Abstract
Purpose:
Some pseudophakic patients implanted with monofocal intraocular lens (IOL) have good near visual acuity with their distance correction. This apparent accommodation has been called "pseudo-accommodation". The objective of this study was to evaluate the prevalence of pseudo-accommodation in children after bilateral congenital cataract surgery, without amblyopia, and to define its mechanisms.
Methods:
We included 40 eyes of 23 children aged 6 to 18, with a corrected distance visual acuity above 8/10 and a normal near visual acuity (P2) with +3 addition. We also included a group of 14 pseudophakic adults, with a corrected distance visual acuity superior to 8/10 and a normal near visual acuity (P2) with +3 addition. Pseudo-accomodation was defined as a near visual acuity better than P4 with the distance correction and without addition. Prevalence of pseudo-accommodation was calculated in each group. In order to determine the factors accounting for pseudo-accommodation in children, we compared the group of children with pseudo-accommodation with to that of adults without pseudo- accommodation under several parameters : refraction, axial length, corneal topography, aberrometry, pupillary diameter, implant’s shift after cyclopentolate mesured with OCT-SD.
Results:
In the children group, 36 (90%) had a near visual acuity at equal to P4 without addition. Among the 28 included adults eyes, 2 (7%) had pseudo-accommodation. When we compared the 36 children eyes with pseudo-accommodation and the 26 adults eyes without pseudo-accommodation, we found that spherical equivalent, implant’s power, corneal multifocality and corneal higher-order aberrations (mainly coma and trefoil) were significantly higher in the group with pseudo- accommodation, while pupil diameter and implant’s shift were statistically the same in both groups. Axial length was smaller in the pseudo-accommodation group.
Conclusions:
Pseudo-accommodation in pseudophakic children is a poor known phenomenon. With this study, we have highlighting its high prevalence among non-amblyopic children. In children no mechanism has ever really been identified. This study found several possible mechanisms to explain pseudo-accommodation in children : a high power of the IOL and a small axial length, maximizing the effect of the IOL’s shift, corneal multifocality and corneal higher-order aberrations.