2019

Purpose: Clinical manifestations of photoreceptor degeneration include gradual thinning of the outer nuclear layer (ONL) and progressive reduction of electroretinogram (ERG) amplitudes and vision loss. Although preclinical evaluations of treatment strategies greatly depend on rodent models, the courses of these changes in mice remain unclear. We thus sought to investigate the temporal correlations in changes of spatial vision, ERG response, and ONL thickness in mice with progressive photoreceptor degeneration. Methods: Adult wild-type (WT) mice and mice carrying rhodopsin deficiency (Rho-/-), a frequently used mouse model of human retinitis pigmentosa, were selected for investigation. Mouse spatial vision, including visual acuity (VA) and contrast sensitivity (CS), was determined using optomotor response (OMR) assays; ONL thickness was quantified by spectral-domain optical coherence tomography (SD-OCT), and ERG was performed to evaluate retinal functions. The mice were killed when they were 14 weeks old, and the cone photoreceptors in retinal sections were counted. Results: Spatial vision, ONL thickness, and ERG amplitudes remained stable in WT mice at all examined time points. While 6-week-old Rho-/- mice had VA, CS, as well as ERG responses similar to those of WT mice, progressive reductions in the spatial vision and retinal functions were recorded thereafter. Most tested 12-week-old Rho-/- mice had no visual-evoked OMR and ERG responses. Moreover, CS, but not VA, displayed a linear decline that was closely associated with ONL thinning, reduction of ERG amplitudes, and loss of cones. Conclusions: We presented a comprehensive study of the relation between the changes of spatial vision, retinal function, and ONL thickness in postnatal week (PW)6 to PW12 Rho-/- mice. CS is a more sensitive indicator of spatial vision compared to VA, although both are required as separate parameters for monitoring the visual changes in retina undergoing photoreceptor degeneration.

: To investigate to what extent the OSDI can be utilized as a discriminative test for clinical findings. : One thousand and ninety patients with dry eye disease (DED) were consecutively included and examined for osmolarity, tear film break-up time (TFBUT), ocular protection index (OPI), ocular surface staining (OSS), Schirmer I test (ST), meibum expressibility (ME), meibum quality (MQ), and diagnosis of meibomian gland dysfunction (MGD). Receiver-operating characteristic curve (ROC) analysis considering optimum balanced sensitivity and specificity (close to 50%) was used for assessment. : The present study on more than 1,000 patients indicates that the OSDI in the ROC curve analysis is a poor discriminator of pathological scores for TFBUT ≤ 5 (AUC = 0.553; = .012) and ≤10 s (AUC = 0.608; = .002), OSS ≥ 3 (AUC = 0.54; = .043), ST ≤ 5 (AUC = 0.550; = .032) and ≤10 mm/5 min (AUC = 0.544; = .016), and ME ≥ 1 (AUC = 0.594; = <0.001). Pathological scores for osmolarity >308 and >316 mOsm/L, OPI, OSS > 1, MQ, and MGD could not be discriminated by OSDI ( > .05). : Cut-off values for the OSDI can be defined to discriminate pathological TFBUT (≤5 and ≤10), OSS (≥3), ST (≤5 and ≤10) and ME, however, the discriminability was low. Our comprehensive study emphasises the importance of taking both symptoms and signs into account in DED management.

The optic nerve conveys information about the outside world from the retina to multiple subcortical relay centers. Until recently, the optic nerve was widely believed to be incapable of re-growing if injured, with dire consequences for victims of traumatic, ischemic, or neurodegenerative diseases of this pathway. Over the past 10-20 years, research from our lab and others has made considerable progress in defining factors that normally suppress axon regeneration and the ability of retinal ganglion cells, the projection neurons of the retina, to survive after nerve injury. Here we describe research from our lab on the role of inflammation-derived growth factors, suppression of inter-cellular signals among diverse retinal cell types, and combinatorial therapies, along with related studies from other labs, that enable animals with optic nerve injury to regenerate damaged retinal axons back to the brain. These studies raise the possibility that vision might one day be restored to people with optic nerve damage.

