Vision loss associated with silicone oil endotamponade in vitreoretinal surgery - a review.

PURPOSE: To clarify the definition, prevalence and classification of different types of unexplained vision loss associated with silicone oil (SO) endotamponades (SO in situ (SOIS) or after removal of SO (ROSO)) in vitreoretinal surgery and identifying the most specific clinical findings and suggesting possible causes. METHODS: Review of the literature regarding randomized clinical trials (RCTs), retrospective case-control, cohort studies and case series evaluating the risk of using SO, published in English between 1994 and 2023, conducting a computer-based search of the following databases: PubMed, Web of Science, Scopus and Embase. The search was supplemented using the Medline option 'Related Articles' and consulting review articles on the topic. RESULTS: Findings from reported clinical examinations in SOIS and ROSO are analyzed and finally different theories regarding the underlying pathophysiology are described. From the clinical point of view, findings have been found in OCT, OCTA, microperimetry and electrophysiological studies. Other clearly identifiable causes of vision loss related to the use of SO are listed and commented as differential diagnosis. Finally, the different physiopathological theories of the two types of causes of unexplained vision have been analyzed. CONCLUSION: Unexpected vision loss under or after SO tamponade (SOIS and ROSO) is a significant concern which is probably underestimated because it is not a clearly defined and known entity. The most frequently described changes were in the ganglion cell complex but this unexpected vision loss remains a serious and unexplained concern for vitreoretinal surgeons and should be identified by clinicians, addressed by manufacturers and reported to Health Authorities as a serious incident according to the new regulation.

Clinical Experience of Two Sutureless Intrascleral Fixation Techniques for Secondary Intraocular Lens Implantation.

INTRODUCTION: The aim of this study was to evaluate the outcome of the modified Carlevale intraocular lens (IOL) fixation technique, using two different vitrectomy ports (23- vs. 27-gauge) as anchor fixation. METHODS: Retrospective, consecutive study of 282 eyes (282 patients) who underwent a secondary IOL implantation using the Carlevale IOL (Soleko IOL Division, Italy) with two anchor haptics for intrascleral implantation with either 23- or 27-gauge (G) port. RESULTS: Transient post-operative ocular hypotonia (intraocular pressure ≤5 mm Hg) was observed less in the 27-G group (13 vs. 4 patients, p = 0.057) three requiring additional tunnel sutures (2 cases for 23-G; 1 case 27-G). Post-operative vitreous haemorrhage was recorded more often in the 23-G group (8 vs. 1 patient, p = 0.034), but all cases in both groups resolved without intervention. Visual acuity did improve post-operatively in the two groups. No post-operative complications such as retinal detachment, endophthalmitis, and IOL-dislocation tilt were observed in the follow-up. CONCLUSION: The 27-G modified technique for sutureless intrascleral implantation is simple and effective and causes less post-operative hypotony.

MODIFIED SUTURELESS INTRASCLERAL FIXATION TECHNIQUE FOR SECONDARY INTRAOCULAR LENS IMPLANTATION: A Pilot Study.

BACKGROUND/PURPOSE: To demonstrate possible complications of a new intraocular lens for sutureless secondary scleral implantation and modifications of the surgical technique to optimize outcomes. METHODS: A retrospective study of 16 eyes (16 patients) who underwent a secondary intraocular lens implantation using the Carlevale intraocular lens (Soleko, Italy) with two anchor haptics for intrascleral implantation (mean follow-up 2.2 months). RESULTS: The visual acuity did not improve statistically significantly postoperatively ( P = 0.601). Seven (44%) patients suffered from postoperative hypotonia (intraocular pressure <5 mmHg) during the first three postoperative days. CONCLUSION: Owing to the early postoperative hypotony, we decided to modify the surgical technique. We present several suggestions to optimize the technique and outcome such as positioning the sclerotomies at the 2 and 8 o'clock positions, using 27 G trocars alone and suturing the frown incisions using self-resorbing sutures.

Efficacy of a new fragmentation pattern in femtosecond laser-assisted cataract surgery with the Ziemer FEMTO LDV Z8.

