- Browse by Author
Browsing by Author "Moore, Nicholas A."
Now showing 1 - 6 of 6
Results Per Page
Sort Options
Item The acute and chronic effects of intravitreal anti-vascular endothelial growth factor injections on intraocular pressure: A review(Elsevier, 2017) Bracha, Peter; Moore, Nicholas A.; Ciulla, Thomas A.; WuDunn, Darrell; Cantor, Louis B.; Department of Ophthalmology, School of MedicineThe acute and chronic effects of repeated intravitreal antivascular endothelial growth factor (VEGF) injections on intraocular pressure have not been fully characterized, and the development of sustained ocular hypertension could adversely affect patients who are at risk of glaucomatous optic neuropathy. As expected, volume-driven, acute ocular hypertension immediately follows intravitreal injection, but this pressure elevation is generally transient and well tolerated. Several medications have been investigated to limit acute ocular hypertension following anti-VEGF therapy, but the benefits of pretreatment are not conclusive. Chronic, sustained ocular hypertension, distinct from the short-term acute ocular hypertension after each injection, has also been associated with repeated intravitreal anti-VEGF injections. Risk factors for chronic ocular hypertension include the total number of injections, a greater frequency of injection, and preexisting glaucoma. Proposed mechanisms for chronic ocular hypertension include microparticle obstruction, toxic or inflammatory effects on trabecular meshwork, as well as alterations in outflow facility by anti-VEGF agents. Although limiting anti-VEGF therapy could minimize the risk of both acute and chronic ocular hypertension, foregoing anti-VEGF therapy risks progression of various macular diseases with resulting permanent central vision loss. While definitive evidence of damage to the retinal nerve fiber layer is lacking, patients receiving repeated injections should be monitored for ocular hypertension and patients in whom sustained ocular hypertension subsequently developed should be periodically monitored for glaucomatous changes with optic nerve optical coherence tomography and static visual fields.Item Gene Therapy for Inherited Retinal and Optic Nerve Degenerations(Taylor & Francis, 2018) Moore, Nicholas A.; Morral, Nuria; Ciulla, Thomas A.; Bracha, Peter; Ophthalmology, School of MedicineIntroduction: The eye is a target for investigational gene therapy due to the monogenic nature of many inherited retinal and optic nerve degenerations (IRD), its accessibility, tight blood-ocular barrier, the ability to non-invasively monitor for functional and anatomic outcomes, as well as its relative immune privileged state.Vectors currently used in IRD clinical trials include adeno-associated virus (AAV), small single-stranded DNA viruses, and lentivirus, RNA viruses of the retrovirus family. Both can transduce non-dividing cells, but AAV are non-integrating, while lentivirus integrate into the host cell genome, and have a larger transgene capacity. Areas covered: This review covers Leber’s congenital amaurosis, choroideremia, retinitis pigmentosa, Usher syndrome, Stargardt disease, Leber’s hereditary optic neuropathy, Achromatopsia, and X-linked retinoschisis. Expert opinion: Despite great potential, gene therapy for IRD raises many questions, including the potential for less invasive intravitreal versus subretinal delivery, efficacy, safety, and longevity of response, as well as acceptance of novel study endpoints by regulatory bodies, patients, clinicians, and payers. Also, ultimate adoption of gene therapy for IRD will require widespread genetic screening to identify and diagnose patients based on genotype instead of phenotype.Item Induced pluripotent stem cell-based therapy for age-related macular degeneration(Taylor & Francis, 2017) Bracha, Peter; Moore, Nicholas A.; Ciulla, Thomas A.; Ophthalmology, School of MedicineIntroduction: In age-related macular degeneration (AMD), stem cells could possibly replace or regenerate disrupted pathologic retinal pigment epithelium (RPE), and produce supportive growth factors and cytokines such as brain-derived neurotrophic factor. Induced pluripotent stem cells (iPSCs)-derived RPE was first subretinally transplanted in a neovascular AMD patient in 2014. Areas covered: Induced PSCs are derived from the introduction of transcription factors to adult cells under specific cell culture conditions, followed by differentiation into RPE cells. Induced PSC-derived RPE cells exhibit ion transport, membrane potential, polarized VEGF secretion and gene expression that is similar to native RPE. Despite having similar in vitro function, morphology, immunostaining and microscopic analysis, it remains to be seen if iPSC-derived RPE can replicate the myriad of in vivo functions, including immunomodulatory effects, of native RPE cells. Historically, adjuvant RPE transplantation during CNV resections were technically difficult and complicated by immune rejection. Autologous iPSCs are hypothesized to reduce the risk of immune rejection, but their production is time-consuming and expensive. Alternatively, allogenic transplantation using human leukocyte antigen (HLA)-matched iPSCs, similar to HLA-matched organ transplantation, is currently being investigated. Expert opinion: Challenges to successful transplantation with iPSCs include surgical technique, a pathologic subretinal microenvironment, possible immune rejection, and complications of immunosuppression.Item Neomycin, polymyxin B, and dexamethasone allergic reactions following periocular surgery(Springer Open, 2017-12) Moore, Nicholas A.; Czyz, Craig N.; Carter, Tracy