The retinal venous pressure at different levels of airway pressure measured with a new method.

PURPOSE: This study is to investigate the increase in retinal venous pressure (RVP) induced by a stepwise increase in airway pressure (AirP) using the new IOPstim method, which is designed to artificially increase the intraocular pressure (IOP) and thus to stimulate vascular pulsation. METHODS: Twenty-eight healthy subjects were examined in the left eye. The RVP was measured at baseline and at four different levels of AirP (10, 20, 30, and 40 mmHg) using the new IOPstim method: a half balloon of 8 mm diameter is inflated laterally to the cornea under observation of the central retinal vein. As soon as the vein pulsates at a certain AirP level, the IOP is measured with a commercially available tonometer, which then corresponds to the RVP. RESULTS: Spontaneous venous pulsation was observed in all study participants. The mean RVP values at baseline and at the AirP levels of 10, 20, 30, and 40 mmHg were 17.6 ± 2.8 mmHg; 20.1 ± 3.0 mmHg; 22.1 ± 3.5 mmHg; 24.3 ± 3.7 mmHg, and 26.6 ± 4.2 mmHg, respectively. The mean RVP values of each AirP level were statistically significantly different from each other in pairwise comparison. In a linear mixed model, the effect of AirP on RVP was highly significant (p < 0.001). In the model, a 10-mmHg increase in AirP resulted in a linear increase in RVP of 2.2 mmHg. CONCLUSION: An increase in AirP was accompanied by a linear increase in RVP. The influence of AirP on RVP, and thus on retinal perfusion pressure during the Valsalva maneuver, is less than was assumed based on previous studies in which contact lens dynamometry was used.

Measurement of the retinal venous pressure with a new instrument in patients with primary open angle glaucoma.

PURPOSE: To compare the results of retinal venous pressure (RVP) measurement performed with contact lens dynamometry (CLD) and with the new IOPstim. METHODS: In this cross-sectional study, we included 36 patients with primary open angle glaucoma with a median age (Q25; Q75) of 74 (64; 77) years (m/f = 18/18), baseline intraocular pressure (IOP): 13.9 (12.2; 15.1) mmHg. Median mean defect: - 5.8 (- 11.9; - 2.6) db. Principle of the IOPstim: an empty balloon with a diameter of 8 mm is positioned on the eye, laterally of the limbus. Under observation of the central retinal vein (CRV), the examiner inflates the balloon. As soon as the CRV starts pulsation, the inflation is stopped and the IOP is measured, equaling the RVP at this moment. In the CLD, the pulsation of the CRV is observed with a contact lens. The RVP is calculated from the attachment force applied when pulsation appears. COURSE OF EXAMINATIONS: Three single measurements of RVP in quick succession with both methods. The sequence of the two methods was randomized. The means of the three RVP measurements were compared. RESULTS: Pressures in mmHg. RVP: IOPstim: 19.4 ± 5.4 (mean ± SD), CLD: 20.3 ± 5.9. Range of three single measurements: IOPstim: 2.9 ± 1.5, CLD: 2.2 ± 1.1. The differences were RVPIOPstim - RVPCLD = - 0.94 ± 1.15, and approximately normally distributed. Bland-Altman analysis: only one data point was 0.5 mmHg higher than the upper line of agreement. The confidence interval of this line was 0.65 mmHg. Concordance correlation coefficient according to Lin (CCC): 0.96. Intraclass correlation coefficient: both methods, 0.94. CONCLUSION: In both methods, the range of the single measurements may be taken as a sign of good reliability, the CCC of 0.96 as a sign of a very good agreement. At the mean, the IOPstim RVP values were 1 mmHg lower than those obtained with the CLD. This difference may be due to the different directions of the prevailing force vectors induced by the instruments. The IOPstim seems applicable in glaucoma diagnostics.

Efficacy of selective laser trabeculoplasty on lowering intraocular pressure fluctuations and nocturnal peak intraocular pressure in treated primary open-angle glaucoma patients.

PURPOSE: To investigate the efficacy of adjunctive selective laser trabeculoplasty (SLT) in reducing 24-h intraocular pressure (IOP) fluctuations and nocturnal IOP peaks. METHODS: In this prospective interventional case series, 157 medically treated eyes of 157 patients with primary open-angle glaucoma (POAG) who were assigned SLT to further reduce IOP were consecutively included. Each patient had a complete glaucoma work-up and 24-h IOP monitoring (6 measurements, including one in the supine position) taken before and on average 6 months after SLT. The main outcome measures were the reduction of 24-h IOP fluctuations and nocturnal peak IOP. Secondary outcome measures were success rates, factors influencing the reduction of high 24-h IOP fluctuations and nocturnal peak IOP, complications, and severe adverse events. RESULTS: Medicated mean 24-h IOP (mmHg) was statistically significantly reduced from 15.1 ± 2.6 to 13.8 ± 2.4 (P < 0.001) and IOP fluctuations from 6.5 ± 2.7 to 5.4 ± 2.6 (P < 0.001) 6 months after SLT. Ninety-four eyes (59.9%) initially had high IOP fluctuations (more than 5 mmHg). These were reduced from 8.1 ± 2.3 to 5.6 ± 2.7 at 6 months (P < 0.001). Fifty-two eyes (55.3%) had fluctuations below 5 mmHg post-SLT which was defined as success. Fifty-one patients (32.5%) had nocturnal IOP peaks. In these cases, nocturnal IOP was reduced by 19.2% from 20.1 ± 3.4 to 16.2 ± 3.3 mmHg at 6 months (P = 0.001). CONCLUSIONS: The current study demonstrates that adjunctive SLT not only reduces mean 24-h IOP in treated POAG patients, but also has an additional benefit in reducing IOP fluctuations and nocturnal peak IOP. TRIAL REGISTRATION: Clinical trial registration: NCT02959242.

