Does delay in referral of proliferative diabetic retinopathy from the diabetic eye screening programme lead to visual loss?

AimsTo ascertain the effect on visual acuity (VA) of a delay in Hospital Eye Service (HES) consultation for patients referred with proliferative diabetic retinopathy (PDR; R3) from the Diabetic Eye Screening Programme (DESP).MethodsAll patients referred to Moorfields Eye Hospital from DESP between April and December 2013 with a referral diagnosis of PDR in at least one eye were eligible. Screening programme VA was compared with VA at first HES appointment and final follow-up appointment. Reasons for any VA loss were noted.ResultsA total of 86 patients were included. Of these, 28 (33%) were seen in more than 4 weeks after their DESP referral. At first HES appointment, 39 (45%) patients were graded as having active PDR in at least one eye. Delay in referral did not significantly predict the likelihood of vision loss in all patients referred (χ(2), P=0.49) or in just those patients with a definitive HES diagnosis of active PDR (χ(2), P=1.00). In only 3 patients with active PDR was a delay in presentation thought to have led directly to VA loss.ConclusionsThere may be minimal short-term visual consequence in several weeks of delayed referral for many patients with a diagnosis of R3. However, the national guidance remains important. This is due to the occasional patient at very high risk of vision loss and the many gains for the patients in terms of time to properly assess medical and ocular conditions and counsel and consent them for treatment where necessary.

Structural changes of the choroid in sarcoid- and tuberculosis-related granulomatous uveitis.

AIM: The aim of this study is to characterise the choroidal features of patients diagnosed with sarcoid- and tuberculosis (TB)-associated granulomatous uveitis using spectral domain optical coherence tomography (OCT). METHODS: Twenty-seven patients (27 eyes) diagnosed with sarcoid- (13 eyes) and TB (14 eyes)-related uveitis were included in this retrospective, cross-sectional study. Over a six-month period, patients diagnosed with sarcoid and TB granulomatous uveitis were scanned using enhanced depth imaging OCT. Clinical and demographical characteristics were recorded, including the method of diagnosis, disease activity, site of inflammation (anterior or posterior), treatments, and visual acuity (VA). Manual segmentation of the choroidal layers was performed using custom image analysis software. RESULTS: The main outcome measure was OCT-derived thickness measurements of the choroid and choroidal sublayers (Haller's large vessel and Sattler's medium vessel layers) at the macula region. The ratio of Haller's large vessel to Sattler's medium vessel layer was significantly different at the total macula circle in eyes diagnosed with TB uveitis (1.47 (=140.71/95.72 µm)) compared with sarcoid uveitis (1.07 (=137.70/128.69 µm)) (P=0.001). A thinner choroid was observed in eyes with a VA ≥0.3 LogMAR (Snellen 6/12; 198.1 µm (interquartile range (IQR)=147.0-253.4 µm) compared with those with VA <0.3 LogMAR (292.4 µm (IQR=240.1-347.6 µm)) at the total macula circle (P=0.004). At the foveal central subfield, the median choroidal thickness was 336.8 µm (IQR=272.3-375.4 µm) in active compared with 239.3 µm (IQR=195.3-330.9 µm) in quiescent disease (P=0.04). CONCLUSION: A disproportionately enlarged Sattler's layer may indicate a diagnosis of sarcoid-related uveitis, and choroidal thickening may be a feature of active granulomatous uveitis.

A detailed phenotypic description of autosomal dominant cone dystrophy due to a de novo mutation in the GUCY2D gene.

PURPOSE: The purpose of this study is to describe the phenotype of a family with de novo mutation in the GUCY2D. MATERIALS AND METHODS: Five subjects, including two monozygotic twins, underwent ophthalmic clinical examination while some had autofluorescence imaging (AF) and optical coherence tomography (OCT). Symptomatic individuals underwent electrophysiological testing. The youngest subject (21 years) was also evaluated psychophysically. DNA obtained from the individuals was screened for mutations in GUCY2D. Microsatellite markers were used to determine the haplotype of 17p surrounding the GUCY2D gene. RESULTS: The youngest subject had 6/18 visual acuity, an annulus of hyper-autofluorescence in the perifoveal region, and a subfoveal absence of outer segments on OCT. In the older individuals, severe thinning of inner retina and a patchy loss of photoreceptors and retinal pigment epithelium were observed in the perifoveal region. All three showed generalised cone system dysfunction with preserved rod function on electrophysiology. Psychophysical evaluation was consistent with poor cone function. Screening of the GUCY2D gene revealed the mutation p.R838H in all the affected individuals and was absent in the asymptomatic patients. Haplotyping showed that the mutation originated from the unaffected mother. CONCLUSIONS: Autosomal dominant cone dystrophy due to GUCY2D can occur without a history in the antecedents due to a de novo mutation. This is important to consider in any simplex case with a similar phenotype. The phenotype description of this disorder is expanded with detailed description of the OCT findings. This paper describes the concordance of the phenotypic findings in the monozygotic twins.

