Publications

2014

Proliferative vitreoretinopathy (PVR) is a nonneovascular blinding disease and the leading cause for failure in surgical repair of rhegmatogenous retinal detachments. Once formed, PVR is difficult to treat. Hence, there is an acute interest in developing approaches to prevent PVR. Of the many growth factors and cytokines that accumulate in vitreous as PVR develops, neutralizing vascular endothelial growth factor (VEGF) A has recently been found to prevent PVR in at least one animal model. The goal of this study was to test if Food and Drug Administration-approved agents could protect the eye from PVR in multiple animal models and to further investigate the underlying mechanisms. Neutralizing VEGF with aflibercept (VEGF Trap-Eye) safely and effectively protected rabbits from PVR in multiple models of disease. Furthermore, aflibercept reduced the bioactivity of both experimental and clinical PVR vitreous. Finally, although VEGF could promote some PVR-associated cellular responses via VEGF receptors expressed on the retinal pigment epithelial cells that drive this disease, VEGF's major contribution to vitreal bioactivity occurred via platelet-derived growth factor receptor α. Thus, VEGF promotes PVR by a noncanonical ability to engage platelet-derived growth factor receptor α. These findings indicate that VEGF contributes to nonangiogenic diseases and that anti-VEGF-based therapies may be effective on a wider spectrum of diseases than previously appreciated.

Hypotropia following orbital fracture repair is traditionally attributed to residual tissue entrapment, scarring, direct muscle injury, or damage to the branches of the oculomotor nerve serving the inferior oblique or inferior rectus muscles. We present a case of acquired hypotropia and incyclotropia that occurred following repair of an orbital fracture involving the floor and medial wall. In order to enable adequate visualization and treatment of the combined fractures, access via a transcaruncular approach and disinsertion of the inferior oblique muscle at its origin was necessary. Whereas the possibility of inferior oblique paresis due to repair of an orbital fracture via the transcaruncular approach has received some acknowledgment, there are no prior reports in the ophthalmic literature. Strabismus surgeons should be aware of this possibility when planning surgical correction of hypotropia and incyclotropia in similar cases.

Stevenson W, Chen Y, Lee SM, Lee HS, Hua J, Dohlman T, Shiang T, Dana R. Extraorbital lacrimal gland excision: a reproducible model of severe aqueous tear-deficient dry eye disease.. Cornea. 2014;33(12):1336–41.
PURPOSE: The aim of this study was to establish and characterize extraorbital lacrimal gland excision (LGE) as a model of aqueous tear-deficient dry eye disease in mice. METHODS: Female C57BL/6 mice at 6 to 8 weeks of age were randomized to extraorbital LGE, sham surgery, or scopolamine groups. Mice that underwent extraorbital LGE or sham surgery were housed in the standard vivarium. Scopolamine-treated mice were housed in a controlled environment chamber that allowed for the continuous regulation of airflow (15 L/min), relative humidity (30%), and temperature (21-23°C). Clinical disease severity was assessed over the course of 14 days using the phenol red thread test and corneal fluorescein staining. Real-time polymerase chain reaction was performed to assess corneal mRNA expression of interleukin 1β, tumor necrosis factor α, and matrix metalloproteinase 9. Flow cytometry was used to assess T helper cell frequencies in the conjunctivae and draining lymph nodes. RESULTS: Extraorbital LGE markedly reduced aqueous tear secretion as compared with the sham procedure and induced a more consistent decrease in aqueous tear secretion than was observed in mice that received scopolamine while housed in the controlled environment chamber. Extraorbital LGE significantly increased corneal fluorescein staining scores as compared with those of both the sham surgery and scopolamine-treated groups. Extraorbital LGE significantly increased the corneal expression of interleukin 1β, tumor necrosis factor α, and matrix metalloproteinase 9. Further, extraorbital LGE increased T helper 17-cell frequencies in the conjunctivae and draining lymph nodes. CONCLUSIONS: Extraorbital LGE induces aqueous tear-deficient dry eye disease in mice as evidenced by decreased aqueous tear secretion, increased corneal epitheliopathy, and induced ocular surface inflammation and immunity.
Ent W, Burrello C, Teunisse A, Ksander B, Van der Velden P, Jager M, Jochemsen, Snaar-Jagalska E. Modelling of human uveal melanoma in Zebrafish xenograft embryos.. Invest Ophthalmol Vis Sci. 2014;

