with cataract surgery at two study centres (Düsseldorf, Cologne). Surgery was classified as either 'success' or 'failure' based on three scores: IOP at follow-up <21 mmHg (Score A) or IOP < 18 mmHg (Score B), with an IOP reduction >20% respectively, without re-surgery and IOP ≤ 15 mmHg with an IOP reduction ≥40%, without re-surgery (Score C). RESULTS: The IOP lowering outcomes of first and second eyes did not differ significantly. There was a significantly higher chance of success in the second eye after effective surgery in the first eye compared with cases after a preceding failure. Within our cohort, a 76% probability of success for the subsequent eye was determined following prior success for Score A. This probability was reduced to 13% if surgery in the first eye failed. The respective probabilities were 75% and 13% for Score B and 40% and 7% for Score C. CONCLUSIONS: In bilateral trabecular bypass implantation combined with cataract surgery, there is a high predictive potential for subsequent eyes based on the extent of IOP-lowering in the initial eye, which should be considered by the surgeon for second eye surgeries.

A Case of Endocarditis Following Endophthalmitis After XEN45 Gel Stent Implantation.

INTRODUCTION: We report a case of endophthalmitis and endocarditis that developed after stent perforation following a XEN45 Gel Stent implantation 10 months ago. CASE REPORT: A 79-year-old man was referred to our hospital because of endophthalmitis of the right eye. The patient had undergone XEN45 Gel Stent implantation in the same eye 10 months ago. On examination, the conjunctiva was perforated by the stent, and it was no longer covered by the conjunctiva. A 27-G pars plana vitrectomy with intravitreal antibiotic injection was performed. Moreover, the patient received intravenous antibiotic treatment and local anti-inflammatory and anti-infectious therapy. Streptococcus gordonii was identified as a bacterial cause of the endophthalmitis. Therefore, transesophageal echocardiography was performed, which revealed aortic valve endocarditis. DISCUSSION: Although not proven, it is possible that the exposed XEN45 Gel Stent served as an entry point for S. gordonii, which caused the exogenous endophthalmitis and subsequent endocarditis. S. gordonii belongs to the viridans group streptococci, which is the etiological agent for endocarditis which is a severe and potentially life-threatening infection. Ophthalmologists should therefore consider the risk of systemic infections as endocarditis after endophthalmitis, particularly caused by the viridans group streptococci, which are known etiological agents of endocarditis.

Predictability of ab-interno trabeculectomy success in the subsequent eye: A contralateral eye comparison study.

BACKGROUND: To determine whether the outcome of the first eye may serve as a predictor for intraocular pressure (IOP)-lowering effectiveness in the second eye following bilateral ab interno trabeculectomy. METHODS: This retrospective single-centre study included 168 eyes from 84 participants, who underwent combined Trabectome surgery with phacoemulsification cataract surgery in a hospital setting. The clinical endpoint was defined as either 'success' or 'failure' based on four separate scores at the longest follow-up time point: IOP at follow-up <21 mm Hg (Score A) or IOP < 18 mm Hg (Score B), without re-surgery and IOP reduction >20%; IOP ≤15 mm Hg without re-surgery and IOP reduction ≥40% (Score C); and the sole absence of re-surgery according to the discretion of the surgeon (Score D). RESULTS: No significant difference was observed between the outcomes of first and second eyes. The frequency of success in the second eye after effective surgery in the first eye significantly exceeded that after prior failure. Within our analysis, the probability calculations determined a 75% chance of success following prior success for Score A. If surgery in the first eye failed, the chance of success in the subsequent eye was 37%. The corresponding probabilities were 79% and 32% for Score B, 56% and 9% for Score C, and 99% and 50% for Score D. CONCLUSION: The results of our study offer a useful tool to assess the success of subsequent eye surgeries based on the outcome in the initial eye, owing to the high predictive potential.