Failure of ES-62 to inhibit T-helper type 1 responses to other filarial nematode antigens.

ES-62 is a secreted protein of filarial nematodes that possesses multiple immunomodulatory activities. A full characterization of these activities awaits elucidation but to date it has been shown that ES-62 can inhibit pro-inflammatory/Th1 immune responses and in some studies, it has been found to actively support Th2 development. As an active filarial nematode infection is associated with a Th2-like immunological phenotype, this study investigated whether ES-62 was likely to be responsible for, or at least contribute to, this phenotype. Specifically, we determined ES-62's effect on the immune response to two other filarial nematode antigens, chosen for their ability to promote Th1 responses. The two antigens were recombinant Onchocerca volvulus-Fatty acid And Retinol-binding-1 (rOv-FAR-1) and recombinant Onchocerca volvulus-Activation associated Secreted Protein-1 (Ov-ASP-1). Overall the results show that in spite of its previously characterized immunomodulatory properties, ES-62 was unable to modulate/reverse the Th1 immune responses induced by the two Onchocerca antigens. Therefore, in this study no support is provided for the idea that ES-62 might be a major player in facilitating the overall immunological phenotype in filariasis and reasons for this somewhat surprising outcome are discussed.

Attitudes and perceptions regarding skin cancer and sun protection behaviour in an Irish population.

BACKGROUND: Although people seem to be well educated on the harmful effects of the sun, they continue to intentionally expose themselves without adequate protection. AIMS: To ascertain baseline knowledge regarding skin cancer and review the sun protection behaviours in an Irish population and the effect of doctor-based education on these behaviours. METHODS: Two hundred participants were recruited for a questionnaire-based study on their perceptions regarding skin cancer and their sun protection behaviour. They were divided into two groups, with one group receiving doctor-based education following the initial survey, and a follow-up questionnaire was carried out within 3 months. RESULTS: Ninety per cent of participants knew that sun exposure was the major risk factor for skin cancer, and 95% knew that sun beds were not a safe way to tan. Despite this, < 20% used regular sunscreen, and 30% had used or were currently using sun beds in order to tan. CONCLUSION: Our study indicated that although the participants' knowledge of skin cancer and risk of sun exposure is high, their sun-protective attitudes were not influenced by education in the clinical setting.

The pathology of Plasmodium chabaudi infection is not ameliorated by the secreted filarial nematode immunomodulatory molecule, ES-62.

ES-62 is a phosphorylcholine-containing glycoprotein secreted by filarial nematodes. This molecule has been shown to reduce the severity of inflammation in collagen-induced arthritis (CIA) in mice, a model of rheumatoid arthritis, via down-regulation of anti-collagen type 1 immune responses. Malaria parasites induce a pro-inflammatory host immune response and many of the symptoms of malaria are immune system-mediated. Therefore we have asked whether the immunomodulatory properties of ES-62 can down-regulate the severity of malaria infection in BALB/c mice infected with Plasmodium chabaudi. We have found that ES-62 has no significant effect on the course of P. chabaudi parasitaemia, and does not significantly affect any of the measures of malaria-induced pathology taken throughout infection.

Phosphorylcholine mimics the effects of ES-62 on macrophages and dendritic cells.

