Table 4

Effect of corneal thickness on SPAC measurement

Scanning distance (mm)	Corneal thickness (mm)											maximum difference
Scanning distance (mm)	0.40	0.42	0.44	0.46	0.48	0.50	0.52	0.54	0.56	0.58	0.60	mm	%
NA = not available.
0.0	2.520	2.532	2.544	2.556	2.568	2.580	2.593	2.605	2.617	2.630	2.642	0.123	4.646
0.4	2.392	2.404	2.415	2.427	2.439	2.451	2.463	2.475	2.487	2.499	2.511	0.120	4.758
0.8	2.266	2.278	2.289	2.301	2.312	2.324	2.335	2.347	2.359	2.371	2.383	0.116	4.880
1.2	2.142	2.153	2.165	2.176	2.187	2.199	2.210	2.221	2.233	2.244	2.256	0.114	5.046
1.6	2.018	2.029	2.040	2.051	2.063	2.074	2.085	2.096	2.108	2.119	2.130	0.113	5.297
2.0	1.891	1.902	1.913	1.925	1.936	1.948	1.959	1.970	1.982	1.993	2.004	0.114	5.680
2.4	1.758	1.770	1.782	1.794	1.806	1.818	1.829	1.841	1.853	1.864	1.876	0.117	6.255
2.8	1.618	1.630	1.643	1.655	1.668	1.680	1.693	1.705	1.717	1.729	1.741	0.124	7.112
3.2	1.464	1.478	1.491	1.505	1.519	1.532	1.545	1.559	1.572	1.585	1.598	0.134	8.389
3.6	1.292	1.307	1.323	1.338	1.353	1.368	1.383	1.397	1.412	1.4216	1.441	0.149	10.323
4.0	1.096	1.113	1.131	1.148	1.165	1.182	1.199	1.215	1.232	1.248	1.264	0.168	13.325
4.4	1.870	0.890	0.910	0.929	0.949	0.968	0.987	1.006	1.025	1.044	1.062	0.192	18.087
4.8	0.618	0.639	0.661	0.682	0.704	0.725	0.746	0.67	0.788	0.809	0.830	0.212	25.535
5.2	0.364	0.384	0.404	0.425	0.446	0.466	0.488	0.509	0.530	0.551	0.573	0.209	36.410
5.6	0.151	0.166	0.182	0.198	0.214	0.231	0.249	0.267	0.285	0.303	0.322	0.172	53.265
6.0	NA	0.006	0.017	0.028	0.040	0.052	0.064	0.077	0.090	0.103	0.177	0.111	94.994