Purpose: Retinitis Pigmentosa is a term that includes a group of inherited bilateral and progressive retinal degenerations, with the involvement of rod photoreceptors, which frequently leads to blindness; oxidative stress may be involved in the degeneration progression as proposed by several recent studies. The goal of this study is to evaluate whether circulating free radicals taken from capillary blood are related to one of the most important features of Retinitis pigmentosa that can affect frequently patients: cystoid macular oedema (CME). Materials: A total of 186 patients with Retinitis Pigmentosa (range: 25–69 years) were enrolled; all patients completed an ophthalmologic examination and SD-OCT at baseline and were divided into three subgroups according to the SD-OCT features. ROS blood levels were determined using FORT with monitoring of free oxygen radicals. Results: Test levels of free oxygen radicals were significantly increased, almost twice, in RP patients showing cystoid macular oedema and significantly increased compared to the control group. (p < 0.001). Discussion: Our findings suggest that oxidative stress may speed cone photoreceptors’ morphological damage (CMT); because long lasting oxidative stress in the RP may cause oxidative damage, with animal models of RP suggesting this is a micromolecular mechanism of photoreceptors’ (cone) death, it can be similar to cone damage in human RP eyes. The limitations of this paper are the relatively small sample, the horizontal design of the study, and the lack of data about the levels of ROS in the vitreous body.
Introduction. To analyze the morphological and functional features of choroidal neovascularizations (CNVs) in eyes affected by pattern dystrophies (PD), evaluating their long-term response to intravitreal ranibizumab, and comparing them with CNVs in age-related macular degeneration (AMD). The mean goal is to identify possible disease biomarkers and to evaluate the long-term prognosis of CNVs in PD. Materials and Methods. A retrospective study of 42 patients with naïve CNV (26 PD and 16 AMD), for a total of 47 eyes (29 eyes in the PD group and 18 eyes in the AMD group). Each patient received a loading dose of ranibizumab (one monthly for three months) followed by pro re nata (PRN) reinjection protocol for a period of at least three years. Morphological OCT parameters (CRT, central retinal thickness; SRF, subretinal fluid; IRF, intraretinal fluid; SHRM, subretinal hyperreflective material; HRF, hyperreflective foci; HCD, hyperreflective crystalline deposits; cCT, central choroidal thickness; slCT, sublesional choroidal thickness; EZd, ellipsoid zone disruption; and best corrected visual acuity (BCVA in logMAR scale)) were reported at baseline and last follow-up. Results. At baseline, no significant differences were found between the two groups, except for choroidal thickness parameters that were significantly greater in the PD group ( p = 0.009). Longitudinal PD analysis demonstrated reduction in BCVA ( p = 0.009), decrease in CRT ( p = 0.046), resolution of SRF in 61.6% of cases ( p = 0.004) and SHRM in 30% ( p = 0.034), and choroidal thinning both centrally ( p = 0.004) and sublesional ( p = 0.011) compared to baseline. At 3 years, the PD group received significantly more injections than the AMD ( p = 0.011) and showed significantly thicker choroid ( p = 0.033) and more frequent HRF ( p = 0.006). Regarding the PD group, we found a negative correlation between age and choroidal thicknesses at baseline and at 3 years ( p < 0.05); significant positive correlations were found between baseline BCVA and at 3 years ( p < 0.001), BCVA at 3 years and IRF ( p = 0.003) and SHRM at 3 years ( p = 0.003); CRT baseline and CRT 3 years ( p = 0.017); HCD at 3 years was associated with greater CRT ( p = 0.04) and IRF at 3 years ( p = 0.019). Conclusions. Early and long-term morphofunctional features of CNVs in PD and in AMD are overlapping. CNVs in PD have poorer long-term response to ranibizumab and higher choroidal thickness suggesting different pathogenetic and evolutionary mechanisms.
The chapter examines the use of stem cells in ophthalmological pathologies affecting both the anterior and posterior segments. The authors review the clinical trials that have most contributed to defining the role and potential of stem cell regenerative therapy in corneal and retinal pathology. The results described in the scientific literature are analyzed and commented, without neglecting the possible side effects related to the use of this therapy. Within the anterior segment, the greatest efforts were made to study the possible uses of limbal epithelial stem cells (LESCs). They were the first stem cells to be discovered at the level of the anterior segment and currently the only ones involved in clinical practice with satisfactory results. At this juncture there have been significant successes in the treatment of corneal stem cell deficiency and of corneal scars. The chapter later investigates the possible applications of stem cell therapy in degenerative retinal diseases, with particular reference to retinitis pigmentosa, Stargardt's disease, and age-related macular degeneration. It then describes how the use of cell therapies, in particular those that use ADSC, can contribute, through various methods, to the containment of the evolution of retinal degenerative diseases. These mechanisms cover various biological aspects and can be summarized as follows: neurotrophism, oxidation, vascular changes, apoptosis, inflammation, or immunology. The ophthalmological modalities of the cell graft and what is the ideal approach for an ophthalmological cellular surgery are later on described. Finally, the technique used by the author and the possible outcomes in the course of degenerative retinopathy are described.
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