Modulation of macrophage/dendritic cell (DC) cytokine production by the filarial nematode phosphorylcholine (PC)-containing product, ES-62, is mediated by Toll-like receptor (TLR) 4 and signal transduction depends on the TLR adaptor MyD88. Intriguingly, comparison of TLR4 knock-out (ko) mice with TLR4 mutant C3H/HeJ mice indicates that ES-62 cytokine responses are not dependent on the Pro712 residue of TLR4, which is crucial for the response to bacterial lipopolysaccharide (LPS). Because other immunomodulatory effects of ES-62 have been attributed to PC we have now investigated, using PC conjugated to ovalbumin (PC-Ova), whether PC is responsible for the interaction of ES-62 with TLR4. PC-Ova mimicked the modulation of interleukin (IL)-12 production by ES-62 in a TLR4- and MyD88-dependent manner and as with native ES-62, PC-Ova effects were not dependent on Pro712. Furthermore, both native ES-62 and PC-Ova suppressed Akt phosphorylation, whereas neither altered the activation of p38 or Erk MAP kinases. To rule out any role for the ES-62 protein component, we tested a PC-free recombinant ES-62 (rES-62) generated in the yeast Pichia pastoris. Surprisingly, rES-62 also modulated IL-12 production, but in a TLR4/MyD88-independent manner. Furthermore, rES-62 strongly activated both the p38 and Erk MAP kinases and Akt. However, recent biophysical analysis suggests there are differences in folding/shape between native and rES-62 and hence data obtained with the latter should be treated with caution. Nevertheless, although our study indicates that PC is likely to be primarily responsible for the modulation of cytokine production observed with native ES-62, an immunomodulatory role for the protein component cannot be ruled out.

Functional observations in vitamin A deficiency: diagnosis and time course of recovery.

AIMS: To describe the effects of vitamin A deficiency (VAD) on retinal function and the subsequent recovery following treatment in three patients with systemic conditions (two with Crohn disease; one secondary to IgE syndrome). METHODS: Electrophysiological testing (including pattern electroretinogram, PERG; electroretinogram, ERG; visual-evoked potential) established the diagnosis of VAD. Repeat testing was carried out in two patients to monitor the time course of recovery following intramuscular vitamin A injection. The third patient had repeat recordings following 13 months of oral supplementation. RESULTS: All three patients initially displayed a characteristic absence of rod function associated with VAD. In addition, delayed and reduced amplitude cone ERGs, loss of short wavelength cone (S-cone) function and subnormal macular function were observed in two patients. Restoration of rod and generalised cone function was rapid in the two patients who received intramuscular injection, with normalisation of some electrophysiological responses after only 3 days. Normal S-cone amplitudes and cone latencies were reached within 12 days of vitamin A injection. Macular function returned to within normal limits by 12 days postinjection in one patient, but remained mildly subnormal in the second patient. Full recovery was present after 13 months oral supplementation in the third patient. CONCLUSIONS: Novel observations regarding dark-adapted cone function, S-cone function, and PERG are presented. The differences between the effects of VAD on rod and cone function, and their rate of recovery, may reflect differences in the visual cycle between the two photoreceptor classes. The importance of rapidly and accurately diagnosing VAD, a treatable condition, is noted.

Investigation of strategies with potential for producing a phosphorylcholine-free version of the filarial nematode immunomodulator, ES-62.

Phosphorylcholine (PC) is found attached to N-type glycans of proteins secreted by filarial nematodes, where it appears to act as an immunomodulator. Based on information on the structure and biosynthesis of the PC-glycan of a major secreted protein, ES-62, strategies were designed with potential for preparing PC-free material to better understand the importance of PC in filarial nematode immunomodulation. The strategies involve either enzymatic removal of PC or inhibition of its attachment during ES-62 synthesis. No method tested was found to be 100% effective although approximately 70% removal was obtained by culturing worms in Et18OCH3. Reasons for failure to obtain complete absence of PC moieties are discussed in relation to the structure and synthesis of PC-glycans and in addition PC-glycan biosynthesis is briefly commented on as a target for chemotherapy.

Lack of immunological cross-reactivity between parasite-derived and recombinant forms of ES-62, a secreted protein of Acanthocheilonema viteae.

