The effect of prostaglandin analogs on the biomechanical properties and central thickness of the cornea of patients with open-angle glaucoma: a 3-year study on 108 eyes

Figures & data

Table 1 Characteristics of the study by treatment groups at the start of the study

	Latanoprost		Latanoprost and timolol
Therapy
Number of eyes	66 (47.1%)		42 (30%)
	Mean	SD	Mean	SD	P-value
Variable
Age	61.82	10	62.57	8.88	0.487
Goldmann	17.59	3.91	19.38	3.61	0.019
CCT	558.5	32.65	564.67	28.27	0.316
CRF	10.11	1.34	10.56	1.36	0.082
CH	9.22	0.76	9.17	0.81	0.733

Abbreviations: SD, standard deviation; CCT, central corneal thickness; CRF, corneal resistance factor; CH, corneal hysteresis.

Table 2 Intraocular pressure values during the study

Time	Mean	Mean difference	SD	Median	Median difference	IQR	P-value
Latanoprost
0	17.59	–	3.910	17.00	–	7	–
1	14.47	−3.120	1.703	15.00	−2.00	2	<0.001
2	14.29	−3.300	1.895	14.00	−3.00	2	<0.001
3	13.86	−3.730	1.188	14.00	−3.00	2	<0.001
4	13.83	−3.760	1.158	14.00	−3.00	2	<0.001
5	13.81	−3.780	1.162	14.00	−3.00	2	<0.001
6	13.74	−3.850	1.396	14.00	−3.00	2	<0.001
Latanoprost and timolol
0	19.38	–	3.609	20.50	–	6.00	–
1	14.67	−4.71	1.262	14.00	−6.50	2.00	<0.001
2	14.29	−5.09	1.066	14.00	−6.50	1.00	<0.001
3	14.26	−5.12	0.885	14.00	−6.50	1.00	<0.001
4	14.14	−5.24	0.843	14.00	−6.50	1.00	<0.001
5	14.13	−5.25	0.820	14.00	−6.50	1.00	<0.001
6	14.10	−5.28	1.078	14.00	−6.50	2.00	<0.001

Abbreviations: SD, standard deviation; IQR, interquartile range.

Figure 1 Intraocular pressure (IOP) values during the study for the latanoprost group.

Abbreviation: GAT, goldmann applanation tonometry.

Figure 2 Intraocular pressure (IOP) values during the study for the latanoprost and timolol group.

Abbreviation: GAT, goldmann applanation tonometry.

Table 3 Central corneal thickness evolution during the study, sorted by treatment

Time	Mean	Mean difference	SD	Median	Median difference	IQR	P-value
Latanoprost
0	558.50	–	32.652	559.00	–	44.75	–
1	558.89	0.390	32.437	559.50	0.50	43.75	<0.001
2	559.48	0.980	32.294	560.00	1.00	42.75	<0.001
3	560.20	1.700	32.099	560.50	1.50	42.25	<0.001
4	560.58	2.080	32.138	561.00	2.00	43.25	<0.001
5	560.70	2.200	32.124	561.00	2.00	43.25	<0.001
6	561.27	2.770	32.108	562.00	3.00	44.25	<0.001
Latanoprost and timolol
0	564.67	–	28.268	570.50	–	38.50	–
1	564.88	0.21	28.017	572.00	1.50	37.00	0.122
2	565.67	1.00	27.764	572.50	2.00	36.75	<0.001
3	566.31	1.64	27.338	573.00	2.50	35.00	<0.001
4	567.07	2.40	27.318	574.50	4.00	35.25	<0.001
5	567.29	2.62	27.147	574.50	4.00	35.00	<0.001
6	568.07	3.40	27.165	576.00	5.50	35.25	<0.001

Abbreviations: SD, standard deviation; IQR, interquartile range.

Figure 3 Central corneal thickness (CCT) evolution during the study, sorted by treatment.

