Purchase this article with an account.
Spencer James Harris, Saeideh Ghahghaei, Ian Cunningham, Ashraf Harb, Arvind Chandna; Axial length growth in eyes with childhood cataract does not follow norms. Invest. Ophthalmol. Vis. Sci. 2021;62(8):2737.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Normal axial length growth (ALG) in infancy is modulated by hyperopic defocus on the retina and accommodation. Childhood cataract (CC) and CC surgery disrupt both mechanisms with potential for altered ALG. We compared axial length (AL) in children with CC before and after surgery to typical children (norms) to determine whether CC and surgery affect ALG.
110 eyes of 55 children (age 2 weeks - 7 years) with CC were included: 30 eyes, 15 children with unilateral CC and 80 eyes, 40 children with bilateral CC. Eyes with structural abnormalities were excluded. AL data for cataracts was retrospective. AL norms were derived from a cross-sectional prospective study of 332 typical children (age 8 weeks - 7 years) at the same center. AL was measured pre- and postoperatively. Surgical procedures were performed by a single surgeon (AC). Bilateral CC data was combined, as there was no significant difference between eyes. Preoperative ALG curves were calculated for each population and best described by the function AL = a + b*ln(t), where t is age in weeks. 95% confidence intervals were calculated via the bootstrap method. We then found the difference in AL between age-matched norms and pre- and postoperative AL 13 months after surgery (range 9-18 months), again via the bootstrap method.
For healthy eyes, a was 16.62 (16.21, 17.01, 95% CI) and b was 1.01 (0.92, 1.09). Between groups, b did not differ significantly. For bilateral CC, a was 15.65 (14.80, 16.48). The trend was towards shorter AL but was not significant. For unilateral CC, the a value for affected eyes was 14.37 (12.33, 16.12) and for fellow eyes 16.47 (15.29, 17.41). The affected eye was significantly shorter than norms. The unaffected eye was no different than controls. 13 months postoperatively, eyes with bilateral CC did not approximate normal ALG; change in difference was only 0.1% (-3.3%, 3.7% 95% CI), but affected eyes of unilateral CC did approximate normal ALG, changing by 5.9% (3.4%, 8.7%) and no longer differing significantly from fellow eyes or norms.
In CC there is altered ALG, and the affected eye(s) at presentation is shorter. This indicates a disease process beyond a structural abnormality alone; the presence of cataract itself is enough to cause a difference in ALG. Additionally, there are likely different mechanisms of visual deprivation between unilateral and bilateral CC and altered ALG mechanisms following surgery.
This is a 2021 ARVO Annual Meeting abstract.
This PDF is available to Subscribers Only