Purpose:
To study the effect of cumulative dissipated energy by phaco-emulsification cataract surgery on Macular edema measured by central subfield thickness using HD-OCT in normal and diabetic patients.
Methods:
Consecutive cataract surgeries underwent HD-OCT with Raster and Macular cube analysis of the central macular thickness (CMT), pre-operatively,one week,one month and 3 months post-operatively. The CDE (cumulative dissipated energy) was measured by the Alcon Phaco-emulsification system recorded during surgery.Pre- operative CMT was compared with post operative CMTs at 1 week, 1 month and 3 month intervals for normal and diabetic patients.The diabetic patients that developed significant CMT changes underwent intra-vitreal injections of steroid and Bevacuzamab as an interventional protocol.
Results:
89 eyes of 66 patients(normal 44, diabetic 22) underwent phacoemulsification-cataract surgeryNon diabetic eyesPre-operative macular OCT Normal: 59 eyesAverage CMT thickness changes: 7.47 microns +/- 18Diabetic eyesBackground diabetic retinopathy with no macular edema: 12 eyesAverage CMT change: 8.54 microns +/- 7Pre-existing Diabetic macular edema: 18 eyesAverage CMT change: 38.16 +/- 36(p<.027)Number of Patients studied: 66 and Total number of eyes: 89 evaluated.No correlation was found between the change in CMT and level of CDE in all patients. However, in diabetic patients with pre-existing macular edema,there was a statistically significant increase in CMT p=0.027 compared to normal macula 1 to 3 months post-operatively.
Conclusions:
The degree of hardness of cataract is correlated to the measured CDE during surgery. No correlation was found between the change in CMT and level of CDE in all patients. However, in diabetics with macular edema a statistically significant increase in CMT was observed at all levels of CDE, requiring intra-vitreal treatment, indicating increased susceptibility to phaco energy. Pre-op intra-vitreal anti-VEGF/steroids may be indicated.
Keywords: macula/fovea • edema • cataract