EVect of age on visual outcome following cataract extraction

Aim—To determine the eVect of age on final corrected visual acuity following cataract extraction. Methods—A case series of 880 patients aged 60 years and older undergoing cataract extraction between 1996 and 1999 was studied. The best corrected visual acuity was assessed at discharge from the service and the proportion of patients who achieved a postoperative acuity of >6/12 was determined for diVerent age groups. Analysis was also performed after exclusion of patients identified preoperatively as having ocular comorbidity that was thought to limit their final corrected acuity. The odds ratios for visual outcome were calculated for age using multiple logistic regression analysis to adjust for other prognostic factors. Results—A significant age eVect was observed, with the proportion of patients who had no ocular comorbidity identified preoperatively and who achieved a visual acuity of >6/12 at discharge decreasing with age (p<0.001). In patients with no comorbidity the odds of achieving an acuity of >6/12 were 4.6 times higher in the 60–69 year age group than in the oldest age group (80+ years). Conclusions—Age is a significant determinant of visual outcome. This has implications if a points system incorporating an assessment of visual acuity or if visual acuity alone is used to determine the threshold for eligibility for cataract surgery. (Br J Ophthalmol 2000;84:1380–1382) Cataract and age related macular degeneration are both common causes of visual loss and reduced quality of life in the elderly. The conditions may coexist, in which case the presence of macular disease may limit the final visual result after cataract surgery. Cataract extraction is one of the most common operations performed worldwide. The number of patients eligible for surgery is predicted to increase as a result of falling thresholds for surgery and an increase in the proportion of elderly people in the population. 2 Various strategies have been proposed to reduce the number of patients on waiting lists for cataract surgery, including the scoring of visual disability or the introduction of a Snellen acuity threshold. According to this latter system, only patients with a defined level of visual loss—for example, an acuity level of 6/12 or worse—would be placed on the waiting list for surgery. Patients with a better level of visual acuity would be returned to the care of their general practitioner for re-referral should their vision subsequently deteriorate. Although such a system is easy to implement, it assumes that the expected gain in acuity following cataract surgery is the same for all age groups. As age related macular degeneration (and more subtle macular disease) is more common in the elderly, a system of rationing determined by a uniform level of acuity across all age groups may discriminate against older patients. Although it has been reported that the visual outcome following cataract surgery declines in the elderly, the magnitude of this eVect has not been determined. We have therefore examined the eVect of age on postoperative visual acuity outcome in a large consecutive case series of patients over 60 years of age undergoing cataract extraction. Patients and methods A consecutive case series of patients who underwent surgery between 1996 and 1999 was studied. The case mix was predominantly age related cataract, as patients attending Moorfields Eye Hospital with diabetic retinopathy or glaucoma who develop cataract receive surgery within specialist services. Patients were admitted under the care of one surgeon (ST) although surgeons at diVerent levels of training also performed operations. Data were collected prospectively on the age at surgery, ocular comorbidity, type of surgery, grade of surgeon, complications of surgery, and the best spectacle corrected acuity at the time of discharge from the service. All postoperative refractions were performed within the hospital service. Ocular comorbidity was defined as co-existing ocular disease identified preoperatively that was thought likely to limit the final corrected visual acuity outcome to 6/12 or worse. Patients under 60 years of age were excluded because this younger age group contained a high proportion of non-age related cataract, reflecting the referral pattern within Moorfields Eye Hospital. Because of the diYculty in assuming statistical non-independence of a patient’s two eyes, one eye only was randomly selected for analysis in bilateral surgical cases. Table 1 Stratification of the three age groups by preoperative eye comorbidity (numbers of eyes) Age Preoperative comorbidity Absent Present Total 60–69 214 43 257 70–79 306 54 360 80+ 222 41 263 Subtotal 742 138 880 Br J Ophthalmol 2000;84:1380–1382 1380 Moorfields Eye Hospital, London EC1V 2PD, UK M C Westcott S J Tuft Institute of Ophthalmology, London EC1V 9EL, UK D C Minassian Correspondence to: Mr S Tuft [email protected] Accepted 5 July 2000 www.bjophthalmol.com group.bmj.com on May 28, 2017 Published by http://bjo.bmj.com/ Downloaded from