PRESERFLO ™ MicroShunt versus trabeculectomy: 1-year results on efficacy and safety.

PURPOSE: To compare the efficacy and safety of the PRESERFLO™ MicroShunt versus trabeculectomy in patients with primary open-angle glaucoma (POAG) after one year. PATIENTS AND METHODS: Institutional prospective interventional cohort study comparing eyes with POAG, which had received the PRESERFLO™ MicroShunt versus trabeculectomy. The MicroShunt group was matched with the trabeculectomy group for age, known duration of disease, and number and classes of intraocular pressure (IOP) lowering medications to have similar conjunctival conditions. The study is part of the Dresden Glaucoma and Treatment Study, using a uniform study design, with the same inclusion and exclusion criteria, follow-ups and standardized definitions of success and failure for both procedures. PRIMARY OUTCOME MEASURES: mean diurnal IOP (mdIOP, mean of 6 measurements), peak IOP, and IOP fluctuations. SECONDARY OUTCOME MEASURES: success rates, number of IOP lowering medications, visual acuity, visual fields, complications, surgical interventions, and adverse events. RESULTS: Sixty eyes of 60 patients, 30 in each group, were analyzed after 1-year follow-ups. Median [Q25, Q75] mdIOP (mmHg) dropped from 16.2 [13.8-21.5] to 10.5 [8.9-13.5] in the MicroShunt and from 17.6 [15.6-24.0] to 11.1 [9.5-12.3] in the trabeculectomy group, both without glaucoma medications. Reduction of mdIOP (P = .596), peak IOP (P = .702), and IOP fluctuations (P = .528) was not statistically significantly different between groups. The rate of interventions was statistically significantly higher in the trabeculectomy group, especially in the early postoperative period (P = .018). None of the patients experienced severe adverse events. CONCLUSION: Both procedures are equally effective and safe in lowering mdIOP, peak IOP and IOP fluctuations in patients with POAG, one year after surgery. CLINICAL TRIAL REGISTRATION: NCT02959242.

Effectiveness and safety of VISULAS® green selective laser trabeculoplasty: a prospective, interventional multicenter clinical investigation.

PURPOSE: To evaluate the effectiveness and safety of Selective Laser Trabeculoplasty (SLT) with the SLT mode of the VISULAS® green laser in patients with primary open-angle glaucoma (POAG). METHODS: This prospective, interventional multicenter clinical investigation included patients with POAG who either needed a treatment escalation because the individual intraocular pressure (IOP) target was not met or treatment initiation and had an IOP ≥ 17 mmHg at baseline in the study eye. The study was conducted in five research centers across Germany. Approximately 100 laser applications were delivered to 360° of the trabecular meshwork. Glaucoma medications were not modified during the 3-month follow-up to allow evaluation of the sole effect of VISULAS® green with SLT. Efficacy outcomes were postoperatively absolute and relative IOP changes at 1 and 3 months. Safety outcomes analyzed the rate of intra- and postoperative adverse events. RESULTS: Thirty-four eyes of 34 POAG patients were included. The overall mean number of preoperative glaucoma medications was 2.2 ± 1.4 in 29 treated eyes, 5 eyes were treatment naïve. Mean baseline IOP (mmHg) was 21.0 ± 2.69 and was reduced by - 3.53 ± 3.34 [95% CI - 4.61; - 2.45] and - 3.59 ± 3.41 [95% CI - 4.64; - 2.53] at the 1- and 3-month follow-up, respectively (p < 0.0001), with 48.5% of cases achieving a ≥ 20% IOP reduction at 3 months [95% CI = 30.8%; 66.5%]. The mean relative IOP reduction was - 16.4% and - 16.3% at 1 and 3 months, respectively (p < 0.0001). Potentially device- or procedure-related adverse events were mild to moderate and included 3 postoperative IOP-spikes and 6 reports regarding eye pain and discomfort. All were resolved without sequelae. CONCLUSIONS: SLT performed with the VISULAS® green laser achieved clinically significant additional IOP reductions in medically treated as well as in treatment naïve eyes with POAG and there were no relevant safety issues. The results are comparable to other reported SLT studies.

