A New Technique with Scleral Grooves for Sutureless Scleral Fixation of the Carlevale Intraocular Lens.

INTRODUCTION: A novel technique is described employing scleral grooves to facilitate sutureless scleral fixation of the Carlevale intraocular lens (CIL). We describe its use in a series of 47 patients with aphakia. METHODS: A retrospective study of all patients with aphakia who underwent CIL implantation with the new technique by a single surgeon during 1 year. The novelty of this technique consists in the creation of two partial-thickness linear sclerotomies (grooves), 180° apart, 2 mm from and parallel to the limbus. In the middle of each groove a full-thickness sclerotomy is performed to facilitate externalization of the CIL anchors. The groove allows the anchor to plug the full-thickness sclerotomy and to rest within the sclera without protrusion. Reported outcomes include pre-operative/post-operative visual acuity, post-operative spherical equivalent and surgical complications. Follow-up was a minimum of 6 months. RESULTS: Forty-eight eyes of 47 patients with aphakia with a mean age of 74 years (range 31-90 years) are included. The commonest causes of aphakia were intraocular lens (IOL) subluxation,with or without exfoliation (54.2%), complicated cataract surgery (29.2%), crystalline lens luxation (6.3%) and trauma (4.1%). All CILs inserted with the new technique stayed successfully in situ during follow-up. Median pre-operative best-corrected visual acuity (0.75 logMAR; range 0.1-2.7) significantly improved to 0.5 logMAR post-operatively (p < 0.001). Moreover, 78% and 65% of the operated cases were within 1.0 and 0.5 diopters, respectively, from intended refraction. The most common complications were transient cystoid macular oedema (8.3%) and transient intraocular pressure rise (8.3%), all of which resolved within 2 months. CONCLUSIONS: The proposed modification of sutureless scleral fixation of the CIL appears safe and effective. In our experience it is less time consuming and easier to perform than previous techniques and may therefore offer a useful future option.

Novel SIX6 mutations cause recessively inherited congenital cataract, microcornea, and corneal opacification with or without coloboma and microphthalmia.

Purpose: To investigate the molecular basis of recessively inherited congenital cataract, microcornea, and corneal opacification with or without coloboma and microphthalmia in two consanguineous families. Methods: Conventional autozygosity mapping was performed using single nucleotide polymorphism (SNP) microarrays. Whole-exome sequencing was completed on genomic DNA from one affected member of each family. Exome sequence data were also used for homozygosity mapping and copy number variation analysis. PCR and Sanger sequencing were used to confirm the identification of mutations and to screen further patients. Evolutionary conservation of protein sequences was assessed using CLUSTALW, and protein structures were modeled using PyMol. Results: In family MEP68, a novel homozygous nucleotide substitution in SIX6 was found, c.547G>C, that converts the evolutionarily conserved aspartic acid residue at the 183rd amino acid in the protein to a histidine, p.(Asp183His). This residue mapped to the third helix of the DNA-binding homeobox domain in SIX6, which interacts with the major groove of double-stranded DNA. This interaction is likely to be disrupted by the mutation. In family F1332, a novel homozygous 1034 bp deletion that encompasses the first exon of SIX6 was identified, chr14:g.60975890_60976923del. Both mutations segregated with the disease phenotype as expected for a recessive condition and were absent from publicly available variant databases. Conclusions: Our findings expand the mutation spectrum in this form of inherited eye disease and confirm that homozygous human SIX6 mutations cause a developmental spectrum of ocular phenotypes that includes not only the previously described features of microphthalmia, coloboma, and congenital cataract but also corneal abnormalities.

Management of Full-Thickness Macular Hole in A Genetically Confirmed Case with Usher Syndrome.

