Nonsurgical options for treatment of diabetic macular edema

In the new book series 'ESASO Course Series', the essentials of the courses of the European School for Advanced Studies in Ophthalmology (ESASO) are made available to interested ophthalmologists, optometrists, technicians and residents all over the world. In this volume, the seminars on surgical retina presented by renowned experts during ESASO's activities are collected. Many specialists have contributed their knowledge to make this volume a device to give practical support. The topics range from prevention to state-of-the-art diagnostic techniques and the latest surgical treatment options for many eye conditions such as diabetic retinopathy and rhegmatogenous retinal detachment. This publication provides the ophthalmologist with the main aspects of surgical retina in a simple and practical update.

Whole genome sequencing in patients with retinitis pigmentosa reveals pathogenic DNA structural changes and NEK2 as a new disease gene.

We performed whole genome sequencing in 16 unrelated patients with autosomal recessive retinitis pigmentosa (ARRP), a disease characterized by progressive retinal degeneration and caused by mutations in over 50 genes, in search of pathogenic DNA variants. Eight patients were from North America, whereas eight were Japanese, a population for which ARRP seems to have different genetic drivers. Using a specific workflow, we assessed both the coding and noncoding regions of the human genome, including the evaluation of highly polymorphic SNPs, structural and copy number variations, as well as 69 control genomes sequenced by the same procedures. We detected homozygous or compound heterozygous mutations in 7 genes associated with ARRP (USH2A, RDH12, CNGB1, EYS, PDE6B, DFNB31, and CERKL) in eight patients, three Japanese and five Americans. Fourteen of the 16 mutant alleles identified were previously unknown. Among these, there was a 2.3-kb deletion in USH2A and an inverted duplication of ∼446 kb in EYS, which would have likely escaped conventional screening techniques or exome sequencing. Moreover, in another Japanese patient, we identified a homozygous frameshift (p.L206fs), absent in more than 2,500 chromosomes from ethnically matched controls, in the ciliary gene NEK2, encoding a serine/threonine-protein kinase. Inactivation of this gene in zebrafish induced retinal photoreceptor defects that were rescued by human NEK2 mRNA. In addition to identifying a previously undescribed ARRP gene, our study highlights the importance of rare structural DNA variations in Mendelian diseases and advocates the need for screening approaches that transcend the analysis of the coding sequences of the human genome.

Chromatic pupillometry in patients with retinitis pigmentosa.

OBJECTIVE:: To evaluate the chromatic pupillary response as a means of assessing outer and inner retinal function in patients with retinitis pigmentosa (RP). DESIGN:: Evaluation of diagnostic technology. PARTICIPANTS:: Thirty-two patients with RP and visual loss and 43 normal subjects. METHODS:: Patients were tested with a chromatic pupillometer using red and blue lights (1, 10, and 100 cd/m(2)), and their pupil responses were compared with those from 43 normal subjects (reported previously). Visual field and electroretinography (ERG) results were examined and compared with the pupil responses. MAIN OUTCOME MEASURES:: The percent pupil contraction of the transient response to a low-intensity (1 cd/m(2)) blue light and high-intensity (100 cd/m(2)) red light and the sustained response to a high-intensity blue light was calculated for 1 eye of each subject. RESULTS:: The pupil responses to red and blue light at all intensities were recordable in all patients except 1, whose pupil responded only to bright blue light. There was a significant difference of the pupil response between patients with RP and normal subjects in testing conditions that emphasized rod (1 cd/m(2) blue light) or cone (100 cd/m(2) red light) contribution (P<0.001). Patients with a non-recordable scotopic ERG showed significantly reduced pupil responses (P<0.001) to low-intensity blue light (1 cd/m(2)). Patients with a non-recordable or abnormal photopic ERG showed significantly reduced pupil responses (P<0.05) to high-intensity red light (100 cd/m(2)). Patients with a nonrecordable ERG had the most visual field loss and reduced pupil responses. Unexpectedly, patients with RP showed a slower re-dilation of the pupil after termination of bright blue light compared with red light, a pattern not observed in normal subjects. CONCLUSIONS:: Pupil responses to red and blue light stimuli weighted to favor cone or rod input are significantly reduced in patients with RP but are still recordable in patients having a non-recordable ERG. In addition, outer photoreceptor disease appears to unmask a post-illumination pupillary constriction to bright blue light, most likely mediated by intrinsic activation of melanopsin ganglion cells. Chromatic pupillometry provides a novel, noninvasive method for following retinal functional status, particularly in patients with severe RP and non-recordable ERG. FINANCIAL DISCLOSURE(S):: Proprietary or commercial disclosure may be found after the references.

