Analysis of different types of anesthesia in descemet membrane endothelial keratoplasty

PURPOSE

The purpose of this study is to compare the safety and clinical results of descemet membrane endothelial keratoplasty (DMEK) in topical, peribulbar or general anesthesia.

METHODS

This is a retrospective, post hoc matched study of 120 patients having received DMEK surgery with different types of anesthesia (n = 40 topical, n = 40 peribulbar, n = 40 general anesthesia). Endpoint criteria were intraoperative complications, endothelial cell count, central corneal thickness and graft rejection rate, rebubbling rate and best-corrected visual acuity after 1, 3 and 6 months.

RESULTS

The group with topical anesthesia showed more often intraoperative difficulties such as vitreous pressure (p < 0.05), difficult graft unfolding (p = 0.14) and patient restlessness (p = 0.07). However, all three groups achieved comparable functional visual results after 6 months (p = 0.96).

CONCLUSION

DMEK in topical anesthesia is feasible and shows comparable final visual results but should be restricted to selected cooperative patients and performed by experienced surgeons due to possible higher intraoperative challenges.

[Toxicity of heavy liquids]

BACKGROUND

Acute toxicity of perfluorocarbon liquids (PFCL) is a relevant problem in retinal surgery due to impurities in the medicinal product.

OBJECTIVE

This article gives an overview of the current problems, possible explanations, interactions with other medicinal products and approaches to improved patient safety.

RESULTS

Toxicity is caused by impurities in the raw material but can also be caused by interactions with other medicinal products or drugs. The current test procedures do not ideally represent the ophthalmological application but there are promising activities to set the course for the future.

CONCLUSION

The use of PFCL in retinal surgery is generally considered safe. Users should pay attention to the quality of medicinal products.

One-Year Safety and Performance Assessment of the Argus II Retinal Prosthesis: A Postapproval Study

Importance

The Argus II Retinal Prosthesis System is indicated for patients with vision loss due to severe to profound outer retinal degeneration, a group with few treatment options.

Objectives

To collect postapproval safety and visual function data for the Argus II.

Design, Setting, and Participants

Multicenter, postapproval clinical trial conducted at 9 sites in Germany and Italy. Data were collected from December 2, 2011, to September 30, 2017, and patients were followed-up for 12 months or longer. Patients were 25 years or older with severe to profound outer retinal degeneration, some residual light perception or the ability of the retina to respond to electrical stimulation, and a history of useful form vision and were already planning to undergo Argus II implantation.

Main Outcomes and Measures

The primary end point of this study was the nature and rate of adverse events. Secondary end points included 3 visual function tests: square localization (SL), direction of motion, and grating visual acuity (GVA).

Results

Forty-seven patients were followed for 12 months or longer after implant. Mean (SD) age was 56 (12) years, 37 (79%) had retinitis pigmentosa, and 27 (57%) were male. Through the first 12 months postimplantation, 23 patients (49%) experienced 51 nonserious adverse events and 12 (26%) experienced 13 serious adverse events (SAEs), 9 of which were judged to be related to the Argus II, and 4 of which were judged to be related to the procedure. The most common SAE was conjunctival erosion, reported in 4 patients. No significance testing was done for group analysis for the SL or direction-of-motion tests. When averaged across the group, patients' accuracy on the SL test, but not on the direction-of-motion test, appeared better when the Argus II was on than when it was switched off. For GVA, more patients at each point in time achieved the 2.9 GVA cutoff in the implanted eye when the Argus II was on compared with it switched off.

Conclusions and Relevance

Safety and visual function outcomes in this clinical practice setting cohort of patients with Argus II implants were consistent with previously reported results. Longer follow-up of these patients and data from additional patients are required to better outline the risks and benefits of this approach to addressing blindness secondary to severe-to-profound outer retinal degeneration.

Trial Registration

ClinicalTrials.gov identifier: NCT01490827.

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.

[Acute monocular loss of vision : Differential diagnostic considerations apart from the internistic etiological clarification]

We report the case of acute painless monocular loss of vision in a 53-year-old man. An interdisciplinary etiological evaluation remained without pathological findings with respect to arterial branch occlusion. A reevaluation of the patient history led to a possible association with the administration of phosphodiesterase type 5 inhibitor (PDE5 inhibitor). A critical review of the literature on PDE5 inhibitor administration with ocular participation was performed.

