A double-masked, randomized, 1-year study comparing the corneal effects of dorzolamide, timolol, and betaxolol. Dorzolamide Corneal Effects Study Group.
OBJECTIVE
To compare the long-term effects of dorzolamide hydrochloride (Trusopt, Merck and Co Inc, White-house Station, NJ), timolol maleate, and betaxolol hydrochloride on corneal endothelial cell density and corneal thickness.


METHODS
This 1-year multicenter study was conducted in 298 patients with ocular hypertension or open-angle glaucoma who had a baseline central corneal endothelial cell density greater than 1500 cells/mm2 and central corneal thickness less than 0.68 mm in each eye. Patients were randomized to 0.5% betaxolol twice daily, 0.5% timolol twice daily, or 2.0% dorzolamide 3 times daily. Specular microscopy and ultrasonic pachymetry of the central cornea was performed at baseline and 6 and 12 months following institution of therapy. Endothelial cell densities were determined by a single masked observer.


RESULTS
The mean percent changes from baseline for both outcome measures were similar in all 3 treatment groups at both 6 and 12 months. After 1 year of treatment, the mean percent loss in endothelial cell density from baseline was 3.6%, 4.5%, and 4.2% for the dorzolamide, timolol, and betaxolol groups, respectively. The mean percent change from baseline for corneal thickness was 0.47%, -0.25%, and 0.39% for the dorzolamide, timolol, and betaxolol groups, respectively.


CONCLUSIONS
Dorzolamide is equivalent to timolol and betaxolol in terms of the change in central endothelial cell density and thickness after 1 year of therapy. All 3 treatments exhibit good long-term corneal tolerability in patients with normal corneas at baseline.
Department of Ophthalmology, Case Western Reserve University, Cleveland, Ohio, USA.
J H
JH
Lass
S A
SA
Khosrof
J K
JK
Laurence
B
B
Horwitz
K
K
Ghosh
I
I
Adamsons
D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage* / Q000009:adverse effects; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015784:Betaxolol / Q000008:administration & dosage* / Q000009:adverse effects; D002257:Carbonic Anhydrase Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects; D002452:Cell Count / Q000187:drug effects; D004311:Double-Blind Method; D004728:Endothelium, Corneal / Q000187:drug effects*; D005260:Female; D005902:Glaucoma, Open-Angle / Q000188:drug therapy; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000188:drug therapy; D009883:Ophthalmic Solutions; D013449:Sulfonamides / Q000008:administration & dosage* / Q000009:adverse effects; D013876:Thiophenes / Q000008:administration & dosage* / Q000009:adverse effects; D013999:Timolol / Q000008:administration & dosage* / Q000009:adverse effects
D000319:Adrenergic beta-Antagonists; D002257:Carbonic Anhydrase Inhibitors; D009883:Ophthalmic Solutions; D013449:Sulfonamides; D013876:Thiophenes; D013999:Timolol; C062765:dorzolamide; D015784:Betaxolol