Effect of volume used in sub-Tenon's anesthesia on efficacy and intraocular pressure in vitreoretinal surgery.
OBJECTIVE
To compare the effect of volumes used in sub- Tenon's anesthesia on efficacy and intraocular pressure (IOP) in vitreoretinal surgery.


METHODS
A prospective clinical trial was conducted on patients undergoing sub-Tenon's anesthesia for vitreoretinal surgery. Patients were randomized to receive either 3-, 5- or 7-ml volumes of anesthetic solution. IOP were measured immediately prior to injection, immediately after injection and at 2, 5 and 10 min after injection. Pain scores were assigned using a numerical visual analogue scale immediately after surgery, and again on postoperative day 1.


RESULTS
A total of 108 patients (119 eyes) were studied, including 35 eyes in the 3-ml group, 48 eyes in the 5-ml group, and 36 eyes in the 7-ml group. There were significant elevations in mean IOP following injection in all groups, and a trend for larger rises in IOP with larger volumes of anesthesia (p < 0.01). Mean IOP were elevated after injection, and reduced at all time intervals. However, the reduction in the 3-ml group took levels to preinjection amounts. There were no significant differences in patient-reported pain scores among the groups when assessed immediately after surgery or on postoperative day 1. The incidence of chemosis and high IOP elevations (>or=40 mm Hg) were more frequent in the 7-ml group (p < 0.05).


CONCLUSIONS
Sub-Tenon's anesthesia is effective in vitreoretinal surgery. It would appear that a 3-5-ml volume of anesthetic is safe, when considering the associated complications.
Department of Ophthalmology, Gachon University of Medicine and Science, Gil Medical Center, Incheon, Korea.
Hee Jin
HJ
Sohn
Hyun Seung
HS
Moon
Dong Heun
DH
Nam
Hae Jung
HJ
Paik
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000772:Anesthesia, Local / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D003238:Connective Tissue; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005123:Eye; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007267:Injections; D007429:Intraocular Pressure / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D013508:Ophthalmologic Surgical Procedures / Q000379:methods*; D010147:Pain Measurement; D011446:Prospective Studies; D012164:Retinal Diseases / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome; D014822:Vitreous Body / Q000601:surgery*; D055815:Young Adult
D000779:Anesthetics, Local