D.; Foster, Jill A.; Cahill, Kenneth V.; Ophthalmology, School of MedicineBACKGROUND: The aim of this study was to evaluate the rate of periocular allergic skin reactions to topical neomycin, polymyxin B, and dexamethasone (NPD) ophthalmic ointment. METHODS: A consecutive patient prospective study was performed. A total of 522 patients who had a procedure involving incision of the periocular skin with subsequent postoperative application of NPD ophthalmic ointment were included. Patients were evaluated for signs of allergy at 1 week postoperatively or prior if the patient had complaints. A periocular allergic reaction was defined as any periocular skin pruritus, erythema, edematous papules, vesicles, or plaques at the site of ointment application beyond that of the typical postprocedure presentation. The patients continued to be monitored for 30 days postoperatively. RESULTS: Of the 522 patients who completed the study, eight (1.5%) had a definitive periocular allergic contact dermatitis to the NPD ophthalmic ointment. Allergic presentation ranged from postoperative day 3 to 14. CONCLUSIONS: The rate of periocular allergic reactions to NPD ophthalmic ointment is significantly lower than reported in the literature for other topical preparations of neomycin and polymyxin B. The low rate of allergy in this study suggests that NPD ophthalmic ointment can safely be applied to the periocular skin with a very minimal risk of inciting an allergic reaction.Item Reductions in retrobulbar and retinal capillary blood flow strongly correlate with changes in optic nerve head and retinal morphology over four years in open-angle glaucoma patients of African descent compared to patients of European descent(Wolters Kluwer, 2016-09) Siesky, Brent; Harris, Alon; Carr, Joseph; Vercellin, Alice Verticchio; Hussain, Rehan; Hembree, Priyanka Parekh; Wentz, Scott; Isaacs, Michael; Eckert, George; Moore, Nicholas A.; Ophthalmology, School of MedicinePurpose To investigate the relationship of changes in ocular blood flow with optic nerve head and retinal morphology in open-angle glaucoma patients of African versus European descent over four years. Materials and Methods In this study, 112 patients with open-angle glaucoma were examined at baseline, 79 (59 European descent, 20 African descent) of which were followed for four years. Retinal capillary blood flow was assessed with Heidelberg retinal flowmetry. Retrobulbar blood flow was measured by color Doppler imaging. Retinal structural changes were examined with optical coherence tomography and Heidelberg retinal tomography-III. Mixed-model analysis of covariance was used to test for the significance of change from baseline to four-year follow-up, and Pearson correlation coefficients were calculated to evaluate linear associations. Results In open-angle glaucoma patients of African descent, structural changes of the optic nerve head demonstrated a strong association with the end diastolic velocities and resistive indices of the short posterior ciliary arteries over four years. In addition, there was a significantly larger increase in the avascular area of the inferior retina in patients of African descent, and this reduction in retinal capillaries strongly correlated with a reduction in macular thickness. Conclusion Reductions in retinal capillary and retrobulbar blood flow strongly correlated with changes in the optic nerve head and macular thickness over four years in open-angle glaucoma patients of African descent compared to European descent. This data suggests that ocular vascular health may be a more influential contributing factor in the pathophysiology of open-angle glaucoma in patients of African descent compared to European descent.Item Surgical approach to limiting skin contracture following protractor myectomy for essential blepharospasm(Massachusetts Eye and Ear Infirmary, 2017-11-05) Clark, Jeremy; Randolph, John; Sokol, Jason A.; Moore, Nicholas A.; Lee, Hui Bae H.; Nunery, William R.; Ophthalmology, School of MedicinePurpose: To report our experience with protractor myectomy in patients with benign essential blepharospasm who did not respond to serial botulinum toxin injection, and to describe intra- and postoperative techniques that limited skin contracture while also providing excellent functional and cosmetic results. Methods: The medical records of patients with isolated, benign, essential blepharospasm who underwent protractor myectomy from 2005 to 2008 by a single surgeon were reviewed retrospectively. The technique entailed operating on a single eyelid during each procedure, using a complete en bloc resection of all orbicularis tissue, leaving all eyelid skin intact at the time of surgery, and placing the lid under stretch with Frost suture and applying a pressure dressing for 5-7 days. Results: Data from 28 eyelids in 7 patients were included. Average follow-up was 21.5 months (range, 4-76 months). Of the 28 eyelids, 20 (71.4%) showed postoperative resolution of spasm, with no further need for botulinum toxin injections. In the 8 eyelids requiring further injections, the average time to injection after surgery was 194 days (range, 78-323 days), and the average number of injections was 12 (range, 2-23 injections). All but one eyelid had excellent cosmetic results, without signs of contracture; one eyelid developed postoperative skin contracture following premature removal of the Frost suture and pressure dressing because of concerns over increased intraocular pressure. Conclusions: In our patient cohort, this modified technique resulted in excellent cosmetic and functional results and limited postoperative skin contracture.