INTRODUCTION: Full-thickness macular hole (FTMH) formation is rarely seen in patients with retinitis pigmentosa (RP) and can have an adverse impact on their residual visual function. The underlying mechanisms are unknown, and clinical experience is limited regarding surgical outcomes. Here, we describe the surgical management of FTMH in a young patient with genetically confirmed Usher syndrome, the most common form of syndromic RP. CASE REPORT: A 28-year-old woman presented with blurred vision in her right eye (RE). She had a history of RP and bilateral hearing impairment since childhood. Fundoscopy and spectral-domain optical coherence tomography revealed a FTMH in the RE along with typical RP features bilaterally. After pars plana vitrectomy (PPV) with internal limiting membrane peel and gas tamponade, the FTMH closed. Six months after PPV the patient underwent cataract surgery in the affected eye, and the visual acuity remained stable compared to baseline. The clinical diagnosis of Usher syndrome was genetically confirmed by whole exome sequencing (WES), which revealed the presence of two pathogenic nucleotide variants in trans (compound heterozygosity) in the gene USH2A. CONCLUSION: We report a rare case of successful closure of a FTMH in a patient with Usher syndrome. Surgical treatment of FTMH can help preserve the central vision in RP patients, whose peripheral vision is severely affected.

How Successful is Switching from Bevacizumab or Ranibizumab to Aflibercept in Age-Related Macular Degeneration? A Systematic Overview.

Emerging anti-vascular endothelial growth factor (anti-VEGF) therapies for neovascular age-related macular degeneration (nAMD) have revolutionised medical retina practice and the management and eventual outcome of nAMD. Recent research has focused on evaluating and comparing the efficacy of the two most widely employed anti-VEGF agents, bevacizumab and ranibizumab; however, a subgroup of patients with nAMD demonstrates a suboptimal response to standard therapy. We have therefore conducted a review of pertinent studies published until August 2018 which have documented the clinical efficacy when switching to a different anti-VEGF. Evidence on baseline disease characteristics, injection frequency and disease outcome has been obtained for patients treated with ranibizumab 0.5 mg and/or bevacizumab 1.25 mg and were switched to aflibercept 2 mg. Our review identified 45 studies investigating switching to aflibercept. Our review showed a clear anatomical benefit after the switch in terms of central retinal thickness and pigment epithelium detachment characteristics, whereas the functional outcomes were variable. Remarkable heterogeneity was documented among the relevant studies with regard to several factors including the baseline characteristics of the cohorts, the non-response definition and previous treatment protocols. Larger prospective trials with appropriate control arms are therefore required to elucidate the potential benefit when switching between anti-VEGF agents in refractory nAMD.

Preservative-free tafluprost/timolol fixed combination: comparative 24-h efficacy administered morning or evening in open-angle glaucoma patients.

Background: Ideal dosing for the preservative-free (PF) tafluprost/timolol fixed combination (TTFC) remains to be elucidated. Research design and methods: This study was a prospective, observer-masked, placebo-controlled, crossover, comparison in 42 consecutive open-angle glaucoma patients whose intraocular pressure (IOP) was insufficiently controlled with preserved latanoprost monotherapy (mean 24-h IOP >20 mmHg). Patients were randomized to either morning (08:00) or evening (20:00) PF TTFC for 3 months and then crossed over. After each treatment period, patients underwent habitual 24-h IOP monitoring with Goldmann tonometry in the sitting position (at 10:00, 14:00, 18:00, and 22:00) and Perkins tonometry in the supine position (at 02:00 and 06:00). Results: Mean 24-h IOP on latanoprost was 22.2±3.9 mmHg. Both PF TTFC dosing regimens obtained greater reduction in mean 24-h, daytime, nighttime, and peak 24-h IOP (P < 0.001). Evening dosing provided tighter 24-h IOP fluctuation versus latanoprost (P < 0.001). Evening dosing was superior to morning dosing at four time points (P < 0.01), for the mean daytime IOP (P < 0.001) and mean 24-h IOP fluctuation (P < 0.001). Hyperemia was more common with preserved latanoprost (21.4 vs. 7.1%; P = 0.031). Patients (n = 19; 45%) preferred evening dosing. Conclusions: PF TTFC provided greater 24-h IOP control and less hyperemia compared with preserved latanoprost. Evening administration of this novel medication offered superior 24-h efficacy. Trial registration: Clinicaltrials.gov (NCT03612817).

Defects in the Cell Signaling Mediator ß-Catenin Cause the Retinal Vascular Condition FEVR.

