Influence Of Corneal Incision Technique On Early Visual And Refractive Outcomes In Phakic Iol Implantation: A Comparison Of Two Femtosecond Platforms And Manual Keratome.

To evaluate the impact of corneal incision methodology—comparing high-energy pulse femtosecond laser (HE), low-energy pulse femtosecond laser (LE), and manual keratome (MK) — on surgical outcomes, early visual recovery, and refractive stability in phakic intraocular lens (pIOL) implantation.

A single-centre, high-volume tertiary refractive surgery centre. All surgeries were performed by a single experienced surgeon to ensure procedural consistency and eliminate inter-surgeon variability.

Retrospective comparative study of 159 eyes undergoing pIOL implantation: High-energy pulse (μJ)/low-frequency (kHz) femtosecond laser-assisted corneal incision (HE; n=56), Low-energy pulse (nJ)/high-frequency (MHz) femtosecond laser-assisted corneal incision (LE; n=51), and Manual Keratome (MK; n=52). Outcomes were assessed using standard refractive 9-graph reporting at postoperative (PO) day 1, week 1, and month 1. Statistical analysis using SPSS was performed across all groups.

All groups (HE:28 patients; LE:26 patients; MK:26 patients) had comparable demographics (p>0.05). At PO day 1, MK and LE showed superior uncorrected distance visual acuity (UDVA) (20/16: 65% and 57% vs 38% HE; p<0.05). Vision loss of ≥1 line (UDVA/CDVA) was significantly higher in HE (18%/15.8%) vs LE (2%/2%) and MK (2%/2%; p<0.001). By month 1, visual acuity differences diminished (p > 0.05) and all groups achieved zero line loss (p>0.05).

Early astigmatic control (≤0.5D) at day 1 favoured MK (67%) and LE (41%) over HE (7%; p<0.001). Axis accuracy (±15°) was superior in MK (89%) and LE (78%) vs HE (46%; p<0.001). This advantage persisted at month 1 (p<0.05). Refractive predictability and stability were comparable across all groups (p>0.05).

While all 3 methods are ultimately safe and achieve comparable outcomes by postoperative month 1, manual incisions and low-energy pulse system provide significantly faster visual recovery and superior early astigmatic control in pIOL surgery compared to high-energy pulse systems. The higher rate of early vision loss and lower axis precision in the high-energy group suggest that pulse energy profiles significantly influence immediate postoperative corneal architecture and inflammation. For optimal early patient satisfaction, manual or low-energy automated techniques may be preferable.