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PURPOSE: The study aims to evaluate visual outcome, central corneal thickness, and rebubbling rate in a cohort with oversized DMEK grafts after failed penetrating keratoplasty (PK). The unique feature of the study is a descemetorhexis diameter larger than the full-thickness graft, i.e., peripheral to the PK interface. METHODS: A monocentric, retrospective evaluation of all patients with endothelial graft failure after PK treated with an oversized DMEK graft and descemetorhexis outside of the PK interface (i.e., in host tissue) between January 2015 and July 2019 at the Department of Ophthalmology at the University of Düsseldorf (Germany) was performed. RESULTS: Eleven eyes of 10 patients were identified. Mean age was 69 years. On average (arithmetic mean ± standard deviation), 1.7 ± 1.0 previous PKs have been performed per eye in this cohort. The mean time between last PK and DMEK was 10.1 ± 7.3 years (range 2 to 23 years). In all cases, the graft diameter exceeded the diameter of the previous PK and descemetorhexis was performed in host tissue, that is, peripheral to the graft-host interface. Rebubbling was performed in 18.2% of the patients (n = 2 eyes) because of central graft detachment. Mean central corneal thickness showed a statistically significant improvement at 5.3 ± 3.5 months after surgery from 688.23 ± 151.01 to 527.75 ± 88 µm (p = 0.002). Visual acuity increased significantly by 5 lines from 1.24 ± 0.5 logMAR (range from 0.5 to 2) to 0.73 ± 0.76 logMAR (range from 0.1 to 2) within 3 months (p = 0.006). Excluding patients without visual potential and transplant failure, visual acuity improved significantly by 8 lines (p < 0.001), and stayed stable until the last follow-up at 15.1 ± 11.4 months (range 6 to 39 months, p < 0.001, n = 8) after surgery. CONCLUSION: DMEK can be successfully used to treat endothelial cell failure after PK, and can provide good postoperative results with regards to visual acuity. This study shows that stripping of Descemet's membrane (DM) peripheral to the PK interface is surgically feasible. Overlapping, larger DMEK grafts with more endothelial cells can be used without increasing rebubbling rates and may potentially improve long-term graft survival.

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BACKGROUND: A hospital partnership between the University Eye Hospital Düsseldorf (UAK Düsseldorf) and Fundación Visión in Asunción has existed since 2014 based on a memorandum of understanding. Fundación Visión plays a leading role in ophthalmological treatment and prevention of blindness in Paraguay. Since 2016 a program for the promotion of international hospital partnerships of the German government has been in place. MATERIAL AND METHODS: Following a written application in 2016 the hospital partnership Düsseldorf-Asunción is funded by the Federal Ministry for Economic Cooperation in Germany. The aim of the project was to establish modern minimally invasive corneal transplantation techniques with faster postoperative rehabilitation and less follow-up in Paraguay with the help of several activities within a defined schedule. Secondary aims were to obtain first data on the prevalence of eye diseases in a typical patient cohort of the Fundación Visión and to establish an infrastructure for modern eye banking techniques in Paraguay. RESULTS: First a Paraguayan surgeon was trained to carry out Descemet membrane endothelial keratoplasty (DMEK) transplantations in Germany. At the same time, the surgical instruments required for the DMEK technique were purchased and delivered to the Fundación Visión. In September 2018 the first lamellar corneal transplantations were successfully performed in Paraguay by the team from the Fundación Visión under the supervision of an experienced surgical team from Düsseldorf. Subsequently, the split cornea approach using a donor cornea for a posterior and an anterior lamellar keratoplasty (DMEK and DALK) was also implemented in Asunción. In November 2019 epidemiological data on eye diseases were collected during a field campaign of the Fundación Visión in a rural region of Paraguay. In the course of data collection an employee of the University Eye Hospital Düsseldorf learned small incision cataract surgery. In March 2019, a technician from the Fundación Visión was trained in Düsseldorf in corneal tissue culture techniques and preparation of amniotic membrane transplants in the Lions eye bank North-Rhine/Westfalia. CONCLUSION: With the aid of a supported hospital partnership modern minimally invasive corneal transplantation techniques can be successfully transferred to the eye hospital of a developing country and in return surgical skills can be taught to surgeons from Germany who are in training. Therefore, an efficient hospital partnership is the basis for a mutual exchange and is not purely one-way traffic.

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Visual stimulation and communication with the surroundings are crucial factors for childhood development. In children with intellectual disability the developmental delay can be exacerbated by visual impairment leading to visual autism. Uncorrected refractive error is one of the leading causes of visual impairment and spectacles are the gold standard for treatment. For some children with developmental delay or intellectual disability, the fitting and wearing of spectacles can be impossible due to severe craniofacial malformations, poor neck control or involuntary head movements. In these cases, if wearing contact lenses is also impossible the refractive error remains untreated and the child visually impaired. In certain situations cornea-based laser refractive surgery or lens-based refractive surgery can treat these refractive errors to enable better unaided visual acuity and therefore enhanced stimulation and integration of these developmentally delayed children. This article describes and discusses the indications, technical aspects and results of refractive surgery for children with developmental delay and intellectual disability.