PURPOSE: To report the long-term outcome of Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE) for delivery of bevacizumab in the treatment of corneal neovascularization (KNV). METHODS: Retrospective, non-comparative, interventional case series of 13 sequential patients treated for KNV at the BostonSight between 2006 and 2017. In all cases, PROSE treatment was initiated for management of ocular surface disease and patients wore PROSE consistently on a daily wear basis prior to bevacizumab treatment. Patients applied a drop of 1% preservative free bevacizumab to the reservoir of PROSE device twice daily. Patients continued with daily wear of the device during treatment and afterwards. RESULTS: 13 patients (8 female and mean age of 45 years) are included with a mean follow-up of 5.1 years (range 6 months-11 years). Underlying ocular diagnoses included Stevens-Johnson syndrome (7), ocular chronic graft-versus-host disease (2), corneal transplant (2), contact lens-related corneal ulcer and limbal stem cell deficiency (1), and familial dysautonomia (1). Median duration of bevacizumab use was 6 months (range 3 months-10 years). Twelve cases (92%) had regression of KNV and 10 cases (77%) had improved best-corrected visual acuity (BCVA) with treatment. Median BCVA improved from -1.1 (LogMAR) at baseline, to -0.66 at end of bevacizumab treatment, and remained -0.63 at last follow-up (P = 0.047). KNV progressed in one eye after discontinuation of bevacizumab. There were no ophthalmic or systemic complications. CONCLUSIONS: Topical bevacizumab used in PROSE is effective in treating KNV and improving vision. Long-term follow-up reveals durable response and no complications.

How somatic mutations accumulate in normal cells is poorly understood. A comprehensive analysis of RNA sequencing data from ~6700 samples across 29 normal tissues revealed multiple somatic variants, demonstrating that macroscopic clones can be found in many normal tissues. We found that sun-exposed skin, esophagus, and lung have a higher mutation burden than other tested tissues, which suggests that environmental factors can promote somatic mosaicism. Mutation burden was associated with both age and tissue-specific cell proliferation rate, highlighting that mutations accumulate over both time and number of cell divisions. Finally, normal tissues were found to harbor mutations in known cancer genes and hotspots. This study provides a broad view of macroscopic clonal expansion in human tissues, thus serving as a foundation for associating clonal expansion with environmental factors, aging, and risk of disease.

The Joslin Medalist Study characterized people affected with type 1 diabetes for 50 years or longer. More than 35% of these individuals exhibit no to mild diabetic retinopathy (DR), independent of glycemic control, suggesting the presence of endogenous protective factors against DR in a subpopulation of patients. Proteomic analysis of retina and vitreous identified retinol binding protein 3 (RBP3), a retinol transport protein secreted mainly by the photoreceptors, as elevated in Medalist patients protected from advanced DR. Mass spectrometry and protein expression analysis identified an inverse association between vitreous RBP3 concentration and DR severity. Intravitreal injection and photoreceptor-specific overexpression of RBP3 in rodents inhibited the detrimental effects of vascular endothelial growth factor (VEGF). Mechanistically, our results showed that recombinant RBP3 exerted the therapeutic effects by binding and inhibiting VEGF receptor tyrosine phosphorylation. In addition, by binding to glucose transporter 1 (GLUT1) and decreasing glucose uptake, RBP3 blocked the detrimental effects of hyperglycemia in inducing inflammatory cytokines in retinal endothelial and Müller cells. Elevated expression of photoreceptor-secreted RBP3 may have a role in protection against the progression of DR due to hyperglycemia by inhibiting glucose uptake via GLUT1 and decreasing the expression of inflammatory cytokines and VEGF.

: This is the first review article examining literature specific to the use of corneal cross-linking (CXL) to treat pellucid marginal degeneration (PMD). : CXL appears to be an effective treatment that may halt the progression of PMD to stabilize vision. This could postpone or eliminate the need for corneal transplantation in the management of these patients. Furthermore, combining CXL with keratorefractive surgery in a single procedure has been shown to be safe and successful in improving vision in PMD patients. : The data reported in literature is limited at this time, consisting mostly of retrospective studies with short term follow up. Further research is needed to evaluate refractive effects of combined CXL and excimer laser procedures.

