Reinier O. Schlingemann

The RESTORE study: ranibizumab monotherapy or combined with laser versus laser monotherapy for diabetic macular edema.

OBJECTIVE To demonstrate superiority of ranibizumab 0.5 mg monotherapy or combined with laser over laser alone based on mean average change in best-corrected visual acuity (BCVA) over 12 months in diabetic macular edema (DME). DESIGN A 12-month, randomized, double-masked, multicenter, laser-controlled phase III study. PARTICIPANTS We included 345 patients aged ≥18 years, with type 1 or 2 diabetes mellitus and visual impairment due to DME. METHODS Patients were randomized to ranibizumab + sham laser (n = 116), ranibizumab + laser (n = 118), or sham injections + laser (n = 111). Ranibizumab/sham was given for 3 months then pro re nata (PRN); laser/sham laser was given at baseline then PRN (patients had scheduled monthly visits). MAIN OUTCOME MEASURES Mean average change in BCVA from baseline to month 1 through 12 and safety. RESULTS Ranibizumab alone and combined with laser were superior to laser monotherapy in improving mean average change in BCVA letter score from baseline to month 1 through 12 (+6.1 and +5.9 vs +0.8; both P<0.0001). At month 12, a significantly greater proportion of patients had a BCVA letter score ≥15 and BCVA letter score level >73 (20/40 Snellen equivalent) with ranibizumab (22.6% and 53%, respectively) and ranibizumab + laser (22.9% and 44.9%) versus laser (8.2% and 23.6%). The mean central retinal thickness was significantly reduced from baseline with ranibizumab (-118.7 μm) and ranibizumab + laser (-128.3 μm) versus laser (-61.3 μm; both P<0.001). Health-related quality of life, assessed through National Eye Institute Visual Function Questionnaire (NEI VFQ-25), improved significantly from baseline with ranibizumab alone and combined with laser (P<0.05 for composite score and vision-related subscales) versus laser. Patients received ∼7 (mean) ranibizumab/sham injections over 12 months. No endophthalmitis cases occurred. Increased intraocular pressure was reported for 1 patient each in the ranibizumab arms. Ranibizumab monotherapy or combined with laser was not associated with an increased risk of cardiovascular or cerebrovascular events in this study. CONCLUSIONS Ranibizumab monotherapy and combined with laser provided superior visual acuity gain over standard laser in patients with visual impairment due to DME. Visual acuity gains were associated with significant gains in VFQ-25 scores. At 1 year, no differences were detected between the ranibizumab and ranibizumab + laser arms. Ranibizumab monotherapy and combined with laser had a safety profile in DME similar to that in age-related macular degeneration.

Polarized Vascular Endothelial Growth Factor Secretion by Human Retinal Pigment Epithelium and Localization of Vascular Endothelial Growth Factor Receptors on the Inner Choriocapillaris: Evidence for a Trophic Paracrine Relation

The retinal pigment epithelium (RPE) maintains the choriocapillaris (CC) in the normal eye and is involved in the pathogenesis of choroidal neovascularization in age-related macular degeneration. Vascular endothelial growth factor-A (VEGF) is produced by differentiated human RPE cells in vitro and in vivo and may be involved in paracrine signaling between the RPE and the CC. We investigated whether there is a polarized secretion of VEGF by RPE cells in vitro. Also, the localization of VEGF receptors in the human retina was investigated. We observed that highly differentiated human RPE cells, cultured on transwell filters in normoxic conditions, produced two- to sevenfold more VEGF toward their basolateral side as compared to the apical side. In hypoxic conditions, VEGF-A secretion increased to the basal side only, resulting in a three- to 10-fold higher basolateral secretion. By immunohistochemistry in 30 human eyes and in two cynomolgus monkey eyes, KDR (VEGFR-2) and flt-4 (VEGFR-3) were preferentially localized at the side of the CC endothelium facing the RPE cell layer, whereas flt-1 (VEGFR-1) was found on the inner CC and on other choroidal vessels. Our results indicate that RPE secretes VEGF toward its basal side where its receptor KDR is located on the adjacent CC endothelium, suggesting a role of VEGF in a paracrine relation, possibly in cooperation with flt-4 and its ligand. This can explain the known trophic function of the RPE in the maintenance of the CC and its fenestrated permeable phenotype and points to a role for VEGF in normal eye functioning. Up-regulated basolateral VEGF secretion by RPE in hypoxia or loss of polarity of VEGF production may play a role in the pathogenesis of choroidal neovascularization.

