Lars Wagenfeld

Glaucoma progression is associated with decreased blood flow velocities in the short posterior ciliary artery

Background: An altered perfusion of the optic nerve head has been proposed as a pathogenic factor in glaucoma. Aim: To investigate potential differences in the ocular haemodynamics of patients having glaucoma with progressive versus stable disease, as well as healthy volunteers. Methods: Peak-systolic velocity (PSV), end-diastolic velocity (EDV) and resistivity index in the short posterior ciliary artery (SPCA), central retinal artery (CRA) and ophthalmic artery were recorded in 114 consecutive patients having glaucoma with an intraocular pressure (IOP) ⩽21 mm Hg, as well as in 40 healthy volunteers, by colour Doppler imaging (CDI). Results: Of the 114 patients with glaucoma, 12 showed glaucoma progression (follow-up period: mean 295 (standard deviation (SD) (18) days). CDI measurements in these patients showed decreased PSV and EDV in the SPCA (p<0.001 and p<0.05, respectively) and decreased PSV in the CRA compared with patients with stable glaucoma and healthy controls (p<0.05). No differences in flow velocities were found for the ophthalmic artery. IOP and systemic blood pressure was similar in all the three groups. Conclusions: Progressive glaucoma is associated with decreased blood flow velocities in the small retrobulbar vessels supplying the optic nerve head. The detected difference could represent a risk factor for progression of glaucomatous optic neuropathy.

Effects of glaucoma drugs on ocular hemodynamics in normal tension glaucoma: a randomized trial comparing bimatoprost and latanoprost with dorzolamide [ISRCTN18873428]

BackgroundReduced choroidal perfusion is hypothesized to play a role in the pathogenesis of normal tension glaucoma. Thus the impact of antiglaucomatous eye drops on ocular perfusion has been the focus of recent research and the subject of intensive investigations. The present study investigates whether topically applied latanoprost or bimatoprost influence ocular perfusion in patients with normal tension glaucoma and compares these effects with that changes detected after the treatment with dorzolamide.MethodsOcular hemodynamics were assessed by color Doppler imaging (CDI) shortly before and after a one-month treatment with either latanoprost, bimatoprost or dorzolamide. Primary end-points of the study were peak systolic and end-diastolic blood flow velocities in the short posterior ciliary artery (SPCA) under the new therapy. Intraocular pressure (IOP) and additional perfusion parameters in the SPCA and other retrobulbar vessels were tracked as observational parameters. n = 42 patients with normal tension glaucoma were enrolled in the study.ResultsSystolic and diastolic blood flow velocities in the SPCA showed no significant alteration after the treatment with latanoprost or bimatoprost. Dorzolamide lead to increase of peak systolic velocity. IOP was reduced by all three agents in a range reported in the literature.ConclusionTopically applied latanoprost and bimatoprost act in a hemodynamically neutral manner and have the capability to lower IOP even in patients with normal tension glaucoma and low initial IOP level. Dorzolamide accelerates blood flow in systole. None of the tested compounds has a negative impact on hemodynamics in the short posterior ciliary arteries.

Progress in the Development of Vision Prostheses

Degenerative retinal diseases like retinitis pigmentosa and age-related macular degeneration are among the most common causes of blindness worldwide. Electronic visual prostheses represent a potential therapeutic option of increasing importance in otherwise incurably impaired patients. Based on extensive animal experiments, several devices are now being tested in clinical trials. According to the placement of the electrodes, possible stimulation sites are located subretinally, epiretinally, along the optic nerve or cortically. Anatomical, physiological and pathophysiological aspects must be considered in development and clinical application. To provide an appropriate retinal substitute, the optimal integration and adaptation of the prosthesis into the highly complex system of the visual pathway is important. This article aims to summarize the relevant studies and provides an overview of the current status of developments and challenges that still need to be mastered.

Neural stem cell-based intraocular administration of ciliary neurotrophic factor attenuates the loss of axotomized ganglion cells in adult mice.

