Dina Y. Gewaily

Efficacy and safety of voretigene neparvovec (AAV2-hRPE65v2) in patients with RPE65-mediated inherited retinal dystrophy: a randomised, controlled, open-label, phase 3 trial

BACKGROUND Phase 1 studies have shown potential benefit of gene replacement in RPE65-mediated inherited retinal dystrophy. This phase 3 study assessed the efficacy and safety of voretigene neparvovec in participants whose inherited retinal dystrophy would otherwise progress to complete blindness. METHODS In this open-label, randomised, controlled phase 3 trial done at two sites in the USA, individuals aged 3 years or older with, in each eye, best corrected visual acuity of 20/60 or worse, or visual field less than 20 degrees in any meridian, or both, with confirmed genetic diagnosis of biallelic RPE65 mutations, sufficient viable retina, and ability to perform standardised multi-luminance mobility testing (MLMT) within the luminance range evaluated, were eligible. Participants were randomly assigned (2:1) to intervention or control using a permuted block design, stratified by age (<10 years and ≥10 years) and baseline mobility testing passing level (pass at ≥125 lux vs <125 lux). Graders assessing primary outcome were masked to treatment group. Intervention was bilateral, subretinal injection of 1·5 × 1011 vector genomes of voretigene neparvovec in 0·3 mL total volume. The primary efficacy endpoint was 1-year change in MLMT performance, measuring functional vision at specified light levels. The intention-to-treat (ITT) and modified ITT populations were included in primary and safety analyses. This trial is registered with ClinicalTrials.gov, number NCT00999609, and enrolment is complete. FINDINGS Between Nov 15, 2012, and Nov 21, 2013, 31 individuals were enrolled and randomly assigned to intervention (n=21) or control (n=10). One participant from each group withdrew after consent, before intervention, leaving an mITT population of 20 intervention and nine control participants. At 1 year, mean bilateral MLMT change score was 1·8 (SD 1·1) light levels in the intervention group versus 0·2 (1·0) in the control group (difference of 1·6, 95% CI 0·72-2·41, p=0·0013). 13 (65%) of 20 intervention participants, but no control participants, passed MLMT at the lowest luminance level tested (1 lux), demonstrating maximum possible improvement. No product-related serious adverse events or deleterious immune responses occurred. Two intervention participants, one with a pre-existing complex seizure disorder and another who experienced oral surgery complications, had serious adverse events unrelated to study participation. Most ocular events were mild in severity. INTERPRETATION Voretigene neparvovec gene replacement improved functional vision in RPE65-mediated inherited retinal dystrophy previously medically untreatable. FUNDING Spark Therapeutics.

RPGR-associated retinal degeneration in human X-linked RP and a murine model

PURPOSE We investigated the retinal disease due to mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene in human patients and in an Rpgr conditional knockout (cko) mouse model. METHODS XLRP patients with RPGR-ORF15 mutations (n = 35, ages at first visit 5-72 years) had clinical examinations, and rod and cone perimetry. Rpgr-cko mice, in which the proximal promoter and first exon were deleted ubiquitously, were back-crossed onto a BALB/c background, and studied with optical coherence tomography and electroretinography (ERG). Retinal histopathology was performed on a subset. RESULTS Different patterns of rod and cone dysfunction were present in patients. Frequently, there were midperipheral losses with residual rod and cone function in central and peripheral retina. Longitudinal data indicated that central rod loss preceded peripheral rod losses. Central cone-only vision with no peripheral function was a late stage. Less commonly, patients had central rod and cone dysfunction, but preserved, albeit abnormal, midperipheral rod and cone vision. Rpgr-cko mice had progressive retinal degeneration detectable in the first months of life. ERGs indicated relatively equal rod and cone disease. At late stages, there was greater inferior versus superior retinal degeneration. CONCLUSIONS RPGR mutations lead to progressive loss of rod and cone vision, but show different patterns of residual photoreceptor disease expression. Knowledge of the patterns should guide treatment strategies. Rpgr-cko mice had onset of degeneration at relatively young ages and progressive photoreceptor disease. The natural history in this model will permit preclinical proof-of-concept studies to be designed and such studies should advance progress toward human therapy.

OBSTRUCTIVE SLEEP APNEA AND CENTRAL SEROUS CHORIORETINOPATHY

Purpose: The purpose of this study was to determine if there is an association between obstructive sleep apnea (OSA) and central serous chorioretinopathy (CSCR). Methods: Patients with CSCR without a history of steroid use or secondary retinal disease were matched based on age/gender/body mass index with control patients and administered the Berlin Questionnaire to assess for OSA risk. Patients were scored “OSA+” if they were at “high risk” on the Berlin Questionnaire or reported a previous OSA diagnosis. Rates of OSA+ were compared between the 2 groups, odds ratio and its 95% confidence interval was calculated using exact conditional logistic regression. Results: Forty-eight qualifying patients with CSCR were identified. There were no statistically significant differences between the CSCR and control groups by age (mean = 55 years), gender (79% male), body mass index (mean = 28.2), history of diabetes, or hypertension. Within the CSCR group, 22 patients (45.8%) were OSA+ versus 21 control patients (43.8%) (difference = 2.1%; 95% confidence interval, −18.2% to 22.2%; exact odds ratio = 1.08, 95% confidence interval, 0.47–2.49; P = 1.00). Conclusion: When compared with matched controls, patients with CSCR did not have statistically significant higher rates of OSA risk or previous diagnosis. This finding contrasts with previous work showing a strong association between the diseases. The divergence is likely due to our matching controls for body mass index, a significant risk factor for OSA.

