Primary Topography-Guided LASIK: A Comparative Study Comparing Treating the Manifest versus the Topographic Astigmatism

Figures & data

Figure 1 Contoura planning of the manifest refraction correction (group A).

Figure 2 Contoura planning of the full topography modified refraction correction (group B).

Table 1 Preoperative Refractive Variables

Parameter	Manifest Group (A)				Full TMR (B)				Partial TMR (C)
	Mean	SD	Range		Mean	SD	Range		Mean	SD	Range
CDVA [logMAR]	0.01	0.08	−0.10	0.30	0.04	0.07	−0.10	0.10	0.01	0.06	−0.10	0.20
RA [D]	−2.33	0.60	−3.00	−1.50	−2.75	0.90	−4.50	−1.50	−2.20	0.85	−5.25	−1.50
ACA [D]	2.47	0.78	1.00	3.57	2.97	1.09	1.00	4.75	2.31	0.65	1.25	4.50
SE [D]	−2.79	2.21	−1.00	−6.25	−3.16	1.89	−0.50	−7.50	−3.07	1.68	−0.50	−5.75

Abbreviations: SD, standard deviation; D, diopters; RA, refractive astigmatism; ACA, anterior corneal astigmatism; CDVA, corrected distance visual acuity; SE, spherical equivalent.

Table 2 Postoperative Refractive Variables

Parameter	Manifest Group (A)				Full TMR (B)				Partial TMR (C)				P-value
	Mean	SD	Range		Mean	SD	Range		Mean	SD	Range
UDVA logMAR	−0.06	0.11	−0.20	0.20	−0.05	0.12	−0.20	0.20	−0.13	0.13	−0.20	0.10	0.041*
CDVA logMAR	−0.09	0.10	−0.20	0.20	−0.11	0.10	−0.20	0.00	−0.15	0.09	−0.20	0.10	0.072
residual RA [D]	−0.23	0.33	−1.00	0.00	−0.25	0.29	−0.75	0.00	−0.16	0.31	−1.00	0.00	0.541
residual ACA [D]	0.94	0.43	0.20	1.50	0.59	0.28	0.20	1.50	0.47	0.22	0.10	0.80	0.001*
SE [D]	−0.06	0.15	−0.40	0.25	−0.09	0.20	−0.50	0.25	−0.06	0.16	−0.50	0.25	0.802
Sphere [D]	0.06	0.16	0.00	0.50	0.08	0.18	0.00	0.50	0.03	0.11	0.00	0.50	0.538

Note: *Statistically significant.

Abbreviations: SD, standard deviation; D, diopters; RA, refractive astigmatism; ACA, anterior corneal astigmatism; CDVA, corrected distance visual acuity; SE, spherical equivalent; UDVA, unaided distance visual acuity.

Figure 3 (A) Comparison between the mean postoperative UDVA in the three groups. (B) The cumulative postoperative UDVA in the three groups in logMAR. (C) The mean preoperative and postoperative vision in group (A). (D) The mean preoperative and postoperative vision in group (B). (E) The mean preoperative and postoperative vision in group (C).

Figure 4 (A) The residual postoperative spherical equivalent in the three groups. (B) The residual anterior corneal astigmatism of the three groups. (C) The postoperative line gain in the three groups. (D) The cumulative postoperative CDVA in the three groups in logMAR.

Table 3 Vector Analysis

Parameter	Manifest Group (A)				Full TMR (B)				Partial TMR (C)
	Mean	SD	Range		Mean	SD	Range		Mean	SD	Range
TIA vector [D]	2.16	0.59	1.31	2.89	2.78	1.04	0.87	4.52	2.14	0.61	1.21	4.24
SIA vector [D]	2.29	0.71	0.88	3.72	2.64	0.77	1.31	4.27	2.01	0.78	1.31	5.01
DV vector [D]	0.20	0.33	0.00	1.00	0.89	0.58	0.25	1.96	0.49	0.18	0.19	0.79
Correction index	1.04	0.16	0.64	1.36	0.99	0.27	0.59	1.50	0.95	0.21	0.70	1.39
AE	−1.22	2.55	−10	0	−2.15	8.54	−14	15	−2.78	3.92	−10	5
% with AE within 15º	100%				100%						100%
%with AE>15º	0.0				0.0						0.0
%with AE<-15º	0.0				0.0						0.0

Abbreviations: SD, standard deviation; D, diopters; TIA, target induced astigmatism; SIA, surgically induced astigmatism; DV, difference vector; AE, angle of error.

Figure 5 Single-angle polar plots generated using the ASSORT software to illustrate the target induced astigmatism (TIA) vector, the surgically induced astigmatism (SIA) vector, the difference vector (DV), and the correction index (CI) in the manifest group (A) vs full TMR group (B) and partial TMR group (C). The vector means are plotted as a red diamond.

Figure 6 Target induced astigmatism (TIA) vector vs surgically induced astigmatism (SIA) vector (calculated at the corneal plane) of the manifest group (A), the full TMR group (B), and the partial TMR group (C).