Intravitreal dexamethasone to manage post endothelial keratoplasty cystoid macular oedema refractory to topical therapy

Dear Editor,

Our group has read with great interest the article by Panthagani et al. on the use of intravitreal sustained-release dexamethasone implant (Ozurdex) for refractory cystoid macular oedema (CMO) after endothelial keratoplasty (EK). ¹ They have found a 5.8% incidence of CMO after EK (DSAEK or DMEK), of which 5 eyes (4 patients) were refractory to their first-line treatment (FLT) protocol of topical treatment only [corticosteroid (CS) plus non-steroidal anti-inflammatory drug (NSAID)]. All cases resolved following Ozurdex implantation, with one case requiring two implants; and one eye required glaucoma surgery due to uncontrolled intraocular pressure (IOP).

In their study, spectral-domain optical coherence tomography (SD-OCT) was performed only when CMO after EK was suspected. This should most appropriately be called “visually significant” CMO (vs-CMO), to differentiate from studies where SD-OCT was systematically performed in all patients after EK, regardless of visual function. We have found a comparable 4.8% incidence of post-DMEK vs-CMO. ² However, we have found resolution of vs-CMO after FLT (topical treatment plus oral acetazolamide) in 71.4% of eyes, significantly higher compared with their FLT success (28.6%). Although a standardized management protocol for CMO after EK is currently lacking and the level of evidence for most treatments of postoperative CMO is low, ³ we suggest that: 1) an intensified topical CS regime in the early postoperative period be adopted as standard prophylaxis of CMO ⁴ ; and 2) oral acetazolamide be added to the topical treatment as FLT for CMO. ⁵

The authors reported Ozurdex was a successful second-line treatment (SLT) in eyes refractory to FLT. ⁴ In our study, three eyes were refractory to FLT, and our SLT was intravitreal CS; one eye received an Ozurdex implant, showing complete resolution of CMO without IOP increase or other complications. ²

We once again congratulate the authors on their study. We believe that larger, multicentric, prospective randomized studies are encouraged to determine a standardized management strategy for post-EK CMO.