"Predicting intraocular lens tilt using a machine learning concept".

OBJECTIVE: Aim of this study was to use a combination of partial least squares regression and a machine learning approach to predict IOL tilt using pre-operative biometry data. SETTING: Patients scheduled for cataract surgery at the Kepler University Clinic Linz. DESIGN: Prospective single center study. METHODS: Optical coherence tomography, autorefraction and subjective refraction was performed at baseline and 8 weeks after cataract surgery. In analysis I only one eye per patient was included and a tilt prediction model was generated. In analysis II a pair-wise comparison between right and left eyes was performed. RESULTS: In analysis I 50 eyes of 50 patients were analysed. Difference in amount, orientation and vector from pre- to post-operative lens tilt was -0.13°, 2.14° and 1.20° respectively. A high predictive power (variable importance for projection) for post-operative tilt prediction was found for pre-operative tilt (VIP=2.2), pupil decentration (VIP=1.5), lens thickness (VIP=1.1), axial eye length (VIP=0.9) and pre-operative lens decentration (VIP=0.8). These variables were applied to a machine learning algorithm resulting in an out of bag score of 0.92°. In analysis II 76 eyes of 38 patients were included. The difference of pre- to post-operative IOL tilt of right and left eyes of the same individuum was statistically relevant. CONCLUSION: Post-operative IOL tilt showed excellent predictability using pre-operative biometry data and a combination of partial least squares regression and a machine learning algorithm. Pre-operative lens tilt, pupil decentration, lens thickness, axial eye length and pre-operative lens decentration were found to be the most relevant parameters for this prediction model.

Unilateral intraindividual comparison and bilateral performance of a monofocal spherical and diffractive extended depth of field intraocular lens mix-and-match approach.

BACKGROUND: To evaluate the intraindividual visual performance of a spherical and extended depth of field (EDOF) IOL used in a mix-and-match approach. METHODS: Single centre (tertiary care centre), retrospective consecutive case series. Included patients had uneventful cataract surgery with implantation of a spherical monofocal IOL (CT Spheris 204) in the dominant eye and a diffractive EDOF IOL (AT LARA 829) in the non-dominant eye. Monocular and binocular defocus curves and visual acuity at various distances were assessed. In addition, binocular reading speed, contrast sensitivity, and patient satisfaction using QOV, Catquest 9SF, and glare/halo questionnaires are reported. RESULTS: A total of 29 patients (58 eyes) were included. We observed significant intra-individual differences for monocular DCIVA, DCNVA, UIVA, and UNVA. There were no differences in monocular BCDVA or UDVA. The monocular defocus curves for the two IOLs significantly differed at defocus steps between -1.0 and -3.5 D. 93.10% of patients reported they would opt for the same combination of IOLs. CONCLUSION: Excellent uncorrected and corrected distance visual acuity was demonstrated in both groups. The mix-and-match approach described in this study yielded good intermediate vision and improved near vision with high-patient satisfaction.

Enhancing Scleral Buckling Surgery Using an Illuminated Scleral Depressor.

PURPOSE: To report a technique for scleral buckling surgery under the operating microscope with wide-field viewing. METHODS: The identification and reliable marking of retinal breaks is one of the key steps for successful surgery in scleral buckling. For sufficient visualization of retinal breaks, some kind of indentation and illumination is necessary. In this technique, one instrument (Visible Periphery illuminated scleral indentor; Oertli Instrumente AG, Switzerland) combines scleral depression, illumination, and color marking (using a surgical marking pen) of the corresponding sclera above the retinal break. RESULTS: The illuminated scleral depressor enables the surgeon to safely and precisely mark the retinal break while stabilizing and rotating the eye with the other hand. This technique simplifies scleral buckling surgery by improving the handling and visualization of marking retinal breaks at the corresponding scleral. Neither intraoperative indirect ophthalmoscopy nor sclerotomies for chandelier light systems or any intraocular instrument are necessary. CONCLUSION: The illuminated scleral depressor facilitates scleral buckling surgery in a convenient way for easy and precise scleral marking of the retinal breaks even in challenging situations and positions of retinal breaks under the operating microscope with wide-field viewing. Indirect ophthalmology or other illumination sources are no longer needed.