Measurement of the retinal venous pressure with a new instrument in healthy subjects.

BACKGROUND: The retinal venous pressure (RVP) is a determining factor for the blood supply of the retina as well as the optic nerve head and until recently has been measured by contact lens dynamometry (CLD). A new method has been developed, potentially offering better acceptance. The applicability and the results of both methods were compared. METHODS: The type of this study is cross sectional. The subjects were 36 healthy volunteers, age 26 ± 5 years (mean ± s). Tonometry: rebound tonometer (RT) (iCare). The measurements were performed during an increase in airway pressure of 20 mmHg (Valsalva manoeuvre). Principle of RVP measurement: the central retinal vein (CRV) is observed during an increase of intraocular pressure (IOP) and at the start of pulsation, which corresponds with the RVP. Two different instruments for the IOP enhancement where used: contact lens dynamometry and the new instrument, IOPstim. PRINCIPLE: a deflated balloon of 8 mm diameter-placed on the sclera laterally of the cornea-is filled with air. As soon as a venous pulsation occurs, filling is stopped and the IOP is measured, equalling the RVP. Examination procedure: randomization of the sequence: CLD or IOPstim, IOP, mydriasis, IOP three single measurements (SM) of the IOP with RT or of the pressure increase with CLD at an airway pressure of 20 mmHg, 5 min break, IOP, and three SM using the second method at equal pressure (20 mmHg). RESULTS: Spontaneous pulsation of the CRV was present in all 36 subjects. Pressures are given in mmHg. IOP in mydriasis 15.6 ± 3.3 (m ± s). Median RVP (MRVP)) of the three SM: CLD/IOPstim, 37.7 ± 5.2/24.7 ± 4.8 (t test: p < 0.001). Range of SM: 3.2 ± 1.8/2.9 ± 1.3 (t test: p = 0.36). Intraclass correlation coefficient (ICC) of SM: 0.88/0.83. ANOVA in SM: p = 0.48/0.08. MRVP CLD minus MRVP IOPstim: 13.0 ± 5.6. Ratio MRVP CLD/MRVP IOPstim: 1.56 ± 3.1. Cooperation and agreeability were slightly better with the IOPstim. CONCLUSION: This first study with the IOPstim in humans was deliberately performed in healthy volunteers using Valsalva conditions. As demonstrated by ICC and ANOVA, reproducible SM can be obtained by both methods and the range of the SM does not differ greatly. The higher MRVP in CLD could be explained by the different directions of the force vectors.

Corneal Biomechanics in Glaucoma. / Biomechanische Parameter der Hornhaut als Biomarker beim primären Offenwinkelglaukom und Normaldruckglaukom.

Now that is possible to measure the biomechanical parameters of the cornea in vivo, scientific and clinical interest has increased in changes in these parameters in glaucoma. These parameters may act as biomarkers for early diagnosis, but also serve to emphasize the increased vulnerability to intraocular pressure, reduced blood flow or changing ocular perfusion pressure. Measuring and interpreting these parameters may help in achieving better and individually tailored glaucoma management.

The Distribution of Retinal Venous Pressure and Intraocular Pressure Differs Significantly in Patients with Primary Open-Angle Glaucoma.

INTRODUCTION: Until now, venous pressure within the eye has widely been equated with intraocular pressure (IOP). Measurements with dynamometers calibrated in instrument units or in force showed that the retinal venous pressure (RVP) may be higher than the IOP in glaucoma patients. In this study, the RVP was measured with a contact lens dynamometer calibrated in mmHg. METHODS: Study type: cross-sectional. SUBJECTS: Fifty consecutive patients with primary open-angle glaucoma (POAG) who underwent diurnal curve measurement under medication. Age: 69 ± 8 years. Measurement of RVP: contact lens dynamometry. IOP measurement: dynamic contour tonometry. RESULTS: Pressures are given in mmHg. In all 50 patients, the IOP was 15.9 (13.6; 17.1) [median (Q1; Q3)], and the RVP was 17.4 (14.8; 27.2). The distribution of the IOP was normal and that of the RVP was right skewed. In the subgroup of 34 patients with spontaneous pulsation of the central retinal vein (SVP), the IOP and therefore, by definition, the RVP was 16.5 (13.7; 17.4). In the subgroup of 16 patients without SVP, the IOP was 14.8 (13.3; 16.4), and the RVP was 31.3 (26.2; 38.8) (p ≤ 0.001). In systemic treatment, the prescribed drugs were (the number of patients is given in parentheses): ACE inhibitors (20), ß-blockers (17), angiotensin II-receptor blockers (13), calcium channel blockers (12), diuretics (7). No difference in RVP was observed between patients receiving these drugs and not receiving them, except in the ß-blocker group. Here, the 17 patients with systemic ß-blockers had a median RVP of 15.6 mmHg and without 20.2 mmHg (p = 0.003). In the 16 patients with a higher RVP than IOP, only one patient received a systemic ß-blocker. The median IOP was 15.7 mmHg with systemic ß-blockers and 16.1 mmHg without (p = 0.85). CONCLUSION: In a subgroup of 16 of the 50 patients studied, the RVP was greater than the IOP by a highly statistically and clinically significant degree. According to the widely accepted thinking on the pathophysiology of retinal and optic nerve head circulation, the blood flow in these tissues may be much more compromised in this group of patients than has been assumed. They may be identified by a missing SVP. Topical and systemic medications showed no statistically significant influence on the RVP, except for the systemic ß-blockers, in which the RVP was lower by 4.6 mmHg than for the patients who did not receive these drugs (p = 0.003).

