Active clinical trials for "Retinitis Pigmentosa"

A single arm, single center trial to evaluate the safety and efficacy of autologous purified populations of bone-marrow derived stem cells in patients with Retinitis Pigmentosa (BM-SCs) through a 48 month follow up period.

The purpose of this study is to assess the safety and efficacy of intravitreal injections of Aflibercept (Eylea) in treating Cystoid Macula Oedema (CMO) in patients with underlying Retinitis Pigmentosa (RP).

This study is designed to assess and to evaluate the therapeutic effect of retrobulbar injection of autoserum in the treatment of retinitis pigmentosa.

Investigate whether blind subjects that fulfil the patient criteria provided with a Retinal Implant are able to differentiate between simple patterns like horizontal bar, vertical bar and cross.

The purpose of this study is to evaluate the effect of L-Dopa on the progression of retinitis pigmentosa.

Retinitis pigmentosa (RP) is the most common hereditary retinal disorder (accounts for 20% of children attending blind schools in Pakistan) which causes degeneration of rod and cone photoreceptors. Rods and cones largely depend on the retinal pigment epithelium for their proper functioning. Various growth factors and their receptors are present in retinal epithelium and a number of genes are responsible for the production of these growth factors. Genetic mutation in any of these genes causes retinal degeneration by progressive loss of retinal pigment epithelium and photoreceptors. The disease initially starts with night blindness and leads to the loss of central vision and eventually total blindness. To date, there is no definitive cure for patients suffering from RP. Recently, stem cell based therapies have shown great promise for the management of RP. It is well documented that umbilical cord derived mesenchymal stem cells (UMSCs) have the ability to release various paracrine and immunomodulatory factors that are similar to those synthesized by retinal pigment epithelium. Multiple routes including systemic (intravenous) and localized (subretinal, intravitreal, suprachoroidal and sub-tenon) have been employed to administer UMSCs for the management of RP. It is important to note that deep sub-tenon region (space between the sclera and the conjunctiva) acts as both natural culture medium for cells and as immune privileged site because of avascularity of the region. It has been reported that the injection of UMSCs in sub-tenon space of human subjects have improved the visual acuity even after 1 year post-injection. In addition, the injection of UMSCs in suprachoroidal space enhances the entry of growth factors released by the cells into choroidal flow and maintain the constant growth factors secretion to the choroidal and retinal tissues. Limoli and colleagues were the first to report the suprachoroidal administration of cells being the safe mode of cell delivery with no complications. The present study is aimed to investigate the safety and therapeutic efficacy of UMSC injection employing two different routes (sub-tenon injection versus suprachoroidal injection) for the treatment of RP in human subjects.

Retinitis pigmentosa (RP) is an inherited retinal disease with great heterogeneity. RP comprises a large group of genetic disorders causing progressive loss of vision. Despite many suggested treatments, there is actually no effective therapy for most types of RP at present. Mutations that cause RP initially lead to rod cell death. After rod photoreceptors' death, cone photoreceptors also gradually die. There are several hypotheses as to why mutation-induced rod photoreceptor cell death invariably leads to gradual dysfunction and death of cone photoreceptors resulting in severe visual acuity loss and blindness. Rods constitute 95 percent of cells in the outer retina. As they degenerate, oxygen consumption is reduced and the level of tissue oxygen markedly increases. After rods degeneration, several markers of oxidative damage appear in cones. This oxidative stress over time may lead to cone dysfunction and death. Antioxidants reduce markers of oxidative damage and promote cone function and survival. In RP, cone death occurs as a result of the death of rods, rather than as the result of the pathogenic mutations and therefore treatment with antioxidants may have the potential to be applied to all patients with RP irrespective of the disease-causing mutation. N-acetylcysteine is a derivative of L cysteine that plays a role in the biosynthesis of glutathione and neutralizes reactive oxygen species. It also has a direct antioxidant activity via its reactive sulfhydryl agent. Its systemic use shows an acceptable safety profile. It has been shown that the use of systemic N-acetylcysteine provides significant intraocular concentration and antioxidant activity that may lead to the promotion of cone function and survival. In a recent phase 1 randomized clinical trial (RCT), it was revealed that oral N-acetylcysteine (NAC) was safe and well-tolerated in patients with moderately advanced RP and might improve sub-optimally functioning macular cones. The authors concluded that a randomized, placebo-controlled trial is needed to determine if oral NAC can provide long-term stabilization and/or improvement in visual function in patients with RP. In this phase 2 RCT, eligible patients with the diagnosis of moderately advanced RP are randomly divided into two groups; treatment group (N-acetylcysteine tablets) and controls (placebo). Each group will be treated for 6 months. In this study, we will investigate if the use of oral N- acetylcysteine as a potent antioxidant agent can slow down or reverse the disease process in RP patients with prior moderate loss of vision. It may potentially demonstrate a treatment modality regardless of the genetic type of RP. The primary outcome measure will be the stability or improvement of the best-corrected visual acuity (BCVA). The secondary outcome measures will be changes in color vision, electroretinogram, visual field, structural OCT indices after 6 months. The same parameters will be re-evaluated 3 months after discontinuation of treatment at month 9.

Identify new genes responsible for autosomal dominant retinitis pigmentosa (ADRP), one of the most common causes of hereditary diseases of the retina, and thus better understand the mechanisms involved of the disease."

This study is being done to determine if wearable text-to-speech (TTS) and visual pattern recognition (VPR) technology can be used to extend the capabilities of the Argus II to allow patients to read and recognize faces and objects. The Argus II retinal prosthesis can restore rudimentary forms of vision to patients with bare light-perception vision. Using the prosthesis, patients can identify obstacles, handles, switches, eating utensils and demonstrate improved navigation when used in conjunction with other ambulation-assist tools. Current limits in the resolution of the device prevent useful reading or face recognition. The FDA has approved the Argus II as a humanitarian device. Present-day wearable text-to-speech converters are also capable of object and face recognition. Such systems have been developed to assist with these tasks in patients with severe low-vision. ORCAM is a commercially-available eyeglass-mounted visual pattern recognition system capable of converting photographs of text to speech. It is comprised of a camera, a small belt-worn computer, pattern recognition software and a small audio transducer. ORCAM can acquire the image of a sheet of paper and read the text to the user through a small speaker adjacent to the ear. In addition, ORCAM can be trained to recognize faces and speak the name of the individual to the user. ORCAM can also be used to recognize everyday products after being programmed.

The development of new oculometry techniques allows fine and dynamic measurements of pupillary diameter and use in routine clinical practice. The preliminary results obtained with innovative devices on healthy sjuets make it possible to envisage a clinical study on a population of patients suffering from retinal pathologies. This is a "proof of concept" study, which, if the expected results are confirmed, will make it possible to consider a study on a larger population, as well as the industrial development of a commercial device.