Background: Innovations in engineering and neuroscience have enabled the development of sophisticated visual prosthetic devices. In clinical trials, these devices have provided visual acuities as high as 20/460, enabled coarse navigation, and even allowed for reading of short words. However, long-term commercial viability arguably rests on attaining even better vision and more definitive improvements in tasks of daily living and quality of life. Purpose: Here we review technological and biological obstacles in the implementation of visual prosthetics. Conclusions: Research in the visual prosthetic field has tackled significant technical challenges, including biocompatibility, signal spread through neural tissue, and inadvertent activation of passing axons; however, significant gaps in knowledge remain in the realm of neuroscience, including the neural code of vision and visual plasticity. We assert that further optimization of prosthetic devices alone will not provide markedly improved visual outcomes without significant advances in our understanding of neuroscience.
Retinal imaging is a fundamental tool for clinical and research efforts in the evaluation and management of diabetic retinopathy. Adaptive optics (AO) is an imaging technique that enables correction of over 90% of the optical aberrations of an individual eye induced primarily by the tear film, cornea and lens. The two major tasks of any AO system are to measure the optical imperfections of the eye and to then compensate for these aberrations to generate a corrected wavefront of reflected light from the eye. AO scanning laser ophthalmoscopy (AOSLO) provides a theoretical lateral resolution limit of 1.4 μm, allowing the study of microscopic features of the retinal vascular and neural tissue. AOSLO studies have revealed irregularities of the photoreceptor mosaic, vascular loss, and details of vascular lesions in diabetic eyes that may provide new insight into development, regression, and response to therapy of diabetic eye disease.
PURPOSE: Light scatter results in degradation of visual function. An optical bench model was used to identify the origins of scatter in the setting of a Boston keratoprosthesis (KPro). The effect of various modifications in the device design and light-blocking configurations was explored. METHODS: A KPro was mounted on a contact lens holder on a bench, and forward light scatter was recorded with a camera attached to a rotating goniometer arm. Scattered light was recorded at different angles for different KPro modifications, and the point-spread function (PSF) curves were recorded. The area under the curve (AUC) was calculated for each PSF curve. RESULTS: The isolated KPro optical cylinder in a totally blackened holding lens had a tight PSF (AUC = 3.3). Additional blackening of the walls of the KPro stem did not further diminish forward scatter significantly. If the holding lens is made translucent by sandblasting (to simulate an in vivo carrier cornea) and the KPro is inserted without a backplate, forward scatter is substantial (AUC = 11.3). If a standard backplate (with holes) is added, light scatter is considerably reduced regardless of whether the backplate is made of polymethyl methacrylate or titanium (AUC = 5.3 and 4.4, respectively). Addition of an acrylic intraocular lens behind the KPro (the pseudophakic KPro setup) did not increase scatter. CONCLUSIONS: Most of the scattered light in eyes implanted with a KPro originates from the surrounding hazy corneal graft. The standard addition of a backplate reduces light scatter. There was no difference in forward light scatter between the aphakic and the pseudophakic KPro.
Technological advances provide a number of options for glaucoma monitoring outside the office setting, including home-based tonometry and perimetry. This has the potential to revolutionize management of this chronic disease, improve access to care, and enhance patient engagement. Here, we provide an overview of existing technologies for home-based glaucoma monitoring. We also discuss areas for future research and the potential applications of these technologies to telemedicine, which has been brought to the forefront during the ongoing COVID-19 pandemic.
Glaucoma refers to a heterogenous group of disorders characterised by progressive loss of retinal ganglion cells and associated visual field loss. Both early-onset and adult-onset forms of the disease have a strong genetic component. Here, we summarise the known genetic associations for various forms of glaucoma and the possible functional roles for these genes in disease pathogenesis. We also discuss efforts to translate genetic knowledge into clinical practice, including gene-based tests for disease diagnosis and risk-stratification as well as gene-based therapies.
