Successive trabecular meshwork photocoagulation in the treatment and prevention of refractory hypotony

To evaluate the effect of successive trabecular meshwork photocoagulation (sTMP) on the elevation of intraocular pressure (IOP) to treat or prevent refractory hypotony.

The IOP changes of 15 refractory hypotonic eyes (or estimated to be hypotonic after silicon oil removal) in 15 consecutive patients were retrospectively analysed after sTMP. Fourteen eyes had intraocular silicone oil that was to be removed. Different lasers were used to destroy the trabecular meshwork 1-5 times (2.00±1.20 times on average) via the gonioscope or endoscope. Twelve eyes had a large area of exposed retinal pigment epithelium due to a large area of retinecotomy, one eye had a severe cyclitic scar, and two eyes had both a scar and a retinal defect.

After sTMP (1 to 125 months of follow-up, 22.87 ± 38.88 months), the average IOP in the 15 eyes was 11.70 ± 3.19mmHg (n = 15), significantly higher than the value before sTMP (8.26 ± 1.93 mmHg, P < 0.05). The IOP of the 15 eyes increased by 3.44 ± 2.61 mmHg, Eight eyes with an IOP of less than 10 mmHg before sTMP showed an IOP ≥10 mmHg after sTMP. Following sTMP, the silicone oil was removed from six eyes, and one of these eyes suffered a retinal detachment.

sTMP can significantly increase the IOP with a long-lasting effect and provide an opportunity for the removal of silicone oil despite large-area retinal defects or cyclitic scars in selected eyes.