Intraocular pressure measurement with Corvis ST in comparison with applanation tonometry and Tomey non-contact tonometry.

PURPOSE: Intraocular pressure (IOP) measurement can be performed with different methods. Newer methods have to be compared to the standard method, the Goldmann applanation tonometry (GAT). We herein compare two air-puff tonometers, the non-contact tonometer (Tomey NCT) and the Corvis ST (CST) with GAT in eyes with a broad spectrum of IOP. METHODS: Two hundred and forty-nine eyes of 249 patients (with diagnosis of either glaucoma or ocular hypertension) were included in this monocenter prospective cohort study. Each eye underwent IOP measurements via GAT, NCT and CST. Bland-Altman plots were calculated to compare the different methods in the three groups. Paired t tests were used for statistical comparison between the three measurement methods. The difference between the different methods was tested on correlation against central corneal thickness (CCT). RESULTS: Mean IOP in GAT was 17.6 mmHg (standard deviation (SD) 5.9), 16.3 mmHg (SD 5.6) in NCT and 18.0 mmHg (SD 5.5) in CST. Comparisons between GAT and CST vs. NCT showed significant differences (p < 0.001), while GAT vs. CST showed no significant difference (p = 0.1162). Mean CCT was 538.7 µm (SD 35.1). CONCLUSIONS: Mean values of GAT and CST show comparable results. However, both GAT and CST differ significantly from NCT. NCT shows lower IOP values compared to both other methods.

[Scleral melting after cyclophotocoagulation]. / Skleraeinschmelzung nach Zyklophotokoagulation.

We report on a case of a scleral melting as a rare but severe complication of transscleral cyclophotocoagulation. The tissue defect was successfully repaired by tectonic keratoplasty.

Bleb-related infections and long-term follow-up after trabeculectomy.

PURPOSE: Bleb-related infections are serious complications after trabeculectomy. They can be limited to the bleb or disseminate and lead to endophthalmitis. We herein report on all bleb-related infections that have been diagnosed at the Eye Center of the University of Freiburg, Germany, since 1999. METHODS: We reviewed a total of 1816 consecutive trabeculectomies that were performed at our hospital between the years 1999 and 2014 (353 without and 1463 with intraoperative application of mitomycin C). All bleb-related infections that were diagnosed at our clinic during the same period were included in the analysis. We fitted a Cox proportional hazards model to characterize risk factors for bleb-related infections. RESULTS: We diagnosed a total of 19 bleb-related infections in this period. Three patients with bleb-related infections that came to our clinic had their trabeculectomy performed elsewhere. The overall percentage of bleb-related infections was 0.1% after 2 years (Kaplan-Meier estimate at median follow-up). Nine eyes suffered from only localized infection of the bleb. Seven eyes developed endophthalmitis. Four infections occurred during the first postoperative month. The median age on the day of diagnosis was 71 years; the median age at surgery was 69 years. In the Cox model, intraoperative application of mitomycin C and a fornix-based conjunctival flap were identified as significant risk factors (hazard ratio: 79.02, 4.69; p < 0.01, p < 0.01). The whole group showed a reduction of visual acuity in the median from logMAR 0.12 to 0.2. Eyes that suffered from endophthalmitis showed a loss from 0.3 to 0.96, while the localized infections had a reduction from 0.04 to 0.07. CONCLUSION: Bleb-related infections are a rare complication following trabeculectomy and can be localized on the bleb or can lead to endophthalmitis, thereby threatening visual acuity. The risks and benefits of mitomycin C-augmented trabeculectomies should be taken into consideration.

The effect of additional trabecular aspiration to phacoemulsification and trabectome as a triple procedure in pseudoexfoliation glaucoma: a case-matched study.

