Outcomes of cataract surgery in Pakistan: results from The Pakistan National Blindness and Visual Impairment Survey

Abstract

Aim: To evaluate the outcomes of cataract surgery in Pakistan. Methods: Cross-sectional, nationally representative sample of 16 507 adults (aged >30 years). Each underwent interview, logarithm of the minimum angle of resolution visual acuity (VA), autorefraction, examination of optic disc. Those with ,6/12 VA on presentation underwent best-corrected VA and dilated biomicroscopic ocular examination. Results: 1317 subjects (633 men) had undergone surgery in one or both eyes. Of the 1788 operated eyes, 1099 (61%) had undergone intracapsular cataract extraction (ICCE) and 607 (34%) extracapsular surgery with an intraocular lens (ECCE+IOL). Presenting VA: 275 (15.4%) eyes: 6/12 or better; 253 (14.1) ,6/12 >6/18; 632 (35.3%) 6/18 to 6/60; 85 (4.8%): 6/60 to 3/60; 528 (29.5%): ,3/60. With ''best'' refractive correction, these values were: 563 (31.5%), 332 (18.6%), 492 (27.5%), 61 (3.4%), 334 (18.7%), respectively. Of the 1498 eyes with VA (6/12 on presentation, 352 (23.5%) were the result of coincident disease, 800 (53.4%) refractive error and 320 (21.4%) operative complications. Eye camp surgery (OR 1.72, p = 0.002), ICCE (OR 3.78; p,0.001), rural residence (OR 1.36, p = 0.01), female gender (OR 1.55, p,0.001) and illiteracy (OR 2.44, p,0.001) were associated with VA of ,6/18. More recent ICCE surgeries were associated with a poorer outcome. The ratio of ECCE+IOL:ICCE in the last 3 years was 1.2:1, compared with 1:3.3 >4 years before the survey. Conclusion: Almost a third of cataract operations result in a presenting VA of ,6/60, which could be halved by appropriate refractive correction. This study highlights the need for an improvement in quality of surgery with a more balanced distribution of services.

Distribution and visual impact of postoperative refractive error after cataract surgery in rural China

“…Postoperative refractive error, presumably resulting from inaccurate IOL selection and aphakia, has been reported as a leading risk factor for poor postoperative vision in several studies from rural Asia. [16][17][18][19][20][21][22] The median value (C21.5 D) of the IOLs implanted in this study agrees surprisingly well with values in other areas of the world. A median IOL power of C21.6 D has been reported in Vietnam 29 and of C21.9 D in Kenya.…”

“…6,11,12 Risk factors for deviation from desired emmetropia include older age, 2 clear corneal (as opposed to limbal) incisions, 2 and use of anterior chamber IOLs. 13 Some studies in the developing world 14,15 report acceptable accuracy in the prediction of postoperative refraction, even using average-power IOLs, 14,15 with 45% to 54% of patients having a postoperative refraction within G1.00 D. 14 However, postoperative refractive error has been implicated as one of the most significant risk factors for poor visual and functional outcomes after cataract surgery in many reports from rural Asia, including those from Bangladesh, 16 Pakistan, 17 China, 18 and India. [19][20][21][22] Few studies from rural Asia have reported in detail the distribution of refractive error after cataract surgery.…”

Visual Function and Quality of Life Among Visually Impaired and Cataract Operated Adults. The Pakistan National Blindness and Visual Impairment Survey

“…3 Over half of blindness in adults (51.5%) is due to cataract 4 and although cataract surgical coverage is high (77.1%) 5 31% of eyes that had undergone cataract extraction within 3 years of the survey had a presenting VA of < 6/60. 6 Limited evidence is available within Pakistan regarding subjective visual perceptions. This article, using data collected during the national survey, aims to evaluate VF and vision related QOL in a representative sample of normal, visually impaired and pseudo/aphakic adults (≥30 years).…”

Causes of poor outcome after cataract surgery in Satkhira district, Bangladesh

“…The national survey of blindness in Pakistan identified 1788 operated eyes, of which outcome was good in 30%, borderline in 36%, and poor in 34%. 6 Again, refractive error was the dominant cause of poor/ borderline outcome, followed by surgical complications and concomitant diseases.…”