UNLABELLED: Oral delivery of poorly soluble and permeable drugs represents a significant challenge in drug development. The oral delivery of drugs remains to be the ultimate route of any drugs. However, in many cases, drugs are not absorbed well in the gastrointestinal tract, or they lose their activity. Polymer micelles were recognized as an effective carrier system for drug encapsulation, and are now studied as a vehicle for oral delivery of insoluble compounds. We characterized the properties of monomethoxy polyethylene glycol-poly lactic acid (mPEG-PLA) micelles, and visualized their internalization in mouse small intestine. Using Caco-2 cells as a cellular model, we studied the kinetics of particle uptake, their transport, and the molecular mechanism of their intestinal absorption. Moreover, by inhibiting specific endocytosis pathways, pharmacologically and genetically, we found that mPEG-PLA nanoparticle endocytosis is mediated by clathrin in an energy-dependent manner, and that the low-density lipoprotein receptor is involved. FROM THE CLINICAL EDITOR: Many current drugs used are non-water soluble and indeed, the ability to deliver these drugs via the gastrointestinal tract remains the holy grail for many researchers. The authors in this paper developed monomethoxy polyethylene glycol-poly lactic acid (mPEG-PLA) micelles as a drug nanocarrier, and studied the mechanism of uptake across intestinal cells. The findings should improve our current understanding and point to the development of more nanocarriers.
Wolfram syndrome was initially reported as an autosomal recessive (AR), progressive neurodegenerative disorder that leads to diabetes insipidus, childhood onset diabetes mellitus (DM), optic atrophy, and deafness (D) also known as DIDMOAD. However, heterozygous dominant pathogenic variants in Wolfram syndrome type 1 (WFS1) may lead to distinct, allelic conditions, described as isolated sensorineural hearing loss (SNHL), syndromic SNHL, congenital cataracts, or early onset DM. We report a family with a novel dominant, likely pathogenic variant in WFS1 (NM_006005.3) c.2605_2616del12 (p.Ser869_His872del), resulting in cataracts, SNHL, and DM in a female and her mother. A maternal aunt had cataracts, DM, and SNHL but was not tested for the familial WFS1 mutation. Both the mother and maternal aunt had early menopause by age 43 years and infertility which may be a coincidental finding that has not been associated with autosomal dominant AD WFS1-related disorder to the best of our knowledge. Screening at risk individuals in families with the AR Wolfram syndrome, for DM, SNHL, and for cataracts is indicated.
PURPOSE: To evaluate the safety and efficacy of topical tacrolimus 0.05% versus topical methylprednisolone 0.5% in patients with ocular graft-versus-host disease (GVHD). DESIGN: Phase 1/2 prospective, randomized, double-masked clinical trial. PARTICIPANTS: Eighty eyes of 40 patients diagnosed with chronic ocular GVHD were enrolled. METHODS: Forty patients with ocular GVHD were randomized; 24 patients were treated with topical tacrolimus 0.05% and 16 patients were treated with topical methylprednisolone 0.5% twice daily for 10 weeks, in addition to continuing their baseline treatment regimen. MAIN OUTCOME MEASURES: Safety was evaluated based on occurrence of adverse events. Tolerability was assessed based on subject reports of discomfort after drop instillation. Intraocular pressure (IOP) was monitored. The main efficacy end points were corneal fluorescein staining (CFS), tear film break-up time (TBUT), Schirmer test results, and expression of the ocular surface inflammatory markers human leukocyte antigen-DR (HLA-DR) and intercellular adhesion molecule-1 (ICAM-1). Symptoms were evaluated using the Ocular Surface Disease Index (OSDI). RESULTS: After 10 weeks of treatment, no major adverse events occurred in either treatment group, and there was no significant difference in the composite tolerability scores between the 2 groups (P = 0.06). However, burning sensation was more pronounced with tacrolimus (P = 0.002). Topical tacrolimus was more effective than methylprednisolone in reducing the CFS score at week 10 (55% vs. 23% reduction, respectively; P = 0.01) and achieved significant improvement in TBUT when compared with baseline (P < 0.001). Reduction in OSDI score achieved statistical significance with tacrolimus (27% reduction; P = 0.02), but was marginal with methylprednisolone (32% reduction; P = 0.06). Expression of ICAM-1 by ocular surface epithelium decreased significantly in both groups (tacrolimus, P = 0.003; methylprednisolone, P = 0.008), whereas HLA-DR expression decreased significantly only in the tacrolimus group (P = 0.03). Schirmer test scores did not change significantly in either group during the study; IOP increased significantly with methylprednisolone at week 10 (P = 0.04). CONCLUSIONS: Topical tacrolimus 0.05% is safe, generally well tolerated, and effective for the treatment of ocular GVHD without the hypertensive effects of topical corticosteroids.
