Dexamethasone concentration in the subretinal fluid after a subconjunctival injection, a peribulbar injection, or an oral dose.
OBJECTIVE
To determine dexamethasone concentrations in the subretinal fluid of patients after a peribulbar injection, a subconjunctival injection, or an oral dose of dexamethasone and to compare the results with those of previous similar studies of dexamethasone concentrations in the vitreous.


METHODS
Prospective, nonrandomized, comparative trial.


METHODS
One hundred forty-eight patients with a rhegmatogenous retinal detachment.


METHODS
Fifty patients received a peribulbar injection of 5 mg dexamethasone disodium phosphate, 49 received a subconjunctival injection of 2.5 mg dexamethasone disodium phosphate, and 49 received an oral dose of 7. 5 mg dexamethasone at various time intervals before surgery. At the time of surgery, a subretinal fluid sample was taken from each patient.


METHODS
The dexamethasone concentration in the subretinal fluid measured by radioimmunoassay.


RESULTS
The estimated maximum dexamethasone concentrations in the subretinal fluid after the peribulbar injection, the subconjunctival injection, and the oral dose were, respectively, 82.2 ng/ml (standard error, 17. 6), 359 ng/ml (standard error, 80.2), and 12.3 ng/ml (standard error, 1.61). Corrected for dose, the maximum dexamethasone concentrations after subconjunctival injection and peribulbar injection were, respectively, 120 (95% confidence interval, 54/180) and 13 (95% confidence interval, 6.8/20) times greater than after oral administration.


CONCLUSIONS
A subconjunctival injection of dexamethasone disodium phosphate is more effective in delivering dexamethasone into the subretinal fluid of patients with a rhegmatogenous retinal detachment compared with peribulbar injection or oral administration. The subretinal dexamethasone concentrations were higher than concentrations measured in the vitreous in previous studies with a similar setup after all three delivery methods.
Weijtens
O
O
The Rotterdam Eye Hospital, Rotterdam, The Netherlands.
Schoemaker
R C
RC
Lentjes
E G
EG
Romijn
F P
FP
Cohen
A F
AF
van Meurs
J C
JC
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001682:Biological Availability; D001826:Body Fluids / Q000378:metabolism*; D003228:Conjunctiva; D003907:Dexamethasone / Q000031:analogs & derivatives / Q000493:pharmacokinetics*; D005122:Exudates and Transudates / Q000378:metabolism*; D005260:Female; D005938:Glucocorticoids / Q000493:pharmacokinetics*; D006801:Humans; D007267:Injections; D008297:Male; D008875:Middle Aged; D009915:Orbit; D011446:Prospective Studies; D011863:Radioimmunoassay; D012163:Retinal Detachment / Q000150:complications
D005938:Glucocorticoids; C004180:dexamethasone 21-phosphate; D003907:Dexamethasone