Safety and Efficacy of a Flexible Dosing Regimen of Ranibizumab in Neovascular Age-Related Macular Degeneration: The SUSTAIN Study

OBJECTIVE To evaluate the safety and efficacy of individualized ranibizumab treatment in patients with neovascular age-related macular degeneration. DESIGN Twelve-month, phase III, multicenter, open-label, single-arm study. PARTICIPANTS A total of 513 ranibizumab-naïve SUSTAIN patients. INTERVENTION Three initial monthly injections of ranibizumab (0.3 mg) and thereafter pro re nata (PRN) retreatment for 9 months based on prespecified retreatment criteria. Patients switched to 0.5 mg ranibizumab after approval in Europe. MAIN OUTCOME MEASURES Frequency of adverse events (AEs), monthly change of best-corrected visual acuity (BCVA) and central retinal thickness (CRT) from baseline, the time to first re-treatment, and the number of treatments were assessed. RESULTS A total of 249 patients (48.5%) reported ocular AEs, and 8 (1.5%) deaths, 5 (1.2%) patients with ocular serious AEs of the study eye (retinal hemorrhage, cataract, retinal pigment epithelial tear, reduced visual acuity [VA], vitreous hemorrhage), and 19 (3.7%) patients with arteriothromboembolic events were observed. Most frequent AEs in the study eye were reduced VA (18.5%), retinal hemorrhage (7.2%), increased intraocular pressure (7.0%), and conjunctival hemorrhage (5.5%). The average number of re-treatments from months 3 to 11 was 2.7. Mean best-corrected visual acuity increased steadily from baseline to month 3 to reach +5.8 letters, decreased slightly from month 3 to 6, and remained stable from month 6 to 12, reaching +3.6 at month 12. Mean change in CRT was -101.1 μm from baseline to month 3 and -91.5 μm from baseline to month 12. CONCLUSIONS The safety results are comparable to the favorable tolerability profile of ranibizumab observed in previous pivotal clinical studies; individualized treatment with less than monthly re-treatments shows a similar safety profile as observed in previous randomized clinical trials with monthly ranibizumab treatment. Efficacy outcomes were achieved with a low average number of re-treatments. Visual acuity in SUSTAIN patients with individualized re-treatment based on VA/optical coherence tomography assessment reached on average a maximum after the first 3 monthly injections, decreased slightly under PRN during the next 2 to 3 months, and was then sustained throughout the treatment period.

Efficacy and Safety of Monthly versus Quarterly Ranibizumab Treatment in Neovascular Age-related Macular Degeneration: The EXCITE Study

OBJECTIVE To demonstrate noninferiority of a quarterly treatment regimen to a monthly regimen of ranibizumab in patients with subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). DESIGN A 12-month, multicenter, randomized, double-masked, active-controlled, phase IIIb study. PARTICIPANTS Patients with primary or recurrent subfoveal CNV secondary to AMD (353 patients), with predominantly classic, minimally classic, or occult (no classic component) lesions. INTERVENTION Patients were randomized (1:1:1) to 0.3 mg quarterly, 0.5 mg quarterly, or 0.3 mg monthly doses of ranibizumab. Treatment comprised of a loading phase (3 consecutive monthly injections) followed by a 9-month maintenance phase (either monthly or quarterly injection). MAIN OUTCOME MEASURES Mean change in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) from baseline to month 12 and the incidence of adverse events (AEs). RESULTS In the per-protocol population (293 patients), BCVA, measured by Early Treatment Diabetic Retinopathy Study-like charts, increased from baseline to month 12 by 4.9, 3.8, and 8.3 letters in the 0.3 mg quarterly (104 patients), 0.5 mg quarterly (88 patients), and 0.3 mg monthly (101 patients) dosing groups, respectively. Similar results were observed in the intent-to-treat (ITT) population (353 patients). The mean decrease in CRT from baseline to month 12 in the ITT population was -96.0 μm in 0.3 mg quarterly, -105.6 μm in 0.5 mg quarterly, and -105.3 μm in 0.3 mg monthly group. The most frequent ocular AEs were conjunctival hemorrhage (17.6%, pooled quarterly groups; 10.4%, monthly group) and eye pain (15.1%, pooled quarterly groups; 20.9%, monthly group). There were 9 ocular serious AEs and 3 deaths; 1 death was suspected to be study related (cerebral hemorrhage; 0.5 mg quarterly group). The incidences of key arteriothromboembolic events were low. CONCLUSIONS After 3 initial monthly ranibizumab injections, both monthly (0.3 mg) and quarterly (0.3 mg/0.5 mg) ranibizumab treatments maintained BCVA in patients with CNV secondary to AMD. At month 12, BCVA gain in the monthly regimen was higher than that of the quarterly regimens. The noninferiority of a quarterly regimen was not achieved with reference to 5.0 letters. The safety profile was similar to that reported in prior ranibizumab studies.

