[Correction of corneal astigmatism during phacoemulsification]

Area of Science:

• Ophthalmology
• Corneal Surgery
• Astigmatism Correction

Background:

• Phacoemulsification is a common cataract surgery technique.
• Corneal astigmatism can affect visual outcomes after surgery.
• Clear corneal incisions are used for wound closure and astigmatism management.

Purpose of the Study:

• To evaluate the efficacy of clear corneal incisions (CCIs) versus combined CCIs and opposite clear corneal incisions (OCCIs) for correcting pre-operative corneal astigmatism.
• To assess the astigmatic neutralizing effect of incisions placed on the steepest corneal axis.

Main Methods:

• A prospective study involving 37 eyes undergoing phacoemulsification with intraocular lens implantation.
• Group 1 (28 eyes): Standard 4.0 mm CCI on the steepest axis for astigmatism ≥1.5 D.
• Group 2 (9 eyes): Additional 3.0 mm OCCI on the opposite side to enhance flattening for astigmatism =1.5 D.
• Keratometry measurements were taken pre-operatively and at multiple post-operative intervals (1 day, 2-3 weeks, 6 months).

Main Results:

• In Group 1, corneal astigmatism reduced from 0.96 D to 0.78 D after 6 months (p≤0.05).
• In Group 2, corneal astigmatism decreased from 2.23 D to 1.56 D after 6 months (p<0.05).
• Both techniques showed a statistically significant reduction in corneal astigmatism.

Conclusions:

• Clear corneal incisions placed on the steepest corneal axis provide a neutralizing effect on pre-operative astigmatism.
• The addition of opposite clear corneal incisions significantly enhances the astigmatism-flattening effect.
• These findings support the use of specific CCI and OCCI placement for effective astigmatism management during phacoemulsification.