New suture probe canaloplasty combined with suprachoroidal collagen implantation

PURPOSE

To present the modified surgery technique of new suture probe canaloplasty with a specially prepared monofilament 4.0 polypropylene suture combined with suprachoroidal drainage (ScD) and collagen sheet implantation for non-penetrating glaucoma surgery.

METHODS

Prospective study with a twelve months follow-up. A standard 4/0 polypropylene suture (ProleneTM by Ethicon; thickness: approximately 250 m) is cut and shaped with an ophthalmic knife (MANI® Crescent Knife, Mani Inc 8-3 Kiyohara Industrial Park, Utsunomiya, Tochigi 321-3231, Japan) to create a blunt end without sharp or compressed edges. This improves suture probe canaloplasty by providing a more stable and smoother probing device. Schlemm's canal is prepared using the standard technique of canaloplasty with suprachoroidal drainage. Then, instead of using the canaloplasty microcatheter or the previously published 6/0 double-helix suture, Schlemm's canal is probed with the blunt ending of the 4/0 Prolene suture. After successful 360-degree probing, a doubled 10/0 polypropylene tension suture is threaded through the tip of the 4/0 suture. The 4/0 suture is then pulled back and the 10/0 tension sutures are tied at both ends to tension Schlemm's canal. A special collagen sheet (Ologen®) is placed in suprachoroidal space, and the scleral flap is firmly sewed.

RESULTS

115 eyes were included in this prospective study. In 113 cases the Schlemm's canal could completely be probed with the suture probe and canaloplasty with ScD and collagen sheet implantation succeeded. In two cases the intervention was transformed to 360-degree suture trabeculotomy due to an intraoperative cheese-wiring. Twelve months after successful new suture probe canaloplasty with ScD and Collagen Implantation the IOP had decreased by 37.1% (from 21.6 ± 6.0 mmHg with 3.3 different IOP lowering eye drops to 13.5 ± 3.5 mmHg with 1.0 eye drops). 16 Patients did not achieve sufficient IOP levels and underwent 360-degree suture trabeculotomy during the follow-up. One patient had to be treated with further glaucoma surgery to achieve a sufficient IOP level. Complications were hyphema, postoperative IOP elevation and transient hypotony. No serious or sight-threatening complications occurred.

CONCLUSION

New suture probe canaloplasty with ScD and collagen sheet implantation yields the opportunity to conduct a cost-effective canaloplasty easier and less complicated than with the previously described method with the twisted 6/0 suture. The safety profile and IOP lowering effect is comparable. In cases where complete probing fails, there is still the opportunity to switch to suture trabeculotomy over the majorly probed part of Schlemm's canal. The pressure lowering effect of the deep sclerectomy with ScD and suprachoroidal collagen sheet implant seems to have an additional impact on the sufficient pressure lowering procedure.

Descemet Membrane Endothelial Keratoplasty (DMEK) Anesthesia Analysis

PURPOSE

Comparison of safety and clinical results of Descemet membrane endothelial keratoplasty (DMEK) in topical, peribulbar, or general anesthesia.

METHODS

Retrospective, post hoc matched study of 346 patients who received DMEK surgery with different types of anesthesia (n = 54 topical, n = 137 peribulbar, n = 155 general anesthesia). Outcome criteria were intraoperative complications, endothelial cell count (ECC), central corneal thickness (CCT) and graft rejection rate, rebubbling rate, and visual acuity (VA). Mean follow-up time was 9.4 ± 2.8 months.

RESULTS

The group with topical anesthesia showed intraoperative difficulties such as vitreous pressure (p = 0.01) and difficult graft unfolding (p = 0.4), possibly leading to a higher rebubbling rate (p = 0.03) and therefore graft failure (p = 0.39). However, rebubbling and graft failure occurred more often when the graft preparation was more difficult (p = 0.2, p = 0.13, respectively), which was independent of anesthesia. All three groups achieved comparable functional results regarding VA, ECC, and CCT after 6 months.