First Simultaneous Explantation and Re-Implantation of an Argus II Retinal Prosthesis System

A 59-year-old blind woman with retinitis pigmentosa had undergone implantation of an Argus II system without complications and took advantage of the system for 7 months. Due to a technical error of the system, the glasses of the prosthesis developed increased heat generation, making the use of the system unbearable. Because of the initial satisfaction and high motivation of the patient, it was decided to strive for an implant exchange. In a 4-hour surgery session, the implant was removed and a new system was implanted. Hereby, several critical surgery steps could be identified that are important to consider for future surgeries. Besides a strong fibrotic scarring of conjunctiva and tenon aggravating the extraction of the extraocular components, the preparation of the sclerotomy proved to be difficult for achieving water tightness. Furthermore, the extraction of the retinal tack and the repositioning of the new array were challenging steps. During the postoperative course, a severe hemorrhagic choroidal detachment occurred but resolved without surgical intervention. The implant was well-placed and showed good function. The exchange of an Argus II is feasible, however, with the challenge of hypotony and hemorrhage as well as possible fibrosis complicating the repositioning of the chip. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:462-465.].

Age-Related Loss of Human Vitreal Viscoelasticity

Purpose

To determine the viscoelasticity of human vitreous bodies and its changes with age in order to benefit the understanding and therapy of vitreoretinal diseases.

Methods

In a postmortem study, 190 human vitreous bodies were extracted from 33- to 92-year-old donors, analyzed with regard to their viscoelastic properties via dynamic mechanical analyses, and compared with bovine and porcine vitreous. Postmortem intervals and donor-related parameters were examined as potential parameters influencing vitreous viscoelasticity. Dynamic moduli of different hyaluronic acid (HA) solutions as well as human vitreous treated with HA injections were determined by frequency sweep tests.

Results

With age the viscoelasticity of human vitreous bodies decreased significantly and independently of postmortem intervals, diabetes, and the donor's sex. The storage modulus G′ and loss modulus G″ correlated strongly with the donor's age with r = −0.789 and r = −0.764, respectively. Bovine and porcine vitreous bodies exhibited dynamic moduli comparable only to the viscoelastic properties of aged human vitreous and are thus limited models for the simulation of the human vitreous. The viscoelasticity of aged human vitreous bodies was found to be increased after intravitreal injections of highly concentrated HA.

Conclusions

The present postmortem study is the first to show a significant age-related reduction in the viscoelasticity of entire human vitreous bodies. Highly concentrated HA injections may serve as a possible therapeutic approach for restoring the viscoelasticity of aged vitreous bodies.

Translational Relevance

These findings improve the understanding and therapy of the vitreous liquefaction with age and the associated vitreoretinal diseases.

Retinal Anatomy and Electrode Array Position in Retinitis Pigmentosa Patients After Argus II Implantation: An International Study

PURPOSE

To assess the retinal anatomy and array position in Argus II retinal prosthesis recipients.

DESIGN

Prospective, noncomparative cohort study.

METHODS

Setting: International multicenter study.

PATIENTS

Argus II recipients enrolled in the Post-Market Surveillance Studies.

PROCEDURES

Spectral-domain optical coherence tomography images collected for the Surveillance Studies (NCT01860092 and NCT01490827) were reviewed. Baseline and postoperative macular thickness, electrode-retina distance (gap), optic disc-array overlap, and preretinal membrane presence were recorded at 1, 3, 6, and 12 months.

MAIN OUTCOME MEASURES

Axial retinal thickness and axial gap along the array's long axis (a line between the tack and handle); maximal retinal thickness and maximal gap along a B-scan near the tack, midline, and handle.

RESULTS

Thirty-three patients from 16 surgical sites in the United States and Germany were included. Mean axial retinal thickness increased from month 1 through month 12 at each location, but reached statistical significance only at the array midline (P = .007). The rate of maximal thickness increase was highest near the array midline (slope = 6.02, P = .004), compared to the tack (slope = 3.60, P < .001) or the handle (slope = 1.93, P = .368). The mean axial and maximal gaps decreased over the study period, and the mean maximal gap size decrease was significant at midline (P = .032). Optic disc-array overlap was seen in the minority of patients. Preretinal membranes were common before and after implantation.