PURPOSE: To determine the efficacy of different fragmentation patterns in femtosecond laser-assisted cataract surgery (FLACS) using Ziemer FEMTO LDV Z8. METHODS: We compared three different types of surgery: conventional cataract surgery (CCS), FLACS with conventional radial slices (named No-Spiderweb), and FLACS with a novel fragmentation pattern (radial slices combined with one or two rings) called "Spiderweb." Visual acuity (VA), nuclear opacity (NO) according to the Lens Opacities Classification System (LOCS lll), effective phacoemulsification time (EPT) and vacuum time were obtained for 845 eyes. RESULTS: Using FLACS (Spiderweb + No-Spiderweb), EPT was significantly reduced by 26% compared to CCS (FLACS: 2.46 ± 2.60 s; CCS: 3.34 ± 2.89 s; ΔM = - 0.88 s, p < .001). Furthermore, EPT as a function of progression of lens opacity was found to be not only lower in Spiderweb compared to CCS, but also in comparison with No-Spiderweb. At NO3, a significant reduction of 65% in EPT was observed by using Spiderweb compared to CCS (Spiderweb: 0.68 ± 1.23 s; CCS: 1.96 ± 1.53 s; ΔM = - 1.28 s, p <.001). Interestingly, EPT at NO3 was also significantly reduced by 57% in Spiderweb compared to No-Spiderweb (Spiderweb: 0.68 ± 1.23 s; No-Spiderweb: 1.57 ± 1 .59 s; ΔM = - 0.90 s, p <.001). The use of Spiderweb only marginally extends the vacuum time compared to No-Spiderweb by 11 s (Spiderweb: 209.13 ± 35.83 s; No-Spiderweb: 198.35 ± 36.84 s; p = .003) and the postoperative improved VA showed no significant difference among the different types of surgery (all ps ≥ .05). CONCLUSION: FLACS significantly reduces EPT compared to CCS. Furthermore, the novel Spiderweb pattern significantly reduces EPT in patients with a cataract of NO3 compared to CCS, but also to FLACS with the existing radial pattern (No-Spiderweb).

[Acquired Cataracts]. / Erworbene Katarakte.

Senile or age-related cataract is well known to ophthalmologists and also to colleagues in other medical specialties. Age-related cataract represents the most common cause of blindness worldwide but can be treated very successfully by a standard outpatient surgery. Far less common and therefore less known is the acquired cataract that can present a diagnostic and surgical challenge. The following article provides the reader with an overview of secondary acquired cataracts. The most common subtypes are mentioned first and then discussed in more detail so that the reader should have a structured knowledge after reading this article. This article focuses on acquired cataracts primarily in adults and highlights the surgical features including perioperative characteristics.

Novel vitreous substitutes: the next frontier in vitreoretinal surgery.

PURPOSE OF REVIEW: After removing the native vitreous during vitreoretinal surgery, an adequate substitute is required to ensure homeostasis of the eye. Current clinically used endotamponades (silicone oil, gases, semifluorinated alkanes) are effective in promoting retinal reattachment, but lead to complications such as emulsification, prolonged inflammation, blurred vision, raised intraocular pressure, cataract formation or the need for revision surgery. The aim of this review is to provide an update on novel vitreous substitutes with a focus on polymer-based systems. RECENT FINDINGS: Polymeric hydrogels provide favourable properties such as high water content, optical transparency, suitable refractive indices and densities, adjustable rheological properties, injectability, biocompatibility and their ability to tamponade the retina via viscosity and swelling pressure, comparable to the native human vitreous body. Here, vitreous replacement strategies can be divided into chemically or physically crosslinked hydrogel systems that are applied as preformed or in-situ gelling matrices. SUMMARY: Several hydrogel-based vitreous substitutes have already been positively evaluated in preclinical tests and have the potential to enter the clinical phase soon.

Effectiveness of immediate vitrectomy and intravitreal antibiotics for post-injection endophthalmitis.

PURPOSE: To show that an immediate vitrectomy with an intravitreal injection of antibiotics can be an effective approach for the treatment of acute endophthalmitis following intravitreal injections. METHODS: We reviewed all cases of clinical endophthalmitis caused by an intravitreal injection that were treated in our department between March 2012 and November 2019. Only patients that underwent a vitrectomy within 6 h after presentation to the clinic and with a documented visual acuity shortly before the causative event were included. Baseline best-corrected visual acuity (BCVA) before the causative event was compared to BCVA measured within a follow-up period of 8 months (up to 14 months). RESULTS: In total, 30 eyes of 30 patients were included. The BCVA before the intraocular infection was a mean value of 0.55 logMAR, and the BCVA on the day of the endophthalmitis decreased significantly to 1.66 logMAR. Within 2 months following the pars plana vitrectomy (PPV), the mean BCVA improved to 0.83 logMAR. Eight months following PPV (mean value, 8.20 months; SD, 3.59 months), the mean BCVA was 0.63 logMAR. In the last follow-up interval most of the eyes recovered, and the BCVA did not differ significantly from baseline. Two eyes underwent further pars plana surgery during the follow-up period. No enucleation was required. CONCLUSION: In this study, we have shown that an immediate vitrectomy with subsequent intravitreal injection of antibiotics is an effective option for treating post-injection endophthalmitis and frequently results in recovery of vision; thus, it should be performed as early as possible, where available.

