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Purpose: To compare objective accommodation of phakic and pseudophakic eyes between two different age groups.Methods: Eighty-three eyes (83 participants aged ≥ 40 years) with a visual acuity of 20/25 or better, and refractive error < spherical − 1.0 diopters (D) and cylindrical 1.0 D, were included. Forty-four patients had undergone phacoemulsification and monofocal intraocular lens implantation and were examined 6 months post-surgery. Participants were divided into groups 1 (pseudophakic, age < 60 years), 2 (pseudophakic, ≥ 60 years), 3 (phakic, < 60 years), and 4 (phakic, ≥ 60 years). Objective accommodation and pupil diameter to 2.0- and 3.0-D stimuli were measured with a binocular open-field autorefractor.Results: The mean objective accommodation was 0.29 ± 0.47 D, 0.01 ± 0.21 D, 1.00 ± 0.88 D, and 0.01 ± 0.13 to a 2.0-D stimulus, and 0.26 ± 0.51 D, − 0.06 ± 0.21 D, 1.42 ± 1.21 D, and − 0.06 ± 0.21 to a 3.0-D stimulus in groups 1, 2, 3, and 4, respectively. For both stimuli, the values in group 1 exceeded those in groups 2 and 4, and were smaller than those in group 3, while the values in group 3 exceeded those in groups 2 and 4. The mean pupillary diameter was − 0.5 ± 0.8 mm, − 0.3 ± 0.8 mm, − 0.6 ± 0.5 mm, and − 0.6 ± 0.9 mm to a 2.0-D stimulus, and − 0.6 ± 0.8 mm, − 0.6 ± 0.8 mm, − 0.9 ± 0.5 mm, and − 1.0 ± 1.1 mm to a 3.0-D stimulus in groups 1, 2, 3, and 4, respectively. There was significant correlation between objective accommodation and changes of pupil size for both stimuli.Conclusion: Age seems to play a role in objective accommodation among relatively young pseudophakic patients. [ABSTRACT FROM AUTHOR]

Introduction: Accommodation is the ability to see over a range of distances by changing the power of the natural lens. With cataract surgery, this ability is partially or completely abolished. Apparent accommodation or pseudo-accommodation is the potential of pseudophakic eyes to sustain a good amount of near vision. Aim: To measure near vision in children with pseudophakia unaided, with distance vision correction alone (mono focal lens) in-situ and to measure the minimum near add (bifocal near segment power) required to read 1M (normal reading print size) at 30 cm and 40 cm. Materials and Methods: A cross-sectional study was conducted among children between 5-15 years of age with pseudophakia. Vision assessment was done using Lea symbol chart, at 3 metres for distance and at 30 cm and 40 cm for near. Near vision assessment was done unaided and with distant vision correction alone in place. Minimum spherical power needed to read 1M and child's class textbooks were also assessed. Results: Sixty-four children were included in the study. Mean age was 10.5 (±3.12) years. Refractive status showed spherical power ranging from -7.00 DS to +1.00 DS (-0.8 Mean, (±1.33 SD), astigmatism ranging from -4.50 DC to +3.00 DC (-1.29 mean, ±1.37 SD). Unaided near vision assessment showed that 41 (64%) could read <2M at 30 cm. Nine children could read 1M at 30 cm and three children could read 1M at 40 cm with distant vision correction alone in place. Conclusion: Sixteen (25%) children in our study were independent of spectacles for reading 1M at a reading distance of 30 cm. Nine children (14.1%) read 1M at 30 cm with monofocal spectacles. Twenty-three children (35.9%) had good functional near vision and did not require any add for near work. Forty-six children (71.8%) required only 2 D or less near add for their classwork at 30 cm. Thus, monofocal or reduced near add can give these children a better quality of vision. [ABSTRACT FROM AUTHOR]