Two-Year Follow-up of MicroPulse Transscleral Laser Therapy in Patients with Primary Open-Angle Glaucoma. / 2-Jahres-Ergebnisse nach transskleraler MicroPulse-Lasertherapie bei Patienten mit primärem Offenwinkelglaukom.

PURPOSE: To determine the long-term efficacy and safety of MicroPulse transscleral laser therapy (TLT) over a 24-month period in patients with primary open angle glaucoma. METHODS: This prospective interventional case series evaluated data from 44 medically treated eyes of primary open angle glaucoma (POAG) patients who received MicroPulse TLT to achieve further reduction in IOP. The reduction in 24-hr mean diurnal intraocular pressure (IOP), diurnal IOP fluctuations, and peak IOP were monitored after 3, 12, and 24 months. Postoperative complications, failure rates, and factors influencing IOP reduction were also evaluated. RESULTS: IOP decreased from 16.1 ± 3.4 mmHg preoperatively to 13.0 ± 2.9 mmHg (n = 31; p < 0.001), 12.3 ± 3.0 mmHg (n = 27; p < 0.001), and 13.1 ± 2.6 mmHg (n = 23; p < 0.001) at the 3-month, 12-month and 24-month follow-ups. At 24 months, 23 eyes (52%) had a sufficient IOP reduction to reach the individual target pressure. No severe complications were observed. No parameters could be identified that correlated with successful IOP reduction after treatment. The highest failure rate was observed during the first 3 months and remained stable thereafter. CONCLUSION: For about 50% of POAG eyes receiving the maximum tolerated treatment, MicroPulse TLT proved an effective method of further lowering IOP so as to reach the individual target pressure.

Effect of upper eyelid blepharoplasty on corneal biomechanical, topographic and tomographic parameters 4 weeks after surgery.

PURPOSE: To investigate the effect of "skin-only" upper eyelid blepharoplasty on corneal biomechanics and central as well as peripheral topographic/tomographic parameters before and 4 weeks after surgery. METHODS: In a prospective study, the corneal hysteresis (CH) and corneal resistance factor (CRF) were evaluated before and after blepharoplasty. Corneal topographic (maximum simulated keratometry value, inferior-superior value, index of surface variance, index of vertical asymmetry, index of height asymmetry, index of height decentration) and tomographic parameters (corneal thickness, corneal astigmatism and mean 5-mm- and 7-mm-zone keratometry value) were measured by the Pentacam HR. Statistical analysis was performed using a linear mixed model considering correlated data of both eyes. RESULTS: This study included 42 eyes of 35 patients (mean age: 64.5 years, range 52-82 years). Four weeks after surgery CH and CRF increased (9.4 ± 2.3 to 10.2 ± 2.2 mmHg and 9.7 ± 2.1 to 10.5 ± 2.2 mmHg) but did not reach statistical significance (P = 0.100 and P = 0.072). A significant increase in central maximum simulated keratometry value (Kmax) from 45.0 ± 2.3 to 45.4 ± 2.2 diopters (D) was observed (P = 0.004). Inferior-superior value (I-S) and index of surface variance (ISV) showed significant changes from 0.32 ± 0.98 to 0.10 ± 0.98 D (P = 0.02) and from 19.98 ± 9.84 to 22.93 ± 11.23 (P = 0.009), respectively. These alterations did not affect the subjective spherical equivalent (-0.09 ± 4.71 to -0.04 ± 4.51 D; P = 0.437) and the best-corrected distance visual acuity of patients (0.11 ± 0.14 to 0.15 ± 0.15 logMAR; P = 0.142). Age, gender and corneal thickness were not correlated with pre and postoperative differences of CH, CRF, corneal compensated IOP, Kmax, corneal astigmatism or I-S. CONCLUSION: The trend of increasing CH and CRF values might indicate a rise of corneal damping capacity. Despite statistically significant differences of Kmax, I-S and ISV, all other tomographical and topographical parameters did not change 4 weeks after surgery. The corneal steepening with a mean change of 0.4 diopters and the decrease of I-S with a mean of 0.22 diopters do not seem to have a clinically relevant effect for blepharoplasty patients in daily practice.