CONCLUSIONS

Progressive macular thickening under the array was common and corresponded to decreased electrode-retina gap over time. By month 12, the array was completely apposed to the macula in approximately half of the eyes.

Retinal Toxicity of Medical Devices Used during Vitreoretinal Surgery: A Critical Overview

Retinal toxicity/biocompatibility of medical devices in direct contact with the retina is an important subject for clinicians and scientists. As these effects are not very frequent, there is also a relative lack of information for many clinicians. The past has taught us multiple times that there is a significant safety problem associated with severe loss of vision in affected patients. In this review, we want to classify medical products that are used in the back of the eye, describe recent examples of toxicity, critically reflect on the regulations that exist and suggest improvements that can be done to ensure patient safety without hindering innovation.

METHODS

Critical review of the recent papers and personal experience of the authors in this issue. Medical devices used in the back of the eye and recent examples of toxicity are described, regulations that exist are critically reflected and improvements suggested that can ensure patient safety without hindering innovation.

RESULTS

There is clear evidence of toxicity after intraocular surgery in any category. Some cytotoxic indirect methods have failed in detecting this toxicity. Some ISO rules do not seem appropriate. Postmarketing safety is missing. There is little data on this issue.

CONCLUSIONS

The absence of a clear regulation of the production, purification and evaluation of the toxic effects of the medical devices supposes the possibility that products are not sufficiently safe to obtain the CE mark.

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.

Long-Term Visual Acuity and its Predictors after Cataract Surgery in Patients with Uveitis

Purpose.

To analyze the outcomes of phacoemulsification and posterior intraocular lens (IOL) implantation in patients with uveitis and to determine factors responsible for poor visual outcome.

Methods.

The records of 155 patients (180 eyes) with uveitis who had phacoemulsification and IOL implantation between August 2001 and March 2008 were examined retrospectively. Best-corrected visual acuity (BCVA) was recorded at the immediate preoperative visit and at follow-up examinations every 3 months. At each postoperative visit, a complete ophthalmologic examination was performed. The postoperative visual outcomes and complications were analyzed. Univariate regression analysis was done to determine risk factors for poor visual acuity during follow-up.

Results.

The mean follow-up was 31.4 months (range 3–78 months). An underlying systemic disease was present in 70 (45.2%) patients (82 eyes, 45.6%). The mean preoperative logMAR BCVA was 1.13±0.62 (95% CI: 0.85–1.02) and increased to 0.42±0.57 (95% CI: 0.32–0.59) at last medical visit (p<0.001). A total of 107 eyes (59.4%) had postoperative complications including posterior capsular opacification, newly developed macular edema, recurrence of uveitis, macular epiretinal membrane, and deposits on the IOL surface. Preoperatively observed macular lesions was the factor most strongly associated with poor visual outcome after cataract surgery (odds ratio: 5.43; 95% CI: 3.41–7.34; p<0.001). Anterior segment pathologies, age at surgery, etiology of uveitis (idiopathic, uveitis associated systemic disease), and gender did not influence visual rehabilitation after surgery (p>0.05).

Conclusions.

The outcomes of phacoemulsification and IOL implantation in patients with uveitis were satisfactory. Patients with observed preoperative macular lesions are at risk for poor visual outcome.

Calculating the individual probability of successful ocriplasmin treatment in eyes with VMT syndrome: a multivariable prediction model from the EXPORT study

Background/Aims

To evaluate predictive factors for the treatment success of ocriplasmin and to use these factors to generate a multivariate model to calculate the individual probability of successful treatment.

Methods

Data were collected in a retrospective, multicentre cohort study. Patients with vitreomacular traction (VMT) syndrome without a full-thickness macular hole were included if they received an intravitreal injection (IVI) of ocriplasmin. Five factors (age, gender, lens status, presence of epiretinal membrane (ERM) formation and horizontal diameter of VMT) were assessed on their association with VMT resolution. A multivariable logistic regression model was employed to further analyse these factors and calculate the individual probability of successful treatment.

