Development and characterization of an in vitro system of the human retina using cultured cell lines.

BACKGROUND: Previously developed in vitro cultures of the human retina have been solo or dual cell cultures. We developed a triple-cell culture in vitro model utilizing a membrane system to produce a better representation of a functional and morphological human retina. METHODS: Retinal microvascular endothelial cells (HRMVEC/ACBRI181, cell systems), retinal pigment epithelium cells (RPE/ARPE-19, ATCC) and Müller glial cells (Moorfield Institute of Ophthalmology-Müller 1, UCL) were grown in a triple culture. Our optimized triple-culture media contained a mix of specific endothelial medium and high glucose Dulbecco's Modified Eagle's medium, where all three layers were viable for up to 5 days. Co-culture effect on morphological changes (cell staining) and gene expression of functional genes (pigment epithelium derived factor [PEDF] and vascular endothelial growth factor [VEGF]) were measured from RNA via real-time polymerase chain reaction. Expression of tight junction protein 1 (TJP1) was measured in RNA isolated from ARPE-19s, to assess barrier stability. RESULTS: The triple-culture promotes certain cell functionality through up-regulation of TJP1, increasing PEDF and decreasing VEGF expression highlighting its importance for the assessment of disease mechanisms distinct from a solo culture which would not allow the true effect of the native microenvironment to be elucidated. CONCLUSIONS: This model's novelty and reliability allows for the assessment of singular cellular function within the retinal microenvironment and overall assessment of retinal health, while eliminating the requirement of animal-based models.

Ranibizumab 0.5 mg for Diabetic Macular Edema with Bimonthly Monitoring after a Phase of Initial Treatment: 18-Month, Multicenter, Phase IIIB RELIGHT Study.

PURPOSE: To evaluate ranibizumab 0.5 mg using bimonthly monitoring and individualized re-treatment after monthly follow-up for 6 months in patients with visual impairment due to diabetic macular edema (DME). DESIGN: A phase IIIb, 18-month, prospective, open-label, multicenter, single-arm study in the United Kingdom. PARTICIPANTS: Participants (N = 109) with visual impairment due to DME. METHODS: Participants received 3 initial monthly ranibizumab 0.5 mg injections (day 0 to month 2), followed by individualized best-corrected visual acuity (BCVA) and optical coherence tomography-guided re-treatment with monthly (months 3-5) and subsequent bimonthly follow-up (months 6-18). Laser was allowed after month 6. MAIN OUTCOME MEASURES: Mean change in BCVA from baseline to month 12 (primary end point), mean change in BCVA and central retinal thickness (CRT) from baseline to month 18, gain of ≥10 and ≥15 letters, treatment exposure, and incidence of adverse events over 18 months. RESULTS: Of 109 participants, 100 (91.7%) and 99 (90.8%) completed the 12 and 18 months of the study, respectively. The mean age was 63.7 years, the mean duration of DME was 40 months, and 77.1% of the participants had received prior laser treatment (study eye). At baseline, mean BCVA was 62.9 letters, 20% of patients had a baseline BCVA of >73 letters, and mean baseline CRT was 418.1 µm, with 32% of patients having a baseline CRT <300 µm. The mean change in BCVA from baseline to month 6 was +6.6 letters (95% confidence interval [CI], 4.9-8.3), and after institution of bimonthly treatment the mean change in BCVA at month 12 was +4.8 letters (95% CI, 2.9-6.7; P < 0.001) and +6.5 letters (95% CI, 4.2-8.8) at month 18. The proportion of participants gaining ≥10 and ≥15 letters was 24.8% and 13.8% at month 12 and 34.9% and 19.3% at month 18, respectively. Participants received a mean of 6.8 and 8.5 injections over 12 and 18 months, respectively. No new ocular or nonocular safety findings were observed during the study. CONCLUSIONS: The BCVA gain achieved in the initial 6-month treatment period was maintained with an additional 12 months of bimonthly ranibizumab PRN treatment.

Pain related to intravitreal injections for age-related macular degeneration: a qualitative study of the perspectives of patients and practitioners.

