Ministry of Health Minna, Niger State, Nigeria.
Ophthalmology. 2011 Apr;118(4):719-24. doi: 10.1016/j.ophtha.2010.08.025. Epub 2010 Nov 4.
To describe presenting and corrected visual acuities after cataract surgery in a nationally representative sample of adults. Another objective was to describe refractive errors in operated eyes and to determine the optimal range of intraocular lens (IOL) powers for this population.
Cross-sectional, population-based survey.
Adults aged 40 years and more were selected using multistage stratified sampling and proportional to size procedures. A sample size of 15027 was calculated, and clusters were selected from all states.
Individuals who had undergone cataract surgery were identified from interview and examination. All had their presenting visual acuity (VA) measured using a reduced logarithm of the minimum angle of resolution chart and underwent autorefraction. Corrected VAs were assessed using the autorefraction results in a trial set. An ophthalmologist conducted all examinations, including slit-lamp and dilated fundus examination. Causes of visual loss were determined for all eyes with a presenting VA <6/12 using the World Health Organization recommendations. Biometry data were derived from 20449 phakic eyes using the SRK-T formula after excluding those with poor VA or corneal opacities.
Presenting and corrected visual acuities in pseudo/aphakic individuals and autorefraction findings; biometry profile of Nigerian adults.
Data from 288 eyes of 217 participants were analyzed. Only 39.5% of eyes had undergone IOL implantation at surgery. Only 29.9% of eyes had a good outcome (i.e., ≥6/18) at presentation, increasing to 55.9% with correction. Use of an IOL was the only factor associated with a good outcome at presentation (odds ratio 9.0; 95% confidence interval, 4.3-18.9; P=0.001). Eyes undergoing cataract surgery had a higher prevalence and degree of astigmatism than phakic eyes. Biometry data reveal that posterior chamber IOL powers of 20, 21, and 22 diopters (D) (A constant 118.0) will give a postoperative refraction range of -2.0 D to emmetropia in 71.4% of eyes, which increases to 82.6% if 19 D is also included.
Postoperative astigmatism needs to be reduced through better surgical techniques and training, and use of biometry should be standard of care.
描述在具有全国代表性的成年人样本中白内障手术后的初始和矫正视力。另一个目的是描述手术眼的屈光不正，并确定该人群中人工晶状体（IOL）的最佳范围。
横断面、基于人群的调查。
使用多阶段分层抽样和按比例大小的程序选择年龄在 40 岁及以上的成年人。计算出 15027 个样本量，并从所有州选择聚类。
通过访谈和检查确定接受过白内障手术的个体。所有个体均使用简化最小角分辨率图表的对数视力测量，并进行自动折射。在试戴组中使用自动折射结果评估矫正视力。眼科医生进行了所有检查，包括裂隙灯和散瞳眼底检查。使用世界卫生组织的建议，根据所有初始视力（VA）<6/12 的眼睛确定视力丧失的原因。在排除视力差或角膜混浊的眼睛后，使用 SRK-T 公式从 20449 个非白内障眼中得出生物测量数据。
假性/无晶状体个体的初始和矫正视力以及自动折射结果；尼日利亚成年人的生物测量特征。
对 217 名参与者的 288 只眼进行了数据分析。只有 39.5%的眼睛在手术中植入了 IOL。仅 29.9%的眼睛在初始时具有良好的结果（即≥6/18），矫正后增加到 55.9%。使用 IOL 是初始时获得良好结果的唯一因素（优势比 9.0；95%置信区间，4.3-18.9；P=0.001）。接受白内障手术的眼睛比非白内障眼睛的散光发生率和程度更高。生物测量数据显示，20、21 和 22 屈光度（D）（常数为 118.0）的后房 IOL 可使 71.4%的眼睛术后屈光度在-2.0D 至正视范围内，如包括 19D，则增加到 82.6%。
需要通过更好的手术技术和培训来降低术后散光，并应将生物测量作为标准护理。
