RESUMEN
OBJECTIVE: Ocular function is fundamental for environmental adaptation and survival capacity. Growth factors are necessary for a mature eyeball, needed for adequate vision. However, the consequences of the deficiency of circulating growth hormone (GH) and its effector insulin-like growth factor I (IGF-I) on the physical aspects of the human eye are still debated. A model of untreated isolated GH deficiency (IGHD), with low but measurable serum GH, may clarify this issue. The aim of this study was to assess the ocular aspects of adult IGHD individuals who have never received GH therapy. DESIGN: Cross sectional study. METHODS: Setting: University Hospital, Federal University of Sergipe, Brazil. PATIENTS: Twenty-five adult (13 males, mean age 50.1years, range 26 to 70years old) IGHD subjects homozygous for a null mutation (c.57+1G>A) in the GHRH receptor gene, and 28 (15 males, mean age 51.1years, range 26 to 67years old) controls were submitted to an endocrine and ophthalmological assessment. Forty-six IGHD and 50 control eyes were studied. MAIN OUTCOME MEASURES: Visual acuity, intraocular pressure, refraction (spherical equivalent), ocular axial length (AL), anterior chamber depth (ACD), lens thickness (LT), vitreous depth (VD), mean corneal curvature (CC) and central corneal thickness (CCT). RESULTS: IGHD subjects exhibited unmeasurable serum IGF-I levels, similar visual acuity, intraocular pressure and LT, higher values of spherical equivalent and CC, and lower measures of AL, ACD, VD and CCT in comparison to controls, but within their respective normal ranges. While mean stature in IGHD group was 78% of the control group, mean head circumference was 92% and axial AL was 96%. CONCLUSIONS: These observations suggest mild ocular effects in adult subjects with severe IGF-I deficiency due to non-treated IGHD.
Asunto(s)
Hormona de Crecimiento Humana/deficiencia , Hipopituitarismo/complicaciones , Hipopituitarismo/genética , Mutación con Pérdida de Función , Receptores de Neuropéptido/genética , Receptores de Hormona Reguladora de Hormona Hipofisaria/genética , Visión Ocular/fisiología , Adulto , Anciano , Estudios Transversales , Enanismo Hipofisario/genética , Enanismo Hipofisario/patología , Enanismo Hipofisario/fisiopatología , Ojo/patología , Femenino , Humanos , Hipopituitarismo/fisiopatología , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Agudeza VisualRESUMEN
OBJECTIVE: Experimental models demonstrate an important role of GH in retinal development. However, the interactions between GH and the neuro-vascularization of the human retina are still not clear. A model of untreated congenital isolated GH deficiency (IGHD) may clarify the actions of GH on the retina. The purpose of this work was to assess the retinal neuro-vascularization in untreated congenital IGHD (cIGHD). DESIGN: In a cross sectional study, we performed an endocrine and ophthalmological assessment of 25 adult cIGHD subjects, homozygous for a null mutation (c.57+1G>A) in the GHRH receptor gene and 28 matched controls. Intraocular pressure measurement, retinography (to assess the number of retinal vascular branching points and the optic disc and cup size), and optical coherence tomography (to assess the thickness of macula) were performed. RESULTS: cIGHD subjects presented a more significant reduction of vascular branching points in comparison to controls (91% vs. 53% [p=0.049]). The percentage of moderate reduction was higher in cIGHD than in controls (p=0.01). The percentage of individuals with increased optic disc was higher in cIGHD subjects in comparison to controls (92.9% vs. 57.1%). The same occurred for cup size (92.9% vs. 66.7%), p<0.0001 in both cases. There was no difference in macula thickness. CONCLUSIONS: Most cIGHD individuals present moderate reduction of vascular branching points, increase of optic disc and cup size, but have similar thickness of the macula.