Ranibizumab With Cataract Surgery Significantly Reduces Diabetic Macular Edema

Ranibizumab injections delivered in conjunction with cataract surgery can help manage diabetic macular edema better than triamcinolone acetonide.

Patients with diabetic macular edema (DME) can experience reduced central macular thickness (CMT) from cataract surgery, especially when combined with either triamcinolone acetonide (TA), or ranibizumab, according to a study published in BMC Ophthalmology. However, the effect was more prominent in patients who received ranibizumab therapy, the study shows.

Investigators examined medical records for 73 eyes of 65 individuals with diabetes mellitus type 1 or 2 who received phacoemulsification at a university hospital in Cairo, Egypt from January 2019 to September 2020. In addition to 21 eyes in the ranibizumab cohort and 23 of the subtenon TA group, a control set included 29 eyes undergoing cataract surgery alone. Those previously treated for macular edema, or with tractional DME were excluded. One surgeon performed the procedures, and all were prescribed postoperative steroid and antibiotic eye drops.

After 1 month, compared with control participants, mean CMT was significantly reduced in the ranibizumab group from 400.9±87.69 to 280.7±25.94 µm, and for subtenon TA patients from 395.8±105.51 to 310.1±42.8 µm (both P <.001). Comparing the 2 case cohorts, ranibizumab was even more effective than TA (P =.023). At 3 months, the improvements persisted for each drug; with ranibizumab, CMT decreased to 268.13±32.94 μm and slightly increased with TA to 315.53±55 μm — both agents measured lower than the control set at 431.03±89.66 μm, and there remained a difference between medications (P =.009).

“These results indicate that both ranibizumab and TA improved postoperative CMT with relatively better significant results in ranibizumab group,” according to the researchers..

CMT decrease correlated to better visual acuity (VA). From baseline to 3 months, the average VA improved for control individuals, in logMAR from 0.9±0.09 to 0.54±0.17. The change in the ranibizumab set was from 1.0±0.06 to 0.38±0.16, and was significant compared with the control group (P <.001), as was change for patients receiving subtenon TA, from 1.01±0.19 to 0.4±0.18 (P =.030). 

These results indicate that both ranibizumab and TA improved postoperative CMT with relatively better significant results in ranibizumab group.

Researchers noted no incidences of post-surgery infection, but there were 5 and 8 cases of subconjunctival hemorrhage in the ranibizumab and TA cohorts, respectively. A few participants with elevated intraocular pressure were treated successfully with a topical beta-blocker.

Previous studies have demonstrated that despite better best-corrected VA (BCVA) after subtenon or intravitreal TA, more adjunctive treatments may be needed after subtenon than intravitreal TA — also significant improvements in CMT and vision have been found with intravitreal ranibizumab. A meta-analysis of ranibizumab injections at the time of cataract removal for individuals with diabetic retinopathy (DR) represented 6 papers and 283 eyes. Results showed improved BCVA with ranibizumab compared with control groups after 3 months, but similar outcomes at 6 months. However, with ranibizumab, CMT was significantly lower than control eyes at 6 months.

Limitations of the current analysis comprised a relatively small sample, as well as lack of DR stage identification and analysis for the impact of more advanced stages on outcomes. A strength was a wide-ranging look at the literature — including topics of vascular endothelial growth factor levels after phacoemulsification, and CMT changes in patients with or without diabetes.

References:

Khalil MMAA, Mansour HO, Tawfik AMR, and Elmahdy AG. Comparison between intravitreal ranibizumab injection and posterior subtenon triamcinolone acetonide injection at time of cataract surgery for prevention of progression of diabetic macular edema. BMC Ophthalmol. Published online on December 16, 2022. doi:10.1186/s12886-022-02625-2