Safety and Efficacy of Three Modifications of Canaloplasty to Treat Open-Angle Glaucoma: 3-Year Outcomes.

BACKGROUND: This is a report of 3-year results of a prospective assessment of three modifications of canaloplasty (C): ab externo (ABeC), mini-canaloplasty (miniABeC), and ab interno (ABiC) performed concomitantly with cataract removal in subjects suffering from primary open-angle glaucoma (POAG). METHODS: Forty-eight individuals were randomized for one of the surgeries: ABeC, miniABeC, or ABiC and cataract removal-16 eyes for each group. Follow-up examinations were carried out on the day of the surgery, on days 1 and 7, after 1, 3, 6 months, and at 1, 2, and 3 years. Complete and qualified success was an IOP ≤ 15 mmHg without or with antiglaucoma eye drops, respectively. The IOP reduction of 20% or more was considered an additional success criterion. RESULTS: Within three years the probability of qualified success was ABiC and miniABeC-94%, ABeC-100%, and of complete success ABiC-75%, miniABeC-100%. At the 3-year follow-up, the median IOP decreased from 22 to 15 mmHg in the ABeC group (p = 0.001), from 22 to 15 mmHg in the miniABeC group 15 (p < 0.001), and from 21 to 15 mmHg in the ABiC group (p = 0.001) compared to the post-washout stage. The IOP dropped by 20% or more without medications in 56.2% of patients post ABiC, 68.8% post miniABeC and 75% post ABeC. The median number of antiglaucoma medications dropped in all three groups; at the 3-year follow-up, only one patient following ABeC and four subjects following miniABeC required treatment. One patient required reoperation and further intensification of topical treatment-post miniABeC. The levels of IOP, CDVA, and success probability at the 36-month follow-up showed no significant difference for individual groups. CONCLUSIONS: ABeC, miniABeC, and ABiC have significant IOP-lowering potential in individuals diagnosed with POAG at a mild to moderate stage and no history of IOP ≥ 30 mmHg with a good safety profile.

Alternative application of an iTrack microcatheter and canaloplasty: case report and literature review.

INTRODUCTION: Glaucoma is the leading cause of irreversible blindness worldwide. Schlemm's canal surgery using an iTrack flexible microcatheter has become popular because of its high quality-of-life issues and the growing demand for less invasive but effective procedures. The unique design of the microcatheter makes it a multimodal tool, which can be used not only in the field of antiglaucoma surgery but also as a drug delivery system to treat various conditions. AREAS COVERED: This review presents an update on the selected aspects of a drug delivery system using the iTrack microcatheter, including glaucoma gene therapy and posterior-segment diseases, both in animal models and human patients. The authors also report the case of a patient with branch retinal vein occlusion treated with suprachoroidal bevacizumab in the submacular region administered with the iTrack catheter. EXPERT OPINION: The findings presented in this study may indicate that the application of a microcatheter in open-angle glaucoma gene therapy is reasonable and can be combined with full or partial surgical canaloplasty procedures. Translation of this potential into a treatment modality would require overcoming multiple barriers.

Safety and Efficacy of Three Variants of Canaloplasty with Phacoemulsification to Treat Open-Angle Glaucoma and Cataract: 12-Month Follow-Up.

BACKGROUND: A single-center prospective randomized observational study to compare three types of canaloplasty, i.e., ab externo (ABeC), minicanaloplasty (miniABeC) and ab interno, (ABiC) combined with cataract surgery in primary open-angle glaucoma (POAG) patients over 12 months. METHODS: 48 POAG patients underwent one of three canaloplasty procedures: ABeC (16 eyes), miniABeC (16 eyes) or ABiC (16 eyes) or combined with phacoemulsification. Patients were assessed at baseline, at day 0-1-7 and at month 1-3-6-12. Successful treatment was defined as unmedicated IOP reduction ≥20%. Complete surgical success was defined as an IOP ≤ 15 mmHg without medications, and a qualified surgical success as IOP ≤ 15 mmHg with or without medications. RESULTS: Pre-washout IOP median values (mmHg) were 17 (ABeC), 18 (miniABeC) and 17 (AbiC) and decreased at 12-month follow up postoperatively to 13 (p = 0.005), 13 (p = 0.004) and 14 (p = 0.008), respectively-successful treatment was achieved in approximately 100% of patients for ABeC and in 93.8% for both miniABeC and AbiC groups. Preoperatively, the median number of medications was 2.0 (range 1-3) (ABeC), 2.0 (1-3) (miniABeC) and 2.0 (0-4) (ABiC); 12-month post-operatively, all medications were withdrawn except in two patients (followed miniABeC and AbiC). CONCLUSIONS: The three variants of canaloplasty significantly reduced IOP and the number of medications in patients with mild to moderate POAG and gave no significant complications.

