-
Eye (London, England) Jul 2019To report the customized approach of patients with anophthalmia or microphthalmia with bespoke ocular prosthesis.
PURPOSE
To report the customized approach of patients with anophthalmia or microphthalmia with bespoke ocular prosthesis.
METHODS
Retrospective analysis of case series.
RESULTS
The study included cases with anophthalmia with upper eyelid deformity (one patient), microphthalmia and contralateral corectopia (one patient), microphthalmia with contralateral corneal graft (one patient), and congenital clinical anophthalmia with contralateral sclerocornea (one patient). Using techniques of embedded autologous hair and coating of adhesive pigment emulsion in the ocular prosthesis, the physical appearance of, respectively, an upper eyelid, corectopia, corneal graft, and sclerocornea was reproduced.
CONCLUSION
Tailoring the ocular prosthesis to the distinct condition of the anophthalmic socket and contralateral eye adds to the success of rehabilitative prosthetic treatment of the patient.
Topics: Adult; Aged; Anophthalmos; Eye, Artificial; Female; Humans; Infant; Male; Microphthalmos; Middle Aged; Prosthesis Design
PubMed: 30837709
DOI: 10.1038/s41433-019-0385-3 -
BMJ Case Reports Apr 2019A 54-year-old Caucasian woman presented with corneal ulcer of the right eye of 4 weeks duration after scratching her cornea while removing her contact lens and...
A 54-year-old Caucasian woman presented with corneal ulcer of the right eye of 4 weeks duration after scratching her cornea while removing her contact lens and artificial eye lashes. Her visual acuity was 20/32 (left eye) and finger counting (right eye). She had a 3x3 mm epithelial defect with underlying corneal oedema and hypopyon. Right eye cultures grew species. Topical and systemic antifungal agents were initiated. Due to the sight-threatening disease, the patient underwent surgical intervention with intrastromal injection of amphotericin B and a large conjunctival flap covering 75% of the right eye corneal ulcer. After 3 months of therapy, she had near-complete resolution of the corneal ulcer. Unfortunately, recurrence of the corneal ulcer occurred within 3 weeks of cessation of therapy, prompting reinitiation of ophthalmic and systemic antifungal agents. The patient was advised to continue therapy for 6 months with regular follow-up.
Topics: Amphotericin B; Antifungal Agents; Corneal Edema; Corneal Ulcer; Eye Infections, Fungal; Female; Humans; Injections, Intraocular; Keratitis; Middle Aged; Mycoses; Paecilomyces; Recurrence; Surgical Flaps; Treatment Outcome; Visual Acuity
PubMed: 31023737
DOI: 10.1136/bcr-2019-229226 -
Survey of Ophthalmology 2000The three most common indications for enucleation are intraocular malignancy, trauma, and a blind, painful eye. Recommending enucleation is one of the most difficult... (Review)
Review
The three most common indications for enucleation are intraocular malignancy, trauma, and a blind, painful eye. Recommending enucleation is one of the most difficult therapeutic decisions in ophthalmology. In some cases of malignancy, cryotherapy, laser photocoagulation, diathermy, chemotherapy, and radiation therapy may be viable alternatives to surgery. When surgery is chosen, evisceration or exenteration may be alternatives to enucleation. Once the decision is made to perform enucleation or evisceration, the surgeon must choose from several types of implants and wrapping materials. These devices can be synthetic, autologous, or eye-banked tissues. With certain implants, the surgeon must decide when and if to drill for subsequent peg placement. In this review, the authors discuss choices, techniques, complications, and patient consent and follow-up before, during, and after enucleation. Controversies and results of the Controlled Ocular Melanoma Study are summarized.
Topics: Eye Enucleation; Eye Injuries; Eye Neoplasms; Eye, Artificial; Humans; Informed Consent; Intraoperative Complications; Orbital Implants; Postoperative Complications; Treatment Outcome
PubMed: 10667436
DOI: 10.1016/s0039-6257(99)00112-5 -
Arquivos Brasileiros de Oftalmologia Sep 2022This work is a critical review of the current understanding of the effect of ultraviolet radiation on the eye. It deals with the classification of this radiation,...
This work is a critical review of the current understanding of the effect of ultraviolet radiation on the eye. It deals with the classification of this radiation, environmental level, and the factors that determine it, along with penetration into the human eye, toxicity to ocular structures, associated morbidities, events that may increase the vulnerability of the eye, and artificial eye filters.
