Laser treatment in diffuse diabetic macular oedema

The characteristics of diffuse edema are:³
A. Enhanced visibility of retinal capillary bed.
B. Leakages from extensive areas of capillary bed in the macular area.
C. Scarcity or even absence of hard exudates.
D. Cystoid changes.

Diffuse maculopathy is a difficult form of diabetic retinopathy to treat. ETDRS scatter laser photocoagulation has been accepted as the mainstay of therapy.^4–6 Intraocular injections of crystalline steroid preparations (Triamcinolone) has been advocated for treatment of refractory clinically significant macular oedema (CSME) which has not responded to laser therapy.^7–11

Methods

Paper questionnaires were sent by post to 300 consultant ophthalmologists that were randomly selected from approximately 100 hospitals in England.

Result

Of the 300 consultant ophthalmologists, 137 completed and returned the questionnaire. 32% described themselves as a retinal specialist, 31% as a general ophthalmologist with an interest in medical retina while 37% described themselves as an ophthalmologist with different subspecialties.

Clinical assessment of DME

The data collected showed that after biomicroscopic identification of diffuse DME, only 5% would always request fluorescein angiography, 30% would request it most of the time while 65 % of them would only request occasionally. 63% will request OCT most of the time and the rest 37% only request it occasionally,

Treatment of DME

The analysed data reveals that 91% of the participants would recommend, as the first choice, argon green grid laser, the remaining 9% would use other laser types

Only 52% would repeat the grid if vision deteriorated, while 37% would only repeat if vision remained stable and the edema persisted. The remaining 11% would require additional information before treating

Retreatment

When a decision was made to retreat, 86% would perform the procedure, a minimum of 3 months after the previous treatment, 9% after 2 months, while 5% were unclear,

Intravitreal injection was recommended if laser treatment failed to achieve its goal by 51% of the participants, while 49% would not recommend it. 57% of them have referred refractory oedema for vitrectomy but 43% have not considered vitrectomy for their patients with refractory oedema (even if other modalities of treatment have failed). 35% of those who refer for vitrectomy would do so if laser treatment failed while the remaining 65% would refer for vitrectomy if both laser and intravitreal treatments failed

Stopping Laser treatment

When our participant colleagues were asked when to give up laser treatment, 3% would perform one grid laser treatment, 49% would perform two grids, 36% would perform three grids. 12% did not adhere to a formal algorithm. 80% will request fluorescein if first grid failed.

Vision Criteria

In our survey, 73% of the participating ophthalmologists would treat diffuse diabetic oedema in an eye with vision of 6/60 or less, however, 27% would not recommend any treatment.