: To report the visual prognosis, electroretinography (ERG) and perimetry outcomes of systemic corticosteroid-sparing immunomodulatory treatment (IMT) for birdshot retinochoroidopathy (BSRC). : Retrospective non-comparative case series of 132 patients (264 eyes) with BSRC treated with IMT from Massachusetts Eye Research and Surgery Institution. : The average follow-up time was 60.1 months. After one year on IMT, 39.4% showed no clinically active inflammation. After 5 years of IMT, 78.0% had no signs of clinical inflammation. No significant differences were observed on best-corrected visual acuity (BCVA), ERG parameters, and perimetry parameters between baseline and subsequent visits on IMT. : Long-term systemic corticosteroid-sparing IMT was associated with a low rate of BSRC disease exacerbation. While differences were seen on testing parameters, they were not consistent trends and difference were attributed to variability of testing or fluctuation of inflammation that may be expected in the course of the disease.

BACKGROUND AND PURPOSE: No MR imaging measurement criteria are available for the diagnosis of optic nerve atrophy. We determined a threshold optic nerve area on MR imaging that predicts a clinical diagnosis of optic nerve atrophy and assessed the relationship between optic nerve area and retinal nerve fiber layer thickness measured by optical coherence tomography, an ancillary test used to evaluate optic nerve disorders. MATERIALS AND METHODS: We evaluated 26 patients with suspected optic nerve atrophy (8 with unilateral, 13 with bilateral and 5 with suspected but not demonstrable optic nerve atrophy) who had both orbital MR imaging and optical coherence tomography examinations. Forty-five patients without optic nerve atrophy served as controls. Coronal inversion recovery images were used to measure optic nerve area on MR imaging. Retinal nerve fiber layer thickness was determined by optical coherence tomography. Individual eyes were treated separately; however, bootstrapping was used to account for clustering when appropriate. Correlation coefficients were used to evaluate relationships; receiver operating characteristic curves, to investigate predictive accuracy. RESULTS: There was a significant difference in optic nerve area between patients' affected eyes with optic nerve atrophy (mean, 3.09 ± 1.09 mm), patients' unaffected eyes (mean, 5.27 ± 1.39 mm; = .008), and control eyes (mean, 6.27 ± 2.64 mm; < .001). Optic nerve area ≤ 4.0 mm had a sensitivity of 0.85 and a specificity of 0.83 in predicting the diagnosis of optic nerve atrophy. A significant relationship was found between optic nerve area and retinal nerve fiber layer thickness ( = 0.68, < .001). CONCLUSIONS: MR imaging-measured optic nerve area ≤ 4.0 mm has moderately high sensitivity and specificity for predicting optic nerve atrophy, making it a potential diagnostic tool for radiologists.

PURPOSE: To assess the potential of ready-made (spherical) spectacles (RMS) in meeting the need for refractive correction in visually impaired children in China. METHODS: Eligible children aged 5-17 years were identified from the three study sites in China. Distance visual acuity was measured with a retroilluminated logarithm of the minimum angle of resolution chart with tumbling E optotypes. Cycloplegic autorefraction was performed on all children using a handheld autorefractor. If uncorrected visual acuity (UCVA) was ≤20/40 in either eye, best corrected visual acuity was measured with subjective refractive error. RESULTS : A total of 13 702 children were enumerated from the three studies, with 12 334 (90.0%) having both reliable visual acuity measurements and successful cycloplegia. Among the 12 334 study children, the prevalence of UCVA ≤20/40 in the better seeing eye was 16.4% (95% CI 15.0% to 17.8%), with 91.1% (1843) of these improving by ≥3 lines of visual acuity with refractive correction. Prevalence was 12.7% (95% CI 11.5% to 13.9%) for UCVA 20/50 with 97.4% (1521) improving by ≥3 lines, and 9.38% (95% CI 8.39% to 19.4%) for UCVA ≤20/63 with 98.4% (1138) improving by ≥3 lines. Depending on the severity of visual impairment, 62.8%-64.0% of children could be accommodated with RMS if not correcting for astigmatism of ≤0.75 dioptres and anisometropia of ≤0.50 spherical equivalent dioptres. Approximately 87% of children could be accommodated with RMS if astigmatism and anisometropia limits were increased to ≤1.25 and ≤1.50 dioptres, respectively. CONCLUSIONS: RMS could substantially alleviate visual morbidity in two-thirds or more of visually impaired schoolchildren in China. This cost-effective approach to refractive correction might also be useful in low/middle-income countries with poor access to optometric services.