Results

167 eyes of 167 patients were included. Univariate analysis revealed a significant correlation to VMT resolution for all analysed factors: age (years) (OR 0.9208; 95% CI 0.8845 to 0.9586; p<0.0001), gender (male) (OR 0.480; 95% CI 0.241 to 0.957; p=0.0371), lens status (phakic) (OR 2.042; 95% CI 1.054 to 3.958; p=0.0344), ERM formation (present) (OR 0.384; 95% CI 0.179 to 0.821; p=0.0136) and horizontal VMT diameter (µm) (OR 0.99812; 95% CI 0.99684 to 0.99941, p=0.0042). A significant multivariable logistic regression model was established with age and VMT diameter.

Conclusion

Known predictive factors for VMT resolution after ocriplasmin IVI were confirmed in our study. We were able to combine them into a formula, ultimately allowing the calculation of an individual probability of treatment success with ocriplasmin in patients with VMT syndrome without FTHM.

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.

[Vitreous Substitute in Retinal Detachment Surgery - Why We Need a New Tamponade Strategy]

Pars plana vitrectomy combined with an endotamponade is the most important concept in retinal detachment surgery. Numerous advances in techniques and tamponade materials have been made, but the general problems of retinal detachment surgery are still unsolved: The primary success rate is not adequate, and there is no adequate strategy to address proliferative vitreoretinopathy, multiple retinal breaks or persistent hypotony. The story of tamponades is full of myths and misunderstandings. A critical review shows that tamponades have only a minor role in the history of retinal detachment surgery. One might assume that the value of tamponades is overestimated. This may be because the underlying concept is limited: All available tamponades are hydrophobic, so they act by buoyant force and surface tension. This narrow focus on the hydraulic function allows only one tamponade vector and makes complete filling of the vitreous body space impossible. The hydrophobic character of the materials has fundamental disadvantages that tend to increase the risk of new breaks or PVR formation. Thus, a critical revaluation of the value of current tamponades is necessary. One solution might be to develop hydrogels as vitreous body substitute. Such a hydrophilic vitreous body substitute fits the natural and complex function of a juvenile, healthy vitreous much better than gas or silicone oil.

Switch to aflibercept or ranibizumab after initial treatment with bevacizumab in eyes with neovascular AMD

Background

To evaluate changes in central macular thickness (CMT) and visual outcome in patients with neovascular age-related macular degeneration (AMD) treated initially with bevacizumab and subsequently switched to either aflibercept or ranibizumab.

Methods

Observational clinical study was performed. We measured the structural outcome (CMT on SD-OCT; μm) and the visual outcome (best corrected visual acuity (BCVA); logMAR), as follows: before treatment (at baseline), following bevacizumab treatment (switch follow-up) and after switching from bevacizumab to aflibercept- or ranibizumab treatment (final follow-up, AG/, RG).

Results

From a total of 96 eyes treated with intravitreal injections of bevacizumab (10.5 ± 7.6 (mean ± SD)), 58 eyes switched to aflibercept (6.5 ± 3.9; AG) and 38 eyes switched to ranibizumab (7.1 ± 5.3; RG) (≥ 3 injections, each). In addition, these eyes were compared to 37 eyes under bevacizumab monotherapy.

Primary outcome: In the AG, the CMT decreased slightly from 430 ± 220 μm at baseline to 419 ± 212 μm at switch follow-up (p = 0.86), but decreased significantly to 318 ± 159 μm at final follow-up, AG (p < 0.0001). In the ranibizumab group (RG), the CMT increased from 396 ± 174 μm at baseline to 499 ± 333 μm at switch follow-up (p = 0.012), but decreased significantly to 394 ± 202 μm at final follow-up, RG (p = 0.007).

Secondary outcome: In the AG, the mean BCVA worsened from logMAR 0.57 ± 0.33 at baseline to 0.63 ± 0.30 at switch follow-up and improved slightly to 0.53 ± 0.71 at final follow-up, AG (p = 0.46). In the RG, mean BCVA worsened from 0.57 ± 0.28 at baseline to 0.64 ± 0.31 at switch follow-up and improved slightly to 0.60 ± 0.36 at final follow-up, RG (p = 0.64).

Conclusion

Switching from bevacizumab to either aflibercept, or ranibizumab, has a strong anatomical effect in eyes with neovascular AMD. Nevertheless, even if the switch to aflibercept shows a minimal functional benefit over that to ranibizumab, visual prognosis remains limited.