Familial exudative vitreoretinopathy (FEVR) is an inherited blinding disorder characterized by the abnormal development of the retinal vasculature. The majority of mutations identified in FEVR are found within four genes that encode the receptor complex (FZD4, LRP5, and TSPAN12) and ligand (NDP) of a molecular pathway that controls angiogenesis, the Norrin-ß-catenin signaling pathway. However, half of all FEVR-affected case subjects do not harbor mutations in these genes, indicating that further mutated genes remain to be identified. Here we report the identification of mutations in CTNNB1, the gene encoding ß-catenin, as a cause of FEVR. We describe heterozygous mutations (c.2142_2157dup [p.His720∗] and c.2128C>T [p.Arg710Cys]) in two dominant FEVR-affected families and a de novo mutation (c.1434_1435insC [p.Glu479Argfs∗18]) in a simplex case subject. Previous studies have reported heterozygous de novo CTNNB1 mutations as a cause of syndromic intellectual disability (ID) and autism spectrum disorder, and somatic mutations are linked to many cancers. However, in this study we show that Mendelian inherited CTNNB1 mutations can cause non-syndromic FEVR and that FEVR can be a part of the syndromic ID phenotype, further establishing the role that ß-catenin signaling plays in the development of the retinal vasculature.

Twenty-four-hour intraocular pressure monitoring in normotensive patients undergoing chronic hemodialysis.

PURPOSE: To investigate 24-hour intraocular pressure (IOP) changes caused by hemodialysis (HD). METHODS: A prospective, observational, comparative 24-hour trial was performed on consecutive subjects with normal IOP undergoing maintenance HD 3 days a week between 13:00 and 17:00 hours in an academic setting. Following a comprehensive ocular assessment, those with conditions that may influence IOP were excluded and one eye was randomly selected. Twenty-four-hour IOP monitoring was performed on HD day 1 and then on a day without HD. The IOP was measured at 10:00, 13:00, 15:00, 17:00, 22:00, 02:00, and 06:00 employing Goldmann and Perkins tonometry on habitual position. During the course of 1 year, 18 patients completed the study. RESULTS: Monitoring of IOP on HD day showed a significantly higher mean 24-hour IOP (15.4 ± 2.7 vs 14.1 ± 2.2 mm Hg; p = 0.025), higher mean peak 24-hour IOP (18.5 ± 3.5 vs 15.8 ± 2.5 mm Hg; p = 0.003), and wider 24-hour IOP fluctuation (6.2 ± 2.3 vs 4.0 ± 1.9 mm Hg; p = 0.001). When individual time points were compared, IOP was significantly higher at 17:00 on HD day, reflecting a gradual IOP elevation during HD (p = 0.021). Further, during the HD procedure (13:00-17:00), the mean IOP was significantly higher on a HD day (16.4 ± 3.0 vs 14.7 ± 2.4 mm Hg; p = 0.004). CONCLUSIONS: This prospective, before/after trial suggests that HD significantly impacts 24-hour IOP characteristics in normotensive eyes. The long-term significance of these findings requires further elucidation in normotensive patients and, predominantly, in patients with glaucoma undergoing HD.

Novel C8orf37 mutations cause retinitis pigmentosa in consanguineous families of Pakistani origin.

PURPOSE: To investigate the molecular basis of retinitis pigmentosa in two consanguineous families of Pakistani origin with multiple affected members. METHODS: Homozygosity mapping and Sanger sequencing of candidate genes were performed in one family while the other was analyzed with whole exome next-generation sequencing. A minigene splicing assay was used to confirm the splicing defects. RESULTS: In family MA48, a novel homozygous nucleotide substitution in C8orf37, c.244-2A>C, that disrupted the consensus splice acceptor site of exon 3 was found. The minigene splicing assay revealed that this mutation activated a cryptic splice site within exon 3, causing a 22 bp deletion in the transcript that is predicted to lead to a frameshift followed by premature protein truncation. In family MA13, a novel homozygous null mutation in C8orf37, c.555G>A, p.W185*, was identified. Both mutations segregated with the disease phenotype as expected in a recessive manner and were absent in 8,244 unrelated individuals of South Asian origin. CONCLUSIONS: In this report, we describe C8orf37 mutations that cause retinal dystrophy in two families of Pakistani origin, contributing further data on the phenotype and the spectrum of mutations in this form of retinitis pigmentosa.