Sir,

Karacorlu et al's article on the use of intravitreal triamcinolone in patients with diabetic macular oedema and no previous laser treatment suggested that there was some beneficial effect in the short term.1 However , we would like to highlight several points that may affect the conclusions of their study.

Firstly, the medical history of the 12 patients in their study was not disclosed. There was no mention of known risk factors for diabetic maculopathy such as type and duration of diabetes, hypertension, nephropathy, and smoking. It is well recognised that good control of hypertension and serum glucose levels can improve diabetic macular oedema.2, 3 The improvement in the oedema and visual acuity reported in some of the patients could be attributed to concurrent improvement in their other systemic medical problems.

Eligibility criteria included persistent macular oedema despite medical treatment with topical corticosteroids, topical nonsteroidal anti-inflammatory drugs, and systemic acetazolamide. To our knowledge, diabetic macular oedema is not usually treated with any of these medications, which are normally used for cystoid macular oedema (CMO) following cataract surgery. Additionally, the angiographic definition for diabetic macular oedema used in the study appears to be the classic definition of CMO. Therefore, it is unclear which type of macular oedema was actually treated.

Finally, we feel that the three eyes (cases 2, 5, and 8), which developed raised intraocular pressure after intravitreal triamcinolone injection and had treatment with topical beta-blockers, should have been excluded. Topical beta-blockers have been reported to be associated with the occurrence of CMO4 and can also affect ocular blood flow.5 As such, the use of topical beta-blockers could be a source of potential bias in the study.