Does The Routine Prescription Of Nevanac Following Uncomplicated Phacoemulsification And Iol Insertion In Patients With Diabetes Reduce The Incidence Of Pseudophakic Cystoid Macular Oedema?

Since May 2019, in Gloucestershire Hospitals NHS Foundation Trust (GHNHSFT), all patients with diabetes undergoing phacoemulsification and intraocular lens (IOL) insertion are routinely prescribed 4 weeks of postoperative topical Nevanac. This is in addition to topical steroids and antibiotics prescribed to all patients regardless of diabetic status.

Prior to 2019, the practice of prescribing a topical non-steroidal anti-inflammatory (NSAID) differed between surgeons with a lack of consistency in clinical practice. The aim of this audit was to assess if the incidence of pseudophakic CMO in diabetic patients undergoing uncomplicated phacoemulsification and IOL insertion has reduced since the introduction of routine postoperative Nevanac.

This audit of clinical practice was carried out within Gloucestershire Hospitals NHS Foundation Trust (GHNHSFT) , England, UK. GHNHSFT typically undertake 2500 cataract operations annually, and uses the Medisoft/MediSIGHT electronic patient records (EMR) system across the whole ophthalmology service, including for postoperative eye drop prescriptions.

Data for diabetic patients, without pre-existing diabetic macular oedema (DMO) undergoing uncomplicated phacoemulsification and IOL insertion performed between May 2014 and June 2024 were extracted from the EMR system. This data included patient demographics, pre and post operative visual acuity (VA), diabetic retinopathy (DR) grades, surgeon grade and use of topical NSAID medication.

Surgeries were allocated to 5-year time periods before (May 2014 to May 2019) and after (June 2019 to June 2024) the introduction of routine postoperative Nevanac for diabetic patients in May 2019.

Excluded surgeries were combined cataract procedures, unknown surgeon grade and eyes with known risk factors for CMO such as epiretinal membrane.

For the pre-Nevanac group, 3,340 uncomplicated cataract surgeries were performed in 2,632 diabetic patients, with non-trainee surgeons performing 73.1% of operations. CMO occurred in 31 (0.93%) eyes.

For the post-Nevanac group, 2,390 uncomplicated cataract procedures were performed in 1,814 diabetic patients, with non-trainee surgeons performing 74.1% of operations. CMO occurred in 21 (0.88%) eyes.

No statistically significant difference was found in the incidence of CMO since the introduction of Nevanac (p>0.5).  The median preoperative VA for eyes with CMO was 0.48 LogMAR pre-nevanac and 0.50 LogMAR post-Nevanac. The median postoperative VA for eyes with CMO was 0.30 LogMAR pre-Nevanac and 0.25 LogMAR post-Nevanac.  

Although data over 10 years was analysed, the number of cases of pseudophakic CMO in diabetic patients undergoing phacoemulsification and IOL insertion were low and no firm conclusions can be made. From our sample, no significant decline in rates of pseudophakic CMO were noted since the introduction of routine postoperative Nevanac in GHNHSFT. There were no significant differences noted due to surgeon grade, retinopathy levels, or visual acuity levels.

Our data is limited to one centre in England, UK and with a period of altered clinical activity due to the COVID-19 pandemic. However, our findings fit with current literature of no definitive evidence that topical NSAIDs reduce the incidence of pseudophakic CMO in patients with diabetes.