Le multiple evanescent white dot syndrome: une prédisposition génétique [Multiple evanescent white dot syndrome: a genetic predisposition?]

BACKGROUND: Multiple evanescent white dot syndrome (MEWDS) is a benign acquired isolated chorioretinal disorder. Symptoms include photopsia, visual blur and scotomas. Ocular examination reveals multiple white dots at the level of the deep retina. A parainfectious disorder was suggested but the exact mechanism of MEWDS is still unknown. Postulating that MEWDS might be an antigen driven inflammatory reaction, we analyzed HLA subtypes in patients with MEWDS. PATIENTS AND METHODS: Sixteen patients were diagnosed with MEWDS in Lausanne from 1985 to 1994. Blood was withdrawn in 9/16 patients. HLA-A, -B and -DR were sought. RESULTS: HLA-B51 was detected in 4/9 patients (44.4%). Other HLA subtypes were detected sporadically. CONCLUSIONS: The frequency of HLA-B51 haplotype was found to be 3.7 times more elevated than in a normal control caucasian group. This suggests the possibility that MEWDS might be a genetically determined disorder as it is the case for other ocular diseases like Birdshot chorioretinopathy (HLA-A29), Harada's disease (HLA-DRMT3), acute anterior uveitis (HLA-B27) or Behçet's disease (HLA-B51). We have no explanation for the presence of HLA-B51 in both Behçet's disease and MEWDS. The association of HLA-B51 and MEWDS needs confirmation by further testing.

Increased therapeutic window for the R91W mutant form of Rpe65 compared to Rpe65 null backgroud

Purpose:Given the advances of gene therapy studies to cure RPE65-derived Leber Congenital Amaurosis (LCA) (clinical trials phase I) and the heterogeneity of the targeted patients both genetically and phenotypically, it is of prime importance to examine the rescue efficiency of gene transfer in different mutant contexts. Indeed, half of these mutations are missense mutations, leading to potential residual RPE65 activity. Consequently, we wanted to evaluate the effect on retinal activity and cone survival of lentivirus-mediated gene therapy in the R91W knock-in mouse model expressing the mutant Rpe65R91W gene (Samardzija et al. 2008), a mutation found in LCA patients. Notably we investigated whether if the therapeutic window is prolonged in comparison to null mutations. Methods:An HIV-1-derived lentiviral vector (LV) expressing either the GFP or the mouse Rpe65 cDNA under the control of a 0.8 kb fragment of the human Rpe65 promoter (R0.8) was produced by transient transfection of 293T cells. LV-R0.8-RPE65 or GFP was injected into 5-days-old (P5) or 1 month-old R91W mice. Functional rescue was assessed by ERG (1 and 4 months post-injection) and pupillary light response (PLR) recordings and cone survival by histological analysis. Results:Increased light sensitivity was detected by scotopic ERG in animals injected with LV-R0.8-RPE65 at both P5 and 1 month compared to GFP-treated animals or untreated mice. PLR was also improved in some eyes and histological analysis of cone markers showed that the density of cones reached the wild type level in the region of wt RPE65 delivery after treatment at P5. However, the rescue effect of the injection at 1 month was limited and attained 60% of the wild type level, but still more cones were observed in the treated area than in 1 month-old untreated Rpe65R91W mice. Conclusions:We were able to show that lentivirus-mediated Rpe65 gene transfer not only increases retinal activity of the Rpe65R91W mouse and survival of cones after treatment at P5 but also after treatment at 1 month. However even if the treatment at 1 month is more limited (60% of the wild type level) than treatment at P5, the amount of cone markers is increased compared to the proportion found at 1 month of age in untreated animals. This results contrast with the lack of cone rescue by treatment at 1 month of age in Rpe65-/- (Bemelmans et al, 2006). Thus patient suffering from R91W mutation might benefit from a prolonged therapeutic window.

