Cataract surgery in diabetic patients poses greater challenges and requires a modified approach

Prior to surgery
A thorough examination of the fundus should be performed to determine if there is any pre-existing disease and if there is then all attempts should be made to stabilise it. This may include liaising with their endocrinologist to optimise blood glucose control, performing a pan retinal photocoagulation if there is proliferative disease or focal laser if there is clinically significant macular oedema. Additionally, it may be necessary to use intravitreal injections of anti VEGF medication or steroids. Any pre-existing neovascularization of the iris or angle should be managed by PRP as it can lead to neovascular glaucoma. Preoperative OCT is useful to determine if there is any preexisting, subclinical oedema as this is likely to get worse.

Surgical technique
Surgical planning should include the use of acrylic, monofocal lenses. Siilcone should be avoided in case retinal surgery with vitrectomy is required at a later date. Silicone can be used in patients who have very stable disease and are unlikely to progress.
Multifocal IOL should be avoided if there is any history of macular oedema or likelihood of developing it in the future as it can seriously degrade vision. Monofocal or toric lenses are preferred in these patients

Surgical technique needs to be gentler than normal, with the use of less phaco energy and with less fluid infusion during the surgery. Avoiding stretching or contact with the iris is important to minimise release of inflammatory mediators.
Often the pupil dilates poorly making surgery more challenging. In these patients it may be necessary to use intracameral phenylephrine, iris hooks or Malyugin ring.
In some patients who are at risk of developing progressive disease, intravitreal triamcinalone or or anti VEGF medication is given intravitreal at the end of the case.

Postoperative

In eyes with significant retinopathy, cataract surgery may lead to progression. In those with no or minimal retinopathy, cataract surgery is less likely to do so. For this reason it is often beneficial to perform surgery earlier.
Topical steroids are given but in addition, topical non steroidal medication are used to minimise post operative inflammation. Macular thickness can be evaluated at serial postoperative visits using the OCT.
Diabetics need to make every effort to control their blood sugar in the immediate post operative period to minimise progressive disease.
Posterior capsular opacification and persistent inflammation is more common in theses patients.

In summary, cataract surgery in diabetic patients is more challenging and should be performed by more experienced surgeons.