Early DMO: a predictor of poor outcomes following cataract surgery in diabetic patients. The DICAT-II study

Background The prospective DIabetes and CATaract Study II (DICAT II) was performed to characterise the risks of cataract surgery to the retinae of patients with early diabetic macular oedema (E-DMO). Methods DICAT II was a prospective, comparative, multicentre, observational study involving six Italian clinics. Patients were aged ≥55 years, had type 1 or 2 diabetes with spectral-domain optical coherence tomography evidence of ESASO classification Early DMO. Group 1 eyes (78 eyes, 78 patients) underwent phacoemulsification-based cataract surgery. Group 2 eyes (65 eyes, 65 patients) had E-DMO and either clear media or had undergone uncomplicated cataract surgery ≥1 year previously. Central subfield thickness (CST) and best-corrected visual acuity (BCVA) were assessed in both groups. Results The negative impact of surgery on CST was evident after the first postoperative week; CST peaked during the first month, then rapidly decreased. CST worsening ≥10 µm was observed in 63/78 eyes (80.7%) and 29/65 eyes (44.6%) in Groups 1 and 2, respectively ( p < 0.0001). CST worsening of ≥50 µm was observed in 51 eyes (65.4%) and 10 eyes (15.4%) in Groups 1 and 2, respectively ( p < 0.0001). Mean CST worsening was lower in Group 2 than in Group 1 (38.6 ± 30.4 µm vs 85.5 ± 55.3 µm, p < 0.0001) with a lower BCVA loss (−2.6 ± 3.5 letters vs −8.2 ± 6.2 letters, p < 0.0001). Higher glycaemic levels and HBA1c levels were significantly associated with the risk of >50 μm CST worsening in eyes from both groups. Conclusion Early DMO is associated with poorer outcomes after cataract surgery and requires close pre- and postoperative monitoring.