Reducing surgically induced astigmatism by using a scleral tunnel.

Area of Science:

• Ophthalmology
• Surgical Techniques
• Corneal Physiology

Background:

• Pars plana lensectomy and vitrectomy are common procedures.
• Intraocular lens (IOL) implantation is often performed concurrently.
• Minimizing postoperative astigmatism is crucial for visual outcomes.

Purpose of the Study:

• To evaluate the astigmatic outcomes of a specific scleral tunnel technique for IOL implantation.
• To compare astigmatism in eyes with and without IOL implantation after pars plana lensectomy and vitrectomy.

Main Methods:

• Prospective study of 36 eyes undergoing pars plana lensectomy, vitrectomy, and IOL implantation.
• Scleral tunnel created 3 mm posterior to limbus, entering anterior chamber via clear cornea.
• Comparison group of 9 eyes undergoing pars plana lensectomy and vitrectomy alone.

Main Results:

• The scleral tunnel technique resulted in minimal postoperative astigmatism (mean induced: -0.33 D).
• Average change in flatter meridian: -0.07 D; steeper meridian: +0.26 D.
• No significant astigmatic changes in eyes without IOL implantation; no significant difference between groups.

Conclusions:

• The described scleral tunnel technique is effective in minimizing induced astigmatism.
• Pars plana lensectomy, vitrectomy, and IOL implantation via this technique are safe regarding astigmatic outcomes.
• The study supports the safety of concurrent IOL implantation in terms of astigmatism control.