PubMed: 36169437
DOI: 10.5935/0004-2749.2021-0354 -
Progress in Retinal and Eye Research Jan 2021The search for alternatives to allotransplants is driven by the shortage of corneal donors and is demanding because of the limitations of the alternatives. Indeed,... (Review)
Review
The search for alternatives to allotransplants is driven by the shortage of corneal donors and is demanding because of the limitations of the alternatives. Indeed, current progress in genetically engineered (GE) pigs, the introduction of gene-editing technology by clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9, and advanced immunosuppressants have made xenotransplantation a possible option for a human trial. Porcine corneal xenotransplantation is considered applicable because the eye is regarded as an immune-privileged site. Furthermore, recent non-human primate studies have shown long-term survival of porcine xenotransplants in keratoplasty. Herein, corneal immune privilege is briefly introduced, and xenogeneic reactions are compared with allogeneic reactions in corneal transplantation. This review describes the current knowledge on special issues of xenotransplantation, xenogeneic rejection mechanisms, current immunosuppressive regimens of corneal xenotransplantation, preclinical efficacy and safety data of corneal xenotransplantation, and updates of the regulatory framework to conduct a clinical trial on corneal xenotransplantation. We also discuss barriers that might prevent xenotransplantation from becoming common practice, such as ethical dilemmas, public concerns on xenotransplantation, and the possible risk of xenozoonosis. Given that the legal definition of decellularized porcine cornea (DPC) lies somewhere between a medical device and a xenotransplant, the preclinical efficacy and clinical trial data using DPC are included. The review finally provides perspectives on the current standpoint of corneal xenotransplantation in the fields of regenerative medicine.
Topics: Animals; Animals, Genetically Modified; Cornea; Corneal Transplantation; Gene Editing; Gene Regulatory Networks; Genetic Engineering; Graft Survival; Humans; Immunosuppression Therapy; Transplantation, Heterologous
PubMed: 32755676
DOI: 10.1016/j.preteyeres.2020.100876 -
Turkish Journal of Ophthalmology Sep 2019In outer retinal degenerative diseases such as retinitis pigmentosa, choroideremia, and geographic atrophy, 30% of the ganglion cell layer in the macula remains intact.... (Review)
Review
In outer retinal degenerative diseases such as retinitis pigmentosa, choroideremia, and geographic atrophy, 30% of the ganglion cell layer in the macula remains intact. With subretinal and epiretinal prostheses, these inner retinal cells are stimulated with controlled electrical current by either a microphotodiode placed in the subretinal area or a microelectrode array tacked to the epiretinal region. As the patient learns to interpret the resulting phosphene patterns created in the brain through special rehabilitation exercises, their orientation, mobility, and quality of life increase. Implants that stimulate the lateral geniculate nucleus or visual cortex are currently being studied for diseases in which the ganglion cells and optic nerve are completely destroyed.
Topics: Electric Stimulation; Electrodes, Implanted; Humans; Microelectrodes; Quality of Life; Retinal Degeneration; Retinitis Pigmentosa; Vision Disorders; Visual Prosthesis
PubMed: 31486609
DOI: 10.4274/tjo.galenos.2019.44270 -
Therapeutic Advances in Ophthalmology 2019Retinal prosthesis systems have undergone significant advances in the past quarter century, resulting in the development of several different novel surgical and... (Review)
Review
Retinal prosthesis systems have undergone significant advances in the past quarter century, resulting in the development of several different novel surgical and engineering approaches. Encouraging results have demonstrated partial visual restoration, with improvement in both coarse objective function and performance of everyday tasks. To date, four systems have received marketing approval for use in Europe or the United States, with numerous others undergoing preclinical and clinical evaluation, reflecting the established safety profile of these devices for chronic implantation. This progress represents the first notion that the field of visual restorative medicine could offer blind patients a hope of real and measurable benefit. However, there are numerous complex engineering and biophysical obstacles still to be overcome, to reconcile the gap that remains between artificial and natural vision. Current developments in the form of enhanced image processing algorithms and data transfer approaches, combined with emerging nanofabrication and conductive polymerization techniques, herald an exciting and innovative future for retinal prosthetics. This review provides an update of retinal prosthetic systems currently undergoing development and clinical trials while also addressing future challenges in the field, such as the assessment of functional outcomes in ultra-low vision and strategies for tackling existing hardware and software constraints.
PubMed: 30729233
DOI: 10.1177/2515841418817501 -
International Journal of Retina and... Nov 2023To review the available evidence on the different retinal and visual prostheses for patients with retinitis pigmentosa and new implants for other indications including... (Review)
Review
PURPOSE
To review the available evidence on the different retinal and visual prostheses for patients with retinitis pigmentosa and new implants for other indications including dry age-related macular degeneration.
METHODS
The PubMed, GoogleScholar, ScienceDirect, and ClinicalTrials databases were the main resources used to conduct the medical literature search. An extensive search was performed to identify relevant articles concerning the worldwide advances in retinal prosthesis, clinical trials, status of devices and potential future directions up to December 2022.
