方法：回顾性研究了2009/2013年间伊斯坦布尔诊所接受236例低视力患者。分析年龄、性别分布、低视力原因、近亲结婚、低视力辅助类型规定及视力变化。在回顾性研究中，根据世界卫生组织定义基于最佳矫正视力将视力分为(失明，视力<20/400； 视力严重受损，视力<20/200～20/400； 视力轻度到中度受损，视力<20/60～20/200)。基于双眼主要病因，根据国际疾病分类第十版可以确定失明和低视力的病因。根据视力和患者需求规定了视力辅助，并使用平均值±标准差和频率对数据进行了描述。

结果：研究包括236例患者，65%为男性，平均年龄为38.5±24.2岁(年龄范围6～95岁)，男性多于女性。年龄在15～30岁(35.6%)之间是最大的年龄群体。轻度至中度视力受损患者为122例，严重视力受损患者为84例，失明患者为30例，他们分别占总人数的51.6%、35.6%和12.7%。脉络膜疾病和视网膜疾病(62.7%)是导致视力低下的主要原因。老年低视力患者黄斑变性逐渐成为视力低下的首要原因(61.3%)。造成视力低下的原因有视网膜和脉络膜疾病(62.7%)，眼球震颤(23.7%)，视神经和视神经束疾病(11%)，先天性白内障(0.8%)及青光眼(1.7%)。88例患者(37.3%)为伽利略类型，116例患者(49.2%)为开普勒类型。18例患者(7.6%)在接受LVA后视力无明显改善。14例患者被准许使用放大镜矫正视力。在大多数患者中，使用LVA的近视和远视患者视力均得到改善。62例近亲结婚患者占总人数的26.3%。

结论：14岁以上患者视力受损主要原因是视网膜和脉络膜疾病，15岁以下的患者常见原因为眼球震颤。在近亲结婚群体中黄斑营养不良和色素性视网膜炎患者显著增高。研究疾病病因学的遗传非常有效，因此，近亲结婚在土耳其仍是一大问题。

METHODS: We conducted a retrospective study of 236 low vision patients who visited to our clinics in Istanbul from 2009 to 2013. Age and sex distribution, cause of low vision, parental consanguineous marriage, type of prescribed low vision aids, and changes of the visions were reviewed. In this retrospective study, visual acuity was classified based on best-corrected visual acuity in the better eye according to the World Health Organization definition(blindness, visual acuity(VA)<20/400; severe visual impairment, VA<20/200-20/400; mild to moderate visual impairment, VA<20/60-20/200). The causes of blindness and low vision were determined using the 10th version of International Classification of Diseases based on the main cause in both eyes. Vision aids were prescribed based on visual acuity and patients' requirements. To describe data, we used mean±SD and frequency.

RESULTS: The study included 236 patients, 65% male, with a mean age of 38.5±24.2 years(range, 6 to 95year). In result, male were more than female. The age group between 15 and 30-year-old(35.6%)was the largest age group. Mild to moderate visual impairment, severe visual impairment and blindness were present in 122(51.6%), 84(35.6%)and 30(12.7%)of the patients, respectively. Choroid and retina diseases(62.7%)were main causes of low vision. Elderly low vision patients macular degeneration is becoming a leading cause of low vision(61.3%). The causes of visual impairment were retinal and choroidal diseases(62.7%), nystagmus(23.7%), optic nerve and optic tract diseases(11%), congenital cataract(0.8%), and glaucoma(1.7%). Eighty-eight(37.3%)patients Galilean type; 116(49.2%)patients keplerian type telescopic glasses recommended. Eighteen(7.6%)patients had no improvement in visual acuity with low vision aids(LVA). Forteen patients(5.9%)were approved the magnifier for near vision. In most patients, the use of LVA is improved both near and distance visual function. Parental consanguinity is present in 62(26.3%)patients, most commonly between the ages of 15-30 were significantly higher in the group(50%).

CONCLUSION: Diseases of the retina and choroid are the main cause over 14 years old groups, nistagmus is the most common cause under 15 years old group of visual impairment among patients referred to our clinic in Turkey. Parental consanquinity was significantly higher in macular dystrophy and retinitis pigmentosa groups. Of genetics in the etiology of these diseases are known to be effective. For this reason, parental consanguineous marriage is a big problem still in Turkey.