Formation of a unilateral form deprivation myopia (FDM) due to a congenital eyelid entropium with a consecutive corneal ulcer: An illustrated case report

Abstract

Eye growth is regulated by a precise, sharp image of a distant object on the photoreceptor layer. A variety of laboratory investigations report that translucent occluders may induce axial eye elongation in animals. This axial growth is also called form deprivation myopia (FDM). In our pediatric ophthalmology clinic we observed the clinical correlate of FDM in a male infant with unilateral corneal ulcer due to a congenital tarsal malformation. Examination in the postnatal period under anesthesia revealed identical axial length in both eyes. Refraction of the affected eye could not be measured due to severe corneal ulcer. During an observation period of two years, the deep corneal opacification of the affected eye induced unilateral disproportionate axial elongation with formation of myopia. Formation of FDM may complicate treatment of amblyopia following unilateral media opacification. Periodic measurements of refraction should be performed to allow appropriate correction.

Axial length elongation in adults with long-standing unilateral traumatic cataract

“…10 Schellenbeck et al and Mahler et al reported the same phenomenon in infants with visual deprivation due to unilateral corneal scars. 12,13 The only human study in the English literature describing this phenomenon in adults was published by Gradin et al 14 They performed a retrospective cohort study on 13 patients with unilateral traumatic cataracts for more than 1 year and an interocular axial length difference of more than 1 mm. Study patients were found to have a significantly higher median interocular axial length difference (3.09 mm, interquartile range [IQR] 2.45 mm -4.13 mm) than control patients (0.24 mm, IQR 0.15 mm -0.30 mm, p = 0.000).…”

“…This has been described in animal models including primates, 2,3,4 chicks, 5 tree shrews 6 and other lower species. 7,8 Several authors have described axial length elongation in humans with unilateral visual deprivation from birth or early childhood, 9,10,11,12,13 but reports of this phenomenon in adults are uncommon. At the time of our review, we found only one such study on adults in the English literature.…”