CONCLUSION

DMEK under topical anesthesia is feasible and shows comparable final visual outcomes but should be limited to selected cooperative patients and performed by experienced surgeons due to the potential for increased intraoperative challenges.

[Molecular diagnostics for vitreoretinal lymphoma]

Primary vitreoretinal lymphoma (PVRL) represents a subtype of intraocular lymphomas, which are a subgroup of malignant lymphomas of the eye. PVRL is considered a special form of primary diffuse large cell lymphoma (DLBCL) of the CNS (central nervous system) (PCNSL) and arises primary or secondary to PCNSL. According to the cell of origin (COO) classification of DLBCL, PVRL largely belongs to the activated B‑cell (ABC) type of DLBCL. Based on a recently established genetic-biological classification of DLBCL, PCNSL and thus also PVRL belong to a group of DLBCL of the MYD88/CD79B-mutated (MCD) or cluster 5 subtype, which often shows extranodal manifestations and MYD88 and CD79A mutations as well as CDKN2A deletions.PVRL diagnostics is often complicated as it represents a classic masquerade syndrome. Due to the usually limited material with often large numbers of reactive lymphocytes and/or degenerative changes in the cells, the results of diagnostic tests are difficult to interpret. Classic diagnostic tests include cytology on vitreous aspirates, immunocytochemistry, and clonality analysis.New insights into the spectrum of genetic alterations of vitreoretinal lymphomas (VRL) confirm the close relationship to PCNSL and could significantly improve pathological diagnosis. Next-generation sequencing panel-based diagnostics allow VRL diagnosis confirmation with little DNA in almost 100% of patients in cases with insufficient cytological evidence or lack of clonality detection. PVRL, as well as secondary vitreoretinal lymphomas after PCNSL or extracerebral DLBCL, have high mutation frequencies in characteristically mutated genes in PCNSL or MCD/cluster 5 type DLBCL. Supporting diagnostics, mutation detection can also be performed on cell-free DNA from the vitreous supernatant.

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.

A rabbit model for outer retinal atrophy caused by surgical RPE removal

PURPOSE

We aimed to establish a rabbit model with retinal atrophy induced by an iatrogenic retinal pigment epithelium (RPE) removal, for future testing of the efficacy and safety of cell therapy strategies.

METHODS

A localized detachment of the retina from the RPE/choroid layer was created in 18 pigmented rabbits. The RPE was removed by scraping with a custom-made extendable loop instrument. The resulting RPE wound was observed over a time course of 12 weeks with optical coherence tomography and angiography. After 4 days (group 1) and 12 weeks (group 2), histology was done and staining with hematoxylin and eosin, as well as immunofluorescence performed to further investigate the effects of debridement on the RPE and the overlying retina.

RESULTS

Already after 4 days, we observed a closure of the RPE wound by proliferating RPE and microglia/macrophage cells forming a multilayered clump. This pattern continued over the observation time course of 12 weeks, whereby the inner and outer nuclear layer of the retina became atrophic. No neovascularization was observed in the angiograms or histology. The observed changes were limited to the site of the former RPE wound.

CONCLUSIONS

Localized surgical RPE removal induced an adjacent progressive retinal atrophy. Altering the natural course of this model may serve as a basis to test RPE cell therapeutics.

Safety and effectiveness of pre-emptive diabetic vitrectomy in patients with severe, non-fibrotic retinal neovascularisation despite panretinal photocoagulation

OBJECTIVES

To investigate the safety and effectiveness of pre-emptive vitrectomy in eyes with severe non-fibrotic proliferative diabetic retinopathy.

METHODS

A multi-centre, retrospective, observational study. Pre-emptive vitrectomy was performed in non-fibrotic diabetic eyes with a visual acuity (VA) of 20/50 or better, where there was extensive persistent neovascularisation despite prior panretinal photocoagulation, and where the fellow eye had established sight loss despite vitrectomy for tractional complications. The primary outcome measure was the VA at last visit.

