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. 2020 Jan-Mar;13(1):50-58.
doi: 10.1016/j.optom.2019.06.003. Epub 2019 Nov 1.

Patient selection to optimize near vision performance with a low-addition trifocal lens

Joaquín Fernández  1 , Manuel Rodríguez-Vallejo  2 , Javier Martínez  1 , Ana Tauste  1 , David P Piñero  3
Affiliations

Patient selection to optimize near vision performance with a low-addition trifocal lens

Joaquín Fernández et al. J Optom. 2020 Jan-Mar.

Abstract
in English, Spanish

Purpose: To assess the impact of ocular biometric variables on the visual performance achieved with a low addition trifocal intraocular lens (MIOL).

Methods: Retrospective observational study including 34 eyes. Preoperative measured variables included mean corneal power (Km), corneal regular astigmatism (RA), anterior chamber depth (ACD), axial length (AXL), total irregular astigmatism (IA), spherical aberration (SA) and distance from pupil center to vertex normal (µ). Same variables were retrieved from the three month visit follow-up in addition to the actual lens position (ALP), the calculated effective addition (EA), the IOL centration from vertex normal (d), and the visual acuity defocus curve. The area under the defocus curve was computed along the total curve (TAUC) and ranges for far (FAUC), intermediate (IAUC) and near vision (NAUC). The sample was split in two groups of 17 eyes with TAUCs above and below the mean, and the differences among groups for different ocular parameters were assessed.

Results: The group of eyes above TAUC of 2.03 logMAR*m-1 showed significantly lower Km and greater AXL and SA. Km was negatively correlated with TAUC and NAUC. NAUC was negatively correlated with IA and positively with d. A multiple lineal regression model including Km, d, and IA predicted NAUC (r-square = 34%). No significant differences between IA and SA were found between preoperative and postoperative values but µ significantly decreased after surgery.

Conclusions: The mean corneal power, irregular astigmatism, and centration from vertex normal should be considered for optimizing the near visual performance with this MIOL.

Objetivo: Valorar el impacto de las variables biométricas oculares sobre el rendimiento visual con una lente intraocular trifocal de baja adición (MIOL).

Métodos: Estudio observacional retrospectivo que incluyó 34 ojos. Las variables preoperatorias medidas incluyeron potencia corneal media (Km), astigmatismo regular corneal (AR), profundidad de la cámara anterior (ACD), longitud axial (AXL), astigmatismo irregular total (AI), aberración esférica (AE) y distancia entre el centro de la pupila y el vértice normal (µ). Algunas variables se obtuvieron de la visita de seguimiento a los tres meses, a las que se añadieron la posición real de la lente (ALP), la adición efectiva (AE), el centrado de las LIO desde el vértice normal (d), y la curva de desenfoque de agudeza visual. El área bajo la curva de desenfoque se calculó a lo largo de la curva total (TAUC) así como los rangos para visión de lejos (FAUC), intermedia (IAUC) y de cerca (NAUC). La muestra se dividió en dos grupos de 17 ojos con TAUCs por encima y por debajo de la media, valorándose las diferencias entre los grupos para los diferentes parámetros oculares.

Resultados: El grupo de ojos con un valor por encima de TAUC igual a 2,03 logMAR*m-1 reflejó un menor Km y valores mayores de AXL y AE. Km se correlacionó negativamente con TAUC y NAUC. NAUC se correlacionó negativamente con AI, y positivamente con d. Un modelo de regresión lineal múltiple incluyendo Km, d, y AI realizó la predicción de NAUC (R2 = 34%). No se encontraron diferencias significativas entre AI y AE entre los valores preoperatorios y postoperatorios, aunque µ disminuyó significativamente tras la cirugía.

Conclusiones: La potencia corneal media, el astigmatismo irregular y el centrado desde el vértice normal deberían considerarse para optimizar el desempeño visual de cerca con MIOL.

Keywords: Addition; Adición; Agudeza visual; Astigmatismo irregular; Centrado; Centration; Curvas de desenfoque; Defocus curves; Irregular astigmatism; Keratometry; Lentes intraoculares trifocales; Queratometría; Trifocal intraocular lens; Visual acuity.

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Figures

Figure 1
Figure 1
Top image shows an example of the ordinal scale used for evaluating the intraocular lens centration. The diagram describes the right eye with the pupil divided by a vertical line. The first ring of the lens is divided in 4 sections that serve as a reference to measure the displacement to the pupil center. From left to right, the lens is centered (0.0), 25% temporal (−1.0) and 50% temporal (−2.0) the size of the first ring. The last top image shows a real example with pupil divided by a red cross and rings of the lens marked with white circles for a clear visualization. For vertical centration, the same approach was performed dividing the pupil by a horizontal line. Bottom image shows the system of coordinates used in the research (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article).
Figure 2
Figure 2
(A) Mean visual acuity defocus curve of the 34 measured eyes. (B) Defocus curves from eyes with near area under the curve (NAUC) higher and lower to 0.48. Vertical bars describe the standard deviation.
Figure 3
Figure 3
A) Location of the vertex normal from to the pupil center for preoperative and postoperative measures. Black triangles describe the mean and the ellipse around the triangles the standard deviation. B) Location of the intraocular lens (IOL) center to the vertex normal. Black circle describes the mean and the ellipse around the circle the standard deviation. Each ring on the plot describes a 0.2 mm step. Locations are nasal for 0°, superior for 90°, temporal for 180° and inferior for 270°.
See this image and copyright information in PMC

References

    1. Calladine D., Evans J.R., Shah S., Leyland M. Multifocal versus monofocal intraocular lenses after cataract extraction. Cochrane Database Syst Rev. 2012;12 - PubMed
    1. Alio J.L., Plaza-Puche A.B., Férnandez-Buenaga R., Pikkel J., Maldonado M. Multifocal intraocular lenses: An overview. Surv Ophthalmol. 2017;62:611–634. - PubMed
    1. Masket S., Rorer E., Stark W., Holladay J.T. Special report: American Academy of Ophthalmology Task Force consensus statement on adverse events with intraocular lenses. Ophthalmology. 2016;124:142–144. - PubMed
    1. Reinstein D.Z., Archer T.J., Srinivasan S., Mamalis N. Standard for reporting refractive outcomes of intraocular lens–based refractive surgery. J Cataract Refract Surg. 2017;43:435–439. - PubMed
    1. Karhanová M., Pluháček F., Mlčák P., Vláčil O., Šín M., Marešová K. The importance of angle kappa evaluation for implantation of diffractive multifocal intra-ocular lenses using pseudophakic eye model. Acta Ophthalmol. 2015;93:e123–e128. - PubMed