OBJECTIVES: Ocular pain is a commonly reported finding in the intravitreal injection procedure, but post-injection experiences and patient adherence to treatment remain underexplored. We therefore aimed to identify key variations in the intravitreal injection procedure that may influence pain, and to gain insights into the post-injection experience and treatment adherence from the perspective of patients and practitioners. DESIGN: Qualitative semistructured interview study using reflexive thematic analysis of transcripts. SETTING: Hospital Eye Clinic in Wales, UK. Interviews were conducted between May and September 2019. PARTICIPANTS: Purposive sample of patients aged ≥50 years with neovascular age-related macular degeneration and no other retinal pathology who had received at least six intravitreal injections, and practitioners including ophthalmologists, registered nurses and optometrists who performed intravitreal injections at the research site. RESULTS: Data saturation was reached with 21 interviews: 14 patients and 7 practitioners. Three main themes were identified from the analysis: fear of losing eyesight and treatment anxiety influence patient adherence to treatment, variability in pain experience during treatment, and post-injection experience and impact on patient recovery. To reassure patients feeling apprehensive about the injections, practitioners promoted safety and trust, and used techniques to manage anxiety. Key variations that may influence pain identified were application of antiseptic or anaesthetic, injecting methods and communication. During injection, patients reported a dull-aching and sharp pain, contrary to practitioners' perspective of feeling a 'pressure'. Patients described prolonged soreness and irritation of up to 36 hours post-injection affecting their sleep and recovery. CONCLUSION: Establishing rapport supported patients to recognise the necessity of ongoing treatment to prevent sight loss; however, inadequate pain management led to undesirable outcomes. Practitioners should use pain assessment tools during and immediately after injection and provide ongoing consistent information to help patients manage pain at home.

Correction: Diabetic retinopathy and diabetic macular oedema pathways and management: UK Consensus Working Group.

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Diabetic retinopathy and diabetic macular oedema pathways and management: UK Consensus Working Group.

The management of diabetic retinopathy (DR) has evolved considerably over the past decade, with the availability of new technologies (diagnostic and therapeutic). As such, the existing Royal College of Ophthalmologists DR Guidelines (2013) are outdated, and to the best of our knowledge are not under revision at present. Furthermore, there are no other UK guidelines covering all available treatments, and there seems to be significant variation around the UK in the management of diabetic macular oedema (DMO). This manuscript provides a summary of reviews the pathogenesis of DR and DMO, including role of vascular endothelial growth factor (VEGF) and non-VEGF cytokines, clinical grading/classification of DMO vis a vis current terminology (of centre-involving [CI-DMO], or non-centre involving [nCI-DMO], systemic risks and their management). The excellent UK DR Screening (DRS) service has continued to evolve and remains world-leading. However, challenges remain, as there are significant variations in equipment used, and reproducible standards of DMO screening nationally. The interphase between DRS and the hospital eye service can only be strengthened with further improvements. The role of modern technology including optical coherence tomography (OCT) and wide-field imaging, and working practices including virtual clinics and their potential in increasing clinic capacity and improving patient experiences and outcomes are discussed. Similarly, potential roles of home monitoring in diabetic eyes in the future are explored. The role of pharmacological (intravitreal injections [IVT] of anti-VEGFs and steroids) and laser therapies are summarised. Generally, IVT anti-VEGF are offered as first line pharmacologic therapy. As requirements of diabetic patients in particular patient groups may vary, including pregnant women, children, and persons with learning difficulties, it is important that DR management is personalised in such particular patient groups. First choice therapy needs to be individualised in these cases and may be intravitreal steroids rather than the standard choice of anti-VEGF agents. Some of these, but not all, are discussed in this document.

Patient-reported outcomes in the RELIGHT clinical trial of ranibizumab in diabetic macular oedema.

BACKGROUND/AIMS: The RELIGHT clinical trial used an individualised treatment regimen of ranibizumab to treat diabetic macular oedema (DMO). We report findings from two patient-reported outcome instruments. METHODS: The National Eye Institute Visual Function Questionnaire (NEI-VFQ) was administered before starting treatment (M0) and at M6, 12 and 18. The Macular Disease Society Treatment Satisfaction Questionnaire (MacTSQ) was administered 1 month after treatment start (M1) and at M6, 12 and 18. Relationships between best-corrected visual acuity (BCVA) in the study eye (SE) and the status of the eye at baseline (as better or worse eye by BCVA) and the two instrument measures were investigated. RESULTS: BCVA in the SE correlated strongly with the NEI-VFQ composite scores and the majority of the subscales but not with the MacTSQ subscales. Statistically significant improvements were observed in the majority of the subscales of the NEI-VFQ at M6, 12 and 18. For the MacTSQ, improvements between baseline M6, 12 and 18 were seen for subscale 1 but only reached statistical significance at M12. In subscale 2, the changes in mean scores were statistically significant at all timepoints. CONCLUSIONS: Although ranibizumab treatment in DMO over an 18-month period resulted in improvements in visual functioning and patient satisfaction, no correlation was found between the instruments used to measure these outcomes. Our finding of a lack of correlation between BCVA and the MacTSQ suggests the presence of psychophysical factors not measured by traditional means.

Retrospective analysis of newly recorded certifications of visual impairment due to diabetic retinopathy in Wales during 2007-2015.