Evaluating the Treatment of Diabetic Macular Edema with Aflibercept Based on a Regional Network of Ophthalmologic Care Givers.

Purpose: In Austria, anti-VEGF therapies are reimbursed only in clinical settings. This study aimed to describe the outcome of a treat and extend regimen (TER) with aflibercept for diabetic macular edema (DME) in a network of practitioners. Methods: In a prospective study over 36 months, patients with DME were treated with a loading dose of aflibercept and further on with adjusted treatment intervals based on optical coherence tomography (OCT) findings. All patients were monitored in an outpatient setting by regional ophthalmologists, and the treatment was administered in the clinic. Main outcome parameters were best-corrected visual acuity (BCVA) from baseline to the last regular visit. Number of visits at the practitioner's office as well as the number of injections were secondary outcome parameters. Results: Thirty-three patients completed the study at their final visit. BCVA improved significantly by 5.8 letters between baseline and the final visit from 70.4 letters at baseline (p=0.004). Patients visited the practitioner's office 12.8 times in the observation period of 36 months. 3.7, 5.1, and 3.9 visits were performed, respectively, in the first, second, and third years, and 25.5 ± 7.9 injections were performed. The mean interval of injections over the observation period was 6.2 ± 2.2 in weeks. Conclusion: The treat and extend regimen was valuable for treating patients with DME in this specific setting. The functional results of this study were comparable to those of other real-world evaluations. Adherence to the same treating institution seems to be important to avoid differences in therapeutic decision making and may also increase patient's compliance.

Late onset of a persistent, deep stromal and endothelial scarring after corneal collagen crosslinking for keratoconus: A case report.

INTRODUCTION: To report a late onset, deep stromal and endothelial corneal scar in a keratoconus patient after corneal collagen cross-linking (CXL). CASE DESCRIPTION: Observational case report. A 29-year-old man with bilateral keratoconus received an accelerated (A-CXL 10*9) epithelium-off CXL procedure in the left eye.6-months postoperatively, a 2.2 × 1.2 mm inferocentral corneal scar was detected, which was located in the posterior stroma ranging from approximately 350 µm until the endothelium, therefore was situated below the demarcation line. A topical corticosteroid treatment did not influence the magnitude or configuration of the scar. Visual acuity was never affected, which includes the examination 12 months postoperatively. CONCLUSIONS: We report a case of a late onset deep stromal and endothelial corneal scar 6 months after accelerated CXL as postoperative complication without affecting visual acuity.

Project Hyperopic Power Prediction II: The Effects of Second Eye Refinement Methods on Prediction Error in Hyperopic Eyes.

PURPOSE: The purpose of the study was to evaluate the potential accuracy of different second eye refinement methods in a patient cohort with short axial eye length to assess the performance of intraocular lens (IOL) power calculation schemes in high hyperopes. METHODS: The study design was a single-center, single-surgeon retrospective consecutive case series. The setting of the study was in Augen- und Laserklinik, Castrop-Rauxel, Germany. Patients were assessed after uneventful bilateral cataract surgery implanting either spherical (SA60AT) or aspheric (ZCB00) IOLs. Inclusion criteria were an axial eye length of ≤21.5 mm and/or emmetropizing IOL power of >28.5 dpt. Outcome measures were the mean absolute prediction error (MAE), median absolute prediction error, mean prediction error with standard deviation, median prediction error, and the percentage of eyes with an absolute prediction error (absPE) within 0.25 dpt, 0.5 dpt, 0.75 dpt, or 1.0 dpt. Second eye refinement was performed using the first eye prediction error, either with a correction coefficient of 0.50 (SER1), or an individual coefficient optimized for MAE. RESULTS: A total of 55 patients were assessed. A statistically significant reduction in the absPE after the application of SER1 was observed in 9 of 13 formulae. The SER1 refined Hoffer Q, refined Holladay I, refined Holladay II, refined Kane, refined Okulix, and refined PEARL-DGS provided a smaller absPE than other methods. CONCLUSION: In this patient cohort with a short axial eye length, the second eye refinement led to a lower MAE in almost all formulae. The use of refinement in Kane, Okulix, PEARL-DGS, and Castrop formulae exhibited the lowest MAE.