Role of growth factors and the wound healing response in age-related macular degeneration

Growth factors (GF) are important in several stages of the pathogenesis of age-related macular disease (AMD). In choroidal neovascularization (CNV) in exudative AMD, the GF involved are similar to those involved in wound healing of the skin. Like granulation tissue of skin, CNV is characterized by clotting, inflammation, angiogenesis and fibrosis, and like in skin wounds, members of the VEGF, angiopoietin, PDGF and TGF-β families of GF are expressed. However, several of these GF may also serve physiological functions in the normal eye, where the retinal pigment epithelium (RPE) employs them to provide trophic support to the neuroretina and choriocapillaris, in addition to maintaining an anti-angiogenic state. Derangement of these physiological functions may underlie the initiation of CNV in AMD. Basolateral secretion of VEGF-A by the RPE maintains the choriocapillaris, and is enhanced by hypoxia. Age-related changes in Bruch’s membrane lead to impairment of this trophic function and choriocapillaris atrophy, as well as to decreased diffusion of oxygen towards the neuroretina. The resulting outer retina hypoxia may be an important driving force of CNV formation, by stimulating VEGF overexpression by the RPE, in addition to the effects of increased oxidative stress and low-grade inflammation. RPE senescence and hypoxia may also decrease expression of angiogenesis inhibitors such as PEDF, further shifting the balance to a pro-angiogenic state in the aging eye.

Selective Loss of Inner Retinal Layer Thickness in Type 1 Diabetic Patients with Minimal Diabetic Retinopathy

PURPOSE To determine whether type 1 diabetes preferentially affects the inner retinal layers by comparing the thickness of six retinal layers in type 1 diabetic patients who have no or minimal diabetic retinopathy (DR) with those of age- and sex-matched healthy controls. METHODS Fifty-seven patients with type 1 diabetes with no (n = 32) or minimal (n = 25) DR underwent full ophthalmic examination, stereoscopic fundus photography, and optical coherence tomography (OCT). After automated segmentation of intraretinal layers of the OCT images, mean thickness was calculated for six layers of the retina in the fovea, the pericentral area, and the peripheral area of the central macula and were compared with those of an age- and sex-matched control group. RESULTS In patients with minimal DR, the mean ganglion cell/inner plexiform layer was 2.7 microm thinner (95% confidence interval [CI], 2.1-4.3 microm) and the mean inner nuclear layer was 1.1 microm thinner (95% CI, 0.1-2.1 microm) in the pericentral area of the central macula compared to those of age-matched controls. In the peripheral area, the mean ganglion cell/inner plexiform layer remained significantly thinner. No other layers showed a significant difference. CONCLUSIONS Thinning of the total retina in type 1 diabetic patients with minimal retinopathy compared with healthy controls is attributed to a selective thinning of inner retinal layers and supports the concept that early DR includes a neurodegenerative component.

What is orbital pseudotumor

We have reviewed the literature in order to delineate the clinicopathologic definition of orbital pseudotumor, also called idiopathic nonspecific orbital inflammation. The clinical picture of orbital pseudotumor varies widely, with signs of mass effect, inflammation and/or infiltration. On computed tomography, orbital pseudotumor presents as a unilateral focal or diffuse mass. The histopathologic hallmark of orbital pseudotumor is a mixed inflammatory infiltrate with fibrosis of varying degree. Contrary to an old belief, orbital pseudotumor is not related to orbital reactive lymphoid hyperplasia (pseudolymphoma) and is not a lymphoid tumor. Atypical histopathologic findings of orbital pseudotumor include dominant sclerosis, granulomatous inflammation, vasculitis, and tissue eosinophilia. In the absence of systemic fibroinflammatory, granulomatous, and vasculitic disease, these atypical histopathologic patterns can be considered to represent subclasses of orbital pseudotumors rather then distinct entities. Clinical and prognostic characteristics of both histopathologically classical and atypical orbital pseudotumors appear to be heterogeneous. The etiology of orbital pseudotumor is unknown, but infection, autoimmune disorder, and aberrant wound healing have all been put forward as possibilities. In conclusion, orbital pseudotumor is one distinct disease albeit with many clinical and histopathologic guises.