Primary Versus Posttrabeculectomy XEN45 Gel Stent Implantation: Comparison of Success Rates and Intraocular Pressure-lowering Potential in Pseudophakic Eyes.

PRECIS: The XEN45 Gel Stent can be implanted after failed trabeculectomy without disadvantages compared with primary implantation. PURPOSE: We aimed to compare the outcomes of XEN45 Gel Stent implantation in pseudophakic eyes after failed trabeculectomy and in pseudophakic eyes without other previous surgeries. PATIENTS AND METHODS: In this retrospective study, we included 30 pseudophakic eyes of 30 patients who underwent XEN45 Gel Stent implantation after failed trabeculectomy (trabeculectomy group) and 60 eyes of 60 patients with primary XEN45 Gel Stent implantation (control group). The groups were matched for preoperative intraocular pressure (IOP), preoperative medication score, cup-to-disc ratio, follow-up time, visual acuity, and age at a ratio of 1:2. Eyes with concomitant eye diseases, those who had undergone previous surgery, and those with a follow-up duration <6 months were excluded. We compared the success rates on the basis of different criteria: Criteria A (IOP<21 mm Hg, IOP reduction>20%, no repeat surgery); Criteria B (IOP<18 mm Hg, IOP reduction>20%, no repeat surgery); and Criteria C (IOP≤15 mm Hg, IOP reduction≥40%, no repeat surgery). RESULTS: After an average follow-up period of 20 months, the mean IOP was reduced from 24.4±5.7 to 14.0±4.1 mm Hg in all the study subjects (90 patients). There were no significant differences between the 2 groups in postoperative IOP, postoperative medication score, revision rate, and repeat surgery rate or success rate. CONCLUSIONS: XEN45 Gel Stent implantation is a viable option after failed trabeculectomy. According to our results, it has no disadvantage compared with primary XEN45 Gel Stent implantation.

Correction to: Influence of oral anticoagulation on success rates and risk of bleeding events after iStent inject implantation combined with phacoemulsification.

The published online version contains mistake as the author's first name and last name have been interchanged as "Hild Matthias" instead of "Matthias Hild".

Influence of oral anticoagulation on success rates and risk of bleeding events after iStent inject implantation combined with phacoemulsification.

PURPOSE: We conducted a retrospective study to evaluate the intraocular pressure (IOP) lowering effect, the success rates, and the risk of bleeding events of patients receiving an iStent inject combined with phacoemulsification under anticoagulation therapy compared with a matched control group. METHODS: In this retrospective study, sixty-four eyes underwent an iStent inject implantation combined with phacoemulsification at two centers. Thirty-two eyes received surgery while under anticoagulation therapy, and another thirty-two eyes served as a control group matched for visual acuity, IOP, and medication score. Success was defined as criteria A and B (IOP < 18/21 mmHg, > 20% IOP reduction, no resurgery) and criteria C (IOP ≤ 15 mmHg, IOP reduction ≥ 40%, no resurgery). The clinical goal of the study was to determine the difference between the study and control groups with respect to IOP, medication score, and the frequency of intraoperative and postoperative bleeding events. RESULTS: After a mean follow-up time of 1 year, the IOP lowered 28% from 20.1 ± 4.8 to 14.5 ± 3.7 mmHg in the group of 64 eyes. The medication score lowered 38% from 2.1 ± 1.1 to 1.3 ± 1.2. The two groups with and without anticoagulant agents did not significantly differ in postoperative IOP, medication score, success rates, or number of bleeding events. CONCLUSION: We conclude that in cataract surgery combined with the iStent inject a discontinuation of anticoagulant agents might not be necessary. It might be a good option in glaucoma surgery when anticoagulation treatment should not be interrupted and the target pressure is not very low.

Topography of retinal recovery processes in humans.