Project hyperopic power prediction: accuracy of 13 different concepts for intraocular lens calculation in short eyes.

PURPOSE: To evaluate the accuracy of intraocular lens (IOL) power calculation in a patient cohort with short axial eye length to assess the performance of IOL power calculation schemes in strong hyperopes. METHODOLOGY: The study was a single centre, single surgeon retrospective consecutive case series at the Augen- und Laserklinik, Castrop-Rauxel, Germany. Inclusion of patients after uneventful cataract surgery implanting either spherical (SA60AT) or aspheric (ZCB00) IOLs. Inclusion criteria were axial eye length <21.5 mm and/or emmetropising IOL power >28.5 D. Lens constants were optimised on a separate patient cohort considering the full bandwidth of axial eye length. Data of one single eye per patient were randomly included. The outcome measures were: mean absolute prediction error (MAE), median absolute prediction error, mean prediction error with SD and median prediction error and the percentage of eyes with an MAE within 0.25 D, 0.5 D, 0.75 D and 1.0 D. RESULTS: A total of 150 eyes from 150 patients were assessed. Okulix, PEARL-DGS, Kane and Castrop provided a statistically significantly smaller MAE compared with the Hoffer Q and SRK/T formulae. CONCLUSION: In our patient cohort with short axial eye length, the use of PEARL-DGS, Okulix, Kane or Castrop formulae showed the lowest MAE. The Castrop formula has not been published before, but will be disclosed with a ready-to-use Excel sheet as an addendum to this paper.

Efficacy of a Disease Management Program of a Tertiary Center and Ophthalmologic Practitioners for the Treatment of Neovascular Age-Related Macular Degeneration.

PURPOSE: The aim of the study was to examine real-world data of patients with neovascular age-related macular degeneration (nAMD) within a disease management program (DMP) treated with anti-VEGF. METHODS: A monocentric, retrospective chart review of 379 eyes of a local DMP was conducted at the Department of Ophthalmology, Kepler University Clinic Linz. Eyes were treated either with bevacizumab or aflibercept using a pro re nata scheme, consisting of 3 injections every 4 weeks in case of presence of disease activity. The observational period was up to 24 months. Disease activity was monitored by visual acuity (VA), clinical examination, and optical coherence tomography (OCT). For (re-)treatments, ophthalmologic practitioners referred patients directly to the intravitreal injection, avoiding redundant examinations. RESULTS: VA improved significantly for all patients after 2 months (logMAR 0.47 ± 0.36; p = 0.000) compared to baseline (0.55 ± 0.37), and for the aflibercept group for up to 6 months (0.36 ± 0.27; p = 0.018). After 12 months, VA remained stable without further significant improvement and decreased by 24 months compared to baseline. The median number of injections was 6 over the first 12 months and 4 in the second year. CONCLUSION: Data revealed the efficacy of a DMP for nAMD involving both ophthalmologic practitioners and a tertiary center. Avoiding redundant examinations increased the efficacy of a clinical setting.

Rotational Stability, Tilt and Decentration of a New IOL with a 7.0 mm Optic.

Purpose: To evaluate rotational stability, tilt and decentration of a new monofocal IOL with a 7.0 mm optic and frame haptics.Methods: Prospective post-market clinical follow-up study at the Kepler University Hospital Linz, Austria. An Aspira-aXA (HumanOptics, Germany) was implanted in 74 eyes of 42 cataract patients. The lens was manufactured with toric markings. IOL rotational stability was evaluated by comparing its position at the end of surgery (EoS) versus 1 day, 1 week, 1 month and 4 months postoperatively. IOL tilt and decentration were measured using a Scheimpflug camera at 1 week, 1 month and 4 months.Results: Median absolute IOL rotation was 1.42 degrees (n = 52; mean = 2.18 ± 2.23°) within 1 day after surgery and was significantly higher compared to all later intervals (median <1.0 degree; P = .001). At the 4 months follow-up, IOL rotation was within 5.0 degrees in 85% of the eyes (n = 40) and within 10.0 degrees in 98% (n = 46) of the eyes. The only eye with an IOL rotation of ≥ 10.ty0 degrees (EoS vs. 1 day) had an AL of 26.45 mm. At the last follow-up, the IOL vertical and horizontal tilt referenced to the pupillary axis was in average less than 1.5 degrees in both eyes (n = 54; maximum 5.85°). Decentration in both meridians was on average less than 0.10 mm in both eyes (maximum 0.30 mm).Conclusion: The one-piece Aspira-aXA IOL showed good and stable positioning within the capsular bag over a 4 months period.