Predictive factors for the IOP reduction in phacocanaloplasty with suprachoroidal drainage.

PURPOSE: Although the pressure-reducing effect of cataract surgery alone is not very high, it is often cited in the literature. Some authors describe predictive factors correlated with the IOP (intraocular pressure) reduction: in particular noteworthy are age, axial length, preoperative pressure level and the ratio of preoperative pressure/anterior chamber depth. The aim of this study was to determine the applicability of these predictive factors to phacocanaloplasty with suprachoroidal drainage. Setting Eye Clinic Sulzbach Germany. DESIGN: Retrospective study with a 12-month follow-up, including patients that underwent phacocanaloplasty with suprachoroidal drainage between 2012 and 2014. METHODS: Preoperatively, baseline information was collected (including age, diagnosis, medication), and the patients underwent a basic examination and optical biometry. To investigate the relationship between preoperative parameters and the IOP reduction, Pearson's correlation analysis and linear regression were used. Patients with missing data pre- or postoperatively were excluded from the analysis. RESULTS: The study comprised 89 patients. Mean preoperative IOP was 23.0 ± 5.3 mmHg with 4.0 different antiglaucomatous eye drops. After 12 months, IOP was reduced to 12.1 ± 1.4 mmHg with a median medication of 0.0. The preoperative IOP and the ratio of preoperative IOP/anterior chamber depth were identified as predictive factors. There was no influence of axial length and anterior chamber depth. CONCLUSION: Unlike in cataract surgery, anterior chamber depth and axial length have no influence on the pressure reduction caused by phacocanaloplasty. However, a strong predictive factor is the preoperative pressure level. The higher the preoperative IOP, the greater the postoperative pressure reduction.

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.

Investigating retinal toxicity of a lutein-based dye in a model of isolated and perfused bovine retina.

PURPOSE: Retidyne™ is a new lutein-based dye for internal limiting membrane staining. It uses the intrinsic staining characteristics of lutein which is already known to act as an antioxidant and blue-light filter in the human retina. We investigated retinal tolerance to different staining times measured by the electroretinogram (ERG) of an isolated and perfused retina whole mount. METHODS: For functionality, testing bovine retinas were prepared and perfused with an oxygen saturated standard solution and the ERG was recorded until stable b-wave amplitudes were reached. Then the perfusion was stopped and Retidyne™ was applied directly onto the retinal surface for exposure times of 60 or 120 s. After restarting the perfusion with standard solution, the ERG amplitudes were monitored for 75 min. To investigate the effects on photoreceptor function alone, 1 mM asparate was added to block b-waves. RESULTS: For an exposure time of 60 s amplitudes of a- and b-waves remained stable throughout the experiment. Exposure times of 120 s caused an initial drop of amplitudes that reached statistical significance only for a-waves (a, - 21%, p = 0.047; b, - 14%, p = 0.052). This effect was only seen during the first minutes of the washout and the ERG recovered completely. CONCLUSIONS: In the model of isolated and perfused bovine retina, Retidyne™ showed a good safety profile for common intraoperatively used staining times. An initial toxic effect regarding the transient drop of amplitudes cannot be ruled out but the effect might also be explained by the partial blockage of the flashlight due to a more intense staining effect at the beginning of the washout.

NEGATIVE EFFECTS OF VITAL DYES AFTER UNEVENTFUL VITREOMACULAR SURGERY.

PURPOSE: Vital dyes have become a clinical standard during chromovitrectomy but toxicity remains an issue. We compared the clinical outcome of one supposedly toxic vital dye (AV 17 with 5% mannitol) with a standard vital dye (MBB Dual) and performed a power analysis for future comparative studies. METHODS: Retrospective analysis of 270 eyes after chromovitrectomy with internal limiting membrane peeling because of macular holes. Primary endpoint was loss in BCVA >2 lines and photoreceptor atrophy as seen on optical coherence tomography examination. RESULTS: In 173 eyes, staining of the epiretinal membrane and extracellular matrix was performed using MBB (Group A), and in 97 using AV 17-M (Group B). The mean BCVA was not significantly different after more than 3 months and also not in the early postoperative period after surgery between Group A and Group B. The number of patients suffering from a decline in BCVA of two lines and more was not significantly higher in patients of Group B. There was not a significantly higher percentage of patients with an inner segment/outer segment defect. CONCLUSION: Our rather homogeneous study showed no significant difference between both dyes. Thousand five hundred patients would need to be examined to find a significant difference in future studies.