Sutureless technique for repositioning and scleral fixation of the capsular bag-intraocular lens complex with permanent use of iris retractors.

A new sutureless technique used for repositioning and scleral fixation of the capsular bag-intraocular lens (IOL) complex in the surgical treatment of subluxated lenses is described. Iris retractors were used not only to induce a tent effect on the capsule but also to permanently fix the capsular bag to the sclera in this method, without the need to prepare scleral or conjunctival flaps. Surgery with the use of a capsular tension ring (CTR) and iris retractors, the ends of which were brought out through the sclera and cauterized, was performed in 7 eyes of 7 patients with moderate or severe subluxation of the crystalline lens. In all cases, simultaneous use of a CTR and iris retractors ensured good centration of the capsular bag-IOL complex. The method was safe and effective in fixing the capsule to the sclera in the case of significant damage to the ligamentous apparatus of the lens.

Using the entropy of the corneal pulse signal to distinguish healthy eyes from eyes affected by primary open-angle glaucoma.

OBJECTIVE: The purpose of this study was to evaluate whether the complexity of the corneal pulse (CP) signal can be used to differentiate patients with primary open-angle glaucoma (POAG) from healthy subjects. APPROACH: The study sample consisted of 28 patients with POAG and a control, age-matched group of 30 subjects. After standard ophthalmic examination, the CP signal from a randomly selected eye of each participant was measured using non-contact ultrasonic micro-displacement measurement technology. After pre-processing, the complexity of the CP signal was estimated using refined composite multiscale fuzzy entropy (RCMFE) up to scale factor 50. The average RCMFE values were computed from three repeated measurements of the CP signals for each participant and each scale factor. MAIN RESULTS: The complexity of the CP signal in glaucomatous eyes was higher than that observed in healthy ones. Also, RCMFE of the CP signal was found to differentiate (statistically significantly) between the two groups for scales in the range from 26 to 43. For these scales, the one for which the lowest p-value (t-test, p = 0.017) was obtained when comparing RCMFE between the two groups was selected as the optimal scale. Next, a receiver operating characteristic analysis for the optimal scale showed that the proposed approach of calculating the multiscale entropy of the CP signal has some potential to discriminate between patients with POAG and healthy controls (sensitivity, specificity and accuracy of 0.643, 0.700 and 0.672, respectively). SIGNIFICANCE: In conclusion, RCMFE, as a complexity measure, may be considered an auxiliary indicator to support glaucoma diagnostics.

Changes in spectral parameters of corneal pulse following canaloplasty.

PURPOSE: To ascertain whether changes in the spectral content of the corneal pulse (CP) signal, measured in vivo in primary open-angle glaucoma (POAG) patients, indirectly reflect changes in corneal biomechanics after canaloplasty. METHODS: Fifteen eyes of 15 POAG patients who underwent canaloplasty combined with phacoemulsification were enrolled. Standard ophthalmic examinations were conducted before washout, pre-operatively, at days 1, 7, and 1, 3, 6, and 12 months after surgery. Non-contact measurements of the CP signal were performed at pre-washout, pre-operatively, and at 3, 6, and 12 months post-operatively. Then, amplitudes of the CP first five harmonics associated with the heart rate were estimated. Temporal changes of all considered parameters were tested at a Bonferroni-adjusted significance level set to 0.005. RESULTS: A decrease in the amplitude of the first harmonic and an increase in the normalized amplitude of the third harmonic (ACP3n) of the CP signal were noticed between the pre-washout and the pre-operative stages (p = 0.003 and p = 0.004, respectively). This corresponds to an increase in median intraocular pressure (IOP) values by 6.0 mmHg (p = 0.0045). After surgery, ACP3n reached the highest value at 3 months post-operatively, compared with pre-washout level (p = 0.0045). CONCLUSIONS: Alterations in corneoscleral stiffness caused by surgery are reflected in changes in the ACP3n value. Hence, post-operative corneal biomechanics could be monitored indirectly by this supporting indicator that can be used to estimate the time at which measures of IOP are no longer biased by the changed cornea boundary conditions caused by canaloplasty. CLINICAL TRIALS REGISTRATION: NCT02908633.