Leber's hereditary optic neuropathy: Diagnostic pitfalls in genetic testing.

PURPOSE: To investigate the possibility and consequences of false positive testing for Leber's hereditary optic neuropathy (LHON) using repeated testing. METHODS: In three cases of suspected LHON, initial mutation analysis using restriction fragment length polymorphism (RFLP) and direct sequencing showed rare mtDNA mutations at nt 14482 in two cases and a mutation in nt 14484 in the third case which has been associated with a mild variant of LHON. All three patients consulted a specialized neuro-ophthalmology center for a second opinion. During the examinations the clinical diagnosis of LHON was questioned. Therefore the initial DNA samples were reevaluated again using the same probes. RESULTS: The reevaluation by the testing laboratory of the DNA samples of the three patients revealed misinterpreted initial results and could show that there were no LHON typical mutations in none of the three patients. CONCLUSION: A high level of suspicion is important when an accumulation of rare mutations occurs. It is only because of the attentiveness of a specialized neuro-ophthalmologist and the testing laboratory that the diagnosis of LHON was averted. Every laboratory testing can produce false positive results. Therefore, we emphasize that a positive test should be confirmed by a second independent laboratory, at least if the clinical findings seem not to be typical for LHON.

Precision and refractive predictability of a new nomogram for femtosecond laser-assisted corneal arcuate incisions.

PURPOSE: Validating a new nomogram for low to moderate astigmatism (0.75 D to 2.5 D) correction with epithelium- and Bowman-penetrating femtosecond laser-assisted arcuate incisions. METHODOLOGY: Prospective, interventional case series at the Augen- und Laserklinik, Castrop-Rauxel, Germany. Cataract patients with low to moderate corneal astigmatism were treated with femtosecond laser-assisted arcuate incisions. Patients with previous refractive corneal treatment were excluded. Outcome assessment was based on manifest refraction, astigmatic vector analysis and visual acuity. RESULTS: The study analysed 43 eyes of 33 patients after three months and 35 eyes of 27 patients after 12 months. After 12 months, 100% of all eyes treated had ≤1.0 D and 97% ≤0.5 D of subjective residual astigmatism. Mean residual astigmatism was 0.27 D. 90% of all eyes were within one line of difference between UDVA and CDVA. SEQ Mean Absolute Error was 0.26 D and SEQ. Mean error was -0.08 ± 0.32 D. CI was 0.98 ± 0.2 D, and Index of Success, 0.20 ± 0.18 D. CONCLUSION: The Castrop nomogram showed results that are comparable to or better than results presented in the literature for existing nomograms. Our results for astigmatic reduction are comparable to published results for TIOL implantation. It seems to be a predictable and safe measure to reduce manifest astigmatism.

Stability of a non-applanating handheld liquid patient interface for femtosecond laser-assisted cataract surgery.

PURPOSE: A stable and reliable vacuum is crucial for the correct planning and performance of femtosecond laser-assisted cataract surgery (FLACS) in order to avoid complications such as suction loss and cyclorotation. This study investigates, for the first time, the impact of different vacuum levels on the stability of the application of a liquid patient interface for FLACS in view of break-away forces. METHODS: Break-away forces were measured using a multifunctional material testing machine with a mounted digital manometer. Sixteen porcine eyes were docked to the patient interface of a femtosecond laser platform (FEMTO LDV Z8), and the impact of different vacuum levels between 300 and 500 mbar investigated. RESULTS: Mean break-away forces for each vacuum level were as follows: 1.78 N (± 0.58 N) for 300 mbar; 2.24 N (± 0.68 N) for 350 mbar; 2.66 N (± 0.68 N) for 400 mbar; 2.86 N (± 0.77 N) for 420 mbar; and 3.49 N (± 0.86 N) for 500 mbar. CONCLUSION: The stability increases with the vacuum in a nearly linear manner. Vacuum levels higher than 500 mmHg and lower than 350 mmHg are not recommended for FLACS.