Uveitis is a common and serious complication of juvenile idiopathic arthritis. Up to 75% of all cases of anterior uveitis in childhood are associated with juvenile idiopathic arthritis. Despite the remarkable progress in early detection and treatment of inflammation, vision-threatening complications of uveitis still occur in almost 60% of patients. Structural complications include band keratopathy, maculopathy (macular edema, macular cysts, and epiretinal membrane), glaucomatous optic neuropathy, and cataracts. The management of complications in juvenile idiopathic arthritis is usually complex and requires early surgical intervention. In this paper, we review the general concepts of common ocular complications seen in patients with JIA-associated uveitis, with special attention to the recent diagnostic and preferred treatment approaches at the Massachusetts Eye Research and Surgery Institution. Received 9 March 2015; revised 30 September 2015; accepted 30 October 2015; published online 14 January 2016.
Paracrine interactions between epithelial cells and stromal fibroblasts occur during tissue repair, development, and cancer. Crucial to these processes is the production of matrix metalloproteinases (MMPs) that modify the microenvironment. Here, we demonstrated that the carbohydrate-binding protein galectin-3 stimulated microenvironment remodeling in the cornea by promoting the paracrine action of secreted interleukin-1β (IL-1β). Through live cell imaging in vitro, we observed rapid activation of the promoter in clusters of cultured human epithelial cells after direct heterotypic contact with single primary human fibroblasts. Soluble recombinant galectin-3 and endogenous galectin-3 of epithelial origin both stimulated MMP9 activity through the induction of IL-1β secretion by fibroblasts. In vivo, mechanical disruption of the basement membrane in wounded corneas prompted an increase in the abundance of IL-1β in the stroma and increased the amount of gelatinase activity in the epithelium. Moreover, corneas of galectin-3-deficient mice failed to stimulate IL-1β after wounding. This mechanism of paracrine control has broad importance for our understanding of how the proteolytic microenvironment is modified in epithelial-stromal interactions.
PURPOSE: To describe clinical manifestations, diagnostic approaches, therapy, and outcomes of biopsy-proven intraocular lymphoma. METHODS: Review of tertiary referral center records between 2005 and 2015. RESULTS: A total of 51 eyes of 26 patients were included; mean age of onset was 60.42 years. Common ocular complaints included floaters (42%) and blurred vision (35%); 62% of patients had ocular and central nervous system involvement; 11% had systemic lymphoma; and 27% had only ocular involvement. Vitreous analysis was positive for malignant cells in 77% of patients on initial biopsy, and in 100% of patients on repeat biopsy. In total, 20/26 patients received systemic and topical treatment before IOL diagnosis was made; 25 patients received intravitreal methotrexate and/or rituximab; one patient received intracameral rituximab. All patients achieved remission by their final visit. CONCLUSIONS: Intraocular lymphoma often masquerades as intraocular inflammation, resulting in delayed or misdiagnosis with subsequent inappropriate management. Optimal therapy is a challenge for oncologists and ophthalmologists.