BACKGROUND: Trabectome surgery combined with phacoemulsification is effective in lowering (intraocular pressure) IOP in pseudoexfoliation glaucoma. Trabectome surgery usually aims to remove two to four clock hours of the trabecular meshwork. When adding trabecular aspiration, the remaining meshwork can be treated as well, and therefore 360 degrees of the meshwork can be reached. This study was conducted to investigate the additional benefits and risks of adding trabecular aspiration to the combination of phacoemulsification and trabectome as a triple procedure. METHODS: Two groups of patients from two centres were compared. The first group underwent phacoemulsification and trabectome (Freiburg), and the second group underwent additional trabecular aspiration (Düsseldorf). Using a case-matched retrospective study design, 50 patients were included into each group. The clinical endpoint was the intraocular pressure at follow up. RESULTS: The mean follow up was 22 months. Mean intraocular pressure decreased in all 100 patients from 25.0 (SD 4.3) to 14.9 mmHg (SD 4.0). Comparing the two groups, the IOP reduction was from 25.0 (SD 5.0) to 14.1 (SD 4.4) mmHg in the triple procedure group compared to a reduction from 25.0 (3.6) to 15.7 (SD 3.4) mmHg in the phaco/trabectome group. The difference was statistically significant (p = 0.03). The number of medication after surgery was reduced from 2.2 (SD 0.9) to 1.7 (SD 0.9) while in the phaco/trabectome group the medication score was reduced from 2.2 (SD 1.0) to 1.1 (SD 0.1) (p < 0.001). CONCLUSIONS: This study shows that the combination of trabectome surgery and phacoemulsification leads to a clinically significant reduction of IOP over several years in patients with pseudoexfoliation glaucoma. The addition of trabecular aspiration as a triple procedure results in further lowering of IOP without causing more side effects. This finding might be biased by the higher medication score in the triple procedure group.

[Alterations in intraocular pressure and the CorVis parameters after LASIK]. / Änderung des Augeninnendrucks und der CorVis-Parameter nach LASIK.

INTRODUCTION: The reduction of corneal thickness following laser-assisted in-situ keratomileusis (LASIK) requires a correction of intraocular pressure (IOP) measurements. The corneal visualization Scheimpflug technology (CorVis ST, Oculus, Wetzlar, Germany) not only measures the IOP and central corneal thickness (CCT) but also determines 10 additional corneal parameters, such as the time to first and second applanation and velocity. Besides CCT we compared various corneal parameters before and after LASIK in order to detect possible correlations and to correct IOP measurements. METHODS: Measurements with CorVis ST were made before and after LASIK in 45 myopic patients (45 left eyes). We compared the IOP and CorVis ST parameters using a paired t­test before and after LASIK and corrected for possible correlations in a multifactorial linear model. Finally, we correlated the changes in IOP to changes in biomechanical parameters. RESULTS: We observed a direct correlation between the IOP measurements and the corneal thickness. The IOP was underestimated by 0.039 mm Hg per micrometer in reduction of corneal thickness. The multifactorial linear model showed a correlation of IOP change to A2 velocity and the radius of applanation. CONCLUSION: Surgical thinning of the central cornea via LASIK demonstrated a direct correlation between corneal thickness and IOP measurements using the CorVis ST technique. Postoperative changes of the A2 velocity and the applanation radius also had a statistically significant influence on post-LASIK IOP measurements. Our findings could be useful to obtain more precise post-LASIK IOP measurements.

[Diaphanoscopy in cyclophotocoagulation]. / Diaphanoskopie bei der Zyklophotokoagulation.

Transscleral cyclophotocoagulation is not usually considered as the first line surgical therapy for glaucoma. However, it still remains an important tool for lowering intraocular pressure in certain patients. It is quick and easy to perform and acts through an alternative physiological approach compared to filtration surgery. As the ciliary body is not directly visible, an empirical distance from the limbus is often used for placement of the laser probe; however, the anatomical structures can be highly variable. Diaphanoscopy provides a very simple and effective way to visualize the ciliary body before or parallel to the cyclophotocoagulation. It helps to direct the laser beam more precisely to the ciliary body and to prevent a false anterior placement of the beams, that carries a great risk of side effects. This article provides an overview on the concept of diaphanoscopy for cyclophotocoagulation.

[Unilateral periocular angioedema after application of contrast agent]. / Einseitiges periokuläres Angioödem nach Kontrastmittelgabe.

This article presents a case report of unilateral, periocular angioedema after intravenous application of a contrast agent with a temporary increase of intraocular pressure in an eye in which trabeculectomy had been carried out 5 weeks previously.

Refractive and visual outcomes after combined cataract and trabectome surgery: a report on the possible influences of combining cataract and trabectome surgery on refractive and visual outcomes.