The longevity of filarial nematodes is dependent on secreted immunomodulatory products. Previous investigation of one such product, ES-62, has suggested a critical role for post-translationally attached phosphorylcholine (PC) moieties. In order to further investigate this, ES-62 lacking PC was produced, using the Pichia pastoris recombinant gene expression system. Unlike parasite-derived ES-62, which is tetrameric the recombinant material was found to consist of a mixture of apparently stable tetramers, dimers and monomers. Nevertheless, the recombinant protein was considered to be an adequate PC-free ES-62 as it was recognized by existing antisera against the parasite-derived protein. However, subsequent to this, recognition of parasite-derived ES-62 by antibodies produced against the recombinant protein was found to be absent. In an attempt to explain this, recombinant ES-62 was subjected to structural analysis and was found to (i) contain 3 changes in amino acid composition; (ii) demonstrate significant alterations in glycosylation; (iii) show major differences in protein secondary structure. The effects of these alterations in relation to the observed change in immunogenicity were investigated and are discussed. The data presented clearly show that recognition by existing antibodies is insufficient proof that recombinant proteins can be used to mimic parasite-derived material in studies on nematode immunology and vaccination.

An atypical phenotype of macular and peripapillary retinal atrophy caused by a mutation in the RP2 gene.

AIMS: To determine the molecular basis and describe the phenotype of an atypical retinal dystrophy in a family presenting with bilateral, progressive central visual loss. METHODS: Family members were examined. Investigations included Goldman perimetry, electrophysiology, and autofluorescence imaging. Candidate gene screening was performed using SSCP and sequence analysis. The proband's lymphoblastoid cells were examined for protein expression. RESULTS: Fundal examination of the proband, his mother, and brother revealed peripapillary and macular atrophy. Autosomal dominant retinal dystrophy was suspected, but less severe disease in the mother led to screening for mutations in X linked genes. A 4 bp microdeletion in exon 3 of the RP2 gene, segregating with disease, was identified. No RP2 protein expression was detected. CONCLUSION: The distinct phenotype in this family, caused by this frameshifting mutation in RP2, broadens the phenotypic spectrum of X linked retinitis pigmentosa. The absence of RP2 protein suggests that loss of protein function and not novel gain of function could account for the atypical phenotype. A definitive diagnosis of X linked retinitis pigmentosa permits appropriate genetic counselling with important implications for other family members. Clinicians should have a low threshold for screening RP2 in families with retinal dystrophy, including posterior retinal disease, not immediately suggestive of X linked inheritance.

Treatment of epidermolysis bullosa acquisita with the humanized anti-Tac mAb daclizumab.

Epidermolysis bullosa acquisita (EBA) is an autoimmune subepidermal blistering disease characterized by IgG anti-basement membrane autoantibodies to collagen VII. Since autoantibody formation in EBA patients is thought to be T-cell-dependent, the degree of T cell activation in three patients (all males, ages 33-44 years) was assessed by quantitation of soluble Tac, a fragment of the alpha-subunit of the high-affinity IL-2 receptor (CD25). Soluble Tac levels in all patients were elevated [highest random values, 2430, 920, and 560 IU/ml (normal range, 112-502)]. Based on such findings, these patients were treated with the humanized murine monoclonal anti-Tac antibody daclizumab (1 mg/kg, 6-12 iv treatments at 2- to 4-week intervals). All patients had a significant, rapid, and persistent decrease in lymphocyte CD25 expression. Though a moderate decrease in lymphocyte expression of 7G7, an IL-2 receptor epitope not bound by daclizumab, was noted, stable levels of CD3 cells and in vitro saturation studies indicated that daclizumab effectively bound CD25 and did not promote clearance of such cells from peripheral blood. There were no complications and no patient developed antibodies against daclizumab. While no apparent clinical benefit was seen in two patients with dermolytic disease, one patient with inflammatory EBA had a favorable response. While on daclizumab, this patient stopped prednisone, significantly reduced dapsone, and improved clinically. Furthermore, his disease flared when treatment was stopped, and resumption of daclizumab again effected improvement within 2 weeks. Daclizumab therapy is safe and well tolerated in EBA patients. It may be effective as a corticosteroid sparing agent in patients with inflammatory EBA.

Anti-epiligrin cicatricial pemphigoid and relative risk for cancer.

It is not known whether patients with anti-epiligrin cicatricial pemphigoid (AECP) have an increased risk of malignancy. We calculated the expected numbers of cancers in a cohort of 35 such patients based on respective incidence rates for all cancers in the National Cancer Institute's Surveillance, Epidemiology, and End Results (NCI SEER) Registry. Ten patients in this cohort had solitary solid cancers; eight patients developed cancer after onset of AECP (seven within 14 months). The relative risk (RR) for cancer in this cohort was 6.8 (95% confidence intervals [CI]: 3.3-12.5). AECP seems to be associated with an increased relative risk for cancer.