The cornea is an extraordinary component of vision that functions as the principal barrier to pathogens in the eye while allowing light transmission into the retina. Understanding the cellular and molecular mechanisms that maintain homeostasis in this tissue is the subject of intense scientific study given the high prevalence of corneal disease. Over the past decade, the interactions between lectins and glycans on plasma membranes have emerged as important regulatory factors in corneal biology. In particular, members of the galectin family have been shown to bind multiple β-galactoside-containing receptors to regulate immunopathological processes associated with viral and bacterial infection, transplantation, wound healing, dry eye, angiogenesis, and lymphangiogenesis. In this review, we describe the current understanding of how these surface interactions intersect with different pathways to activate unique cellular responses in cornea as well as their potential therapeutic implications.
PURPOSE: Drug-induced uveitis is a well-known effect of ocular inflammation that has been reported with many medications. Pembrolizumab is a newer generation of the anti-programmed cell death-1 monoclonal antibodies that was recently approved by the Food and Drug Administration for the treatment of advanced melanoma. Immune-mediated adverse events involving different organs have been reported in recent literature in association with this drug. We present the first reported case of uveitis in association with pembrolizumab therapy. CASE REPORT: An 82-year-old man with stage IV melanoma was started on pembrolizumab infusion treatment every 3 weeks. Two months after initiating therapy, he presented with bilateral severe anterior uveitis and papillitis with fast and complete recovery after withholding further pembrolizumab infusions and treatment with topical steroid. Uveitis recurred after restarting pembrolizumab therapy. CONCLUSIONS: In current clinical practice, many new drugs are being approved, requiring better characterization of the prevalence, onset, and nature of adverse events in order to aid development of effective management strategies. Ophthalmologists should keep in mind that drugs are always a possible cause of ocular inflammation in patients presenting with uveitis.
PURPOSE: To investigate the relationship between meibomian gland (MG) morphology and clinical dry eye tests in patients with meibomian gland dysfunction (MGD). DESIGN: Cross-sectional study. SUBJECTS: Total 538 MGD patients and 21 healthy controls. METHODS: MG loss on meibography images of upper (UL) and lower lids (LL) was graded on a scale of 0 (lowest degree of MG loss) to 3. MG length, thickness, and interglandular space in the UL were measured. Clinical tests included meibum expression and quality, tear film break-up time, ocular staining, osmolarity, Schirmer I, blink interval timing, and Ocular Surface Disease Index (OSDI) questionnaire. RESULTS: Mean UL and LL meibogrades were significantly higher in MGD patients compared to controls (P < .001 for UL and LL). The sensitivity and specificity of the meibograde as a diagnostic parameter for MGD was 96.7% and 85%, respectively. Schirmer I was significantly increased in MGD patients with meibograde 1 compared to patients with meibograde 0, 2, and 3 in the UL (P < .05). MG thickness increased with higher meibograde (P < .001). MG morphology correlated significantly but weakly with several clinical parameters (P < .05). OSDI did not correlate with any MG morphologic parameter. CONCLUSIONS: Grading of MG loss using meibograde effectively diagnoses MGD. Compensatory mechanisms such as increased aqueous tear production and dilation of MGs make early detection of MGD difficult by standard clinical measures of dry eye, whereas morphologic analysis of MGs reveals an early stage of MGD, and therefore represents a complementary clinical parameter with diagnostic potential.