Decreased Retinal Ganglion Cell Layer Thickness in Patients with Type 1 Diabetes

PURPOSE. To determine which retinal layers are most affected by diabetes and contribute to thinning of the inner retina and to investigate the relationship between retinal layer thickness (LT) and diabetes duration, diabetic retinopathy (DR) status, age, glycosylated hemoglobin (HbA1c), and the sex of the individual, in patients with type 1 diabetes who have no or minimal DR. METHODS. Mean LT was calculated for the individual retinal layers after automated segmentation of spectral domain-optical coherence tomography scans of patients with diabetes and compared with that in control subjects. Multiple linear regression analysis was used to determine the relationship between LT and HbA1c, age, sex, diabetes duration, and DR status. RESULTS. In patients with minimal DR, the mean ganglion cell layer (GCL) in the pericentral area was 5.1 mum thinner (95% confidence interval [CI], 1.1-9.1 mum), and in the peripheral macula, the mean retinal nerve fiber layer (RNFL) was 3.7 mum thinner (95% CI, 1.3-6.1 mum) than in the control subjects. There was a significant linear correlation (R = 0.53, P < 0.01) between GCL thickness and diabetes duration in the pooled group of patients. Multiple linear regression analysis (R = 0.62, P < 0.01) showed that DR status was the most important explanatory variable. CONCLUSIONS. This study demonstrates GCL thinning in the pericentral area and corresponding loss of RNFL thickness in the peripheral macula in patients with type 1 diabetes and no or minimal DR compared with control subjects. These results support the concept that diabetes has an early neurodegenerative effect on the retina, which occurs even though the vascular component of DR is minimal.

Molecular basis of the inner blood-retinal barrier and its breakdown in diabetic macular edema and other pathological conditions

Breakdown of the inner endothelial blood-retinal barrier (BRB), as occurs in diabetic retinopathy, age-related macular degeneration, retinal vein occlusions, uveitis and other chronic retinal diseases, results in vasogenic edema and neural tissue damage, causing loss of vision. The central mechanism of altered BRB function is a change in the permeability characteristics of retinal endothelial cells caused by elevated levels of growth factors, cytokines, advanced glycation end products, inflammation, hyperglycemia and loss of pericytes. Subsequently, paracellular but also transcellular transport across the retinal vascular wall increases via opening of endothelial intercellular junctions and qualitative and quantitative changes in endothelial caveolar transcellular transport, respectively. Functional changes in pericytes and astrocytes, as well as structural changes in the composition of the endothelial glycocalyx and the basal lamina around BRB endothelium further facilitate BRB leakage. As Starlings rules apply, active transcellular transport of plasma proteins by the BRB endothelial cells causing increased interstitial osmotic pressure is probably the main factor in the formation of macular edema. The understanding of the complex cellular and molecular processes involved in BRB leakage has grown rapidly in recent years. Although appropriate animal models for human conditions like diabetic macular edema are lacking, these insights have provided tools for rational design of drugs aimed at restoring the BRB as well as for design of effective transport of drugs across the BRB, to treat the chronic retinal diseases such as diabetic macular edema that affect the quality-of-life of millions of patients.

VEGFR-3 in adult angiogenesis.

Vascular endothelial growth factor receptor 3 (VEGFR‐3, Flt‐4), the receptor for vascular endothelial growth factors (VEGFs) C and D, is expressed on lymphatic endothelium and may play a role in lymphangiogenesis. In embryonic life, VEGFR‐3 is essential for blood vessel development. The purpose of this study was to investigate whether VEGFR‐3 is also involved in blood vessel angiogenesis in the adult. This was studied in human tissues showing angiogenesis andin a model of VEGF‐A‐induced iris neovascularization in the monkey eye, by the use of immunohistochemistry at the light and electron microscopic level. VEGFR‐3 was expressed on endothelium of proliferating blood vessels in tumours. In granulation tissue, staining was observed in the proliferative superficial zone in plump blood vessel sprouts, in the intermediate zone in blood vessels and long lymphatic sprouts, and in the deeper fibrous zone in large lymphatics, in a pattern demonstrating that lymphangiogenesis follows behind blood vessel angiogenesis in granulation tissue formation. At the ultrastructural level, VEGFR‐3 was localized in the cytoplasm and on the cell membrane of endothelial cells of sprouting blood vessels and sprouting lymphatics. In monkey eyes injected with VEGF‐A, blood vessel sprouts on the anterior iris surface and pre‐existing blood vessels in the iris expressed VEGFR‐3. In conclusion, these results support a role for VEGFR‐3 and its ligands VEGF‐C and/or VEGF‐D in cell‐to‐cell signalling in adult blood vessel angiogenesis. The expression of VEGFR‐3 in VEGF‐A‐induced iris neovascularization and in pre‐existing blood vessels exposed to VEGF‐A suggests that this receptor and possibly its ligands are recruited in VEGF‐A‐driven angiogenesis. Copyright