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Penetrating eye injuries often lead to serious symptoms, such as severe inflammation and pain, especially if residual intraocular foreign bodies are present. This case report describes a patient who suffered a penetrating corneal injury resulting in eyelashes being displaced into the anterior chamber. Although no treatment was given the anterior chamber of the eye did not show any inflammatory reactions 2 weeks after the trauma. In addition to the accident mechanism the material of which the foreign body is composed plays a decisive role. While iron, copper and wooden foreign bodies lead to severe intraocular inflammation, keratin is immunologically well-tolerated.

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NEUROTROPHIC KERATOPATHY: Neurotrophic keratopathy (NK) is a rare corneal disease caused by an impaired corneal innervation. It leads to spontaneous recurrent epithelial defects potentially leading to corneal ulcers and perforation. To avoid severe corneal damage, a prompt and stage-adjusted treatment is necessary. Treatment of NK is challenging. Due to the lack of direct causal treatment options, only a supportive therapy was previously possible. ESTABLISHED TREATMENT: The basic treatment of NK consists of intensive ocular surface lubrication with artificial tears free from preservatives. Medication toxic to the epithelium must be discontinued and associated ocular surface diseases must be treated in the best possible way. In advanced stages surgical options, such as amniotic membrane transplantation, tarsorrhaphy and conjunctival flaps are used but autologous serum can also be used to achieve closure of the epithelium. NOVEL AND EXPERIMENTAL TREATMENT OPTIONS: Cenegermin, a recombinant neurotrophic growth factor, has recently become available, which can be used for the causal treatment of advanced stages of NK. Clinical experience with this drug is, however, still limited. Corneal neurotization is an established procedure in other medical disciplines and is currently also being evaluated in the treatment of NK. Keratoplasty is only used in emergencies, such as corneal perforation, as it is associated with a high risk for recurrent neurotrophic corneal ulcers. The various techniques of keratoplasty and the absolutely necessary concomitant treatment are also discussed.

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Regeneration and repair of corneal epithelium rely on a reservoir of unipotent progenitor cells, which is situated within the basal epithelial layer at the corneoscleral limbus. If these cells are lost, corneal surface integrity is disturbed, which may lead to a painful loss of vision. Since the late 1990s cultivated grafts of limbal epithelium are being used therapeutically. Limbal epithelial cells are obtained from the fellow eye or from an allogeneic donor, propagated in culture on different types of carriers, and subsequently transplanted. This process entails removal of progenitor cells from their natural environment. However, surrounding cells and extracellular matrix are widely believed to provide important stimuli for stem cell maintenance and for correct differentiation. Therefore, new approaches aim at providing this so-called stem cell niche ex vivo and following transplantation. Niche factors can also drive transdifferentiation of alternative progenitor cell types towards a corneal phenotype. This permits the use of autologous cells in cases of bilateral limbal stem cell insufficiency. Several biosynthetic substrates have been devised for culture, transdifferentiation and transplantation of donor cells. This work intends to provide an overview of constructs that are currently available and to some extent clinically employed. In addition, a summary is given of novel concepts which aim at integrating putative niche factors into the stem cell carriers to replicate the stem cell niche.

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PURPOSE: The EPIRET3 retinal prosthesis was implanted in six volunteers legally blind from retinitis pigmentosa (RP) and removed after 4 weeks. Two years later, these subjects were re-examined to investigate ocular side effects and potential changes to quality of life. METHODS: Vision-related quality of life was recorded using the NEI-VFQ-25 questionnaire. Clinical data including interval history, visual acuity, and intraocular pressure were obtained. Anterior and posterior segments of the study eyes were examined and photographed; this included fluorescein angiography and optical coherence tomography (OCT). RESULTS: Data from five patients could be analysed. Life-quality score was consistent with results obtained at baseline. No unexpected structural alteration could be found in the study eyes. A moderate epiretinal gliosis was present in areas where the epiretinal stimulator had been fixated using retinal tacks. Angiography revealed no leakage or neovascularisation; OCT showed no generalised increase of central retinal thickness. CONCLUSIONS: Vision-related quality of life is low in patients suffering from end-stage RP. No further deterioration of life quality could however be detected within our monitoring period. Surgery was well tolerated by both patients and their eyes, without adverse events occurring during the follow-up period. Epiretinal gliosis is known to occur with retinal tacks, but seems of no major concern to the integrity of the study eyes. However, it may potentially interfere with functional aspects of active implants. Hence, alternative, possibly biochemical, fixation methods merit further research.

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Neovascularisation is a major cause of visual loss in a number of ophthalmic diseases. This review aims to outline the basic regulators of vessel growth in corneal neovascularisation. An understanding of the underlying principles of physiological and pathophysiological vascular development helps to appreciate current approaches to prevent or treat corneal neovascularisation. Options for future interventions will be discussed in the light of recent evidence provided by animal models of corneal neovascularisation.

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