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

Yıl 2023, Cilt: 1 Sayı: 1, 7 - 9, 17.04.2023

Fatma Sümer

Öz

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.

Anahtar Kelimeler

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

• 1. M A, G F, J S (1988) Changes in astigmatism between the ages of 1 and 4 years: a longitudinal study. Br J Ophthalmol 72:145–149.
• 2. M A, G F, J S (1990) A longitudinal study of a population-based sample of astigmatic children. II. The changeability of anisometropia. Acta Ophthalmol 68:435–440.
• 3. M A, G F, AK A, J S (1990) A longitudinal study of a population-based sample of astigmatic children. I. Refraction and amblyopia. Acta Ophthalmol 68:428–434.
• 4. M A, J S (1996) Natural history of infantile anisometropia. Br J Ophthalmol 80:860–863. 5. Amblyopia: a multidisciplinary approach. Proctor lecture. | IOVS | ARVO Journals.
• 6. (2002) A randomized trial of atropine vs. patching for treatment of moderate amblyopia in children. Arch Ophthalmol (Chicago, Ill 1960) 120:268–278.
• 7. Prevalence of anisometropia in volunteer laboratory and school screening populations. | IOVS | ARVO Journals.
• 8. F O, T N, S H (2001) Mirror image myopic anisometropia in two pairs of monozygotic twins. Ophthalmologica 215:435–438.
• 9. PT DJ, BA O, JT DF (1993) High symmetric anisometropia in monozygotic twins. Ophthalmic Paediatr Genet 14:29–32.
• 10. Dirani M, Islam A, Shekar SN, Baird PN (2008) Dominant Genetic Effects on Corneal Astigmatism: The Genes in Myopia (GEM) Twin Study. 49:1339–1344.
• 11. AR R, GK VN (1971) Clinical findings and therapy in unilateral high myopia associated with amblyopia. Am J Ophthalmol 71:873–879
• 12. Park SJ, Kim JY, Baek S-H, et al (2010) One Sister and Brother with Mirror Image Myopic Anisometropia. Korean J Ophthalmol 24:62–64.
• 13. HF, M M, M F (2019) Mirror image hypermetropic anisometropia in a pair of monozygotic twins. J AAPOS Off Publ Am Assoc Pediatr Ophthalmol Strabismus 23:113–115.