Comparison of Different Nutritional and Lifestyle Factors between Glaucoma Patients and an Age-Matched Normal Population.

PURPOSE: To compare nutritional and lifestyle factors between glaucoma patients and an age-matched control group. METHODS: One hundred and ninety (190) glaucoma patients were enrolled in this study. The control group comprised 97 age-matched participants. Data on physical activity, nicotine smoking, and several nutritional habits like coffee and alcohol consumption as well as high-salt and high-protein intake were collected using a standardised questionnaire. RESULTS: Age and gender were not statistically significantly different between the groups. There was a tendency for higher physical activity in the glaucoma group in comparison to the control group (47.3 vs. 35.4%; p = 0.056). Statistically significantly more glaucoma patients were nonsmokers (n = 169; 89.4%) compared to the control group (n = 64; 66.7%; p = 0.001). Glaucoma patients were also more often teetotal compared to the control group (21.6% compared to 14.4%; p < 0.001). Similarly, more glaucoma patients drank larger amounts of coffee in comparison to the control group (p = 0.001). One hundred and seventy-six (96.7%) glaucoma patients and 88 (90.7%) control subjects had high-protein intake (p = 0.035). High-salt intake was significantly lower in the glaucoma group (69.3 vs. 73.2%; p = 0.018). Of the 190 glaucoma patients, 81 had early visual field impairments (MD > - 6 dB) and 109 patients had moderate (MD between - 6 dB and - 12 dB) to severe (MD < - 12 dB) visual field defects. The severity of visual field defects, whether early, moderate, or severe, had no statistically significant impact on lifestyle parameters. CONCLUSION: Contrary to our original hypothesis that glaucoma patients would tend to follow an unhealthier lifestyle than the control group, the opposite was seen. Presumably, the cause of this healthier lifestyle is the desire to contribute positively through the course of the disease.

The retinal venous pressure at different levels of airway pressure.

PURPOSE: To investigate retinal venous pressure (RVP) as a function of airway pressure (AirP) during the Valsalva maneuver (VM) in human subjects. METHODS: Forty-three healthy volunteers (age, 22.0 (2.3) years) (median and interquartile range) were investigated using the following instruments: dynamic contour tonometer, contact lens dynamometer (CLD), and aneroid manometer. The following measurements were performed in their left eyes: tonometry and dynamometry during VM at different levels of airway pressure (AirP = 0, 10, 20, 30, and 40 mmHg). RESULTS: The median RVP during spontaneous breathing (AirP = 0) was 19.7 (6.4) (median in mmHg (interquartile range)) and the intraocular pressure (IOP) in mydriasis was 16.3 (3.1) mmHg. Spontaneous pulsation occurred in 58.1% of the subjects. RVP increased nonlinearly. The coefficient of variation of four individual measurements of RVP at each pressure level averaged 8.1 (7.6) %. At different AirP levels of 10, 20, 30, and 40 mmHg, the following RVPs were measured: 29.6 (12.6); 34.2 (12.8); 38.0 (10.5); and 40.3 (11.0), respectively. The rise of RVP (Δ RVP) during VM was significantly higher than that of Δ IOP (p < 0.0001, Wilcoxon test). Δ RVP between 0 and 40 mmHg AirP was 20.6 mmHg and Δ IOP 1.5 mmHg. The steepest slope of the RVP/AirP curve was observed at the first step from 0 to 10 mmHg of AirP (∆ RVP = 9.9 mmHg). CONCLUSION: A nonlinear relationship between RVP and AirP was found during VM. Small rises in AirP increase the RVP and affect retinal circulation.

Clinical and visual outcome of endophthalmitis patients: a single-center experience.

PURPOSE: To report the clinical and visual outcome and the therapeutical management in a large cohort of endophthalmitis patients. METHODS: In a monocentric, observational study, we retrospectively analyzed the data of all patients with endophthalmitis who were referred to the department of ophthalmology of the Carl Gustav Carus Hospital Dresden between 2006 and 2018. RESULTS: In total, data of 104 patients (49 female, 55 male) were included in the present analysis. The most frequent clinical scenario for endophthalmitis was postcataract surgery (30.8%). The most frequent treatment at presentation was a pars plana vitrectomy (ppV) in 42 patients, followed by an intravitreal antibiotic in 41 patients. Out of 41 patients who received an intravitreal antibiotic, 35 patients (85%) needed additional treatment. In contrast, out of 42 patients who received a ppV as the initial treatment, 19 patients (42%) needed additional therapy, which was significantly different (p < 0.0001). The best presenting visual acuity improved significantly after treatment (p < 0.0001). CONCLUSION: The results of the present study suggest that, compared with an intravitreal antibiotic, a ppV as the initial therapy of endophthalmitis might reduce the number of additional treatments. From our data, it can be hypothesized that a ppV should be performed as early as possible to achieve the best visual outcome in most endophthalmitis patients. Prospective studies are now needed to address this issue in greater detail and to confirm our findings.