PURPOSE. Uveal melanoma (UM) is fatal in up to 50% of patients because of liver metastases, that are refractory to therapies currently available. While murine xenograft models for human uveal melanoma are available, they have limited utility for screening large compound libraries in drug discovery studies. Therefore, new robust preclinical models are needed that can efficiently evaluate drug efficacy for treatment of this malignancy. METHODS. UM cell lines generated from primary tumors (92.1, Mel270) and metastases (OMM2.3, OMM2.5, OMM1) were injected into the yolk of two-day-old zebrafish embryos. After six days, proliferation and active migration was quantified via automated confocal image analysis. To determine the suitability of this xenotransplantation model for drug testing, drugs with three different activities (Dasatinib, Quisinostat and MLN-4924) were added to the water of uveal melanoma-engrafted embryos. RESULTS. All tested UM cell lines proliferated and migrated in the embryos; significant differences could be discerned between cell lines: cells derived from metastases showed more migration and proliferation than cells derived from the primary tumors, and provided preclinical models for drug testing. Addition of the Src-inhibitor Dasatinib in the water of engrafted embryos reduced proliferation and migration of high Src-expressing 92.1 cells, but did not affect low Src-expressing metastatic OMM2.3 cells. Two experimental anticancer drugs, Quisinostat (a histone deacetylase inhibitor) and MLN-4924 (neddylation pathway inhibitor), blocked migration and proliferation of 92.1 and OMM2.3. CONCLUSIONS. We established a zebrafish xenograft model of human uveal melanoma with demonstrated applicability for screening large libraries of compounds in drug discovery studies.

Springelkamp H, Höhn R, Mishra A, Hysi P, Khor CC, Loomis S, Bailey JC, Gibson J, Thorleifsson G, Janssen S, Luo X, Ramdas W, Vithana E, Nongpiur M, Montgomery G, Xu L, Mountain J, Gharahkhani P, Lu Y, Amin N, Karssen L, Sim KS, Leeuwen E, Iglesias A, Verhoeven V, Hauser M, Loon SC, Despriet D, Nag A, Venturini C, Sanfilippo P, Schillert A, Kang J, Landers J, Jonasson F, Cree A, Koolwijk L, Rivadeneira F, Souzeau E, Jonsson V, Menon G, Blue Mountains Eye Study—GWAS group, Weinreb R, Jong P, Oostra B, Uitterlinden A, Hofman A, Ennis S, Thorsteinsdottir U, Burdon K, NEIGHBORHOOD Consortium, Wellcome Trust Case Control Consortium 2 (WTCCC2), Spector T, Mirshahi A, Saw SM, Vingerling J, Teo YY, Haines J, Wolfs R, Lemij H, Tai ES, Jansonius N, Jonas J, Cheng CY, Aung T, Viswanathan A, Klaver C, Craig J, Macgregor S, Mackey D, Lotery A, Stefansson K, Bergen A, Young T, Wiggs J, Pfeiffer N, Wong TY, Pasquale L, Hewitt A, Duijn C, Hammond C, Blue Mountains Eye Study-GWAS group, NEIGHBORHOOD Consortium, Wellcome Trust Case Control Consortium 2 WTCCC2. Meta-analysis of genome-wide association studies identifies novel loci that influence cupping and the glaucomatous process.. Nat Commun. 2014;5:4883.

Glaucoma is characterized by irreversible optic nerve degeneration and is the most frequent cause of irreversible blindness worldwide. Here, the International Glaucoma Genetics Consortium conducts a meta-analysis of genome-wide association studies of vertical cup-disc ratio (VCDR), an important disease-related optic nerve parameter. In 21,094 individuals of European ancestry and 6,784 individuals of Asian ancestry, we identify 10 new loci associated with variation in VCDR. In a separate risk-score analysis of five case-control studies, Caucasians in the highest quintile have a 2.5-fold increased risk of primary open-angle glaucoma as compared with those in the lowest quintile. This study has more than doubled the known loci associated with optic disc cupping and will allow greater understanding of mechanisms involved in this common blinding condition.

Paschalis E, Eliott D, Vavvas D. Removal of Silicone Oil From Intraocular Lens Using Novel Surgical Materials.. Transl Vis Sci Technol. 2014;3(5):4.