Aqueous humour cytokine changes during a loading phase of intravitreal ranibizumab or dexamethasone implant in diabetic macular oedema.

PURPOSE: To determine the effect of intravitreal ranibizumab and a dexamethasone implant on aqueous humour cytokine, protein and enzyme levels and to correlate findings to morphologic and functional changes. METHODS: In a prospective, randomized, controlled, double-blind study, patients with clinically significant diabetic macular oedema (CSME) were randomly allocated to receive either monthly intravitreal injections of ranibizumab (Lucentis, Novartis Pharma) or a single dexamethasone implant (Ozurdex, Pharm-Allergan) at baseline (BL). Aqueous humour samples were collected at BL and weeks 2, 8 and 20. RESULTS: The study included 18 eyes of 18 patients. In the dexamethasone implant group, soluble intercellular adhesion molecule 1 (sICAM-1) (weeks 2 and 8), CXCL9/monokine induced by gamma interferon (MIG) (weeks 2 and 8), soluble vascular cell adhesion protein 1 (sVCAM-1) (weeks 2 and 8) and monocyte chemo-attractant protein 1 (MCP-1) (week 2) levels were significantly decreased compared with baseline. In the ranibizumab group, placental growth factor (PIGF) (week 2) and vascular endothelial growth factor (VEGF) (week 2 and 8) levels were significantly decreased compared with baseline. No significant changes in central retinal thickness (CRT) or Early Treatment Diabetic Retinopathy Study (ETDRS) best corrected visual acuity (BCVA) were observed in the Ozurdex group at any time-points. ETDRS scores significantly increased at week 20 (84.88 ± 8.88 letters) compared with baseline (74.78 ± 14.85 letters), and the CRT decreased significantly at week 4 (381.00 ± 114.64 µm) compared with baseline (440 ± 144 µm) in the Lucentis group. CONCLUSION: The dexamethasone implant affected the aqueous cytokines and proteins MCP-1, sICAM-1, sVCAM-1 and MIG, whereas ranibizumab treatments reduced VEGF and PIGF levels. Morphological changes may diverge from cytokine changes. Results may indicate a rationale for a combination therapy for CSME using both agents, the dexamethasone implant and repeatedly administered ranibizumab injections.

Impact of Patient Interface Diameter and Vacuum Level on Suction Stability Using a Flat Applanating Interface for Femtosecond Laser-Assisted LASIK.

PURPOSE: To investigate the impact of different patient interface (PI) diameters and different vacuum levels on the suction stability during vacuum application for femtosecond laser-assisted LASIK. METHODS: Break-away forces as a marker for suction stability were measured by an automated test bench set-up. The test bench was based on a customized stamp connected to a digital load cell. Three flat applanating PI with different diameters (8.5, 9.5 and 10.0 mm) and four different vacuum levels (500, 600, 700 and 800 mbar) were investigated using the FEMTO LDV Z8 (Ziemer Ophthalmic Systems AG, Switzerland). RESULTS: Mean break-away force was 5.23N (±0.99N) using the 8.5 mm PI and 500 mbar vacuum, 8.18N (±1.39N) using the 8.5 mm PI and 800 mbar, 3.37N (±0.56N) using the 10.0 mm PI and 500 mbar, and 6.14N (±0.68N) using the 10.0 mm PI and 800 mbar vacuum (p < .001; CI95%). Increasing the PI diameter from 8.5 to 10.0 mm resulted in a 28.89% (+1.97 ± 1.02N) lower break-away force (p < .001) when using default vacuum settings (700 mbar) compared to increasing vacuum from 500 to 800 mbar, which resulted in a 60.37% (+1.95 ± 1.40N) higher mean break away force (p < .001). CONCLUSION: The vacuum level and the diameter of the PI showed significant impact on suction stability measured as break-away force during flat applanating docking for corneal and refractive surgery. Break-away forces were inversely related to the PI diameter and directly to the vacuum level. Increasing the PI diameter by one step or reducing vacuum by 100 mbar resulted in a comparable decrease of break-away forces. Therefore, the surgeon could potentially maintain stabile suction by increasing vacuum when choosing a larger PI diameter to obtain a larger treatment zone. Furthermore, reduction of the PI diameter and/or increasing vacuum could help improving suction stability in situations of poor suction and in situations with increased risk of suction loss during LASIK.