Therapeutic angiogenesis is an experimental frontier in vascular biology that seeks to deliver angiogenic growth factors to ischemic or injured tissues to promote targeted formation of new blood vessels as an alternative approach to surgical revascularization procedures. Vascular endothelial growth factor (VEGF) is a potent angiogenic signal protein that is locally upregulated at sites of tissue injury. However, therapies aimed at increasing VEGF levels experimentally by injecting VEGF gene or protein failed to improve outcomes in human trials in part due to its short half-life and systemic toxicity. We recently designed a novel 12-amino acid peptide (PR1P) whose sequence was derived from an extracellular VEGF-binding domain of the pro-angiogenic glycoprotein prominin-1. In this study, we characterized the molecular binding properties of this novel potential therapeutic for targeted angiogenesis and provided the foundation for its use as an angiogenic molecule that can potentiate endogenous VEGF. We showed that PR1P bound VEGF directly and enhanced VEGF binding to endothelial cells and to VEGF receptors VEGFR2 and neuropilin-1. PR1P increased angiogenesis in the murine corneal micropocket assay when combined with VEGF, but had no activity without added VEGF. In addition, PR1P also enhanced angiogenesis in murine choroidal neovascularization and wound-healing models and augmented reperfusion in a murine hind-limb ischemia model. Together our data suggest that PR1P enhanced angiogenesis by potentiating the activity of endogenous VEGF. In so doing, this novel therapy takes advantage of endogenous VEGF gradients generated in injured tissues and may improve the efficacy of and avoid systemic toxicity seen with previous VEGF therapies.
Importance: Although racial, ethnic, and socioeconomic disparities in visual impairment have been described in adults, few studies have focused on the adolescent population, which may provide insight into the emergence of vision health inequities. Objective: To describe visual health disparities among adolescent children in the US. Design, Setting, and Participants: This was a cross-sectional study of adolescents from the 2005 to 2008 National Health and Nutrition Examination Survey. Participants were aged 12 to 18 years with a completed visual function questionnaire and eye examination. Data analyses were conducted from January 19 to July 20, 2022. Main Outcomes and Measures: Outcomes included subjective (self-reported poor vision) and objective (visual acuity worse than 20/40 in the better-seeing eye) measures of visual function. Multivariable logistic and linear regression analyses were conducted to examine the association between the sociodemographic risk factors and each outcome, adjusting for age, sex, and other covariates. Results: The 2833 included participants (mean [SD] age, 15.5 [2.0] years; 1407 female participants [49%]) represent a survey-weighted 57 million US adolescent children, of whom 14% were non-Hispanic Black participants (876), 11% were Mexican American participants (828), 63% were non-Hispanic White participants (816), and 11% were other race and ethnicity (313). A total of 5% of participants (266) were not US citizens, and 19% (773) had a family income below the poverty threshold. There were increased odds of self-reported poor vision among Black (odds ratio [OR], 2.85; 95% CI, 2.00-4.05; P < .001), Mexican American (OR, 2.83; 95% CI, 1.70-4.73; P < .001), and low-income (OR, 2.44; 95% CI, 1.63-3.65; P < .001) adolescent children. Similarly, there were increased odds of visual acuity worse than 20/40 in the better-seeing eye among Black (OR, 2.13; 95% CI, 1.41-3.24; P = .001), Mexican American (OR, 2.13; 95% CI, 1.39-3.26; P = .001), and non-US citizen (OR, 1.96; 95% CI, 1.10-3.49; P = .02) participants. Conclusions and Relevance: In this nationally representative sample from 2005 to 2008, adolescent children identifying as Black, Mexican American, low-income, or non-US citizen were more likely to report poor subjective visual function and perform worse on objective visual acuity testing. A greater understanding of the underlying etiology of these disparities may yield opportunities for improving vision at the population level.
PURPOSE: To demonstrate the use of a novel measure of neighborhood quality, the Child Opportunity Index (COI), for investigating health disparities in pediatric ophthalmology. METHODS: This study included children 2-12 years of age from a registry of patients diagnosed with amblyopia at an urban pediatric hospital between 2010 and 2014. Children previously treated for amblyopia were excluded. Patient demographics, residential addresses, and logMAR visual acuities were collected. The association between visual acuity at presentation and COI was examined using linear mixed-effects models adjusting for individual-level factors, including age, sex, race, ethnicity, and insurance type. RESULTS: This study included 1,050 amblyopic children, of whom 317 (37%) were non-White and 149 (19%) were Hispanic; 461 (44%) had public insurance. Regarding residence, 129 (12%) lived in areas of very low opportunity (COI <20); 489 (47%) in areas of very high opportunity (COI ≥80). Children residing in the lowest opportunity neighborhoods correctly identified approximately two fewer letters at presentation with their better-seeing eye compared with children from the highest opportunity neighborhoods after adjusting for individual-level factors (-0.0090 logMAR per 20 unit increase in COI; 95% CI, -0.0172 to -0.0008; P = 0.031). No difference was appreciated in the worse-seeing eye. CONCLUSIONS: Amblyopic children residing in communities with low neighborhood opportunity had slightly worse visual acuity in the better-seeing eye at presentation. Although statistically significant in the better-seeing eye, the two-letter difference attributable to neighborhood environment may not be clinically significant, and the impact of this disparity on treatment outcomes deserves further investigation.
