Macular disease and cataract surgery

Sebastian Wolf MD Macular disease can affect the visual outcome after cataract surgery, and the prognosis will vary depending on the exact diagnosis. However, even patients whose visual potential is reduced because of the retinal comorbidity are likely to benefit from cataract surgery, according to Sebastian Wolf MD, PhD. “Careful preoperative evaluation to identify macular disease is important in patients with cataract, because it allows appropriate counselling about the expected result. However, there is a low threshold for performing cataract surgery in patients with macular disease, and it should be done in all patients who have cataract-related visual symptoms affecting their daily activities,” said Dr Wolf, Professor for Ophthalmology, and Director and Chairman, Department of Ophthalmology, University of Bern, Switzerland. The diagnostic evaluation to assess the macula should include best corrected visual acuity (BCVA) and ophthalmoscopy, but optical coherence tomography (OCT) is the preferred modality for imaging the macula. “An opacified lens can compromise visualisation of the posterior segment with ophthalmoscopy and also make results of fluorescein angiography and fundus autofluorescence harder to interpret,” he explained. “In contrast, the infrared light used in OCT can penetrate through the lens unless the cataract is very dense. With the availability of OCT, it is also not necessary to perform cataract surgery to allow for better evaluation of macular disease,” he added. RISKS AND BENEFITS Retinal detachment is one of the risks associated with cataract surgery, and because the risk persists for the patient’s lifetime, the earlier cataract surgery is performed, the longer the risk period. Whether or not cataract surgery affects the risk for age-related macular degeneration (AMD) development or progression has been investigated in many studies and is still a subject of discussion, said Dr Wolf. “As a summary, however, it does not appear to be a big problem, and cataract removal itself is one of the most common, safest, and most effective operations we know,” he said. Reviewing data on the effectiveness of cataract surgery relevant to patients with macular disease, Dr Wolf discussed information from a recently published systematic literature review and meta-analysis that focused on determining who will benefit from surgery. (Kessel L, et al. Acta Ophthalmol. 2016;94:10-20) One paper included in the review analysed visual outcomes data collected in the Blue Mountains Eye Study (BMES) for 128 eyes followed after cataract surgery. Its results showed that BCVA ≥20/40 was achieved by a higher proportion of patients whose baseline BCVA was 'fair' compared with those whose preoperative BCVA was 'poor' (≤20/40). And AMD was the main reported cause of poor BCVA after cataract surgery. However, data from the BMES paper and others reported that >98% of patients in both the fair and poor visual acuity (VA) groups benefited with improved VA after cataract surgery. Patients with poor VA preoperatively also rated their subjective visual outcome the same as their counterparts who had better (fair) VA preoperatively. In addition, data from studies assessing vision-related quality of life with the Visual Function questionnaire (VF-14) found that patients with poor VA preoperatively achieved greater improvement postoperatively than patients whose preoperative VA was fair. As a result, there was no difference in the postoperative VF-14 score comparing patients with fair versus poor preoperative BCVA. “These data demonstrate that, even if patients do not reach 20/20 BCVA after cataract surgery, they may still benefit from the procedure,” Dr Wolf said. As further evidence to support performing cataract surgery in patients with ocular comorbidities, Dr Wolf discussed a clinical tool developed by Swedish surgeons that ranks indications for cataract surgery into four levels based on a variety of patient features. (Lündstrom M, et al. Acta Ophthalmol Scand. 2006;84(4):495-501) He noted that retinal disease was not specifically included as one of the scoring items in this tool. The effect of a visual function-limiting ocular comorbidity was considered and found to possibly lower the priority rating for surgery. “However, it would not lead to a recommendation against performing surgery,” Dr Wolf said. Sebastian Wolf: sebastian.wolf@insel.ch