Pseudophakic astigmatism reduction with femtosecond laser-assisted corneal arcuate incisions: a pilot study

Figures & data

Figure 1 Woodcock nomogram for arcuate incision planning.

Notes: Only one arc should be used for 0.5 D astigmatism; other amounts use paired arcs. Center on visual axis; decentered arcs may overcorrect or cause irregular astigmatism; take caution when using nomogram in red zone; consider pairing LenSx with toric IOL using the ORA™ intraoperative aberrometer (Alcon Laboratories, Inc., Fort Worth, TX, USA). If ORA is available, do not open arcs if astigmatism is not on expected axis, or if astigmatism measures <1.0 D; open later in the office PRN. Mark cornea prior to LenSx application and compensate for cyclorotation.
Abbreviations: IOL, intraocular lens; PRN, as needed; D, diopters.

Figure 2 Spectacle independence questionnaire.

Notes: This questionnaire was completed by subjects preoperatively (Q1) and at 1 month and 2 months postoperatively (Q1, Q2).

Table 1 Subject preoperative demographics

Characteristics	Mean	SD	Minimum	Maximum
Age, years	68.8	6.1	59	83
Days after cataract surgery	1,044	1,377	1,01	5,517
Spherical equivalent refraction, D	−0.14	0.26	−0.50	0.25
Refractive cylinder, D	1.35	0.30	1.00	2.00
Average K, D
IOL Master	44.27	1.41	41.62	46.79
Verion	44.54	1.54	41.65	47.42
AutoK	44.29	1.42	41.31	46.75
Corneal astigmatism, D
IOL Master	1.42	0.54	0.35	2.26
Verion	1.35	0.57	0.11	2.25
AutoK	1.46	1.12	0.25	6.50
Arc subtense, degrees	35.8	6.1	27.0	47.0

Note: Total number of subjects was 18 (12 females, 6 males), and total number of eyes was 28.

Abbreviations: AutoK, autokeratometry; IOL, intraocular lens; SD, standard deviation; K, keratometry; D, diopters.

Figure 3 Visual acuity over time.

Note: Vertical bars denote 95% confidence intervals.
Abbreviation: logMAR, logarithm of the minimum angle of resolution.

Figure 4 Spherical equivalent refraction and refractive cylinder over time.

Note: Vertical bars denote 95% confidence intervals.
Abbreviation: D, diopters.

Table 2 Vector analysis of refractive and keratometric changes

Properties	Mean	Minimum	Maximum	SD
Change in refractive cylinder, D
Total	1.21	0.29	2.00	0.42
Along original refractive cylinder meridian	1.20	0.28	2.00	0.42
Orthogonal	−0.04	−0.50	0.26	0.18
Change in corneal (keratometric) astigmatism, D
Total	1.20	0.13	2.92	0.74
Along original refractive cylinder meridian	1.16	0.09	2.92	0.77
Orthogonal	−0.07	−0.55	0.38	0.22
Percentage of keratometric to refractive correctiona	100.8	5.0	185.7	51.6
Percentage of refractive correction to original refractive cylinder meridian	88.0	28.0	137.0	23.8

Note:

a The percentage of keratometric to refractive correction = the change in corneal (keratometric) astigmatism along original refractive cylinder meridian/the change in refractive cylinder along original refractive cylinder meridian.

Abbreviation: SD, standard deviation.

Figure 5 Change in keratometric astigmatism relative to change in refractive cylinder from the preoperative visit to the 2-month postoperative visit.