Caracterización de las principales variables clínicas del glaucoma en pacientes con retinosis pigmentaria / Main clinical variables in characterization of patients with retinitis pigmentosa and glaucoma

Se realizó un estudio epidemiológico, descriptivo y transversal de 85 pacientes con alguna de las formas clínicas de glaucoma, dispensarizados en el Centro Nacional de Referencia de Retinosis Pigmentaria durante el primer semestre del 2010. Entre las variables analizadas de acuerdo con la clasificación de la Escuela Cubana de Retinosis Pigmentaria, figuraron: agudeza visual, alteraciones campimétricas, herencia de retinosis y consanguinidad, hipertensión ocular y espesor corneal, según los tipos de dichas afecciones. En la serie, 32,9 % tenía visión entre 0,1 y 0,3; 47,05 %, reducción concéntrica del campo visual (5 y 10 °) y patrón autosómico recesivo; 17,64 %, antecedentes de consanguinidad y 38,8 %, comienzo juvenil. Se halló hipertensión ocular en 82,35 %, con predominio en la retinosis típica de grado IV (40,0 %), así como disminución del espesor corneal en 34,1% de la casuística. La letalidad visual por la asociación de ambas oftalmopatías exige que sea investigada detenidamente. Hasta el momento, la medición adecuada de la presión intraocular (aplanación con ajuste a los valores del espesor corneal) constituye la herramienta más útil para diagnosticar la enfermedad y evaluar su evolución en estos pacientes.

An epidemiological, descriptive and cross-sectional study was carried out in 85 patients with some clinical forms of glaucoma, attended and monitored at the National Reference Center of Retinitis Pigmentosa during the first semester of 2010. Among the analyzed variables according to the classification of the Cuban School of Retinitis Pigmentosa were visual acuity, visual field defects, retinitis inheritance and consanguinity, ocular hypertension and corneal thickness according to the types of these conditions. In the series 32,9 % had vision between 0,1 and 0,3; concentric reduction of vision field (5 and 10 °) and autosomal recessive pattern in 47,05 %; history of consanguinity in 17,4 % and juvenile onset in 38.8%. Ocular hypertension was found in 82,35 % with predominance in grade IV typical retinitis (40,0 %), as well as reduction of corneal thickness in 34,1 % of all cases. The visual letality caused by association of both eye diseases requires to be studied carefully. So far, proper measurement of intraocular pressure (applanation adjusted to the values of corneal thickness) is the most useful tool to diagnose disease and to evaluate its progress in these patients.

The safety and efficacy of robotic image-guided radiosurgery system treatment for intra- and extracranial lesions: a systematic review of the literature.

BACKGROUND: The CyberKnife is a new, frameless stereotactic radiosurgery system. This work reviews its safety and efficacy in the treatment of intra- and extracranial lesions. METHODS: A literature search was made of the Medline, Embase, Pascal Biomed, CINAHL and Cancerlit databases. Health technology assessment reports on stereotactic radiosurgery systems were also consulted. All searches were made in June 2007. Data on efficacy and safety were extracted and then synthesized into the present review. RESULTS: Thirty five clinical studies were identified, the majority of which included no patient comparison group. These studies assessed the use of the CyberKnife mainly in the treatment of primary and metastatic intracranial and spinal tumours. CONCLUSIONS: The CyberKnife system allows to carry out standard radiosurgical and fractionated stereotactic radiotherapy procedures. The use of this system offers an alternative for the treatment of inoperable tumours, and of lesions located close to critical structures that cannot be treated using other types of stereotactic radiosurgery system. Unfortunately, the quality of the reviewed papers still does not allow definite conclusions to be drawn regarding the safety and efficacy of these treatments.

Spinocerebellar ataxia type 2: polyQ repeat variation in the CACNA1A calcium channel modifies age of onset.

Nine neurodegenerative diseases, collectively referred to as polyglutamine (polyQ) diseases, are caused by expansion of a coding CAG DNA trinucleotide repeat. PolyQ diseases show a strong inverse correlation between CAG repeat length and age of disease onset (AO). Despite this, individuals with identical repeat expansion alleles can have highly variable disease onset indicating that other factors also influence AO. We examined AO in 148 individuals in 57 sibships from the SCA2 founder population in Cuba. The mutant CAG repeat allele explained 57% of AO variance. To estimate heritability of the residual variance after correction for SCA2 repeat length, we applied variance component analysis and determined the coefficient of intraclass correlation. We found that 55% of the residual AO variance was familial. To test candidate modifier alleles in this population, we selected 64 unrelated individuals from a set of 394 individuals who were highly discordant for AO after correction for SCA2 CAG repeat length. We hypothesized that long normal alleles in the other 8 polyQ disease genes were associated with premature disease onset in SCA2. Of the 8 genes tested, only long normal CAG repeats in the CACNA1A gene were associated with disease onset earlier than expected based on SCA2 CAG repeat size using non-parametric tests for alleles (P < 0.04) and genotypes (P < 0.023) after correction for multiple comparisons. CACNA1A variation explained 5.8% of the residual variation in AO. The CACNA1A calcium channel subunit represents an excellent candidate as a modifier of disease in SCA2. It is highly expressed in Purkinje cells (PCs) and is essential for the generation of the P/Q current and the complex spike in PCs. In contrast to other polyQ proteins, which are nuclear, the CACNA1A and SCA2 proteins are both cytoplasmic. Furthermore, small pathologic expansions of the polyQ domain in the CACNA1A protein lead to PC degeneration in SCA6. Future studies are needed to determine whether the modifier effect of CACNA1A relates to neuronal dysfunction or cell death of Purkinje neurons.