Hildebrand solubility parameters measurement via sessile drops evaporation

A method for the measurement of Hildebrand solubility parameter has been developed. This method was based on the measurement of the sessile drop contact angle and contact base width during its evaporation. Experimental results showed that this method is accurate and insensitive to the measurement conditions. The major advantages of this method are that it is time efficient and requires a small amount of liquid (microliter) for the measurement.

Retinal Structure in Cobalamin C Disease: Mechanistic and Therapeutic Implications

Abstract Purpose: To describe the retinal structure in a patient with cobalamin C (cblC) disease. Methods: A 13-year-old male patient diagnosed with cblC disease during a perinatal metabolic screening prompted by jaundice and hypotony underwent ophthalmic examinations, electroretinography (ERG) and spectral domain optical coherence tomography (SD-OCT). Results: The patient carried a homozygous (c.271dupA) mutation in the methylmalonic aciduria and homocystinuria type C (MMACHC) gene. At age 3 months he had a normal eye exam. A pigmentary maculopathy progressed to chorioretinal atrophy from 5–10 months. ERG at 7 months was normal. A nystagmus remained stable since the age of 2 years. At age 13, visual acuity was 20/250 (right eye) and 20/400 (left eye), with a +5.00 D correction, a level of vision maintained since first measurable at age 5 years. SD-OCT showed bilateral macular coloboma-like lesions; there was also a thickened surface layer with ganglion cell layer thinning. Photoreceptor outer segment loss and thinning of the outer nuclear layer (ONL) transitioned to regions with no discernible ONL with a delaminated, thickened, inner retina. Conclusions: A thick surface layer near the optic nerve resembling an immature retina and an initially normal macula that rapidly developed coloboma-like lesions suggest there may be an interference with retinal/foveal development in cblC, a mechanism of maculopathy that may be shared by other early onset retinal degenerations. Photoreceptor loss and inner retinal remodeling confirm associated photoreceptor degeneration.

Sequence analysis and functional characterization of full-length hepatitis B virus genomes from Korean cirrhotic patients with or without liver cancer

This study aimed to identify and characterize mutations in the hepatitis B virus (HBV) genome associated with advanced liver diseases. The 3.2-kb HBV genome of the C2 subgenotype was amplified from sera of 18 cirrhotic Korean patients with (10) or without (8) hepatocellular carcinoma (HCC), and two clones per patient were characterized by transient transfection experiments in human hepatoma cells. While A1762T/G1764A core promoter mutations were highly prevalent in both groups, the G1896A precore mutation to abolish hepatitis B e antigen (HBeAg) expression was more common in HCC clones (55% vs. 20%). High replication capacity was mostly found in HCC clones and associated with core promoter mutations, whereas more non-HCC clones harbored a nonfunctional core gene (34% vs. 8%). Large in-frame deletions in the preS region were found in 60% of HCC clones and 38% of non-HCC clones. They removed the first 11 residues of large envelope protein or impaired small envelope protein expression, or deleted a neutralizing epitope in the preS2 domain. Additional point mutations prevented middle envelope protein expression, or caused nonsense mutations in the preS or S region to truncate large and/or small envelope protein. Consequently, many clones were unable to express or secrete hepatitis B surface antigen (HBsAg). In conclusion, mutations associated with the advanced stage of chronic HBV infection are complex and diverse. Host immune pressure most likely selected for mutations in the HBV genome to abolish or reduce HBeAg or HBsAg production, to enhance genome replication, or to escape neutralizing antibodies. Some of these mutations may contribute to liver cirrhosis or HCC development.

Association between pseudodrusen and delayed patchy choroidal filling in the comparison of age-related macular degeneration treatments trials

females) did not have amblyopia. Both groups were comparable in terms of dermoid diameter (Wilcoxon signed rank test, p = 0.062), graft diameter (Wilcoxon signed rank test, p = 0.198), preoperative astigmatism (Wilcoxon signed rank test, p = 0.077) and postoperative astigmatism (Wilcoxon signed rank test, p = 0.098). Significant differences were noted in preoperative VA and postoperative VA in both groups (Wilcoxon signed rank test, p ≤ 0.002) (Table 1). However, amblyopia was not responsive to surgical management in those who had failed conservative management. The usual surgical approach in limbal dermoids is simple excision mainly due to ease of the procedure. Lamellar keratoplasty is indicated in deep-seated dermoids. In our study, a lamellar graft was performed after excision of dermoid in majority of the cases. We encountered mild graft opacification in 16 eyes, pseudopterygium in three eyes, and staphyloma in one eye. We speculate that staphyloma may be attributed to a thin residual scleral bed, although we did not measure the scleral thickness before or after the surgery. Watts et al. (2002) reported successful surgical management of 49 children with excellent visual results in the majority of their patients. In our study, the mean VA improved significantly after the surgery. However, there was no significant change in the astigmatism postoperatively. This may be attributed to a relatively small tumour size in our patients. We also analysed our patients based on the presence of amblyopia. Both preoperative VA and postoperative VA were better in patients without amblyopia. The VA improved postoperatively in both groups. Our study showed that simple excision with or without lamellar sclerokeratoplasty is effective for management of grade I and grade II corneal limbal dermoids. Long-term follow-up is mandatory especially in young patients to look for possible complications related to scleral thinning.