RESULTS

Twenty patients were included. The mean age was 39 ± 14 years. Fifteen patients were Type 1 diabetic. The median baseline VA was 20/30 and remained stable at 20/28 at last visit (median follow-up period: 24 months). Eight eyes (40.0%) developed post-operative vitreous cavity haemorrhage; 4 of which required a vitreous cavity washout procedure. There were no post-operative retinal detachments. The index eye remained the significantly better eye at all time points bar one month post-surgery. Regression of retinopathy grading was observed in all eyes.

CONCLUSION

In this pilot study, we found no sight loss with pre-emptive diabetic vitrectomy. Better eye status was maintained in this high-risk group. Further study with larger number of patients and longer-term follow-up is indicated.

Advances in Canaloplasty-Modified Techniques Yield Strong Pressure Reduction with Low Risk Profile

For decades, trabeculectomy (TE) was considered the gold standard for surgical treatment of open-angle glaucoma owing to its powerful intraocular pressure (IOP)-lowering potency. However, owing to the invasive nature and high-risk profile of TE, this standard is changing, and minimally invasive procedures are becoming more preferable. In particular, canaloplasty (CP) has been established as a much gentler alternative in everyday life and is under development as a full-fledged replacement. This technique involves probing Schlemm's canal with a microcatheter and inserting a pouch suture that places the trabecular meshwork under permanent tension. It aims to restore the natural outflow pathways of the aqueous humor and is independent of external wound healing. This physiological approach results in a significantly lower complication rate and allows considerably simplified perioperative management. There is now extensive evidence that canaloplasty achieves sufficient pressure reduction as well as a significant reduction in postoperative glaucoma medications. Unlike MIGS procedures, the indication is not only mild to moderate glaucoma; today, even advanced glaucoma benefits from the very low hypotony rate, which largely avoids a wipeout phenomenon. However, approximately half of patients are not completely medication-free after canaloplasty. As a consequence, a number of canaloplasty modifications have been developed with the goal of further enhancing the IOP-lowering effect while avoiding the risk of serious complications. By combining canaloplasty with the newly developed suprachoroidal drainage procedure, the individual improvements in trabecular facility and uveoscleral outflow facility appear to have an additive effect. Thus, for the first time, an IOP-lowering effect comparable to a successful trabeculectomy can be achieved. Other implant modifications also enhance the potential of canaloplasty or offer additional benefits such as the possibility of telemetric IOP self-measurement by the patient. This article reviews the modifications of canaloplasty, which has the potential to become a new gold standard in glaucoma surgery via stepwise refinement.

Safety and performance of a suprachoroidal sensor for telemetric measurement of intraocular pressure in the EYEMATE-SC trial

AIM

To investigate the safety and performance of a telemetric suprachoroidal intraocular pressure (IOP) sensor (EYEMATE-SC) and the accuracy of its IOP measurements in open angle glaucoma (OAG) patients undergoing simultaneous non-penetrating glaucoma surgery (NPGS).

METHODS

Prospective, multicentre, open-label, single-arm, interventional clinical trial. Twenty-four eyes of 24 patients with OAG regularly scheduled for NPGS (canaloplasty or deep sclerectomy) were simultaneously implanted with an EYEMATE-SC sensor. Six-month follow-up on the sensor's safety and performance as well as on the level of agreement between the EYEMATE-SC measurements and IOP measurements with Goldmann applanation tonometry (GAT).

RESULTS

The eyes underwent canaloplasty (n=15) or deep sclerectomy (n=9) and achieved successful implantation of the sensor. No device migration, dislocation or serious device-related complications occurred. A total of 367 comparisons were included in the IOP agreement analysis. The overall mean difference between GAT and EYEMATE-SC measurements was 1.31 mm Hg (lower limit of agreement (LoA) 7.55 mm Hg; upper LoA -4.92 mm Hg). The maximum difference of 2.5 mm Hg ±3.96 (LoA 0.30-2.29) was reached on day 10 and continuously improved to an agreement of -0.15 mm Hg ±2.28 (LoA -1.24 to 0.89) after 6 months. Accordingly, the percentage of eyes within an IOP difference of ±5 mm Hg improved from 78% (day 3) to 100% (6 months).