RESULTS
Thirteen devices were found to be current and were ordered by stimulation location. Six have active clinical trials. Four have been discontinued, including the Alpha IMS, Alpha AMS, IRIS II, and ARGUS II which had FDA and CE mark approval. Future directions will be presented in the review.
CONCLUSION
This review provides an update of retinal prosthetic devices, both current and discontinued. While some devices have achieved visual perception in animals and/or humans, the main issues impeding the commercialization of these devices include: increased length of time to observe outcomes, difficulties in finding validated meaures for use in studies, unknown long-term effects, lack of funding, and a low amount of patients simultaneously diagnosed with RP lacking other comorbid conditions. The ARGUS II did get FDA and CE mark approval so it was deemed safe and also effective. However, the company became more focused on a visual cortical implant. Future efforts are headed towards more biocompatible, safe, and efficacious devices.
PubMed: 37996905
DOI: 10.1186/s40942-023-00498-1 -
Neuroscience and Biobehavioral Reviews May 2020Between 1-5:100 people worldwide have never experienced normotypic vision due to a condition called amblyopia, and about 1:4000 suffer from inherited retinal dystrophies... (Review)
Review
Between 1-5:100 people worldwide have never experienced normotypic vision due to a condition called amblyopia, and about 1:4000 suffer from inherited retinal dystrophies that progressively lead to blindness. While a wide range of technologies and therapies are being developed to restore vision, a fundamental question still remains unanswered: would the adult visual brain retain a sufficient plastic potential to learn how to 'see' after a prolonged period of abnormal visual experience? In this review we summarize studies showing that the visual brain of sighted adults retains a type of developmental plasticity, called homeostatic plasticity, and this property has been recently exploited successfully for adult amblyopia recovery. Next, we discuss how the brain circuits reorganize when blindness occurs and when visual stimulation is partially restored by means of a 'bionic eye' in late blind adults with Retinitis Pigmentosa. The primary visual cortex in these patients slowly became activated by the artificial visual stimulation, indicating that sight restoration therapies can rely on a considerable degree of spared plasticity in adulthood.
Topics: Amblyopia; Blindness; Cortical Excitability; Humans; Neuronal Plasticity; Retinitis Pigmentosa; Sensory Deprivation; Visual Cortex
PubMed: 32092315
DOI: 10.1016/j.neubiorev.2020.02.028 -
Indian Journal of Ophthalmology Jul 2021Anophthalmic sockets cause disfigurement that may result in emotional and social distress. The choice of procedure and implant is based upon the surgeon's experience.... (Observational Study)
Observational Study
PURPOSE
Anophthalmic sockets cause disfigurement that may result in emotional and social distress. The choice of procedure and implant is based upon the surgeon's experience. There remains no standardization of cosmetic result. We sought to identify quantifiable anatomical features and functional properties related to a successful cosmetic result in patients with ocular prosthesis and to determine correlations between self-reported and third-party assessment of cosmetic success.
METHODS
This was a prospective observational study, which included 107 adult patients (50.1% female; age 53.08 ± 18.64 years, range 18-89) with acquired anophthalmia following prosthesis fitting. Patients completed a self-assessment questionnaire on self-perception of body image and ocular properties. Three independent examiners assessed cosmetic score. Assessed variables included prosthesis movement, eyelid symmetry, prosthesis stability, and socket fullness.
RESULTS
The general cosmetic result was 8.1 ± 2.19 (on a predetermined scale of 1-10) as perceived by the patients and 7.2 ± 0.19 by the examiners. Interexaminer correlation was high for all variables (P < 0.05). A good cosmetic result was correlated with prosthesis movement (P = 0.02), eyelid symmetry (P = 0.001), and prosthesis stability (P = 0.01). Factors that correlated with a good cosmetic result on multivariate analysis were prosthesis movement (odds ratio [OR] 4.95, P = 0.004), eyelid symmetry (OR 4.51, P = 0.006), and socket fullness (OR 3.56, P = 0.005). No correlation was observed between patients' perceptions of the overall cosmetic result and those of the examiners.
CONCLUSION
The cosmetic result of prosthesis use among anophthalmic patients is generally good, as perceived by both patients and examiners. Good eyelid position and symmetry, orbital fullness, and prosthesis motility were associated with a better cosmetic result.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anophthalmos; Eye Diseases; Eye, Artificial; Eyelids; Female; Humans; Male; Middle Aged; Orbital Implants; Prosthesis Implantation; Young Adult
PubMed: 34146048
DOI: 10.4103/ijo.IJO_2682_20