First Department of Neurology, University of Athens, Medical School, Aeginition Hospital, Athens, Greece.
Department of Medical Genetics, University of Athens, School of Medicine, Aghia Sophia Children's Hospital, Athens, Greece.
Eye (Lond). 2018 Mar;32(3):622-625. doi: 10.1038/eye.2017.280. Epub 2017 Dec 8.
PurposeEarly onset posterior subscapular cataract (<50 years of age) is a characteristic feature of myotonic dystrophy type 2 (DM2). Nevertheless, despite being operated at a young age, many patients remain undiagnosed for years. The purpose of this study was to assess the prevalence of early onset posterior subscapular cataract as a presenting symptom of the disease in a cohort of patients with DM2.Patients and methodsWe retrospectively reviewed medical records of DM2 patients followed in our institution for the presence of early onset posterior subscapular cataract, of any secondary causes of cataract, of the age of onset of muscle weakness and of final disease diagnosis.ResultsTwenty-eight patients were studied. Nine patients (32.1%) had presented early onset posterior subscapular cataract at a median age of 43 years (IQR=36-46) and seven (25%) reported it was the presenting sign. No patient was referred for neuromuscular evaluation due to the occurrence of early onset cataract. Median delay between cataract onset and referral for neuromuscular evaluation was 10 years (IQR=6.0-19.5) and final DM2 diagnosis was achieved after a median of 16 years (IQR=6.5-19.5).ConclusionThis study shows that early onset posterior subscapular cataract was the first symptom of the disease in 25% of our DM2 patients. Nevertheless, none was suspected of having cataract in the context of DM2, and referral for neuromuscular evaluation was made after a long delay and usually following the appearance of other symptoms. Ophthalmologists can be the first physicians encountering these patients and should have a low threshold for referring them for neuromuscular evaluation.
早发性肩胛下后白内障（<50 岁）是 2 型肌强直性营养不良（DM2）的特征性表现。然而，尽管在年轻时进行了手术，许多患者仍多年未被诊断。本研究旨在评估早发性肩胛下后白内障作为 DM2 患者疾病首发症状的患病率。
我们回顾性分析了在我们机构就诊的 DM2 患者的病历，以评估早发性肩胛下后白内障、任何继发性白内障的病因、肌无力的发病年龄和最终疾病诊断。
研究共纳入 28 名患者。9 名患者（32.1%）在 43 岁中位年龄（IQR=36-46）时出现早发性肩胛下后白内障，其中 7 名（25%）患者报告其为首发症状。由于早发性白内障的发生，没有患者因该情况而被转至神经肌肉科进行评估。白内障发病与神经肌肉科评估之间的中位时间延迟为 10 年（IQR=6.0-19.5），中位 16 年后（IQR=6.5-19.5）才最终确诊为 2 型 DM2。
本研究表明，早发性肩胛下后白内障是我们 DM2 患者中 25%的首发症状。然而，在 DM2 背景下，均未怀疑白内障，在出现其他症状后，神经肌肉科评估的转诊时间通常很长。眼科医生可能是首次遇到这些患者的医生，他们应降低将这些患者转至神经肌肉科评估的门槛。
