The visual results and changes in retinopathy in diabetic patients following cataract surgery

A study was designed to investigate the visual improvement and incidence of progression of retinopathy in diabetic patients following extracapsular cataract extraction or phacoemulsification. They were compared to a matched group of non-diabetic patients.

A retrospective analysis of all diabetic patients (118) undergoing ECCE (90) or phacoemulsification (28) in 1995. These patients were operation and age matched with 118 non-diabetic patients who underwent surgery during the same year.

There was no statistically significant difference in complications following ECCE in diabetic and non-diabetic patients (p = 0.2). Complications were however more common in non-diabetic patients undergoing phacoemulsification compared to diabetics undergoing the same procedure (p = 0.046). Although consultants performed 42% of the surgery in diabetics compared to 31% in non-diabetics, there was no significant difference in the rate of complications between consultants and residents (p = 0.8). Overall the visual improvement in non-diabetics was better than diabetic patients (p = 0.006). This was due to a better improvement amongst non-diabetic patients undergoing phacoemulsification (p = 0.02). Overall, cataract surgery was found to lead to a worsening in retinopathy in 19 operated eyes (15 had no retinopathy preoperatively) compared to a worsening in 8 fellow eyes. This was statistically significant (p = 0.04). However, ECCE was no more likely to cause worsening of retinopathy than phacoemulsification (p = 0.87).

Diabetic patients due to undergo cataract surgery a) have a good chance of visual improvement but to a level less than if they were not diabetic, b) have a greater chance of visual loss, c) surgery may initiate or worsen any pre-existing retinopathy and this may affect their vision in the future.