BACKGROUND: The purpose of this study was to examine retinal recovery processes to pographically by the application of three flash sequences with specific interstimulus intervals. METHODS: Twelve healthy subjects underwent multifocal electroretinography with a light-emitting diode stimulator. Every flash sequence consisted of three flashes with 25 msec between the first and the second flash and 35 msec between the second and the third flash. The interval between the third and the first flash of the next step was 85 msec. The interstimulus interval-dependent amplitude reductions of the multifocal electroretinographic response for these three intervals yielded three data points that were used to determine the complete curve of the recovery kinetics. RESULTS: Amplitude reductions were higher with shorter interstimulus intervals. The mean half-life periods of the recovery kinetics for the different concentric rings and all subjects were: ring 1, 29.3±5.9 msec; ring 2, 24.2±6.4 msec; ring 3, 23±4.1 msec; ring 4, 23.1±4.6 msec; and ring 5, 22.3±4.4 msec. The differences between the first and all other rings were statistically significant (P<0.05). CONCLUSION: The kinetics of the amplitude recovery after short interstimulus intervals showed a spatial distribution, with faster recovery toward the macular periphery.

Partial Coherence Laser Interferometry in Highly Myopic versus Emmetropic Eyes.

PURPOSE: To investigate the reliability of partial coherence laser interferometry for optical biometry in highly myopic eyes. METHODS: Axial length measurements by the IOLMaster (Carl Zeiss Meditec, Germany) with signal-to-noise ratio (SNR) ≥2 were performed in 52 consecutive myopic subjects with axial length ≥26.5 mm and 45 emmetropic patients before cataract surgery. Axial length measurements and SNR were analyzed and compared among the two study groups. RESULTS: Axial length measurements were feasible in 46 of 52 (88.5%) highly myopic eyes and in 41 of 45 (91.1%) eyes with normal axial length. To achieve two reliable axial length values with SNR ≥2, a mean number of 2.06±0.25 measurements was necessary in myopic eyes and 2.10±0.37 in emmetropic counterparts. Mean SNR after two measurements was 4.98±2.44 in myopic eyes versus 5.56±2.32 in control eyes. Even though successful measurement was independent of preoperative visual acuity, patients with visual acuity better than 20/63 showed significantly higher SNR values. CONCLUSIONS: Partial coherence laser interferometry shows satisfying feasibility and good signal quality for axial length determination in highly myopic eyes with stable retinal condition and clear media.

Accuracy of intraocular lens power calculation using partial coherence interferometry in patients with high myopia.

PURPOSE: Ultrasound-A-scan-biometry intraocular lens power calculation for cataract surgery sometimes shows lack of accuracy in patients with high myopia. The purpose of this retrospective study was to assess the accuracy of lens power calculation with optical biometry using the Zeiss IOLMaster across a large range of myopia levels. METHODS: We included 37 consecutive, myopic eyes with an axial length >26.5mm (31 patients, 62±13years old, average preoperative refraction of -14.46±6.61D, range -3.5 to -32.0D which underwent phacoemulsification and implantation of an intraocular lens following biometry using the IOLMaster. For lens power calculation, the Haigis formula was used in all cases. For comparison, refraction was back-calculated using the SRK/T and Holladay I formulae. RESULTS: The preoperative mean axial length was 29.37±2.44 mm with a range of 26.50-35.52mm. Thirty eyes (81.1%) showed a postoperative spherical equivalent which differed 1.00D or less from the predicted value, in 20 cases (54.1%) the postoperative refractive error was within±0.50D. The mean absolute error (MAE) was 0.70±0.59D (Holladay I, 0.85±0.68; SRK/T, 1.01±0.61D). CONCLUSIONS: Optical biometry for intraocular lens power calculation seems to deliver reliable results for cataract surgery in patients with high myopia, although our data describe an increasing lack of accuracy beyond an axial length of 30mm. The Haigis formula provided the best predictability of postoperative refractive outcome for myopic eyes in general.

Ocular pulse amplitude before and after cataract surgery.