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 Use of a Microsensor in Therapy of Amblyopia]. / Der Einsatz eines Mikrosensors in der Amblyopietherapie.

Amblyopia is one of the most common visual disorders in children. Current therapy of amblyopia is an occlusion therapy of the stronger eye with an occlusion patch until the best corrected visual acuity is achieved. The success of occlusion therapy essentially depends on the compliance of the children and their parents. There is a commercially available 8 × 12 mm small TheraMon microsensor (TheraMon-Chip, MC Technology GmbH). This sensor allows a simple objective documentation of the therapy compliance of patches and glasses. It samples the surrounding temperature in regular intervals. Due to the specific temperatures, it is possible to detect the time of application and, therefore, the compliance. Therefore, TheraMon microsensor could be a study-related approach for monitoring the compliance and further leading to possible improvement of application time protocols in amblyopia therapy.

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.

Suprachoroidal drainage with collagen sheet implant- a novel technique for non-penetrating glaucoma surgery.

PURPOSE: Our purpose was both to introduce the new technique of suprachoroidal drainage with collagen sheet implantation as a novel technique of non-penetrating glaucoma surgery and to present first results of a prospective pilot study. METHODS: A superficial rectangular sclera flap of half-scleral thickness sized 4 × 4.5 mm is dissected anteriorly until clear cornea. Then, a second scleral flap is created underneath the first one sized 3.5x4mm and is cut down full-thickness to the choroid exposing the suprachoroidal space. The flap is then bluntly prepared until the scleral spur is reached. Sharp dissection above the sclera spur exposes Schlemm's canal, which is located directly anteriorly. Schlemm's canal is unroofed, juxtacanalicular meshwork is peeled and the deep flap is cut off at its base. An absorbable collagen sheet (Ologen®, Dahlhausen, Cologne, Germany) is placed into the suprachoroidal space at the level of the ciliary body, and the superficial sclera flap is sutured tightly to prevent leakage. RESULTS: We prospectively analyzed 65 eyes that underwent suprachoroidal drainage with collagen sheet implantation. Mean reduction of intraocular pressure after 3 months was 35.1% (from 21.0 ± 4.3 mmHg to 13.5 ± 3.4 mmHg)(p < 0.01) and after 12 months 35.6% (from 21.0 ± 4.3 mmHg to 13.5 ± 3.0  mmHg)(p < 0.01). The number of topical IOP-reducing medication decreased significantly from 3.5 ± 0.7 to 0.6 ± 0.9 and to 0.9 ± 1.1 after 3 and 12 months, respectively (p < 0.01). No serious complications occurred. CONCLUSION: Suprachoroidal drainage with collagen sheet implantation seems to be a safe and effective surgical technique for non-penetrating glaucoma surgery that yields the opportunity of a sufficient IOP reduction for eyes unsuitable for canaloplasty.

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.

Predictive factors for functional improvement following intravitreal bevacizumab injections after central retinal vein occlusion.

PURPOSE: Vision loss in central retinal vein occlusion (CRVO) is mostly caused by macular edema (ME) and can be treated with intravitreal bevacizumab injections. The goal of this study was to identify predictive factors for improvement in visual acuity. METHODS: Three hundred and sixteen eyes of six centres having received intravitreal bevacizumab for ME due to CRVO were enrolled in this multicentre, retrospective, interventional case series. The follow-up time was 24 to 48 weeks. Investigated patient characteristics were pretreatment, duration of CRVO prior to the first injection, initial best-corrected visual acuity (BCVA), baseline central retinal thickness as measured by optical coherence tomography, gender, eye, age, comorbidity with glaucoma, systemic hypertension, or diabetes mellitus. RESULTS: Multiple regression analysis confirmed the following baseline predictive factors for an increase in visual acuity: low BCVA (p < 0.001), high CRT (p < 0.02), and treatment naïve patients (p = 0.03). None of the other investigated patient characteristics could be identified as prognostic factors for increase in visual acuity (p > 0.1). CONCLUSIONS: Intravitreal injections of bevacizumab in a routine clinical setting effectively improved and stabilized BCVA in CRVO. Our large multicenter study identified initial BCVA, baseline CRT, and pre-treatment as prognostic factors for visual improvement.