CONCLUSIONS

After 6 months, the EYEMATE-SC sensor was safe and well tolerated, and allowed continual IOP monitoring.

TRIAL REGISTRATION NUMBER

NCT03756662.

Safety and performance assessment of hyaluronic acid-based vitreous substitutes in patients with phthisis bulbi

PURPOSE

To assess the safety and performance of hyaluronic acid-based vitreous substitutes in phthitic eyes.

METHODS

In this retrospective interventional study a total of 21 eyes from 21 patients with phthisis bulbi were treated at the Eye Clinic Sulzbach between August 2011 and June 2021. Patients who underwent a 23G pars plana vitrectomy received a vitreous substitute composed of (I) a non-crosslinked hyaluronic acid (Healon GV), (II) a crosslinked hyaluronic acid-based hydrogel (UVHA), or (III) silicone oil (SO-5000). Main outcome measures were the intraocular pressure (IOP), the visual acuity and the structural integrity of the retina and choroid assessed by optical coherence tomography.

RESULTS

An increase in IOP ≥ 5 mmHg was achieved with SO-5000 in 5/8 eyes (6/10 interventions, 60.0%) for 36.4 ± 39.5 days, with Healon GV in 4/8 eyes (7/11 interventions, 63.6%) for 82.6 ± 92.5 days and with UVHA in 4/5 eyes (5/6 interventions, 83.3%) for 93.6 ± 92.5 days. Visual acuity increased in 5/21 eyes (23.8%), remained constant in 12/21 eyes (57.1%) and decreased in 4/21 eyes (19.0%). No enucleations were required during the mean follow-up time of 192 ± 182 days. The OCT images indicated the preservation of retinal structures, while choroidal folds were only diminished in UVHA eyes.

CONCLUSIONS

Hyaluronic acid-based hydrogels are biocompatible vitreous substitutes in humans and can increase and stabilize IOP in patients with phthisis bulbi for about 3 months.

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).

Recurrent corneal erosions related to an ocular injury 15 years before presentation

Purpose

To report the case of a patient who presented with recurrent corneal erosions caused by an undetected plastic foreign body in the upper eyelid, which had remained asymptomatic for nearly 15 years following an ocular injury.

Observations

A 39-year-old patient presented with recurrent corneal erosions and frontal headaches of unknown aetiology over the preceding eight months. The patient had previously been seen by twelve different ophthalmologists and had been treated over a 6-month period with a bandage contact lens, and therapeutic corneal scraping had been performed twice. However, the corneal erosion had repeatedly reappeared after removal of the bandage contact lens. On clinical examination prior to a planned phototherapeutic keratectomy, we extracted a 1.5 cm plastic foreign body, localised in the subtarsal area of the upper conjunctival fornix. Upon specific questioning, the patient denied any recent trauma, but reported a work-related accident with an accompanying eye injury 15 years before presentation.

Conclusions and importance

Posttraumatic foreign bodies in the eye may remain asymptomatic for prolonged periods before giving rise to clinical signs such as recurrent corneal erosions. Hence, a thorough clinical examination with meticulous eyelid eversion should always be performed in such patients.

Translation of hyaluronic acid–based vitreous substitutes towards current regulations for medical devices

PURPOSE

Hydrogel-based vitreous substitutes have the potential to overcome the limitations of current clinically used endotamponades. With the goal of entering clinical trials, the present study aimed to (I) transfer the material synthesis of hyaluronic acid-based hydrogels into a routine, pharmaceutical-appropriate production and (II) evaluate the properties of the vitreous substitutes in terms of the current regulations for medical devices (MDR/ISO standards).

