Effect of 3 years of treatment with a dorzolamide/timolol (1%/0.5%) combination on intraocular pressure

Figures & data

Table 1 Clinical profile of the subjects

	Nonincreased group	Increased group	Total
Number of subjects	4	15	19
Age (years)	66.0±2.9	66.3±7.4	66.3±7.4
Male/female	2/2	9/6	11/8
Glaucoma type (POAG/NTG)	1/3	4/11	5/14
Refraction (diopters)	−4.2±2.6	−2.9±3.4	−3.17±3.0
Baseline IOP (mmHg)	12.8±1.7	14.4±3.2	14.1±3
Prior glaucoma medication(s)
BB		4	4
CAI		2	2
PGA+BB		9	9
PGA/BB combination	1		1
PGA+BB+CAI	3		3

Notes: The subjects were divided into nonincreased and increased groups according to the change in the number of anti-glaucoma agents. The nonincreased group switched from PGA/BB combination to DTFC or from PGA+BB+CAI to PGA+DTFC. The increased group switched from BB or CAI to DTFC or from PGA+BB to PGA+DTFC.

Abbreviations: BB, beta-blocker; CAI, carbonic anhydrase inhibitor; DTFC, dorzolamide/timolol (1%/0.5%) fixed combination; IOP, intraocular pressure; NTG, normal tension glaucoma; PGA, prostaglandin analog; POAG, primary open-angle glaucoma.

Figure 1 IOP at baseline and at each time after switching to the DTFC.

Notes: (A) Comparison of IOP between baseline and each time point after switching in all patients. (B) Comparison of IOP between the nonincreased group (N=4) and increased group (N=15). (C) Comparison of IOP between patients with POAG (N=5) and those with NTG (N=14). *P<0.05 and **P<0.01.
Abbreviations: DTFC, dorzolamide/timolol (1%/0.5%) fixed combination; IOP, intraocular pressure; NTG, normal tension glaucoma; POAG, primary open-angle glaucoma.

Figure 2 The mean percent reduction of IOP from baseline at each time after switching to DTFC, in all patients (A), in the nonincreased and increased groups (B), and in patients with POAG or NTG (C).

Abbreviations: DTFC, dorzolamide/timolol (1%/0.5%) fixed combination; IOP, intraocular pressure; NTG, normal tension glaucoma; POAG, primary open-angle glaucoma.

Figure 3 The correlation between the baseline IOP and percent reduction of IOP, in all patients (A), the nonincreased group (B), and the increased group (C).

Abbreviation: IOP, intraocular pressure.

Table 2 Correlations between the IOP reduction rate and various factors, as well as multivariate odds ratios for the IOP reduction rate (n=19)