Impact of baseline IOP, vacuum, and different docking mechanisms, and their interaction on IOP rise in femtosecond laser-assisted refractive and cataract surgery.

PURPOSE: To study the intraocular pressure (IOP) variation during vacuum and docking of femtosecond laser application. SETTING: Department for Ophthalmology, Kepler University Hospital, Johannes Kepler University Linz, Austria. DESIGN: Experimental study. METHODS: Intracameral intraocular pressure (IOP) was monitored in 30 porcine ex vivo models using a dual femtosecond laser platform (VICTUS). Five different baseline IOP levels (10 to 30 mm Hg) were assessed during fluid-filled (liquid) docking, full-contact (applanating) docking, and vacuum application without docking. RESULTS: Raising the baseline intracameral IOP from 10 to 30 mm Hg increased the IOP from 27.55 mm Hg ± 5.93 (SD) to 56.85 ± 6.10 mm Hg in the fluid-filled docking group, and from 60.91 ± 8.41 mm Hg to 90.11 ± 6.64 mm Hg in the full-contact docking group. The full-contact docking procedure per se (excluding vacuum effect) increased the IOP by 61.7% (+36.58 ± 5.84 mm Hg). In contrast, fluid-filled docking (excluding vacuum effect) raised the IOP by only 3.1% (+0.72 ± 2.71 mm Hg). Each 5 mm Hg reduction of baseline IOP resulted in a mean IOP reduction of 7.33 ± 3.05 mm Hg in the fluid-filled group, and 7.30 ± 6.88 mm Hg in the full-contact docking group (P < .001). Decreasing baseline intracameral IOP from 15 to 10 mm Hg resulted in the highest IOP reduction between all subgroups (P < .01). CONCLUSIONS: Baseline IOP, docking procedures, and vacuum influenced IOP during femtosecond laser application in a synergistic manner. Lowering the baseline intracameral IOP resulted in a significantly lower IOP during fluid-filled docking for cataract surgery and full-contact docking for refractive surgery. Full-contact (applanating) docking resulted in a significantly higher IOP elevation compared with similar IOP values found during fluid-filled (liquid) docking and the application of the suction ring alone without docking.

Preoperative intraocular pressure as a strong predictive factor for intraocular pressure rise during vacuum application in femtosecond laser-assisted cataract surgery.

PURPOSE: To evaluate the effect of preoperative intraocular pressure (IOP) and the vacuum level on IOP during femtosecond laser-assisted cataract surgery. METHODS: Intraocular pressure was measured in 40 enucleated porcine eyes by intracameral manometry prior, during and after vacuum application using the VICTUS femtosecond laser platform (Bausch&Lomb, Technolas Perfect Vision GmbH, Germany). Twenty combinations of different preoperative IOP levels (12, 16, 20 and 24 mmHg) and different vacuum levels (350-550 mbar) were investigated. RESULTS: Multivariate regression analysis indicated that both the vacuum level (beta = 0.138; p < 0.001) but much stronger the preoperative IOP (beta = 0.861; p < 0.001) were predictive factors for IOP rise during vacuum application. Mean IOP was 28.23 ± 3.86, 34.23 ± 3.92, 40.35 ± 4.41 and 46.82 ± 4.11 mmHg in groups with baseline IOP of 12, 16, 20 and 24 mmHg, respectively. In the 350, 450 and 550 mbar group, and mean IOP was 35.85 ± 7.85, 37.33 ± 7.90 and 39.00 ± 8.04 mmHg, respectively. Lowering the preoperative IOP by 2 mmHg and reducing the vacuum from maximum to minimum resulted in a similar reduction in IOP during vacuum application (-3.10 ± 0.79 mmHg versus -3.15 ± 0.88 mmHg; p = 0.015). Furthermore, decreasing the baseline IOP from 20 to 12 mmHg resulted in a 30.0% reduction in intraoperative IOP. CONCLUSION: Preoperative IOP was a stronger predictive factor for intraoperative IOP rise than the applied vacuum level. Measurements and critical interpretation of preoperative IOP in a preliminary examination could help estimating the individual risk of significant IOP rise during femtosecond laser-assisted cataract surgery and could help taking early countermeasures in selected cases. Due to the porcine ex vivo model, further studies are needed to verify these findings.