PURPOSE: To compare combined trabectome-cataract surgery with cataract-alone surgery regarding their refractive and visual outcomes and complications. METHODS: In 137 eyes that underwent combined trabectome-cataract surgery, the postoperative refraction error and best visual acuity after at least 2 months postoperatively were compared to those of an in-house control group of 1,704 eyes that underwent outpatient cataract surgery. RESULTS: Combined trabectome-cataract surgery showed no significant differences regarding the biometry prediction error (BPE, mean 0.53 D vs. 0.48 D, p = 0.24) or visual outcome (BCVA, 0.81 vs. 0.78, p = 0.06). The rate of postoperative cystoid macular edema was slightly higher in the combined surgery group (2.2 % vs. 1.9 %). CONCLUSIONS: Refractive and visual outcomes were similar in both groups. Despite the slightly higher rate of postoperative macula edema, we were able to observe that the combination of these two procedures is a feasible method in glaucoma and cataract surgeries.

[Minimally invasive glaucoma surgery using the trabectome]. / Minimalinvasive Kammerwinkelchirurgie mit dem Trabektom.

The main barrier reducing outflow of aqueous humor in open angle glaucomas is the juxtacanalicular trabecular meshwork. The trabectome removes this pathophysiologically altered tissue by electroablation, thus allowing for the collector channels draining Schlemm's canal to directly communicate with the anterior chamber. In studies published so far, about 30% decrease of intraocular pressure and a simultaneous 42% reduction of pressure-lowering eyedrops could be achieved in primary and secondary open angle glaucomas. A clear cornea tunnel is used to advance the trabectome to the trabecular meshwork, leaving the conjunctiva unaffected. Hence minimally invasive chamber angle surgery using this device is in particular suitable for patients with an altered ocular surface. Lowering of intraocular pressure and reduction of needed topical medication seems to be distinct in pseudoexfoliative glaucoma. Surgery with the trabectome and phacoemulsification can easily be combined in one procedure. Using a minimally invasive approach, the complication profile of the trabectome is rather advantageous, not exceeding the general risks of globe-opening surgery. Ab-interno trabeculotomy is a safe and effective method for treatment of patients with primary or secondary open angle glaucomas and moderate target pressures.

[Body mass index as an influencing factor for outcome of trabectome surgery?]. / Einfluss des Body-Mass-Index auf den Erfolg nach Trabektomoperation?

BACKGROUND: The aim of this study was to investigate a possible influence of body mass index (BMI) to the outcome of trabectome surgery. METHODS: 131 eyes with primary open angle glaucoma, myopia-associated glaucoma and pseudoexfoliation glaucoma were included into this retrospective study. The data were extracted from the Freiburg trabectome database from June 2009 to April 2013. We fitted a Cox proportional hazards model in order to assess the influence of the BMI on trabectome outcome. RESULTS: The absolute success after trabectome surgery (20 % pressure reduction without anti-glaucomatous medication) was statistically significantly better in the group with BMI > 25 kg/m(2) (p = 0.047). No statistically significant effect was observed for relative success or the rate of re-operation respectively. CONCLUSION: In our patient cohort of 131 eyes, a high BMI was associated with a reduced success, as long as an absolute success is required. No difference is seen if additional anti-glaucomatous medication is acceptable (relative success).

[Trauma-related secondary glaucoma in childhood: a therapeutic challenge]. / Traumatisches Sekundärglaukom im Kindesalter : Eine therapeutische Herausforderung.

CASE REPORT: We performed a minimally invasive trabeculotomy using a trabectome on a 9-year-old boy with a trauma-related secondary glaucoma where the intraocular pressure (IOP) could not be controlled by conservative approaches. After a 1-year follow-up the patient showed well controlled IOP values without using drugs to reduce pressure. CONCLUSION: Trabectome surgery seems to be a suitable first step intervention for trauma-related glaucoma in selected cases, even in children.

[Risk factors in the results of the colour vision test Roth 28-hue (E) desaturated in glaucoma patients]. / Einflussfaktoren auf die Ergebnisse des Farbpigmentprobentests Roth 28-hue (E) desaturiert bei Glaukompatienten.

BACKGROUND: Glaucoma is an ocular disease with typical progressive damage of the optic nerve. In the past it was postulated that glaucoma induces acquired colour vision disorders. Until now all studies about glaucoma and colour vision disorders did not include vascular risk factors. In the present study we determined several vascular risk factors concerning the results of the colour vision test Roth 28-hue (E) desaturated in glaucoma patients. PATIENTS AND METHODS: On the basis of an analysis of variance (ANOVA) we determined the influence of several risk factors, such as arteriosclerotic and vasospastic risk factors, on the results of the colour vision test Roth 28-hue (E) desaturated in glaucoma patients. 353 glaucoma patients were included in this study. RESULTS: We detected a strong influence of age and mean defect in perimetry and an additional effect of arteriosclerotic and vasospastic risk factors on the results of the colour vision test Roth 28-hue (E) desaturated in glaucoma patients. CONCLUSIONS: We suspect that arteriosclerotic and vasospastic risk factors independently to glaucoma have an influence on colour vision. In the future attention additionally has to be given to vascular risk factors in the colour vision testing of glaucoma patients.