METHODS

The multistep manufacturing process of the vitreous substitutes, including the modification of hyaluronic acid with glycidyl methacrylate, photocopolymerization with N-vinylpyrrolidone, and successive hydrogel purification, was developed under laboratory conditions, characterized using ¹ H-NMR, FT-IR and UV/Vis spectroscopies and HPLC, and transferred towards a pharmaceutical production environment considering GMP standards. The optical and viscoelastic characteristics of the hyaluronic acid-based hydrogels were compared with those of extracted human vitreous and silicone oil. The effect of the hydrogels on the metabolic activity, proliferation and apoptosis of fibroblast (MRC-5, BJ, L929), retinal pigment epithelial (ARPE-19, hiPSC-derived RPE) and photoreceptor cells (661W) was studied as well as their mucosal tolerance via a HET-CAM assay.

RESULTS

Hyaluronic acid-based hydrogels having a suitable purity, sterility, high transparency (>90%), appropriate refractive index (1.3365) and viscoelasticity (G' > G″) were prepared in a standardized manner under controlled process conditions. The metabolic activity, proliferation and apoptosis of various cell types as well as egg choroid were unaffected by the hyaluronic acid-based vitreous substitutes, demonstrating their biocompatibility.

CONCLUSIONS

The present study demonstrates the successful transferability of the crucial synthesis steps of hyaluronic acid-based hydrogels into a routine, GMP-compliant production process while achieving the optical and viscoelastic properties, biocompatibility and purity required for their clinical use as vitreous substitutes.

Temporary iris-lens diaphragm to assist descemet membrane endothelial keratoplasty in aphakic patients

Purpose

Presenting a simple technique using an inversely implanted contact lens to create a temporary diaphragm to assist DMEK surgery in aphakic, partially aniridic and vitrectomized eyes.

Observations

The postoperative course was without pressure abnormalities and the anterior chamber remained deep. The cornea completely cleared within 3 weeks and remained clear after removal of the contact lens showing a corneal thickness of 544 μm and an intact endothelial cell pattern on endothelial cell microscopy after 3 months.

Conclusion and Importance

The inversely implanted contact lens provides an easily accessible temporary diaphragm, making DMEK surgery a safer procedure even in complex eyes without an adequate posterior barrier.

[Modifications of canaloplasty : Strong pressure-lowering effect with a low risk profile]

Trabeculectomy still achieves the strongest intraocular pressure (IOP) reduction of all glaucoma surgical techniques, but with the drawback of a significant risk profile. Against this background, canaloplasty has established itself as a much gentler alternative which achieves sufficient IOP reduction and enables a significant reduction in postoperative glaucoma medication. However, approximately half of patients are not completely medication free. In response, a number of modifications have been developed with the goal of further enhancing the IOP-lowering effect of canaloplasty, but without the risk of serious complications. By combining canaloplasty with the newly developed suprachoroidal drainage, a uveoscleral drainage is created in addition to the trabecular outflow improvement, which seems to have an additive effect. Thus, for the first time, an IOP-lowering effect comparable to successful trabeculectomy can be achieved. Numerous other modifications with implants also enhance the potential of canaloplasty or offer other additional benefits such as the possibility of telemetric IOP self-measurement by the patient. The additional creation of a subconjunctival drainage with or without use of cytostatic drugs also seems promising. Ab interno procedures, on the other hand, have limited pressure-lowering potential but may provide some additional benefit in mild glaucoma and in the setting of cataract surgery.

Vitreous Substitutes as Drug Release Systems

Vitreous substitutes are traditionally used to stabilize the retina after vitrectomy. In recent years, various approaches have been developed for using the vitreous substitute not only as a tamponade but also as a drug release system to tackle ocular diseases. This review provides an overview of the requirements for vitreous substitutes and discusses the current clinically applied as well as novel polymer-based vitreous substitutes as drug delivery systems, including their release mechanisms, efficiencies, challenges, and future perspectives.