Refractory glaucoma--tube or diode?

BACKGROUND

The aim of the present study was to assess the relative effectiveness of tube surgery and cyclodiode laser in terms of achieving intraocular pressure control.

METHODS

A retrospective study was undertaken to compare patients undergoing double plate Molteno tube implantation with patients undergoing diode cyclophotocoagulation. Intraocular pressure (IOP) was documented at 7 days prior to surgery and postoperatively at various time points. Surgical success was defined as a final IOP between 6 (inclusive) and 21 mmHg (inclusive), without the use of topical medication, while 'qualified' success was defined as IOP within the same range with the use of topical medication.

RESULTS

Twenty-eight diode patients and 26 tube patients were included for the study. An average follow up of 150 weeks (range = 21-322 weeks) was available. Mean preoperative IOP was 37 +/- 12 mmHg for the tube group and 39 +/- 16 mmHg for the diode group (t = 0.51, P = 0.61). The final IOP was 17 +/- 12 mmHg for the tube group and 21 +/- 13 mmHg for the diode group (t = 0.35, P = 0.73). Surgical success was achieved in 46% of tube eyes and 11% of diode eyes, while qualified success was achieved in 81% of tube eyes compared with 64% of eyes in the diode group. Two eyes which underwent diode became phthisical.

CONCLUSIONS

IOP control may be achieved in a greater number of patients with tube surgery. The possible benefits of IOP control in diode patients need to be weighed against the risks of long-term visual loss and the need for multiple re-treatments in this group.