Ranibizumab in the management of advanced Coats disease Stages 3B and 4: long-term outcomes.

BACKGROUND: Laser photocoagulation and cryotherapy to completely destroy telangiectatic vessels and ischemic retina in Coats disease is barely applicable in advanced cases with total retinal detachment, and globe survival is notoriously poor in Stages 3B and 4. Anti-vascular endothelial growth factor intravitreal injections may offer new prospects for these patients. METHODS: This study is a retrospective review of all consecutive patients with Coats disease treated with neoadjuvant or adjuvant intravitreal ranibizumab plus conventional and amblyopia treatment as appropriate. RESULTS: Nine patients (median age, 13 months) presenting Coats Stages 3B and 4 (5 and 4 eyes, respectively) were included. Iris neovascularization resolved within 2 weeks and retinal reapplication within 4 months in all patients. At last follow-up, globe survival was 100% with anatomical success in 8 of the 9 eyes. With a median follow-up of 50 months, fibrotic vitreoretinopathy was developed in 5 of the 9 cases, one leading to tractional retinal detachment and ultimately phthisis bulbi. The remaining 4 of the 9 eyes achieved some vision (range, 0.02-0.063). CONCLUSION: To the best of the authors' knowledge, this is the largest reported series of late-stage Coats undergoing anti-vascular endothelial growth factor therapy, a homogenous cohort of patients treated with a single agent and with the longest follow-up. This study supports the role of ranibizumab in advanced disease by transient restoration of the hemato-retinal barrier and suppression of neovascularization to facilitate classic treatment. At the last follow-up, the authors report unprecedented anatomical success and functional outcome.

Guidelines for imaging retinoblastoma: imaging principles and MRI standardization.

Retinoblastoma is the most common intraocular tumor in children. The diagnosis is usually established by the ophthalmologist on the basis of fundoscopy and US. Together with US, high-resolution MRI has emerged as an important imaging modality for pretreatment assessment, i.e. for diagnostic confirmation, detection of local tumor extent, detection of associated developmental malformation of the brain and detection of associated intracranial primitive neuroectodermal tumor (trilateral retinoblastoma). Minimum requirements for pretreatment diagnostic evaluation of retinoblastoma or mimicking lesions are presented, based on consensus among members of the European Retinoblastoma Imaging Collaboration (ERIC). The most appropriate techniques for imaging in a child with leukocoria are reviewed. CT is no longer recommended. Implementation of a standardized MRI protocol for retinoblastoma in clinical practice may benefit children worldwide, especially those with hereditary retinoblastoma, since a decreased use of CT reduces the exposure to ionizing radiation.

ERK1/2 pathway is activated in degenerated Rpe65-deficient mice.