High-risk human papilloma virus (HR-HPV) is a well-established causative agent of oropharyngeal squamous cell carcinoma (SCC). In addition, HR-HPV has occasionally been reported to be present in dysplastic and malignant lesions of the conjunctiva and lacrimal sac, although its overall incidence and etiological role in periocular SCC are controversial. Sequential surgical samples of 52 combined cases of invasive SCC (I-SCC) and SCC in situ (SCCIS) from 2 periocular sites (conjunctiva and lacrimal sac) diagnosed over a 14-year period (2000 to 2014) were selected for evaluation, and relevant patient characteristics were documented. p16 immunohistochemistry was performed as a screening test. All p16-positive cases were further evaluated for HR-HPV using DNA in situ hybridization (DNA ISH), and a subset was also analyzed by polymerase chain reaction (PCR). Of 43 ocular surface squamous neoplasias (OSSNs), 30% (n=13; 8 SCCIS and 5 I-SCC cases) were positive for HR-HPV. HPV-positive OSSNs occurred in 8 men and 5 women with a mean age of 60 years (range, 39 to 94 y). HPV type-16 was detected in all conjunctival cases evaluated by PCR. All 5 conjunctival I-SCCs were nonkeratinizing (n=4) or partially keratinizing (n=1) and managed by simple excision. In contrast, HPV-negative conjunctival I-SCCs were predominantly keratinizing (11 keratinizing and 2 nonkeratinizing). Of 9 lacrimal sac I-SCCs (LSSCCs), 66.7% (n=6) were positive for HR-HPV by p16 and DNA ISH; HPV subtypes were HPV-16 (n=5) and HPV-58 (n=1). In addition, 2 p16-positive cases with negative DNA ISH results were HR-HPV positive (HPV-16 and HPV-33) when evaluated by PCR, suggesting that the rate of HR-HPV positivity among the LSSCCs may be as high as 89% (n=8). The combined group of HR-HPV-positive LSSCCs was seen in 4 men and 4 women with a mean age of 60 years (range, 34 to 71 y). Seven of the 8 HPV-positive LSSCCs (87.5%) had a nonkeratinizing or partially keratinizing histomorphology, whereas 1 case (12.5%) was predominantly keratinizing. The presence of HR-HPV in 30% of OSSNs and at least 66.7% of LSSCCs suggests the possibility of an etiologic role for HR-HPV at these sites.
PURPOSE: The purpose of this systematic review is to identify techniques used for quantification of choriocapillaris (CC) flow in eyes with uveitis using optical coherence tomography angiography (OCTA), report reliability and level of correlation with techniques such as indocyanine green angiography (ICGA). METHODS: A systematic search of several databases was done. The studies were analyzed for techniques of measurement, reliability, and correlation with other modalities. Risk of bias assessment was performed. RESULTS: Thirteen studies were included. CC vessel density (7 studies) and flow deficit area (4 studies) were the most used indices. There was significant heterogeneity in the studies due to differences in the scan protocol, thresholding strategy, and analysis. Comparison with ICGA was performed by only one study, and reliability indices were reported by only two studies. CONCLUSION: OCTA is a useful tool to measure the CC vascularity in eyes with uveitis. However, standardized acquisition and analysis protocols are needed.