[Combined cataract and glaucoma surgery. Current options]. / Kombinierte Katarakt-Glaukom-Chirurgie. Aktuelle Optionen.

Trabeculectomy is no longer the gold standard for combined cataract glaucoma surgery considering the successful results following cataract surgery combined with trabeculotomy, viscocanalostomy and canaloplasty. The main disadvantage of these mostly non-penetrating procedures is the induction of conjunctival scarring which jeopardizes subsequent filtering surgery. Ab interno glaucoma surgery, including trabecular surgery and endocyclophotocoagulation, does not interfere with the conjunctival situation. These surgical options have a relatively minor risk profile for combined cataract glaucoma surgery compared to traditional filtering surgery; however, the pressure reducing efficacy of these ab interno approaches is limited with respect to the absolute reduction of intraocular pressure (IOP) and the achievable level of IOP. This has to be kept in mind when planning surgery.

[Minimally invasive iridocorneal angle surgery]. / Minimal-invasive Kammerwinkelchirurgie.

The classical filtration surgery with trabeculectomy or drainage of chamber fluid with episcleral implants is the most effective method for permanent reduction of intraocular pressure to lower and normal levels. Even though both operative procedures are well-established the high efficiency of the method causes potentially dangerous intraoperative as well as interoperative complications with a frequency which cannot be ignored. In the past this led to a search for low complication alternatives with non-penetrating glaucoma surgery (NPGS) and the search is still continuing. Trabecular meshwork surgery in particular with continuous development of new operation techniques steered the focus to a complication-poor and minimally invasive, gonioscopic glaucoma surgery.

[Combined phacoemulsification with trabecular aspiration with differing outcomes in pseudoexfoliative glaucoma - a retrospective study]. / Kombinierte Phakoemulsifikation mit Trabekelaspiration bei Pseudoexfoliations-Glaukom mit unterschiedlichem Ausgangsdruck - eine retrospektive Studie.

INTRODUCTION: The aim of this study was to differentiate the pressure-reducing results following trabecular aspiration combined with small incision cataract surgery in eyes with pseudoexfoliation depending on preoperative pressure and medication score. PATIENTS AND METHODS: A retrospective analysis was made of 104 exfoliative eyes of 104 patients who underwent combined phaco/trabecular aspiration. Success was defined as a relative reduction of IOP of at least 20 %, absolute IOP of ≤ 20 mmHg, stable or reduced medication score and a lack of any further pressure-reducing surgery. RESULTS: The success rate was 0.68 and 0.64 after 1 and 2 years. In eyes with medically uncontrolled preoperative IOP (> 20 mmHg) the IOP dropped significantly from 25.4 ± 4.3 mmHg to 17.0 ± 3.4 mmHg after two years. In eyes with preoperative controlled IOP the pressure lowering effect was low (17.1 ± 2.3 to 15.9 ± 2.3 mmHg) with a significant reduction of medication. CONCLUSIONS: Combined cataract surgery and trabecular aspiration is a reasonable option in exfoliative eyes with IOP values in the low twenties in order to achieve a reduction of topical medications and to reach a stable IOP level.

[Factors influencing applanation tonometry - a practical approach]. / Einflussgrößen auf die Applanationstonometrie - ein praxisorientierter Überblick.

Applanation tonometry has been the gold standard in clinical ophthalmology for more than fifty years. The most popular factor is central corneal thickness that is now routinely considered in glaucoma management. However, other individual features of the cornea can also play a key role for the interpretation of the applanation values. Other factors influencing applanation tonometry that have been well known for decades include tear film, fluorescein illumination etc., and should be kept in mind. According to the available literature the absence of a correct calibration cannot be neglected.

[Techniques of intraocular pressure measurement]. / Messverfahren der Tonometrie.