Table 4 Corneal hysteresis evolution during the study sorted by treatment

Time	Mean	Mean difference	SD	Median	Median difference	IQR	P-value
Latanoprost
0	9.2242	–	0.7586	9.3000	–	1.6000	–
1	9.5742	0.350	0.5749	9.7000	0.4000	0.8500	<0.001
2	9.6955	0.471	0.5911	9.8000	0.5000	0.7250	<0.001
3	9.8288	0.605	0.4771	9.9000	0.6000	0.5250	<0.001
4	9.8591	0.635	0.4638	9.9000	0.6000	0.5000	<0.001
5	9.8909	0.667	0.4597	10.0000	0.7000	0.4250	<0.001
6	9.9773	0.753	0.4650	10.0000	0.7000	0.4250	<0.001
Latanoprost and timolol
0	9.171	–	0.816	9.150	–	1.55	–
1	9.710	0.539	0.745	9.800	0.650	1.30	<0.001
2	9.940	0.769	0.702	10.000	0.850	1.03	<0.001
3	10.002	0.831	0.677	10.000	0.850	0.85	<0.001
4	10.069	0.898	0.622	10.050	0.900	0.73	<0.001
5	10.112	0.941	0.611	10.100	0.950	0.73	<0.001
6	10.179	1.008	0.602	10.100	0.950	0.73	<0.001

Abbreviations: SD, standard deviation; IQR, interquartile range.

Figure 4 Corneal hysteresis (CH) evolution during the study, sorted by treatment.

Abbreviation: CCT, central corneal thickness.

Table 5 Corneal resistance-factor evolution during the study sorted by treatment

Time	Mean	SD	Median	IQR	P-value
Latanoprost
0	10.111	1.3455	10.450	1.350	–
1	10.118	1.2661	10.400	1.325	0.854
2	10.123	1.2261	10.400	1.350	0.868
3	10.100	1.1830	10.300	1.350	0.451
4	10.095	1.1666	10.300	1.325	0.398
5	10.094	1.2123	10.300	1.425	0.301
6	10.152	1.2706	10.300	1.350	0.69
Latanoprost and timolol
0	10.562	1.3565	10.800	1.200	–
1	10.579	1.3110	10.800	1.000	0.399
2	10.562	1.2632	10.750	0.975	0.819
3	10.569	1.2573	10.750	0.925	0.77
4	10.550	1.2268	10.700	1.125	0.652
5	10.555	1.2343	10.600	1.125	0.653
6	10.540	1.2208	10.650	1.050	0.463

Abbreviations: SD, standard deviation; IQR, interquartile range.

Table 6 Correlations in changes in intraocular pressure with values of central corneal thickness (CCT) and corneal hysteresis (CH) for the two study groups

	Regression coefficient (CCT)	P-value	Confidence interval (95%)
Latanoprost
0	0.024	0.049	0.00011	0.047
1	0.016	0.024	0.002	0.029
2	0.011	0.034	0.01	0.02
3	0.009	0.079	−0.001	0.018
4	0.003	0.545	−0.007	0.012
5	0.002	0.604	−0.007	0.001
6	−0.002	0.756	−0.013	0.009
	Regression coefficient (CH)	P-value	Confidence interval (95%)
Latanoprost
0	−3.401	<0.001	−4.464	−2.337
1	−0.630	0.2	−1.603	0.343
2	−0.119	0.774	−0.942	0.705
3	0.076	0.884	−0.969	1.122
4	−0.230	0.678	−1.335	0.875
5	−0.349	0.535	−1.470	0.772
6	−0.919	0.150	−2.180	0.343
	Regression coefficient (CCT)	P-value	Confidence interval (95%)
Latanoprost and timolol
0	0.085	<0.001	0.054	0.116
1	0.022	0.003	0.008	0.035
2	0.017	0.012	0.004	0.029
3	0.010	0.074	−0.001	−0.022
4	0.002	0.781	−0.010	0.013
5	0.002	0.792	−0.010	0.013
6	−0.008	0.285	−0.022	0.007
	Regression coefficient (CH)	P-value	Confidence interval (95%)
Latanoprost and timolol
0	−0.460	0.389	−1.529	0.608
1	−0.558	0.034	−1.072	−0.044
2	−0.478	0.061	−0.979	0.024
3	−0.121	0.600	−0.582	0.341
4	0.073	0.768	−0.426	0.572
5	0.080	0.753	0.430	0.590
6	0.532	0.109	−0.124	1.188