It is well known that pattern reversal visual evoked potentials (VEPs) are age-sensitive. Through the use of this technique, it is possible to assess both of the major visual pathways (i.e., the magnocellular and parvocellular ones) in terms of function and development. What developmental path these pathways follow, and if they develop/age in parallel across the human lifespan is a matter of ongoing debate, yet, only a few VEP studies have dealt with this issue. This cross-sectional study examined a sample of 115 healthy volunteers aged 5 to 84 years. Beyond the standard checkerboard pattern reversal stimulation at 97% contrast, we recorded pattern-reversal VEPs at 6% contrast to selectively stimulate the M pathway and isoluminant red and green checkerboard stimulation was also used to selectively stimulate the P pathway. Our results do not support the developmental advantage of any of the pathways. The development of both pathways appear to take a remarkably long time (well into the 30s), and the signs of aging become marked over 50 years of age, especially in the case of the magnocellular pathway.
Retinitis pigmentosa (RP) encompasses inherited retinal dystrophies, appearing either as an isolated eye condition or as part of a broader systemic syndrome, known as syndromic RP. In these cases, RP includes systemic symptoms impacting other organs, complicating diagnosis and management. This review highlights key systemic syndromes linked with RP, such as Usher, Bardet–Biedl, and Alström syndromes, focusing on genetic mutations, inheritance, and clinical symptoms. These insights support clinicians in recognizing syndromic RP early. Ocular signs like nystagmus and congenital cataracts may indicate systemic disease, prompting genetic testing. Conversely, systemic symptoms may necessitate eye exams, even if vision symptoms are absent. Understanding the systemic aspects of these syndromes emphasizes the need for multidisciplinary collaboration among ophthalmologists, pediatricians, and other specialists to optimize patient care. The review also addresses emerging genetic therapies aimed at both visual and systemic symptoms, though more extensive studies are required to confirm their effectiveness. Overall, by detailing the genetic and clinical profiles of syndromic RP, this review seeks to aid healthcare professionals in diagnosing and managing these complex conditions more effectively, enhancing patient outcomes through timely, specialized intervention.
19 September 2023 in Case Reports in Ophthalmology
We present here the case histories of two siblings, a boy and a girl, with Leber’s congenital amaurosis (LCA). The diagnosis was based on non-recordable full-field electroretinogram (ffERG). The long-term ophthalmologic follow-up included kinetic perimetry (Goldmann), visual evoked potentials with flash stimulation, optical coherence tomography (OCT: B-scan images at the area of fovea), and multifocal ERG. The boy (sibling 1, born in 1986) was sent for electrophysiological examination at the age of four because he had nystagmus from birth. The diagnosis would be LCA based on non-recordable ffERG. Four years later, his visual acuity decreased rapidly due to vitreous opacification, caused by the autoimmune reaction of the retinal pigment epithelial cells. This was treated successfully with steroid injections, administered parabulbarly. Retinal autoimmune panel was not performed. Genetic testing became available only in 2019, and it revealed a RPE65 gene mutation: (NM_000329.2) c.{442G>A};{442G>A} (p.{Glu148Lys}; {Glu148Lys}). His sister (sibling 2, born in 1993) showed similar symptoms, caused by the same genetic mutation. Even though their parents were free of symptoms, it appeared that they were heterozygous carriers of the same mutation. Research of the family tree revealed a consanguineous marriage four generations before. Both siblings received successful gene therapy relatively late in their age: sibling 1 was 35 and sibling 2 was 28 years old, meaning that they were at an advanced stage of the disease. Nevertheless, follow-up examinations showed measurable improvements in their retinal function. The study shows that electrophysiological examinations, including flash-evoked responses, are useful in the objective evaluation of the progression in the central photoreceptor loss during the follow-up of LCA. The results also show that gene therapy can have beneficial effects even at an advanced stage of the disease.
This is a case history of a 23-year-old woman suffering from incontinentia pigmenti (IP). The patient’s vision in the left eye started to deteriorate due to cataract progression at the age of 22, and by the age of 23, it dropped from 0.9 to 0.04. Ultrasound examination confirmed tractional vitreoretinal membranes. Vitrectomy was performed, therefore, on her left eye. The histological evaluation of vitreous membrane revealed a complex immunophenotype (positivity for glial fibrillary acidic protein (GFAP), vimentin, S-100, anti-pan cytokeratin antibody (AE/AE3), and smooth muscle-specific actin (SMA) to various extents). The right eye remained unsymptomatic throughout this course. Besides being the first to analyze the tractional vitreoretinal membrane in IP with immunohistochemical methods, this case study points out that extreme cases of asymmetric side involvement in IP do exist, even to the point of one eye being completely unsymptomatic.