title: Reduction of intra-ocular pressure by ocular compression before combined peri- and retrobulbar block.
abstract: The intra-ocular pressure immediately before glaucoma surgery can be raised. We wished to investigate if ocular compression for 20 min before a combined peri- and retrobulbar injection would result in a lower pressure after the block. Sixty consecutive patients scheduled for filtration surgery were randomly assigned to receive ocular compression using an external pressure device for 20 min before combined peri- and retrobulbar injection (intervention group, who also received compression after the block) or to a control group in whom pressure was applied only after the block was completed. The intra-ocular pressure was measured at baseline, after the 20-min pre-injection compression (intervention group), after injecting the block, and after the 10-min post-injection compression. The pressure did not differ between groups at baseline, after the block or after the post-injection compression. In the intervention group, the compression before the block reduced the median (IQR [range]) pressure from 21.0 (17.0-25.0 [12.0-40.0]) mmHg to 16.8 (12.5-22.5 [7.5-33.5]) mmHg (p<0.001). We conclude that external ocular compression reduces the intra-ocular pressure, but applying an additional compression for 20 min before injecting the block is not beneficial.
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, Helsinki University Hospital, Helsinki, Finland. helena.kallio@hus.fi
authors.forename: H
authors.initials: H
authors.lastname: Kallio
authors.forename: M P
authors.initials: MP
authors.lastname: Harju
authors.forename: T
authors.initials: T
authors.lastname: Ihanamäki
authors.forename: E T
authors.initials: ET
authors.lastname: Vesti
authors.forename: T
authors.initials: T
authors.lastname: Kivelä
mesh_terms: D018463:Filtering Surgery; D005901:Glaucoma / Q000503:physiopathology / Q000601:surgery / Q000628:therapy*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D009407:Nerve Block / Q000379:methods*; D011300:Preoperative Care / Q000379:methods*; D011312:Pressure; D013997:Time Factors; D016896:Treatment Outcome