The MAPK family is composed of three majors kinases, JNK, p38 and ERK1/2, and is implicated in many degenerative processes, including retinal cell death. The purpose of our study was to evaluate the activation of ERK1/2 kinase, and its potential role in Müller cell gliosis, during photoreceptor cell death in Rpe65(-/-) mice. We assayed ERK1/2 mRNA and protein levels, and evaluated ERK1/2 phosphorylation involved in kinase activation, in 2, 4 and 6 month-old Rpe65(-/-) mice and in age-matched wild-type controls. No differences in ERK1/2 expression were detected between Rpe65(-/-) and wild-type mice, however, ERK1/2 phosphorylation was dramatically increased in the knock out mice at 4 and 6 months-of-age. Phosphorylated ERK1/2 co-localized with GFAP in the ganglion cell layer, and correlated with an increase in GFAP protein expression and retinal cell death. Accumulation of cFOS protein in the ganglion cell layer occurred concomitant with pERK1/2 activation. Müller cell proliferation was not observed. ERK1/2 activation did not occur in 2 month-old Rpe65(-/-) or in the Rpe65(-/-)/Gnat1(-/-) mice, in which no degeneration was evident. The observed activation ERK1/2 and GFAP, both markers of Müller cell gliosis, in the absence of Müller cell proliferation, is consistent with the activation of atypical gliosis occurring during the slow process of degeneration in Rpe65(-/-) mice. As Müller cell gliosis is activated in many neuronal and retinal degenerative diseases, further studies will be needed to determine whether atypical gliosis in Rpe65(-/-) mice contributes to, or protects against, the pathogenesis occurring in this model of Leber congenital amaurosis.

Intravitreal chemotherapy for vitreous disease in retinoblastoma revisited: from prohibition to conditional indications.

BACKGROUND: Tumour control of vitreous seeds remains challenging owing to their resistance to radiation and systemic chemotherapy. OBJECTIVE: To describe the short-term efficacy of intravitreal melphalan for vitreous disease in retinoblastoma using a new injection technique and dose. METHODS: This study is a retrospective non-comparative review of 23 consecutive heavily pretreated patients (23 eyes) with active vitreous seeding and eligible for intravitreous chemotherapy (IViC). They received a total of 122 intravitreal injections of melphalan (20-30 μg) given every 7-10 days. The ocular status was objectively monitored under anaesthesia with fundus photography. RESULTS: All patients are alive without evidence of extraocular spread (95% CI 82.19% to 100%). Concomitant treatments, including other chemotherapeutic modalities, were used until complete sterilisation of the retinal seeding source and subretinal seeds. Globe retention was achieved in 87% (20/23) of cases. All retained eyes were in complete remission after a median follow-up period of 22 months (range 9-31 months). The Kaplan-Meier estimate of ocular survival rates at 2 years was 84.14% (95% CI 62.48% to 95.28%). A localised peripheral salt-and-pepper retinopathy was noted in 10 eyes (43%) at the site of injection. CONCLUSIONS: This study reports the first clinically documented case series of patients with retinoblastoma treated with IViC. Despite a possible confounding effect of concomitant chemotherapy prescription using other routes of administration in four of the successfully treated eyes (20%), IViC achieved an unprecedented success rate of tumour control in the presence of vitreous seeding. Of note, none of the treated eyes required external beam irradiation to control the vitreous seeding. Further studies are required to assess IViC retinal toxicity and to better delineate its role in the management of retinoblastoma.

The sand rat, Psammomys obesus, develops type 2 diabetic retinopathy similar to humans.

