Copy effect myopic anisometropia in a pair of monozygotic twins: A Case Report

Abstract

This case report aims to report myopic anisometropia with copy-image in monozygotic twins. In February 2021, a 6-year-old identical twin was seen, who was referred to us with the diagnosis of amblyopia in their left eyes from an external center. Both twins had a full ophthalmic examination, which included visual acuity testing, ocular motility testing, cycloplegic refraction, and fundus examination. On examination, “copy image” myopic anisometropia was discovered. Twin 1 had anisometropia with myopic astigmatism in the left eye. His cycloplegic refraction was +1.00 (-0.75x 75) in the right eye and -8.0 (-1.50x175) in the left eye. Similarly, twin 2 had anisometropia with myopic astigmatism in the left eye. His cycloplegic refraction was -7.75 (-1.50x180) in the left eye and +1.25 (-0.75x90 ) in the right eye. The best-corrected visual acuity was 20/60 in the amblyopic eyes and 20/20 in the unaffected eyes. There was no ocular deviation. In either patient, a slit-lamp microscopic examination revealed no abnormalities in the anterior parts of either eye. Fundoscopic examination revealed no abnormalities. No abnormal ocular movements were demonstrated. As far as we have reviewed in the literature, previous studies with twins were mostly concerned with mirror effect myopic anisometropia and myopic anisometropia, whereas ipsilateral amblyopia and anisometropia were not reported in monozygotic twins. This case underscores the possible genetic basis of myopic anisometropia.

Keywords

• Anisometropia
• Myopia
• Twins

Bir çift monozigotik ikizde kopya efektli miyopik anizometropi: Bir Olgu Sunumu

Öz

Giriş: Bu olgu sunumu, monozigotik ikizlerde kopya-görüntü ile miyop anizometropiyi bildirmeyi amaçlamaktadır. Yöntemler: Şubat 2021'de dış merkezden sol gözde ambliyopi tanısı ile tarafımıza sevk edilen 6 yaşında tek yumurta ikizi görüldü. Her iki ikizde de görme keskinliği testi, oküler motilite testi, sikloplejik refraksiyon ve fundus muayenesini içeren tam bir oftalmik muayene yapıldı. Bulgular: Muayenede “kopya görüntü” miyopik anizometropi saptandı. İkiz 1'in sol gözünde miyop astigmatizma ile anizometropi vardı. Sikloplejik refraksiyonu sağ gözde +1.00 (-0.75x 75), sol gözde -8.0 (-1.50x175) idi. Benzer şekilde, ikiz 2'nin sol gözünde miyop astigmatizma ile anizometropi vardı. Sikloplejik refraksiyonu sol gözde -7.75 (-1.50x180), sağ gözde +1.25 (-0.75x90 ) idi. En iyi düzeltilmiş görme keskinliği ambliyopik gözlerde 20/60 ve etkilenmemiş gözlerde 20/20 idi. Oküler deviasyon yoktu. Her iki hastada da, bir yarık lamba mikroskobik incelemesi, her iki gözün de ön kısımlarında herhangi bir anormallik göstermedi. Fundoskopik muayenede anormallik saptanmadı. Anormal oküler hareketler gösterilmedi. Sonuç: Literatürde incelediğimiz kadarıyla, ikizlerle yapılan önceki çalışmalarda çoğunlukla ayna etkisi miyop anizometropi ve miyop anizometropi ile ilgiliyken, monozigotik ikizlerde ipsilateral ambliyopi ve anizometropi bildirilmemiştir. Bu vaka, miyop anizometropinin olası genetik temelinin altını çizmektedir.

Anahtar Kelimeler

• anizometropi
• miyopi
• ambliyopi
• ikizlik

Kaynakça

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