Favourable outcome after late reorientation of an upside-down Descemet Membrane Endothelial Keratoplasty (DMEK) graft: a case report.

BACKGROUND: Clinical outcome after successful reorientation of an upside-down implanted DMEK (Descemet Membrane Endothelial Keratoplasty) graft 4 weeks after initial transplantation. CASE PRESENTATION: A 71-year-old woman presented with Fuchs' endothelial corneal dystrophy for DMEK. After initial DMEK the donor graft was fully attached and well centred during intracameral gas filling. When the gas bubble was fully resorbed the graft started to detach. Therefore, two intracameral gas injections were consecutively performed. During the second re-bubbling, an upside-down orientation was observed and so the graft was flipped, centred, re-attached and finally stabilized by an intracameral gas bubble. Three weeks after reorientation slit lamp examinations showed a well centred and attached graft, endothelial cells that started functioning and a patient's visual acuity of 20/40. Visual acuity increased to a 20/32 vision in the observed eye three months later and further improved to 20/20 6 months after reorientation and stayed stable between 20/32 and 20/20 during the remaining 15 months of follow-up, with a clear and well-attached graft. CONCLUSION: Reorientation of an upside down DMEK graft was successful even 4 weeks after initial DMEK. Visual recovery and endothelial cell count increase were stepwise noticed during the first 6 months and 15 months after reorientation, respectively. Finally a favourable outcome with 20/32 to 20/20 vision at least 6 months after graft reorientation was achieved. Therefore, restoring full graft function could last several weeks or even months following (late) reorientation of an upside-down DMEK graft.

The effect of canaloplasty with suprachoroidal drainage combined with cataract surgery - 1-year results.

PURPOSE: The purpose of this study was to investigate the safety and efficacy of phacocanaloplasty with suprachoroidal drainage (PCscD) and to compare its intraocular pressure (IOP)-lowering and drug-sparing effect to canaloplasty with suprachoroidal drainage (CscD). METHODS: The study retrospective interventional study included patients with open-angle glaucoma or secondary forms of glaucoma who underwent either CscD or PCscD between the year 2011 and 2014 in Knappschaft Eye Clinic Sulzbach. Primary end-points were IOP reduction and the number of IOP-lowering medication after 12 months. Secondary end-points were intraoperative and postoperative complications. RESULTS: A total of 328 eyes were included, 193 were treated with CscD and 135 underwent PCscD. Canaloplasty with scD achieved an IOP reduction of 37.0% (from 20.9 ± 3.6 mmHg to 13.2 ± 2.6 mmHg) after 1 year, whereas PCscD showed a significant higher reduction of 47.4% (from 23.2 ± 5.1 mmHg to 12.2 ± 1.7 mmHg). Reduction in IOP-lowering medication was higher after PCscD (from 3.6 ± 0.6 to 0.2 ± 0.5) than after CscD (from 3.5 ± 0.8 to 0.7 ± 1.0). Twelve months after surgery 55.5% in the CscD group and 80.2% in the PCscD group were free of IOP-lowering medication. In both groups, no severe or sight-threatening complications occurred. CONCLUSION: Combining cataract surgery and CscD achieves a higher IOP reduction, and patients postoperatively need less IOP-lowering medication than after CscD alone.

Implantation and testing of a novel episcleral pressure transducer: A new approach to telemetric intraocular pressure monitoring.

