Ophthalmology Commons^™

Functional Attenuation Coefficient Imaging Of Rod Inner Segment: The Shape Of Things To Come, Cole Goodman

Medical Student Research Symposium

Purpose: Dysfunction of mitochondria and their linked processes within the rod cell (i.e., the rod energy-landscape) are leading hypotheses for rod atrophy in retinitis pigmentosa (RP). It remains unclear how to translate the detailed information available from isolated cell / mitochondria studies into how mitochondria are functioning and responding to treatment in vivo. Here we present a new rod energy-landscape biomarker that can help address this problem using a common clinical tool.

Methods: In mice, OCT data was converted into attenuation coefficients (AC) to map the light-scattering of mitochondria within the inner segment (IS), which fills ~75% of its volume …

Critique Of Experimental Procedures Targeting Retinitis Pigmentosa, Jenna Goss

Honors College

Retinitis Pigmentosa (RP) is a group of hereditary genetic disorders, all causing degradation of the retina through loss of rod photoreceptor cells, ultimately causing loss of vision and in many cases complete blindness. Despite the prevalence o fRetinitis Pigmentosa disorders, safe and effective treatment methods have not yet been approved to stop or regain vision loss in patients diagnosed with RP. However, the ophthalmic field as a whole is working on several new technologies and procedures in order to both slow loss of vision as well as potentially regain lost sight. In this thesis, I describe the genetic causes and …

Metabolic Deregulation Of The Blood-Outer Retinal Barrier In Retinitis Pigmentosa, Wei Wang, Ashwini Kini, Yekai Wang, Tingting Liu, Yao Chen, Eric Vukmanic, Douglas Emery, Yongqing Liu, Xiaoqin Lu, Lei Jin, San Joon Lee, Patrick Scott, Xiao Liu, Kevin Dean, Qingxian Lu, Enzo Fortuny, Robert James, Henry J. Kaplan, Jianhai Du, Douglas C. Dean

Faculty & Staff Scholarship

Retinitis pigmentosa (RP) initiates with diminished rod photoreceptor function, causing peripheral and nighttime vision loss. However, subsequent loss of cone function and high-resolution daylight and color vision is most debilitating. Visual pigment-rich photoreceptor outer segments (OS) undergo phagocytosis by the retinal pigment epithelium (RPE), and the RPE also acts as a blood-outer retinal barrier transporting nutrients, including glucose, to photoreceptors. We provide evidence that contact between externalized phosphatidylserine (PS) on OS tips and apical RPE receptors activates Akt, linking phagocytosis with glucose transport to photoreceptors for new OS synthesis. As abundant mutant rod OS tips shorten in RP, Akt activation …

Posterior Segment Approach For Subretinal Transplantation Or Injection In The Canine Model, Maria E. Verdugo, Julie Alling, Eliot Lazar, Manuel Del Cerro, Jharna Ray, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

A posterior segment approach for cell transplantation or injection into the subretinal space of the dog has been developed. Controlled penetration to the subretinal space was achieved using a 29-gauge injection cannula, either blunted or with a 30° sharpened bevel, and partially ensheathed with moveable plastic tubing. Depending on the injection volume used, the retina detached, and the fluid was reabsorbed within 1–3 weeks, although for smaller volumes the retina reattached within a matter of days. The optimal injection volume used was between 100 and 150 μl, or two injections of 55 μl each. By ophthalmoscopy following the surgery, it …

Identical Mutation In A Novel Retinal Gene Causes Progressive Rod-Cone Degeneration In Dogs And Retinitis Pigmentosa In Humans, Barbara Zangerl, Orly Goldstein, Alisdair R. Philip, Sarah J. P Lindauer, Susan E. Pearce-Kelling, Roberts F. Mullins, Alexander S. Graphodatsky, Daniel Ripoll, Jeanette S. Felix, Edwin M. Stone, Gregory M. Acland, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

Progressive rod–cone degeneration (prcd) is a late-onset, autosomal recessive photoreceptor degeneration of dogs and a homolog for some forms of human retinitis pigmentosa (RP). Previously, the disease-relevant interval was reduced to a 106-kb region on CFA9, and a common phenotype-specific haplotype was identified in all affected dogs from several different breeds and breed varieties. Screening of a canine retinal EST library identified partial cDNAs for novel candidate genes in the disease-relevant interval. The complete cDNA of one of these, PRCD, was cloned in dog, human, and mouse. The gene codes for a 54-amino-acid (aa) protein in dog and human and …

Application Of A New Subretinal Injection Device In The Dog, András M. Komáromy, Signe E. Varner, Eugene De Juan, Gregory M. Acland, Gustavo D. Aguirre

Gustavo D. Aguirre, VMD, PhD

The use of a new subretinal injection device (RetinaJect™ Subretinal Cannula, SurModics, Inc., Eden Prairie, MN) to access the subretinal space in the canine model was evaluated. Subretinal injections were performed in 33 mongrel dogs between 2 and 52 months of age (median = 9 months). In 5 normal dogs the injection of 150 μl saline or India ink occurred by using a conventional subretinal injection device (CSID) with a 30-gauge anterior chamber irrigating cannula. The sclera had to be surgically exposed and penetrated before the subretinal injection with the CSID could occur. After removing the CSID, the conjunctiva over …