Introduction: This paper presents a comparative study of accommodation, pseudoaccommodation (PA) and higher order optical aberrations (HOAs) in children and young people with myopia and hyperopia. Materials and methods: 123 myopic eyes (mean -5.27 ±1.6 D) and 53 hyperopic eyes (mean +3.1 ±1.15 D) of 88 patients aged 5--24 (mean age 12.5 ±0.7) were examined. The parameters measured included objective accommodative response, and relative accom- modation reserves. Pseudoaccomodation amplitude (PA) was determined as the difference between the calculated additional plus lens 3.0 D and the power of the minimum plus lens which allowed reading in cycloplegic conditions (1% cyclopentolate hydrochloride x 2) at a distance of 33 cm. Higher order aberra- tions (root mean square -- RMS), vertical and horizontal trefoil, vertical and horizontal coma (coma7, coma8), and spherical aberration (SA) were also measured. Results: Objective and subjective accommodation parameters were significantly lower in myopia as compared to hyperopia, while wavefront aberrations (RMS HOA, vertical trefoil, coma7) and PA were significantly higher. Aberration and accommodation parameters were found to be differently related in myopia and hyperopia. In myopia, RMS and vertical coma were directly correlated with accommodation, while vertical trefoil and SA were directly correlated with PA. In hyperopia, vertical trefoil was directly correlated to accommodation and PA, while ver- tical coma was negatively correlated with PA, and horizontal trefoil and SA were negatively correlated with accommodation. Spherical aberration measured under cycloplegia correlated dif- ferently with accommodation in myopic and hyperopic patients. In myopia, no correlation with the objective accommodation response was found, while direct correlation with the PA value could be detected. Conversely, in hyperopia, a negative correlation with objective accommodation response and no correlation with PA was detected. A significantly higher value of SA in myopic patients with a broader amplitude of PA was observed. In hyperopic eyes, in contrast to myopic ones, SA was significantly decreasing, moving to negative values in high amplitude PA. Conclusions: Parameters of accommodation were decreased and HOAs, PA were increased in myopia. Accommodation and wave- front parameters exhibit different relationships with each other in myopic and hyperopic eyes. The detected features should be taken into consideration when developing correction methods which are targeted toward refractogenesis. [ABSTRACT FROM AUTHOR]

Purpose: To determine the amplitude of pseudoaccommodation and higher-order aberrations with three types of implanted monofocal intraocular lenses (IOLs): aspheric yellow (IQ); spheric yellow (NT); and spheric clear (AT). Setting: Department of Ophthalmology, Nara Medical University, Nara, Japan. Methods: We studied 60 patients who underwent small incision phacoemulsification with the implantation of a monofocal IQ, NT, or AT IOL. The pseudoaccommodation was measured by the lens-loading method, and the postoperative ocular higher-order aberrations were measured with a Hartmann-Shack wavefront analyzer through natural and 4 mm pupils. Results: Sixty eyes of 60 patients were studied. The average amplitude of the pseudoaccommodation was 0.45±0.24 D with the IQ IOL, which was significantly lower than that with the AT IOL at 0.81±0.37 D (Tukey's test; P<0.01). The differences in the amplitude of the pseudoaccommodation between the IQ and the NT IOLs, and between the NT and the AT IOLs were not significant (Tukey's test; P>0.05). The degree of spherical aberration was significantly different for the IQ, NT, and AT lenses (analysis of variance, P=0.016). The spherical aberration through the IQ IOL was significantly lower than that through the NT and the AT IOLs (Tukey's test; P<0.01). The fourth-order RMS (root mean square) aberration of the IQ lens was also significantly lower than that of the NT and AT IOLs (Tukey's test; P<0.01). Conclusion: Our results suggest that the spherical aberration and selective spectral transmission of IOLs may work together to increase the amplitude of the pseudoaccommodation. [ABSTRACT FROM AUTHOR]

bstract [ABSTRACT FROM AUTHOR]

bstract [ABSTRACT FROM AUTHOR]

This study aimed to determine the optimal spherocylindrical refraction in the monofocal, pseudophakic eye using power vectors in dioptric space. For parallel incident light the defocus of a spherocylinder may be described in dioptric space as: where SEP = spherical equivalent power in dioptres (D) and M = astigmatic magnitude in D. In the pseudophakic eye the defocus for any fixation distance x is: The cumulative defocus over a fixation interval is the integral of D. A minimal value for cumulative defocus will indicate a maximal unaided visual acuity (VA) over the chosen fixation interval. We calculated the summated defocus for various spherocylinders for fixation distances ranging from 0.5 m to 6.0 m. Minimal cumulative defocus was present for pure spheres of − 0.25 D to − 0.5 D. No beneficial effect of the presence of astigmatism was detected. In monofocal pseudophakia the highest possible VAs over the most extended fixation ranges may be achieved with slight myopic refractions without astigmatic components. [ABSTRACT FROM AUTHOR]