RESUMO
RESUMEN Objetivo: Determinar los resultados refractivos en pacientes operados de catarata, según el cálculo del poder dióptrico de la lente intraocular con la fórmula Holladay 2. Métodos: Se realizó un estudio descriptivo prospectivo y longitudinal en 222 ojos de 173 pacientes operados de catarata mediante la técnica de facoemulsificación. Se empleó para el cálculo de la lente el IOL Master 700 y la fórmula Holladay 2. Resultados: Predominó el sexo femenino y el grupo etario mayor de 60 años. En el posoperatorio se observó una mejoría en la agudeza visual sin corrección y corregida de más de 4 líneas en la cartilla de Snellen, independiente de la longitud axial, sin cambios significativos en el cilindro queratométrico. En 69,0 por ciento de los casos el resultado refractivo final estuvo en el rango de la emetropía. Los ojos mayores de 26 mm presentaron una disminución del equivalente esférico superior a 6 dioptrías en el posoperatorio; los menores de 22 mm mostraron la mayor diferencia entre el poder dióptrico de la lente intraocular que se implantó y el que sugiere la fórmula convencional. Conclusiones: La fórmula Holladay 2 resulta útil para el cálculo de la lente intraocular en todos los rangos de longitud axial(AU)
ABSTRACT Objective: Determine refractive results in patients undergoing cataract surgery based on intraocular lens dioptric power calculation with the Holladay 2 formula. Methods: A prospective longitudinal descriptive study was conducted of 222 eyes of 173 patients undergoing cataract surgery by phacoemulsification technique. IOL Master 700 and the Holladay 2 formula were used for lens calculation. Results: There was a predominance of the female sex and the over-60 years age group. The postoperative period was characterized by improvement in visual acuity without correction and corrected of more than 4 lines on the Snellen chart, regardless of axial length, with no significant changes in the keratometric cylinder. In 69.0 percent of the cases, the final refractive result was within the range of emmetropia. Eyes larger than 26 mm displayed a spherical equivalent reduction above 6 diopters postoperative, whereas eyes smaller than 22 mm showed the greatest difference between the dioptric power of the intraocular lens implanted and the one suggested by the conventional formula. Conclusion: The Holladay 2 formula is useful for intraocular lens calculation in all axial length ranges(AU)
Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Catarata/diagnóstico , Acuidade Visual , Facoemulsificação/métodos , Lentes Intraoculares/efeitos adversos , Epidemiologia Descritiva , Estudos Prospectivos , Estudos Longitudinais , Estudos Observacionais como Assunto , Emetropia/fisiologiaRESUMO
Aim of the Study: To establish the normative database for multifocal electroretinogram (mfERG) parameters in a normal emmetropic population. To correlate the data so obtained with the central macular thickness obtained using the optical coherence tomography (OCT) scan. Materials and Methods: mfERG data were obtained from 222 eyes of 111 emmetropic subjects. The amplitude (nv/deg2) and implicit times (ms) of the first-order kernel mfERG responses (N1, P1, and N2 waves) were obtained and grouped into five rings (Ring 1: Central 2°, Ring 2: 2–5°, Ring 3: 5–10°, Ring 4: 10–15°, Ring 5: >15°). The central macular thickness (CMT) was obtained using the macular thickness scan protocol of the OCT. Results: The mfERG data obtained were used to create a normative database. The amplitudes of the mfERG waves were maximum in the fovea and progressively decreased with increasing eccentricity (P = 0.0001). The latencies of the P1 and N2 waves were longest in the central ring and progressively shortened with eccentricity (P = 0.0001). No statistically significant correlations were observed between central ring 1 parameters and the CMT. Conclusion: This study establishes normative database for mfERG parameters in an emmetropic population. No statistically significant correlation was noted between CMT and mfERG parameters.
Assuntos
Adulto , Eletrorretinografia/métodos , Emetropia/fisiologia , Humanos , Pessoa de Meia-Idade , Valores de Referência , Reprodutibilidade dos Testes , Retina/citologia , Retina/fisiologia , Tomografia de Coerência Óptica/métodosRESUMO
The authors conducted a review of classical and conflicting theories of accommodation and presbyopia. They make a critical comparison with the findings of magnetic resonance imaging (MRI) that have been developed in recent decades. Based on these studies, formulates a new approach on the subject, shifting the focus of the discussion of the lens to the posterior pole of the eye.
Os autores revisaram as teorias clássicas e conflitantes sobre acomodação e presbiopia. E as compararam criticamente com os achados de imagem por ressonância magnética (MRI) que têm se desenvolvido nas últimas décadas. Baseado nestes estudos, formulam uma nova abordagem sobre o tema, mudando o foco da discussão do cristalino para o polo posterior do olho.