Background/aims To assess over a 36-month period functional results of the modified INTRACOR femtosecond laser-based intrastromal procedure to treat presbyopia.

Methods 20 eyes of 20 presbyopic patients with mild hyperopia were included. The INTRACOR procedure with a modified pattern (six concentric intrastromal ring cuts) was performed using the FEMTEC femtosecond laser (Bausch+Lomb/Technolas Perfect Vision, Munich, Germany). Patients were also randomly divided into three subgroups to compare the effect of three different small inner ring diameters (1.8/2.0/2.2 mm (Groups A/B/C)). Follow-up examinations were performed at 1, 3, 6, 12, 24 and 36 months, and included near and distance visual acuity tests, slit-lamp examinations and corneal topography.

Results Median uncorrected near visual acuity (UNVA) increased from 0.7/0.7/0.7 logMAR (Groups A/B/C) to −0.1/0.1/0.1 logMAR 36 months after surgery. Uncorrected distance visual acuity changed slightly from 0.1/0.2/0.1 logMAR to 0.2/0.3/0.1 logMAR. Losses of two lines of binocular corrected distance visual acuity (CDVA) were noted in 0/25/0% of eyes. Median spherical equivalent changed from 0.75/0.75/0.75 dioptres to −0.19/0.13/−0.19 dioptres. Overall patient satisfaction with the procedure was 80%.

Conclusions INTRACOR with a modified pattern improved UNVA in all patients over a 36-month follow-up period. The possibility of reduced CDVA underlines the need for careful patient selection.

Trial registration number NCT00928122.