PURPOSE To analyze the neuroprotective effect of intravitreally grafted neural stem (NS) cells genetically modified to secrete ciliary neurotrophic factor (CNTF) on intraorbitally lesioned retinal ganglion cells (RGCs) in adult mice. METHODS Adherently cultivated NS cells were genetically modified to express a secretable variant of mouse CNTF together with the fluorescent reporter protein Venus. Clonal CNTF-secreting NS cell lines were established using fluorescence activated cell sorting, and intravitreally grafted into adult mice 1 day after an intraorbital crush of the optic nerve. Brn-3a-positive RGCs were counted in flat-mounted retinas at different postlesion intervals to evaluate the neuroprotective effect of the CNTF-secreting NS cells on the axotomized RGCs. Anterograde axonal tracing experiments were performed to analyze the regrowth of the injured RGC axons in CNTF-treated retinas. RESULTS Intravitreally grafted NS cells preferentially differentiated into astrocytes that survived in the host eyes, stably expressed CNTF, and significantly attenuated the loss of the axotomized RGCs over a period of at least 4 months, the latest postlesion time point analyzed. Depending on the postlesion interval analyzed, the number of RGCs in eyes with grafted CNTF-secreting NS cells was 2.8-fold to 6.4-fold higher than in eyes with grafted control NS cells. The CNTF-secreting NS cells additionally induced long-distance regrowth of the lesioned RGC axons. CONCLUSIONS Genetically modified clonal NS cell lines may serve as a useful tool for preclinical studies aimed at evaluating the therapeutic potential of a sustained cell-based intravitreal administration of neuroprotective factors in mouse models of glaucoma.

LASIK versus photorefractive keratectomy for high myopic (> 3 diopter) astigmatism.

PURPOSE To compare the efficacy, safety, predictability, and vector analysis indices of LASIK and photorefractive keratectomy (PRK) for correction of high cylinder of greater than 3 diopters (D) in myopic eyes. METHODS The efficacy, safety, and predictability of LASIK or PRK performed in 114 consecutive randomly selected myopic eyes with an astigmatism of greater than 3 D were retrospectively analyzed at the 2- to 6-month follow-up visits. Vector analysis of the cylindrical correction was compared between the treatment groups. RESULTS A total of 57 eyes receiving PRK and 57 eyes receiving LASIK of 114 refractive surgery candidates were enrolled in the study. No statistically significant difference in efficacy [efficacy index = 0.76 (±0.32) for PRK vs 0.74 (±0.19) for LASIK (P = .82)], safety [safety index = 1.10 (±0.26) for PRK vs 1.01 (±0.17) for LASIK (P = .121)], or predictability [achieved astigmatism < 1 D in 39% of PRK- and 54% of LASIK-treated eyes, and < 2 D in 88% of PRK- and 89% of LASIK-treated eyes (P = .218)] was demonstrated. Using Alpins vector analysis, the surgically induced astigmatism and difference vector were not significantly different between the surgery methods, whereas the correction index showed a slight and significant advantage of LASIK over PRK (1.25 for PRK and 1.06 for LASIK, P < .001). CONCLUSIONS LASIK and PRK are comparably safe, effective, and predictable procedures for excimer laser correction of high astigmatism of greater than 3 D in myopic eyes. Predictability of the correction of the cylindrical component is lower than that of the spherical equivalent.

Visual recovery after retinal detachment with macula-off: is surgery within the first 72 h better than after?

Aims To investigate the influence of lag time between the onset of central visual acuity loss and surgical intervention of macula-off retinal detachment. Methods This retrospective case series examined all consecutively treated eyes with primary macula-off retinal detachment at the University Hospital Hamburg (Germany) from February 2010 to February 2015. Records of 1727 patients operated by six surgeons were reviewed. Eighty-nine eyes (5.2%) from 89 patients met the inclusion and exclusion criteria. The main outcome measure studied was final visual acuity as a function of symptom duration of macula-off detachment. Secondary outcome measures studied were influence of age and surgical technique. Symptom duration was defined as the time from the onset of loss of central vision to surgical intervention. Results After 10 days no clinically relevant difference was seen in final visual acuity. Eyes with symptom duration of 3 days or less achieved best final visual acuity (p<0.001). Age and preoperative visual acuity had no influence while vitrectomised eyes had better outcome compared with those with scleral buckling. Conclusions Our study suggests that 1. After 10 days of central visual acuity loss, the final visual outcome is clinically comparable and independent of further delay of surgery up to 30 days. 2. Eyes treated up to 3 days after onset of loss of central vision have better final visual acuity than eyes with longer lag time. However, we did not find statistically significant differences within the first 3 days. 3. Surgery for macula-off retinal detachment may therefore most likely not be postponed without compromising the patients visual prognosis.