PURPOSE: Diabetic retinopathy (DR) is a leading cause of blindness, yet pertinent animal models are uncommon. The sand rat (Psammomys obesus), exhibiting diet-induced metabolic syndrome, might constitute a relevant model. METHODS: Adult P. obesus (n = 39) were maintained in captivity for 4 to 7 months and fed either vegetation-based diets (n = 13) or standard rat chow (n = 26). Although plant-fed animals exhibited uniform body weight and blood glucose levels over time, nearly 60% of rat chow-raised animals developed diabetes-like symptoms (test group). Animals were killed, and their eyes and vitreous were processed for immunochemistry. RESULTS: Compared with plant-fed animals, diabetic animals showed many abnormal vascular features, including vasodilation, tortuosity, and pericyte loss within the blood vessels, hyperproteinemia and elevated ratios of proangiogenic and antiangiogenic growth factors in the vitreous, and blood-retinal barrier breakdown. Furthermore, there were statistically significant decreases in retinal cell layer thicknesses and densities, accompanied by profound alterations in glia (downregulation of glutamine synthetase, glutamate-aspartate transporter, upregulation of glial fibrillar acidic protein) and many neurons (reduced expression of protein kinase Cα and Cξ in bipolar cells, axonal degeneration in ganglion cells). Cone photoreceptors were particularly affected, with reduced expression of short- and mid-/long-wavelength opsins. Hypercaloric diet nondiabetic animals showed intermediate values. CONCLUSIONS: Simple dietary modulation of P. obesus induces a rapid and severe phenotype closely resembling human type 2 DR. This species presents a valuable novel experimental model for probing the neural (especially cone photoreceptor) pathogenic modifications that are difficult to study in humans and for screening therapeutic strategies.

Analysis of photoreceptor abnormality in GUCY2D E837D/R838S transgenic pigs

Purpose: We generated genetically engineered pigs expressing the human dominant GUCY2DE837D/R838S allele to modelize cone dystrophy. After a functional follow-up showing reduced photopic ERG responses (ARVO 2011), we analyzed the eyes by immunohistochemistry and revealed retinal modifications in the transgenic group. Methods: Lentiviral vectors encoding the human double mutant GUCY2DE837D/R838S cDNA under the control of a portion of the pig arrestin-3 promoter (Arr3) were produced and used for lentiviral-mediated transgenesis in pigs. Animals were regularly submitted to behavioral and functional investigations and were sacrificed at 4, 7, 15 and 18 months of age for histological and RT-PCR analyses. Retinal markers were used to evaluate the retinal status of eleven transgenic pigs and 6 non-transgenic controls. The expression of the mutant cDNA was also assayed by RT-PCR. Results: A significant increase in the number of displaced nuclei in the outersegment layer is observed in transgenic animals compared to control animals independently of their age. Part of these nuclei originate from cones as demonstrated by colocalization with cone markers. No significant change in the ONL thickness (central and peripheral retina) was measured between 4 and 18 months of age, showing a slow progression of the disease in the transgenic pigs within this time-frame. Conclusions: Arr3-GUCY2DE837D/R838S pigs show signs of retinal abnormality with slow progression which parallels the loss of photopic function. Further characterization of this model should help to elucidate the molecular mechanisms underlying the disease evolution.

Zapfen-Stäbchen-Dystrophie durch eine neue reinerbige RPE65-Mutation in Leberscher kongenitaler Amaurose Cone-Rod Dystrophy Caused by a Novel Homozygous RPE65 Mutation in Leber Congenital Amaurosis.

Background: The aim of this study was to describe an unexpected phenotype in a family with Leber congenital amaurosis (LCA) due to a retinal pigment epithelium-specific protein 65 kDa (RPE65) homozygous mutation. History and Signs: We analyzed a family from Yemen in which 3 individuals were affected with LCA. Linkage analysis using markers flanking the known LCA genes was done, followed by direct sequencing of RPE65. Therapy and Outcome: Severe visual impairment and night blindness were observed during infancy. We observed photophobia only in the 8-year-old patient. The youngest affected had bilateral hyperopia of + 3.50 and visual acuity of 1/60. The oldest two had visual acuity limited to hand movements in the right eye (OD) and counting fingers in the left eye (OS) for the oldest and of 5/60 OD, 6/60 OS for the other. They showed disc pallor, attenuated vessels, white flecks in the retina mid-periphery and bull's eye maculopathy. ERGs of the oldest child were completely unresponsive. Genomic sequencing identified a novel homozygous missense mutation, IVS2-3C > G, in the second RPE65 intron. Conclusions: We identified a novel LCA-related homozygous RPE65 mutation associated with a severe clinical presentation including an early and severe cone dysfunction. This is in contrast with the presentation associated with other RPE65 mutations predominantly causing rod-cone dystrophy with residual visual function.