Variable	Correlation coefficient		Multivariate analysis
	R	P-value	OR	(95% CI)	P-value
3 months
Age (years)	−0.45	0.0551	0.59	(−1.6 to 0.3)	0.0084
Sex (male)	0.22	0.3574	1.11	(−6.8 to 11.9)	0.5319
R/L (left eye)	0.02	0.9363	1.24	(−3.7 to 14.7)	0.2076
Refraction (diopters)	−0.04	0.8825	1.24	(−1.1 to 2.7)	0.3418
Glaucoma type (POAG)	−0.11	0.6428	0.56	(−28.8 to 5.6)	0.0095
Increased group/nonincreased group (increased group)	0.32	0.1772	1.25	(−4.5 to 18.1)	0.2047
Baseline IOP (mmHg)	0.56	0.0118	2.10	(1.8 to 4.8)	0.0006
6 months
Age (years)	−0.30	0.2075	0.96	(−1.2 to 1.0)	0.8919
Sex (male)	0.28	0.2495	0.92	(−19.4 to 13.7)	0.7587
R/L (left eye)	0.05	0.8323	1.42	(−6.6 to 26.0)	0.2107
Refraction (diopters)	−0.33	0.1676	0.59	(−5.8 to 0.9)	0.1576
Glaucoma type (POAG)	0.04	0.8762	0.60	(−37.7 to 3.3)	0.1079
Increased group/nonincreased group (increased group)	0.35	0.1458	1.66	(−2.8 to 37.0)	0.0846
Baseline IOP (mmHg)	0.41	0.0836	1.54	(−0.6 to 4.7)	0.1152
12 months
Age (years)	−0.03	0.8942	0.86	(−1.7 to 0.8)	0.5013
Sex (male)	0.06	0.8228	1.14	(−13.9 to 22.6)	0.5814
R/L (left eye)	−0.02	0.9494	1.14	(−13.6 to 22.3)	0.5767
Refraction (diopters)	0.21	0.3854	1.39	(−1.1 to 2.7)	0.2838
Glaucoma type (POAG)	−0.22	0.3717	0.57	(−28.8 to 5.6)	0.0452
Increased group/nonincreased group (increased group)	0.13	0.6066	0.93	(−4.5 to 18.1)	0.7579
Baseline IOP (mmHg)	0.54	0.0180	2.37	(1.8 to 4.8)	0.0017
24 months
Age (years)	0.03	0.8891	1.51	(−0.2 to 1.6)	0.1036
Sex (male)	0.33	0.1695	1.13	(−10.4 to 15.9)	0.6256
R/L (left eye)	−0.05	0.8352	1.17	(−9.2 to 16.7)	0.5115
Refraction (diopters)	−0.31	0.2027	0.59	(−4.9 to 0.4)	0.1091
Glaucoma type (POAG)	0.14	0.5685	0.70	(−27.1 to 5.4)	0.1965
Increased group/nonincreased group (increased group)	0.29	0.2269	1.33	(−7.2 to 24.5)	0.2459
Baseline IOP (mmHg)	0.59	0.0084	1.90	(0.7 to 4.9)	0.0141
36 months
Age (years)	−0.34	0.1593	0.71	(−1.9 to 0.4)	0.2226
Sex (male)	0.34	0.1558	1.39	(−8.0 to 27.2)	0.2456
R/L (left eye)	0.22	0.3594	1.33	(−9.0 to 25.6)	0.3015
Refraction (diopters)	−0.09	0.7293	1.38	(−2.1 to 5.0)	0.3717
Glaucoma type (POAG)	0.09	0.7056	0.83	(−28.8 to 14.7)	0.5348
Increased group/nonincreased group (increased group)	0.19	0.4428	1.13	(−17.3 to 25.1)	0.6610
Baseline IOP (mmHg)	0.47	0.0446	1.70	(−0.1 to 5.5)	0.0578

Notes: Correlations between the IOP reduction rate and various factors were calculated using the two-tailed Pearson’s product moment formula. Independent determinants of the IOP reduction rate were investigated by multiple logistic regression analysis.

Abbreviations: R, Pearson’s correlation coefficient; CI, confidence interval; IOP, intraocular pressure; OR, odds ratio; POAG, primary open-angle glaucoma; R/L, right/left.

Figure 4 Kaplan–Meier cumulative probability of treatment success, in the nonincreased group vs the increased group (A) or in patients with NTG vs patients with POAG (B).

Notes: The subjects were divided into nonincreased and increased groups according to the change in the number of anti-glaucoma agents. The nonincreased group switched from PGA/BB combination to DTFC or from PGA+BB+CAI to PGA+DTFC. The increased group switched from BB or CAI to DTFC or from PGA+BB to PGA+DTFC.
Abbreviations: BB, beta-blocker; CAI, carbonic anhydrase inhibitor; DTFC, dorzolamide/timolol (1%/0.5%) fixed combination; NTG, normal tension glaucoma; PGA, prostaglandin analog; POAG, primary open-angle glaucoma; vs, versus.

Table 3 Cox proportional hazards analysis with hazard ratios and 95% confidence intervals for predictors of IOP control after switching

Variable	Univariate			Stepwise multivariate
	HR	(95% CI)	P-value	HR	(95% CI)	P-value
Age (years)	1.0	(0.8–1.3)	0.8439
Sex (male)	0.4	(0.0–12.6)	0.5877
R/L (left eye)	0.4	(0.0–9.9)	0.5528
Refraction (diopters)	1.0	(0.4–2.2)	0.9108
Glaucoma type (POAG)	81.2	(0.6–10,537.9)	0.0766	34.6	(1.4–865.6)	0.0309
Increased group/nonincreased group (increased group)	0.5	(0.0–11.5)	0.6525
Baseline IOP (mmHg)	0.4	(0.2–1.2)	0.1136	0.5	(0.2–1.1)	0.0822

Notes: An increase of the IOP by 10% or more compared with the baseline IOP was considered to indicate failure of DTFC treatment. Univariate and multivariate Cox proportional hazards models were used to determine the hazard ratios for the relative risk of IOP control failure.

Abbreviations: CI, confidence interval; DTFC, dorzolamide/timolol (1%/0.5%) fixed combination; HR, hazard ratio; IOP, intraocular pressure; POAG, primary open-angle glaucoma; R/L, right/left.