Glaucoma Surgery Outcome in Rwanda

Dexmedetomidine as an Additive to Local Anesthesia for Decreasing Intraocular Pressure in Glaucoma Surgery: A Randomized Trial

Background

Nowadays, the peribulbar block is used as a tool in glaucoma surgery. As a side effect, it increases intraocular pressure that raises the need for adjuvant medication to overcome this problem in the diseased eye. Dexmedetomidine has proven to decrease intraocular pressure (IOP) in the non-glaucomatous eye.

Objectives

In a triple-blinded randomized study, dexmedetomidine as an adjuvant to the peribulbar block was used to decrease IOP in the diseased eye.

Methods

We randomized 98 eyes to three groups, including D50 (35 eyes) with dexmedetomidine 50 µg, D25 (33 eyes) with dexmedetomidine 25 µg, or control group (C) (30 eyes) with the plain peribulbar block. The study was randomized triple-blinded, aiming at testing the effect of dexmedetomidine on IOP after block injection.

Results

The pre-injection IOP was 27.71 ± 2.52, 27.25 ± 3.53, and 26.2 ± 3.57 mmHg in groups D50, D25, and C, respectively, then increased to 29.71 ± 1.69, 30.25 ± 2.36 and 29.4 ± 3.756 in groups D50, D25 and C, respectively, with P >0.05. The pressure decreased after the surgery to 10.86 ± 1.478 in group D50, 10.75 ± 1.63 in group D25, and 10.6 ± 1.589 in group C, with no statistical differences (P > 0.05) between the groups.

Conclusions

Dexmedetomidine did not decrease IOP in the glaucomatous eye.

Risk assessment of sudden visual loss following non-penetrating deep sclerectomy in severe and end-stage glaucoma

BACKGROUND/OBJECTIVES

To assess the risk of immediate sudden visual loss ("wipe-out" phenomenon) following non-penetrating deep sclerectomy (NPDS) for end-stages glaucoma within the first 6-months postoperative period.

SUBJECTS/METHODS

Monocenter database study. We reviewed the results for 73 eyes with severe or end-stage glaucoma that underwent NPDS. End-stage glaucoma (stage 5) was defined by the inability of patients to perform the Humphrey visual field test or by a visual acuity <20/200 due to glaucoma, according to the Glaucoma Staging System classification. Severe glaucoma (stage 4) was defined by a mean deviation (MD) <-20 dB by the preoperative 24-2 Humphrey visual field assessment. All eyes had a severe defect on the central 10° visual field: only a central island of vision remained. "Wipe-out" was defined as the permanent postoperative reduction of visual acuity to <20/200 or to "counting fingers" or less if preoperative visual acuity was <20/200.

RESULTS

The mean age was 60 years (range 22-86). Before surgery, the average MD (Humphrey 24-2) was -25.6 ± 3.8 dB, the MD (Humphrey 10-2) -19.9 ± 7.0 dB, and the VFI 24.6 ± 13%. There were no cases of postoperative flat anterior chamber. No patients experienced "wipe-out" within the first 6 months following surgery. At the six-month visit, intraocular pressure (IOP) had decreased significantly from 22.0 ± 8.8 to 13.5 ± 4.5 mmHg (P<0.001). There were no significant changes in mean visual acuity after 6 months (P = 6).

CONCLUSIONS

In our study, NPDS provided considerable IOP decrease with no occurrences of "wipe-out" and few other complications. Consideration of NPDS in end-stage and severe glaucoma is advisable given its low risk of intraoperative and postoperative complications and the low risk of wipe out. This surgery should probably be offered with less apprehension about the risk of "wipe-out" in end-stages glaucoma.