Terson's Syndrome—Rate and Surgical Approach in Patients with Subarachnoid Hemorrhage: A Prospective Interdisciplinary Study

OBJECTIVES To analyze the need for surgical intervention in Tersons syndrome (TS) and the rate of TS, as well as the effect of pars plana vitrectomy (PPV) with or without internal limiting membrane (ILM) peeling, complications, correlations between TS and sex, and the influence of the severity of subarachnoid hemorrhage (SAH) expressed by Glasgow Coma Scale (GCS) score and Hunt and Hess grade on the occurrence of TS. DESIGN Prospective, uncontrolled, interdisciplinary study. PARTICIPANTS A total of 102 patients with SAH over a period of 24 months. METHODS Patients were examined on days 1 and 14. A PPV was indicated in cases of nonresorbing vitreous hemorrhage (VH). Peeling of the ILM was performed with the help of ILM-BLUE (DORC, Zuidland, The Netherlands) using end-gripping ILM forceps. MAIN OUTCOME MEASURES Effect of PPV on visual acuity (VA) and timing of intervention in cases of nonresorbing VH. RESULTS The rate of TS was 19.6% (20/102). The mean age of the patients was 52.1 ± 11.8 years. Patients presenting with an initial GCS of less than 8 or with high Hunt and Hess grades were more affected by TS. Eight (9 eyes) of the 20 patients with TS (40% of the patients with TS) underwent a PPV for nonclearing vitreous bleeding. In 4 patients (4 eyes; 20% of patients with TS), ILM peeling was considered necessary because of sub-ILM bleeding. The mean interval between SAH and PPV was 4.4 months (range, 3-5 months). Postoperative follow-up was 6.4 months. Visual acuity improved in all patients. Best-corrected VAs at first and at last presentations were 2.2 and 0.0625 logarithm of the minimum angle of resolution (logMAR), respectively. For patients who underwent ILM peeling, these values were 1.725 and 0.05 logMAR, respectively. CONCLUSIONS Pars plana vitrectomy and ILM peeling have beneficial effects on the visual rehabilitation of patients with nonclearing VH after TS. We did not identify any safety concerns after PPV in our patients with dense nonclearing hemorrhage that persisted for more than 3 months.

The German ROP Registry: data from 90 infants treated for retinopathy of prematurity.

The German retinopathy of prematurity (ROP) Registry collects data on treated ROP in a multicentre approach to analyse epidemiology and treatment patterns of severe ROP.

Subjective pain, visual recovery and visual quality after LASIK, EpiLASIK (flap off) and APRK — a consecutive, non-randomized study

IntroductionLaser in situ keratomileusis (LASIK) is superior to surface ablation techniques (SAT) such as alcohol photorefractive keratectomy (APRK) or Epi-LASIK (EpiK) in terms of visual recovery and postoperative pain. This study compares subjective symptoms and visual recovery of two different SATs with LASIK.Materials and MethodsOne hundred and twenty seven patients were operated using one of the three techniques. Patients filled out a questionnaire describing symptoms assessing subjective visual recovery on a linear scale from ‘not functioning’ to ‘full visual function’ and pain on a linear scale from ‘no pain’ to ‘severe daily pain’. Subjective symptoms such as halos, double vision, low night vision, reduced contrast and dry eyes were also evaluated.ResultsVisual recovery was faster and discomfort symptoms less pronounced with the LASIK than with surface ablation procedures. More pain was reported after APRK than after EpiK (flap-off technique) in the early postoperative period, with a maximum of pain on postoperative days 3–4. Subjective visual recovery showed no statistically significant difference between the two surface ablation procedures. Halos, double vision, low night vision, reduced contrast and dry eyes were more extensively reported by the EpiK than the APRK group and were less pronounced in the LASIK than in the SAT group.Discussion and conclusionsOur study does not uniformly support the previously published favourable results of EpiK compared to APRK with regard to subjective recovery of vision and postoperative pain.

Long-Lasting Endotamponades in Vitreoretinal Surgery

In modern vitreoretinal surgery, a variety of long-lasting endotamponades is available. These endotamponades differ in physical and chemical properties and their usage is based on certain pathological and surgical considerations. With modern endotamponades the treatment and prognosis for some severe diseases of the posterior segment was improved. Besides these supportive features of new endotamponades, the surgeon has to keep in mind that certain steps, like a complete removal of the vitreous and of any traction, are crucial for the success of an operation and that the most supportive step for the retina is complete endotamponade. This review gives an overview of longlasting endotampoandes in vitreoretinal surgery and of the indications for their usage.