In this retrospective cohort study the authors’ primary objective was to assess whether cataract surgery in eyes with wet age-related macular degeneration (AMD), triggered its progression. The surgical group comprised of 40 eyes versus 42 eyes in the non-surgical control group. Active wet AMD was defined as eyes that had received at least one anti-VEGF injection within the one year study period. The midpoint of the study was defined as the date of cataract surgery for the surgical group and the 1 July 2012 for the control group (2012 being the year that the Stratus optical coherence tomography (OCT) was used most). Both occult and classic wet AMD were included, but eyes with vision threatening co-morbidities such as retinal detachment, vascular occlusions or proliferative diabetic retinopathy were excluded. A separate analysis was done including and excluding eyes that had undergone complicated cataract surgery. The authors compared best corrected visual acuity (BCVA) at three months before and after the midpoint, as well as OCT characteristics (presence or worsening of cysts / subretinal fluid, and presence of macular haemmorhages) and number of anti-VEGF injections between the two arms. Whilst BCVA was equal between the two arms of the study in the three months before midpoint, it significantly improved in the surgical group in the second half of the study (0.23+/-0.65 versus 0.11+/-0.59 logMAR improvement, P=.049). The mean OCT central retinal thickness showed an increase in the surgical group postoperatively (265.4+/-98.4 micron versus 216.4+/-58.3 micron, P=.011). The surgical group was also more likely to develop new or worse cystoid changes after the mid-point i.e. 12 postoperative eyes (54.2%) versus nine non-surgical eyes (28.1%), p=.048. However, there was no change in the number of injections at six months before and after the mid-point in the surgical group (p=.921). The subanalysis excluding eyes that underwent complicated cataract surgery (six eyes excluded) failed to show any significant difference in findings. The authors conclude that cataract extraction in eyes with wet AMD does not contribute to worsening of the condition but rather improves visual acuity. They also point out that OCT based anatomical changes were not followed beyond the three month postoperative period and neither was a fundus fluorescein angiography (FFA) performed to confirm whether the changes were due to pseudophakic cystoid macular oedema (CMO) or worsening of AMD. However despite the characteristic OCT appearances these eyes continued to exhibit a continued visual improvement with ongoing anti-VEGF treatment. Further limitations that are highlighted are the retrospective nature of the study and the predominantly Caucasian population that was included, all of which could be overcome by conducting a larger, prospective and randomised study.
How does cataract surgery affect eyes with wet AMD?
Reviewed by Efrosini Papagiannuli
The effects of cataract surgery on patients with wet macular degeneration.
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Efrosini Papagiannuli
Birmingham and Midland Eye Centre, Birmingham, UK
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