The correct interpretation of measured tonometric values has become more and more complex in recent years. Large clinical studies have shown that an average central corneal thickness (CCT) of 550 µm can be assumed for the general population. Since the standard Glodmann applanation tonometry is based on a central corneal thickness of 520 µm, mathematical correction formula have been discussed for calculation of the true intraocular pressure. Newer tonometry devices, e. g. the dynamic contour tonometry (DCT) which seems to be independent from CCT, or the Ocular Response Analyzer® (ORA), taking into account the biomechanical properties of the cornea, have been designed to measure intraocular pressure (IOP). In this article, several IOP measurement devices and their clinical relevance for a correct and feasible determination of the IOP are discussed.

[Comparison of Rebound tonometry versus Perkins tonometry in the supine glaucoma patient]. / Vergleich zwischen Rebound-Tonometrie und Perkins-Tonometrie am liegenden Glaukompatienten.

BACKGROUND: The aim of this study was to evaluate the concordance of intraocular pressure (IOP) measurements in the supine glaucoma patient using a Perkins applanation tonometer (PAT) compared to the iCare® rebound tonometer (RT), a hand-held device requiring no local anaesthesia. METHODS: 73 left eyes of 73 glaucoma patients were included in this consecutive case study and measured both by supine Perkins applanation tonometry and by right lateral posture rebound tonometry in the supine position (RLP). The patients were divided into three subgroups dependent on IOP (SG-1: 0 - 15 mmHg, SG-2: 16 - 22 mmHg, SG-3: more than 23 mmHg). RESULTS: The mean deviation between RT and PAT was 2.6 ± 4.0 mmHg, the 95 % confidence interval was -5.3 to 10.4 mmHg. 69 % of the measurements showed deviations within 3 mmHg between the two devices. Deviation was smallest in SG-2, and largest in SG-3. CONCLUSIONS: Rebound tonometry is comfortable to use even in supine patients. RT measurement agreed overall significantly with those of Perkins applanation tonometry, generally overestimating PAT measurement. In high IOP values, RT did not correlate as well with PAT as in moderate IOP levels.

[Minimally invasive angle surgery. The Trabectome]. / Minimal-invasive Kammerwinkelchirurgie. Das Trabektom.

The Trabectome provides a new perspective in angle surgery for open angle glaucoma. Through a 1.7 mm clear cornea tunnel, the juxtacanalicular meshwork is electroablated under gonioscopic control. Thereby, the collector channels in the outer wall of Schlemm's canal are uncovered and resistance to trabecular outflow is removed. From the literature and from our own experience, a pressure reduction by 30-35% can be achieved with a simultaneous reduction of eye drops by 50%. The Trabectome can conveniently be combined with phako-emulsification. Serious complications have not yet been reported. As the conjunctiva remains completely untouched, trabeculectomy, if necessary, could be performed without prognostic restrictions. With a realistic target pressure of approximately 16 mmHg, Trabectome surgery is indicated in patients with moderate optic nerve damage.

A prospective randomised trial of trabeculectomy using mitomycin C vs an ologen implant in open angle glaucoma.

PURPOSE: The aim of this study is to assess the efficacy and complications of trabeculectomy with a biodegradable implant (ologen implant) vs trabeculectomy using mitomycin C (MMC) in patients with medically uncontrolled open-angle glaucoma in a prospective randomised clinical trial. METHODS: In the MMC group (10 patients), trabeculectomy was performed according to standard protocols. In the ologen group (10 patients) after standard trabeculectomy the implant was positioned on top of the scleral flap and no MMC was applied. Follow-up was continued for 12 months after surgery and included testing of intraocular pressure (IOP), visual acuity, visual field, ultrasound biomicroscopy, and filtering bleb score. RESULTS: The mean preoperative IOP was 24.8+/-8.9 mm Hg for all patients enrolled. At 1 year after surgery, the mean IOP was 15.6+/-2.4mm Hg in the ologen group (P<0.01, 43% reduction) and 11.5+/-4.1 mm Hg in the MMC group (P<0.01, 50% reduction). No anti-glaucomatous medication was necessary in the MMC group in the first year of follow-up, whereas five patients in the ologen group required topical treatment. The absolute success rate was 100% in the MMC group and 50% in the ologen group (P=0.01). After 1 year, filtering blebs developed significantly more avascular areas in the MMC group (score=1.4) than in the ologen group (score=2.8; P<0.01). CONCLUSION: The complete success rate using trabeculectomy with the ologen implant is lower than that achieved by trabeculectomy with MMC. However, the bleb morphology caused more problems in the MMC group (avascularity score).