Changes in the effective optical zone following hyperopic keratorefractive lenticule extraction

Area of Science:

• Ophthalmology
• Refractive Surgery
• Corneal Surgery

Background:

• Hyperopic keratorefractive lenticule extraction (KLEx) is a refractive surgery procedure.
• Understanding changes in the effective optical zone (EOZ) is crucial for visual outcomes.
• The impact of transition zone (TZ) size on EOZ following hyperopic KLEx requires further investigation.

Purpose of the Study:

• To evaluate longitudinal changes in the effective optical zone (EOZ) after hyperopic keratorefractive lenticule extraction (KLEx).
• To identify surgical and corneal topographic factors influencing the postoperative EOZ.

Main Methods:

• Retrospective study of 27 patients undergoing hyperopic KLEx.
• Patients divided into two groups based on transition zone (TZ) size: 2.0 mm (Group A) vs. 0-0.2 mm (Group B).
• Effective optical zone (EOZ) changes assessed at early (<1 month) and late (>6 months) postoperative stages.

Main Results:

• Group B showed a significantly higher postoperative spherical equivalent than Group A.
• EOZ diameters were smaller in Group B compared to Group A at both early and late stages.
• EOZ reduction was significantly larger at the late postoperative stage and negatively associated with programmed optical zone (POZ) and programmed treatment zone (PTZ).

Conclusions:

• The effective optical zone (EOZ) demonstrates a continuous decrease following hyperopic KLEx.
• A larger transition zone (TZ) and programmed optical zone (POZ) are associated with a larger postoperative EOZ.
• These findings have implications for optimizing surgical planning in hyperopic KLEx.