Comparison of waveform-derived corneal stiffness and stress-strain extensometry-derived corneal stiffness using different cross-linking irradiances: an experimental study with air-puff applanation of ex vivo porcine eyes.

PURPOSE: To assess corneal stiffening of standard (S-CXL) and accelerated (A-CXL) cross-linking protocols by dynamic corneal response parameters and corneal bending stiffness (Kc[mean/linear]) derived from Corvis (CVS) Scheimpflug-based tonometry. These investigations were validated by corneal tensile stiffness (K[ts]), derived from stress-strain extensometry in ex vivo porcine eyes. METHODS: Seventy-two fresh-enucleated and de-epithelized porcine eyes were soaked in 0.1% riboflavin solution including 10% dextran for 10 min. The eyes were separated into four groups: controls (n = 18), S-CXL (intensity in mW/cm2*time in min; 3*30) (n = 18), A-CXL (9*10) (n = 18), and A-CXL (18*5) (n = 18), respectively. CXL was performed using CCL Vario. CVS measurements were performed on all eyes. Subsequently, corneal strips were extracted by a double-bladed scalpel and used for stress-strain measurements. K[ts] was calculated from a force-displacement curve. Mean corneal stiffness (Kc[mean]) and constant corneal stiffness (Kc[linear]) were calculated from raw CVS data. RESULTS: In CVS, biomechanical effects of cross-linking were shown to have a significantly decreased deflection amplitude as well as integrated radius, an increased IOP, and SP A1 (P < 0.05). Kc[mean]/Kc[linear] were significantly increased after CXL (P < 0.05). In the range from 2 to 6% strain, K[ts] was significantly higher in S-CXL (3*30) compared to A-CXL (9*10), A-CXL (18*5), and controls (P < 0.05). At 8% to 10% strain, all protocols induced a higher stiffness than controls (P < 0.05). CONCLUSION: Several CVS parameters and Kc[mean] as well as Kc[linear] verify corneal stiffening effect after CXL on porcine eyes. S-CXL seems to have a higher tendency of stiffening than A-CXL protocols have, which was demonstrated by Scheimpflug-based tonometry and stress-strain extensometry.

Comparison of the diurnal efficacy and safety of cyclocryocoagulation and cyclophotocoagulation in patients with refractory glaucoma.

PURPOSE: To compare the diurnal IOP-lowering efficacy and safety of cyclocryocoagulation (CCC) and cyclophotocoagulation (CPC) in patients with refractory glaucoma. METHODS: Forty eyes of 40 Caucasian patients with advanced primary or secondary glaucoma with only tunnel vision left were included in this retrospective, comparative interventional case series. Twenty eyes treated with CCC were compared with 20 eyes treated with CPC. Primary endpoint was the reduction of 24 h mean diurnal intraocular pressure (IOP; mean of 6 measurements), peak IOP and diurnal IOP fluctuations 3 and 6 months post-treatment. Secondary outcomes were the occurrence of postoperative complications and the identification of factors influencing the postoperative IOP reduction. RESULTS: In the CCC group (mean age 70.6 ± 13.4 years), mean diurnal IOP was significantly reduced from 20.0 ± 4.5 mmHg to 14.7 ± 2.5 (p < 0.001) at 3 months and 13.9 ± 3.34 mmHg at 6-month follow-up (p < 0.001). In the CPC group (mean age 74.9 ± 9.0 years), mean diurnal IOP significantly decreased from 18.2 ± 3.1 mmHg to 13.2 ± 2.2 (p < 0.001) at 3 months and 13.1 ± 2.6 mmHg (p < 0.001) at 6 months. At 6 months, 75% of the CCC and 63% of the CPC group had mean diurnal IOP reductions of 20% or more. The most frequent complication (25%) was a transient IOP increase during the first days after CCC. A higher preoperative mean diurnal IOP was recognized as the only factor influencing the postoperative IOP reduction after CCC and CPC. CONCLUSIONS: Both cyclodestructive methods seem to be reasonably safe and effective in lowering 24 h mean diurnal IOP in the perspective of 6 months in patients with refractory glaucoma. The IOP-lowering effect after CCC was better but not statistically significantly different compared to CPC. A higher rate of complications was observed in the CCC group, however.

Predictive value of positive temporal artery biopsies in patients with clinically suspected giant cell arteritis considering temporal artery ultrasound findings.

