3.1 Clinical observations

In FCMD, both anterior and posterior components of the eye can be affected. Clinical symptoms include myopia, strabismus, and nystagmus [30–32]. Cataract, Ocular Pathology of Fukuyama Congenital Muscular Dystrophy DOI: http://dx.doi.org/10.5772/intechopen.82775

atrophy of the optic nerve, and retinal detachment are also known. Severe cases may show microphthalmia [31]. Electroretinogram (ERG) of FCMD patients may be normal, but abnormal findings may be seen in both dark-adapted and lightadapted ERGs [32]. Patients of WWS and MEB, severe forms of α-dystroglycanopathy, also exhibit abnormalities in anterior and posterior components. In WWS, varieties of lesions are described, such as cataract, microcornea, microphthalmia, retinal detachment, retinal dysplasia, and optic atrophy [4]. Glaucoma and buphthalmos also may be observed. Clinical ocular findings of MEB reported are myopia, nystagmus, optic atrophy, and retinal degeneration [33]. ERG is abnormal as well. Like the CNS, ocular anomalies of FCMD are less severe than those of WWS and MEB [30, 31].

### 3.2 Histological findings

Although histological examinations of the eye of fetal FCMD cases are not so many, findings similar to those of the cerebrum can be found [31]. The inner limiting membrane is irregularly disrupted and ganglion cells exist beyond the inner limiting membrane, while there are areas exhibiting no apparent light microscopical abnormalities (Figure 3). Like child cases, some fetal cases may show local folding and fusion of the retina [31].

In child FCMD cases, detachment, local folding, and fusion of the retina are observed (Figure 4). The inner limiting membrane is discontinuous. A persistent

#### Figure 3.

Retinal findings in FCMD fetus. The internal limiting membrane, clearly depicted by PAM staining, is discontinuous in some part (A, B; arrows), while there are areas showing normal retinal appearance with continuous internal limiting membrane (C, D). Ectopic ganglion cells are observed beyond the inner limiting membrane.

of nerve fibers of retinal ganglion cells is situated beneath the inner limiting membrane that is formed at the inner surface of the retina by Müller cells. The external limiting membrane is formed by zonula adherens between Müller cells and inner segments of photoreceptor [29]. The basement membrane is abutted above the inner limiting membrane and beneath the basal surface of pigmented epithelium, attaching to the Bruch's membrane [29]. The basement membrane is also formed

(A) Schema of normal eye structure and (B) structure of normal retina.

In FCMD, both anterior and posterior components of the eye can be affected. Clinical symptoms include myopia, strabismus, and nystagmus [30–32]. Cataract,

around capillaries.

Muscular Dystrophies

Figure 2.

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3. Ocular lesions of FCMD

3.1 Clinical observations

hyperplastic primary vitreous body and a persistent hyaloid artery are also reported [31]. In severe cases, the layer of retina is markedly distorted with or without rosette formation. The outer and inner nuclear layers became thin in part. The layer of photoreceptor is also deranged with abnormal appearances of periodic acidmethenamine-silver (PAM)-positive structure (Figure 4). Reactive gliosis can be seen [31]. Severity of retinal dysplasia appears to be parallel to that of the CNS lesion [31].