PURPOSE: To investigate the impact of cataract surgery on the association of the ocular pulse amplitude (OPA) and intraocular pressure (IOP) with respect to the interpretation of OPA as an estimate of ocular blood flow. METHODS: Twenty-four patients with cataract were included in a clinical study. OPA was measured using dynamic contour tonometry (DCT, Pascal(®), SMT Swiss Microtechnology AG, Switzerland). IOP was measured by means of Goldmann applanation tonometry (IOP GAT) and DCT (IOP DCT). All measurements were performed before and one day after cataract surgery. RESULTS: At baseline, OPA was correlated to IOP GAT (r = 0.67, P = 0.0002) and IOP DCT (r = 0.82, P < 0.0001), but not to age or axial length. Postoperative OPA was correlated to IOP GAT (r = 0.67, P = 0.0002) and IOP DCT (r = 0.65, P = 0.0004). In 17 patients, IOP GAT decreased after surgery (IOP DCT n = 14), whereas an increase was apparent in seven patients (IOP DCT n = 10). The mean absolute deviation of IOP GAT pre- to post-surgery was 4.54 mmHg ± 2.47 (range 1-10 mmHg) and 5.4 mmHg ± 3.2 (range 1.1-13.1 mmHg) for IOP DCT. The changes of OPA were significantly correlated to changes in IOP GAT (r = 0.48, P = 0.017) and IOP DCT (r = 0.60, P = 0.001). IOP GAT and IOP DCT changes were not correlated to changes in corneal thickness. CONCLUSIONS: The OPA measured with the Pascal(®) device seems to be dependent on IOP changes. Particular caution should be taken in the interpretation of OPA in estimating pulsatile ocular blood flow.

Does surgical experience have an effect on the success of retinal detachment surgery?

PURPOSE: To examine the relationship between surgeon experience and success rates in retinal detachment surgery. METHODS: Success rates during a follow-up of 11 months of 8 surgeons who performed in total 375 retinal detachment procedures ranging from 14 to 115 cases between December 1997 and January 2002 were correlated to the total number of vitreoretinal procedures ranging between 176 and 2,587. All patients received either scleral buckling or vitrectomy, and complicated cases were excluded. RESULTS: Mean primary anatomical success rates were 0.69 ± 0.14 for scleral buckling and 0.9 ± 0.05 for primary vitrectomy (P < 0.05). The primary anatomical success rates did not correlate to the number of vitreoretinal procedures. Seven of the eight surgeons showed an intraindividual learning effect with better success rates in the second versus the first half of the observed procedures. The learning effect was correlated to the total number of procedures with a higher effect in inexperienced surgeons. CONCLUSION: An intraindividual learning effect that was higher in inexperienced surgeons could be demonstrated. The learning effect was reduced by half after 500 vitreoretinal procedures while the primary anatomical success rates were not correlated to the number of vitreoretinal procedures.

Improving the quality of multifocal visual evoked potential results by calculating multiple virtual channels.

PURPOSE: To introduce a method for improvement of multifocal VEP (mfVEP) recordings by prediction of waveforms at multiple positions on the surface of the skull. METHODS: Fifteen healthy participants (mean age 24 ± 3.8 years) underwent mfVEP recordings from 3 surface positions. Two methods of a best-of-mfVEP approach were used and compared. In the first, a standard procedure, further data from 3 calculated channels were used. In the second approach, mfVEPs were obtained by using data derived from 40 virtual electrode positions on the basis of predictions from dipole source calculations. RESULTS: The mean signal-to-noise ratios (SNRs) of the best-of-mfVEPs of both methods were compared. The SNR was significantly higher for mfVEP data using additional virtual recordings revealed by dipole source determination (2.87 vs. 3.36; P < 0.035). CONCLUSION: We conclude that multichannel prediction of mfVEP responses based on dipole source calculation significantly improves the quality of the examination results compared with the currently prevalent standard method.