PURPOSE: To investigate the impact of ocular symptom, non-ocular symptom, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and temporal artery ultrasound (TAU) findings on the predictive value of a positive temporal artery biopsy (TAB) in patients with clinically suspected giant cell arteritis (GCA). METHODS: In a retrospective, interventional study, data from 68 patients with clinically suspected GCA who underwent TAB between 2015 and 2017 were analysed. Analysis included five parameters: ocular symptom, non-ocular symptom, ESR, CRP level and TAU findings. Using a contingency table, each parameter was separately analysed for the predictive value of a positive TAB, and a discriminant analysis was applied to check for the predictive value of a positive TAB under consideration of all five parameters and of the three strongest predictive parameters. RESULTS: A positive TAB was significantly associated with a positive TAU in 15 of 15 patients (p < 0.001), an increased ESR in 37 of 53 patients (p < 0.001), an increased CRP level in 35 of 56 patients (p = 0.004) and non-ocular symptoms in 27 of 40 patients (p = 0.01). A positive TAB was not significantly associated with the presence of ocular symptoms (25 of 46 patients, p = 0.988). Using a discriminant analysis, the combined parameters TAU, ESR and CRP were able to predict a positive TAB in 97.3% of all patients. The positive predictive value was 78.3%, and the negative predictive value was 95.4%. CONCLUSION: Temporal artery biopsy to confirm the diagnosis of GCA may not be mandatory in patients who show an elevated ESR and CRP level and a positive TAU.

Central retinal venous pressure is higher than intraocular pressure during amateur trumpet playing.

BACKGROUND: It has been shown in the literature that the Valsalva manoeuvre influences ocular perfusion by changing intraocular pressure and central retinal venous pressure (CRVP). High-resistance wind instrument (HRWI) playing is a common situation resembling a Valsalva manoeuvre. The aim of this investigation was to explore the influence of amateur trumpet playing on CRVP. METHODS: The left eyes of 20 healthy non-professional trumpet players (median age 26, range 19-52 years; 17 males, 3 females) were included in this investigation. Subjects, sitting at a slit lamp, were asked to play the tone b' flat with their own mouthpiece on the same trumpet for at least 30 s with moderate loudness. The following data were obtained: intraocular pressure (IOP) by applanation tonometry before and during playing, CRVP by contact lens dynamometry before and during playing, airway pressure (AirP) using a pressure sensor during playing and blood pressure and heart rate using the common cuff method before and during playing. RESULTS: The results are presented as the medians before vs during playing: a calculated mean ophthalmic artery pressure of 66 vs 72 mmHg, heart rate of 76 vs 82 beats per minute, airway pressure of 0 vs 17 mmHg, IOP 12 vs 13 mmHg and CRVP of 24 vs 55 mmHg (Wilcoxon test: p = 0.00009), respectively. A correlation between the CRVP during playing and the height of the spontaneous CRVP is noted (Spearman rank correlation coefficient: ρ = 0.68). CONCLUSIONS: Amateur trumpet playing increases CRVP, airway pressure and IOP. The increase in CRVP is greater than that of the intraocular pressure. The increase in CRVP seems to be more important for retinal perfusion changes during trumpet playing than the increase of IOP. It can be hypothesised that high airway pressure during playing may cause a permanent increase in CRVP, at least in a subgroup of trumpet players.

Analyzing biomechanical parameters of the cornea with glaucoma severity in open-angle glaucoma.

PURPOSE: The purpose was to investigate a possible association of corneal hysteresis (CH) and corneal resistance factor (CRF) with open-angle glaucoma and the severity of disease. METHODS: In this prospective cross-sectional study we recruited 86 open-angle glaucoma patients, 16 patients with ocular hypertension (OHT,) and 44 age-matched controls. Each participant had a complete glaucoma workup including measurements with the Ocular Response Analyzer and computerized perimetry with the Humphrey 30-2 SITA Standard program. Visual field damage was based on mean deviation (MD) and considered as early glaucomatous with a MD > - 6 dB, moderate glaucomatous between -6 and -12 dB and advanced glaucomatous < -12 dB. The association between ORA parameters, glaucoma, and disease severity was evaluated using univariate and multivariate linear regression analyses. RESULTS: There was a statistically significant correlation between the biomechanical parameters and intraocular pressure, central corneal thickness, axial length, and age. On average, glaucoma patients had the lowest adjusted CH (8.96 ± 1.43 mmHg) and CRF (9.07 ± 1.93 mmHg) values in comparison to OHT patients (CH: 10.2 ± 1.5 mmHg; CRF: 10.6 ± 2.1 mmHg) and controls (CH: 9.7 ± 1.4 mmHg; CRF: 10.2 ± 1.9 mmHg). This difference was statistically significant (CH: p = 0.003; CRF: p = 0.008). There was also a statistically significant difference in adjusted CH (p = 0.001) and CRF (p = 0.004) values between the controls and the visual field groups, with the lowest values being in the most advanced group. CONCLUSIONS: Before interpreting corneal biomechanical parameters, it seems important to adjust the measured data for their underlying influencing factors. Glaucoma patients with lower adjusted CH and CRF probably have more advanced disease and should, therefore, be treated more aggressively and monitored more carefully and frequently.

Diameter of retinal vessels in patients with diabetic macular edema is not altered by intravitreal ranibizumab (lucentis).