Bilateral Uveal Pigmented Alterations With Remarkable Evolution: Long Term Follow-Up in a Case of Possible Bilateral Diffuse Uveal Melanocytic Proliferation

Purpose: to describe a case of probable bilateral diffuse uveal melanocytic proliferation (BDUMP) with scleral involvement, free from systemic malignancies and cataract. Methods: fifty months of follow up with recurrent complete ophthalmological examinations, including fundus photography, fluorescein/indocyanine green angiography (FA) and optical coherence tomography (OCT). Investigations also included an electroretinography (ERG) and histological examination of scleral biopsy. Extraocular malignancies were repeatedly searched. Results: the patient was a 61 year-old Italian man with chronic hepatitis type C. At first visit his best corrected visual acuity (BCVA) was 20/32 in OS and 20/25 in OD. Funduscopy showed multiple patch-shaped pigmented alterations involving macular region and mid retinal periphery. FA showed corresponding areas of late-phase hyperfluorescent pinpoints (figure 1a, OS) and intemediate-phase hypocyanescence (figure 1b, OS), with subtle serous neurosensory retinal detachment confirmed by OCT. Photopic and scotopic ERG tested normal. Systemic prednisone was administered for one month without any improvement. After ten months round pigmentary lesions appeared also in superior scleral surface of both eyes. Biopsy allowed to disclose slightly pigmented spindle cells. BCVA worsened for further 10 months, with enlargement of FA alteration areas but lenses still clear. After 30 months spontaneous coalescence and atrophy of retinal lesions started, paralleled by progressive visual recovery. At the end of our follow up BCVA was 20/25 in OU while scleral pigmentary lesions remained unchanged. Conclusions: we report the case of a patient with main features of BDUMP and some unusual findings. Although not all classical diagnostic criteria were fulfilled, the presence of scleral pigmented lesions and spontaneous visual recovery may enlarge clinical spectrum of the disease.

Effective temporary analgesia for severe painful blind eye.

There are various methods of providing pain relief for painful blind eyes. We wish to recommend this effective method of providing temporary analgesia in patients suffering from a severe painful blind eye before undergoing enucleation.

Prospective study evaluating the predictability of need for retreatment with intravitreal ranibizumab for age-related macular degeneration.

PURPOSE: To investigate the rhythm and predictability of the need for retreatment with intravitreal injections of ranibizumab for neovascular age-related macular degeneration (nAMD). METHODS: This prospective study enrolled 39 patients with treatment-naïve nAMD. After three loading doses of intravitreal ranibizumab, patients underwent an intensified follow-up for 12 months (initially weekly, then with stepwise increases to every 2 weeks and to monthly after each injection). Patients were retreated on an as-needed basis if any fluid or increased central retinal thickness (CRT) (>50μm) was found on spectral domain optical coherence tomography (OCT). Statistical analysis included patients who received at least two retreatments (five injections). RESULTS: A mean of 7.5 injections (range 0-12) were given between months 3 and 15. The mean visual acuity increased by 13.1 and 12.6 ETDRS letters at months 12 and 15 respectively. Two or more injection-retreatment intervals were found in 31 patients. The variability of their intra-individual intervals up to 14 weeks was small (SD 0-2.13 weeks), revealing a high regularity of the retreatment rhythm. The SD was correlated with the mean interval duration (r = 0.89, p < 0.001). The first interval was a good predictor of the following intervals (regression coefficient =0.81). One retreatment criterion was stable in 97 % of patients (cysts or subretinal fluid). CONCLUSION: The results of this study demonstrate a high intra-individual predictability of retreatment need with ranibizumab injections for nAMD. These findings may be helpful for developing individualized treatment plans for maintained suppression of disease activity with a minimum of injections and visits.