OBJECTIVE: The aim of this study was to analyse the changes in new certifications for both sight impairment (SI) and severe sight impairment (SSI, blindness) in Wales due to diabetic retinopathy (DR)/maculopathy between 2007 and 2015. RESEARCH DESIGN AND METHODS: This is a retrospective analysis of annual data of new certifications for visual impairment and blindness (Certificate of Vision Impairment) for England and Wales derived from the national database provided by the Certifications Office, Moorfields Eye Hospital, over a period of 8 years from 2007. RESULTS: In Wales there were 339 less new certifications for both SI and severe SSI from any cause combined from 2007-2008 to 2014-2015. The number SI and SSI combined specifically due to DR was reduced by 22 in people with known diabetes. This was a reduction in new certifications over the observation period from 82.4 to 46.9 per 100 000 (-43.1%) with a fall in SSI from 31.3 to 15.8 per 100 000 (-49.4%), respectively. During this observation period however, there was a parallel increase in 52 229 (39.8%) persons with diabetes in Wales. CONCLUSIONS: While acknowledging the limitations of the certification process and the increasing numbers of persons with diabetes, the incidence of SI and SSI per 100 000 population of persons with diabetes in Wales has almost halved over an 8-year period up to 2015. This may reflect the earlier diagnosis of DR and sight-threatening DR since the introduction of screening and/or improved diabetes management with timely onward referral and newer treatments.

Factors affecting rejection of second corneal transplants in rats.

BACKGROUND: Second and subsequent corneal transplants in the same eye are more prone to rejection reactions and failure than first grafts. This may be a result of local changes or systemic sensitization to antigen shared by the first and second donors. Because HLA typing is not routine in corneal transplantation, a clear correlation between accelerated rejection and specific sensitization has not been established. METHODS: PVG (RT1), Lewis (LEW; RT1), or AO (RT1) strain corneas were transplanted to PVG strain rats, followed by a LEW strain cornea in the ipsilateral or contralateral eye 6 weeks later. Graft survival was evaluated by slit lamp biomicroscopy. Proliferation of recipient lymph node cells was tested against allogeneic, syngeneic and third-party stimulator cells after the second transplantation. RESULTS: A second allograft in the ipsilateral or contralateral eye was rejected in an accelerated fashion that was not donor MHC specific. Rejection was not significantly accelerated in the ipsilateral eye compared with the contralateral eye. There was a secondary lymphocyte proliferation response to third party (AO strain) in animals previously exposed only to the LEW strain. CONCLUSIONS: Systemic sensitization to donor antigens, rather than local changes induced by first transplantation, contributed to accelerated rejection of a second graft. Accelerated rejection is not dependent on MHC compatibility between the grafts. It could be caused by shared "public" MHC determinants, by minor antigens shared by the first and second donors, or by cross-reactivity of T cells to epitopes on AO and LEW grafts. HLA mismatching of first and second donors may not prolong second graft survival.

Recent developments in the pharmacological treatment and prevention of corneal graft rejection.

At present, given the high initial success rate of corneal transplantation (although late survival is poor), immunosuppression is often reserved for 'high-risk' patients. Despite immune privilege, corneal graft rejection remains the leading cause of corneal allograft failure. Interpreting the limited and also restricted design of most trials, immunosuppressive therapy has not enjoyed the success seen in solid organ grafts. This review discusses the limited data available whilst proposing newer therapies that have developed as a result of our increased understanding of the immunobiology of corneal graft rejection.

Differences in leukocyte phenotype and interferon-gamma expression in stroma and endothelium during corneal graft rejection.

Critical to the success of human corneal transplants is prevention of corneal endothelial rejection, yet little is known about the endothelial infiltrate. To examine the endothelium, a method for removal and processing this layer as a flat sheet was used and the infiltrate was compared with stroma and epithelium. LEW or PVG strain rat corneas were transplanted to PVG strain recipients. Clinical changes after transplantation were monitored by slit lamp and animals sacrificed at a range of time points during rejection. Clinically defined rejection, accompanied by an epithelial rejection line and endothelial cell infiltration, occurred between days 10 and 15. There was some infiltration of leukocytes in the stroma of isografts at these time points, but significantly more in allografts (p<0.003 for all subsets). There was no infiltration of isograft endothelium at any time and no infiltration of allograft endothelium on day 10. On day 15, there were similar numbers of all major subsets except B cells in the stroma, while on the endothelium macrophages, MHC class II(+) cells and CD8(+) cells predominated (p<0.001 CD4(+) vs CD8(+) cells). T cells and NK cells predominated in the epithelial rejection line. While TNF-alpha and IFN-gamma-producing cells were numerous in stroma and epithelium, no IFN-gamma-producing cells were found on endothelium. Distinct differences in infiltrative profile within layers of the cornea suggest that the mechanisms of rejection may also differ. The restricted endothelial cell profile and lack of IFN-gamma suggests that the anti-endothelial response may be modulated by the anterior chamber environment.