PURPOSE: To investigate the effect(s) of intravitreally injected ranibizumab on retinal vessel diameter in patients with diabetic macular edema. METHODS: Participants of this prospective study were 14 men and 16 women (30 eyes) aged 60 ± 11 years (mean ± standard deviation), all with clinically significant diabetic macular edema. Treatment comprised 3 intravitreal injections of ranibizumab given at 4-week intervals. Examinations were conducted before the first (baseline), before the second (Month 1), before the third (Month 2) injections, and 3 months after baseline (Month 3). Measured parameters included systemic blood pressure, static retinal vessel analysis (central retinal artery equivalent and central retinal vein equivalent), and dynamic retinal vessel analysis, as measured by the change in vessel diameter in response to flicker stimulation during three measurement cycles. Flicker stimulation was accomplished using a 50-second baseline recording, followed by an online measurement during 20-second flicker stimulation and 80-second online measurements in both arteriolar and venular vessel segments. RESULTS: Static retinal vessel analysis showed a reduction of central retinal artery equivalent from 186.25 ± 51.40 µm (baseline) to 173.20 ± 22.2 µm (Month 1), to 174.30 ± 27.30 µm (Month 2), and to 170.56 ± 22.89 µm (Month 3), none of which was statistically significant (P = 0.23, 0.12, and 0.14, respectively). Central retinal vein equivalent was reduced from 216.21 ± 25.0 µm (baseline) to 214.48 ± 25.4 µm (Month 1), to 214.80 ± 24.30 µm (Month 2), and to 211.41 ± 24.30 µm (Month 3), revealing no statistically significant differences between examination time points (P = 0.54, 0.06, and 0.24, respectively). Dynamic vessel analysis yielded a mean retinal arterial diameter change of +1.47% ± 2.3 (baseline), +1.91% ± 2.5 (Month 1), +1.76% ± 2.2 (Month 2), and +1.66% ± 2.1 (Month 3), none of which showed statistically significant differences (P = 0.32, 0.49, and 0.70, respectively). Mean retinal venous diameter changes were +3.15% ± 1.7 (baseline), +3.7% ± 2.3 (Month 1), +4.0% ± 2.0 (Month 2), and +4.95% ± 1.9 (Month 3), none of which showed statistically significant differences (P = 0.12, 0.17, and 0.14, respectively). Central retinal thickness, as measured by spectral domain optical coherence tomography, decreased significantly from 435.2 ± 131.8 µm (baseline) to 372.3 ± 142.8 µm (Month 3), P = 0.01. Regression analysis of arteriolar and venular diameters indicated that there was no significant correlation between these 2 parameters (r = 0.053; P = 0.835 and r = 0.06; P = 0.817, respectively). Also, no significant correlation was observed between the difference in the central retinal thickness and change in arteriolar or venular dilatation (r = 0.291, P = 0.241 and r = 0.06, P = 0.435, respectively). CONCLUSION: Intravitreally applied ranibizumab did not significantly affect retinal vessel diameter in patients with diabetic macular edema. Decline in the central foveal thickness after ranibizumab therapy, as measured by spectral domain optical coherence tomography, was not linked to any change in retinal vessel diameter or dilatatory response, neither for arterioles nor venules.

Comparison of normal- and high-tension glaucoma: nerve fiber layer and optic nerve head damage.

PURPOSE: The aim of this study was to investigate differences in the nerve fiber layer and glaucoma-induced structural optic nerve head (ONH) damage in patients with normal- (NTG) and high-tension (HTG) glaucoma. METHODS: In this retrospective pair-matched comparative study, 22 NTG and 22 HTG eyes were matched according to the same glaucomatous damage based on rim volume, rim area and disk size, as measured by Heidelberg retinal tomography (HRT III). Visual fields (VF) were assessed by Humphrey perimetry, and nerve fiber layer thickness was determined both by scanning laser polarimetry (GDxVCC) and spectral-domain optical coherence tomography (SD-OCT). Comparisons of all measured parameters were made between NTG and HTG groups. RESULTS: Based on HRT results, both NTG and HTG eyes displayed comparable structural damage to the ONH (NTG/HTG, mean: disk area, 2.30/2.31 mm(2), p = 0.942; rim area, 1.02/0.86 mm(2), p = 0.082; rim volume, 0.19/0.17 mm(3), p = 0.398). NTG eyes had significantly less VF damage than HTG eyes (NTG/HTG, mean deviation: -4.23/-12.12 dB, p = 0.002; pattern standard deviation: 5.39/8.23 dB, p = 0.022). The inferior nerve fiber layer of NTG patients was significantly thicker than that of HTG patients (NTG/HTG, mean: GDx inferior: 53.5/46.3 µm, p = 0.046). SD-OCT revealed a significantly thicker nerve fiber in NTG compared with HTG patients in all quadrants (NTG/HTG, total mean: 72.72/58.45 µm, p = 0.002). CONCLUSION: At comparable glaucomatous stages, nerve fiber loss was more advanced in HTG patients compared with NTG patients.