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Ophthalmology
Published in Stephan Strobel, Lewis Spitz, Stephen D. Marks, Great Ormond Street Handbook of Paediatrics, 2019
Aetiology: megalocornea is a cornea with a horizontal diameter of more than 13 mm that is not progressive. If the cornea is enlarged in the presence of congenital glaucoma (Fig. 7.16), it is not defined as megalocornea. It is usually inherited as an X-linked recessive trait in most instances, but maybe dominantly inherited.
Unclassified Axenfeld-Rieger Syndrome: A CASE SERIES and Review of Literature
Published in Seminars in Ophthalmology, 2018
Aparna Rao, Debananda Padhy, Sarada Sarangi, Gopinath Das
Posterior embryotoxon was present in six eyes of three patients while polycoria and corectopia was seen in only one eye each. Megalocornea was seen in four eyes of two patients (case 8 and case 10), with enlargement of horizontal corneal diameters and no obvious haab striae. A beaten metal appearance was seen in three eyes with reduced endothelial counts on specular microscopy mimicking ICE syndrome, with no associated features of corneal decompensation in two eyes. One eye (case 3) developed repeated episodes of viral anterior stromal keratatits with endothelitis with progressive corneal decompensation responding partially to antiviral therapy and hypertonic saline (Figure 1). Two patients had a dense corneal leucomatous scar precluding identification of iris pathology, with no associated history or signs of trauma or previous corneal injury or inflammation.
Megalocornea associated with microduplications on chromosome 16
Published in Ophthalmic Genetics, 2018
Megalocornea is characterized by bilateral enlargement of the corneal diameter of 12 mm or greater at birth and 13 mm or greater after 2 years of age in the absence of elevated intraocular pressure. It can occur in isolation or in combination with other ocular and systemic syndromes. The exact etiology of isolated megalocornea is unknown. However, it is postulated to be due to defects in the formation of the optic cup in which the anterior tips of the cup fail to fuse thereby allowing more space for the developing cornea.
Retinal detachment in a child with Frank-ter Haar syndrome
Published in Ophthalmic Genetics, 2023
Onur Furundaoturan, Mine Esen Baris, Durdugul Ayyıldız Emecen, Elif Demirkilinc Biler
On ophthalmological examination at the age of 3, the patient was not cooperative enough for reliable visual acuity testing, but the right eye could fixate and follow objects, whereas the left eye could not fixate on light. Hirschberg test indicated 10 degrees of exotropia with the absence of red reflex in the left eye. Bilateral suspicious megalocorneas were observed with cycloplegic refraction of Plano −5.00 D × 180 degrees against-the-rule corneal astigmatism in the right eye, whereas no measurement could be obtained in the left eye. Due to the patient’s agitation, evaluation under anesthesia was required to measure the intraocular pressure (IOP), corneal diameter (CD), and to carry out a detailed examination of the anterior and posterior segments. In examination under general anesthesia, CD was 13 mm in the right eye and 12.5 mm in the left eye. A diagnosis of megalocornea was made in the right, but the left eye was at the upper limit of normal, borderline for megalocornea (9). IOP measured by Perkin’s tonometer was 14 mmHg in the right eye and 2 mmHg in the left eye. The anterior segment of the right eye was normal; fundus examination revealed a normal retina with increased vascular tortuosity and a large optic disc with 0.2 cup/disk ratio. A suspicious membranous structure just behind the clear lens was observed during the anterior segment examination of the left eye (Figure 2). Indirect ophthalmoscopic fundus examination of the left eye showed fibrotic membranous arrangement on the anterior vitreous with a possible diagnosis of chronic retinal detachment or Persistent Hyperplastic Primary Vitreous (PHPV). Ocular ultrasonography of the left eye revealed a closed-funnel retinal detachment, with no signs of a mass lesion (Figure 3). When questioned about a possible blunt trauma to the eye, the mother declined the occurrence of such an event. The mother also reported that the patient's eye began turning whiter almost 2 years previously; however, the parents did not consult an ophthalmologist.