PURPOSE: To design, fabricate, and evaluate novel materials to remove silicone oil (SiO) droplets from intraocular lenses (IOL) during vitreoretinal surgery. METHODS: Three different designs were fabricated using soft lithography of polydimethylsiloxane (PDMS), three-dimensional (3D) inverse PDMS fabrication using water dissolvable particles, and atomic layer deposition (ALD) of alumina (Al2O3) on surgical cellulose fibers. Laboratory tests included static and dynamic contact angle (CA) measurements with water and SiO, nondestructive x-ray microcomputer tomography (micro-CT), and microscopy. SiO removal was performed in vitro and ex vivo using implantable IOLs and explanted porcine eyes. RESULTS: All designs exhibited enhanced hydrophobicity and oleophilicity. Static CA measurements with water ranged from 131° to 160° and with SiO CA approximately 0° in 120 seconds following exposure. Nondestructive x-ray analysis of the 3D PDMS showed presence of interconnected polydispersed porosity of 100 to 300 μm in diameter. SiO removal from IOLs was achieved in vitro and ex vivo using standard 20-G vitrectomy instrumentation. CONCLUSION: Removal of SiO from IOLs can be achieved using materials with lower surface energy than that of the IOLs. This can be achieved using appropriate surface chemistry and surface topography. Three designs, with enhanced hydrophobic properties, were fabricated and tested in vitro and ex vivo. All materials remove SiO within an aqueous environment. Preliminary ex vivo results were very promising, opening new possibilities for SiO removal in vitreoretinal surgeries. TRANSLATIONAL RELEVANCE: This is the first report of an instrument that can lead to successful removal of SiO from the surface of IOL. In addition to the use of this instrument/material in medicine it can also be used in the industry, for example, retrieval of oil spills from bodies of water.

Wang R, Wiggs J. Common and Rare Genetic Risk Factors for Glaucoma.. Cold Spring Harb Perspect Med. 2014;

The characterization of genes responsible for glaucoma is the critical first step toward the development of gene-based diagnostic and screening tests, which could identify individuals at risk for disease before irreversible optic nerve damage occurs. Early-onset forms of glaucoma affecting children and young adults are typically inherited as Mendelian autosomal dominant or recessive traits whereas glaucoma affecting older adults has complex inheritance. In this report, we present a comprehensive overview of the genes and genomic regions contributing to inherited glaucoma.

Mouw K, Sethi R, Yeap B, MacDonald S, Chen YL, Tarbell N, Yock T, Munzenrider J, Adams J, Grabowski E, Mukai S, Shih H. Proton Radiation Therapy for the Treatment of Retinoblastoma.. Int J Radiat Oncol Biol Phys. 2014;90(4):863–9.
PURPOSE: To investigate long-term disease and toxicity outcomes for pediatric retinoblastoma patients treated with proton radiation therapy (PRT). METHODS AND MATERIALS: This is a retrospective analysis of 49 retinoblastoma patients (60 eyes) treated with PRT between 1986 and 2012. RESULTS: The majority (84%) of patients had bilateral disease, and nearly half (45%) had received prior chemotherapy. At a median follow-up of 8 years (range, 1-24 years), no patients died of retinoblastoma or developed metastatic disease. The post-PRT enucleation rate was low (18%), especially in patients with early-stage disease (11% for patients with International Classification for Intraocular Retinoblastoma [ICIR] stage A-B disease vs 23% for patients with ICIR stage C-D disease). Post-PRT ophthalmologic follow-up was available for 61% of the preserved eyes (30 of 49): 14 of 30 eyes (47%) had 20/40 visual acuity or better, 7 of 30 (23%) had moderate visual acuity (20/40-20/600), and 9 of 30 (30%) had little or no useful vision (worse than 20/600). Twelve of 60 treated eyes (20%) experienced a post-PRT event requiring intervention, with cataracts the most common (4 eyes). No patients developed an in-field second malignancy. CONCLUSIONS: Long-term follow-up of retinoblastoma patients treated with PRT demonstrates that PRT can achieve high local control rates, even in advanced cases, and many patients retain useful vision in the treated eye. Treatment-related ocular side effects were uncommon, and no radiation-associated malignancies were observed.