Investigation of a novel implantable suprachoroidal pressure transducer for telemetric intraocular pressure monitoring.

Intraocular Pressure (IOP) is an important and modifiable risk factor for glaucoma progression. IOP fluctuations and spikes often remain undetected despite clinical routine examinations. Therefore telemetric IOP measurement systems with continuous IOP monitoring can provide major advantages in glaucoma surveillance. To the best of our knowledge, this is the first study to investigate implantable telemetric suprachoroidal IOP sensors. Six novel telemetric pressure transducers were implanted in the suprachoroidal space of 6 eyes from 6 New Zealand White rabbits. Functionality of each microsensor was verified 1, 4, 8, 12 and 30 weeks after implantation. After cannulation of the anterior chamber different intracameral pressure levels were generated using a height adjustable water column. Telemetric assessed IOP and intracameral pressure were analysed using scatter plots and Bland-Altman analysis (95% CI). Mean bias (limits of agreement) 1, 4, 8, 12 and 30 weeks after implantation was 0.14 mmHg (-2.04 to 2.31 mmHg), 0.01 mmHg (-2.83 to 2.86 mmHg), 0.62 mmHg (-2.08 to 3.32 mmHg), 0.47 mmHg (-3.04 to 3.98 mmHg) and 0.33 mmHg (-2.75 to 3.42 mmHg) respectively. Ophthalmological examinations showed no signs of conjunctival, scleral, choroidal or retinal lesions. Histological analyses revealed a small band of fibrosis next to the implantation site but showed no signs of inflammation, necrosis or other pathologies. Implantable telemetric suprachoroidal pressure sensors provided promising concordance between telemetric and intracameral IOP values. Clinical and histological examinations revealed good biocompatibility 30 weeks after implantation. A major advantage of the suprachoroidal approach is that the anterior chamber stays unaffected during implantation. Therefore the procedure can be performed regardless of the lens status and any anterior chamber pathologies.

Ex-vivo-examination of ultrastructural changes in organotypic retina culture using near-infrared imaging and optical coherence tomography.

Optical coherence tomography (OCT) dramatically changed the way of diagnostic assessment in retinal diseases during the last years. Using this technique in-vivo in-depth analysis of the retina and its layers is possible. Since animal research is changing by intrinsic and extrinsic pressure to animal-(in-vivo)-free methods, we adapted OCT-measurements to organotypic cultures. An easy to use protocol was generated to assess standardized OCT assessments in organotypic culture. First, two custom-made devices need to be made to change any commercially available OCT for examinations in humans into a device allowing ex-vivo analyses of organotypic culture. The modification is feasible within seconds. After OCT measurement of the ex-vivo tissues, quantitative evaluation of the retinas were performed via ImageJ software. OCT pictures of ex-vivo retinas were obtained for time periods of seven days and the thickness of retinal tissue was evaluated. The reproducibility of the pictures and measurements was very high (SD < 15%). In conclusion, an easy to use protocol for the investigation of different effects on retinal cultures with commercially available OCT devices was successfully established.

A modified scleral dissection technique with suprachoroidal drainage for canaloplasty.

PURPOSE: A modified canaloplasty technique is described that may facilitate the surgical procedure and potentially maximizes the intraocular pressure (IOP)-lowering effect by altering both the trabecular and uveoscleral aqueous outflow. METHODS: The second deeper layer in the modified technique (about 3.5 × 4 mm, Fig. 1a, b) is not prepared in a lamellar fashion, but is cut down full-thickness to the choroid, hence opening the suprachoroidal space. Furthermore, this second deep scleral flap creates an additional aqueous outflow and drainage into the suprachoroidal space, thus possibly lowering the postoperative IOP by improving the natural uveoscleral outflow facility. RESULTS: Seventy-eight eyes operated with this modified technique in the last 12 months were retrospectively analysed. Mean IOP before surgery was 19.10 mmHg and patients applied 3.0 topical medications. Twelve months after surgery, the IOP was 13.5 mmHg and patients applied 1.0 topical medication; 52.6 % of patients did not use any topical therapy. DISCUSSION: The modified dissection canaloplasty technique potentially improves the IOP-lowering effect due to the creation of additional suprachoroidal drainage and simplifies the most complicated step of the surgery, as the scleral spur and the Schlemm's canal can be located using suprachoroidal access.