Measurement of intraocular pressure (IOP) is an essential tool in monitoring glaucoma. Single IOP assessments during clinical routine examinations represent punctual values and are not able to identify IOP fluctuations and spikes. Telemetric IOP measurements are able to monitor IOP during the day and night, and are location-independent. Six telemetric episcleral IOP sensors were investigated after minimally invasive subconjunctival implantation in 6 eyes of 6 New-Zealand-White rabbits. Three of the 4 edges of the implant were fixated intrasclerally with non-absorbable sutures. The sutures were stitched into the edges of the implants' silicone rubber encasements. Telemetric IOP measurements were validated 1 week, 4 weeks, 8 weeks, 12 weeks and 30 weeks after implantation. For each validation the anterior chamber was cannulated and connected to a height-adjustable water column. Different intracameral pressure levels (10-45 mmHg) were generated by height adjustment of the water column. Measurement reliability and concordance between telemetric and intracameral IOP was validated using Bland-Altman analysis. Overall comparison (10-45 mmHg) between telemetric and intracameral pressure revealed a standard deviation of ±1.0 mmHg. A comparison of pressure values in the range between 10 and 30 mmHg revealed a standard deviation of ±0.8 mmHg. Device deficiency was related to follow-up length: 4 weeks after implantation, 3 of the 6 sensors showed malfunction, with all sensors having failed 30 weeks after implantation. The most likely reason for the sensor malfunction is the loss of hermeticity as a result of penetration of the encasement during the episcleral fixation, resulting from the lack of preformed suture holes at the implants encasement. However, no clinical signs of injury or inflammation of the conjunctiva, sclera, implantation site or any other involved structures were observed, except for an expected mild short-term irritation postoperatively. The episcleral pressure transducer for telemetric IOP monitoring is able to assess IOP without the need for invasive intraocular surgery. Episcleral implantation is an easy and safe procedure and can be undone very easily, so even temporary implantation and IOP measurements could be possible in the future. Sensor malfunction over time is a problem that needs to be addressed. Improvements in sensor encapsulation and especially preformed suture holes could significantly decrease the failure rate and increase durability.

Comparison of intraocular pressure during the application of a liquid patient interface (FEMTO LDV Z8) for femtosecond laser-assisted cataract surgery using two different vacuum levels.

BACKGROUND: To evaluate intraocular pressure (IOP) using the application of a novel liquid patient interface for femtosecond laser-assisted cataract surgery with the FEMTO LDV Z8. METHODS: IOP was evaluated in enucleated porcine eyes prior, during and after the application of the Femto LDV Z8 liquid patient interface (Ziemer Ophthalmic Systems, Switzerland) using intracameral cannulation (n=20), intravitreal cannulation (n=20), rebound tonometry (n=20) and indentation tonometry (n=20). Pressure was assessed prior vacuum, during vacuum (30 s, 1 min, 2 min, 3 min) and after releasing the vacuum (1 min and 2 min). Two groups with different predefined vacuum levels (350 mbar, 420 mbar) were investigated. RESULTS: Mean intracameral pressure (±SD) increased during vacuum application from 20 mm Hg to 52.00 mm Hg (±6.35mm Hg; p=0.005) and 45.18 mmHg (±4.34 mm Hg; p=0.005) for the 420 mbar and the 350 mbar vacuum levels, respectively. Mean intravitreal pressure increased from 20 mm Hg to 25.60 mm Hg (±9.85 mm Hg; p=0.058) and 28.10 mm Hg (±2.54 mm Hg; p=0.059) for the 420 mbar and the 350 mbar vacuum levels, respectively. Pressure values from indentation and rebound tonometry were in between intracameral and intravitreal values. Mean intracameral IOP was 18.1% higher (p=0.019) in the 420 mbar group compared with the 350 mbar group. CONCLUSION: During vacuum application of the liquid patient interface of the Femto LDV Z8 for femtosecond laser-assisted cataract surgery, IOP values were higher in the anterior chamber compared with the intravitreal pressure measurements. The higher predefined vacuum level (350 mbar vs 420 mbar) resulted in significant higher intracameral IOP.