Analyzing small-incision cataract surgery by Orbscan II fourth-dimensional pachymetry mapping

Area of Science:

• Ophthalmology
• Corneal Surgery
• Cataract Surgery

Background:

• Phacoemulsification is a common cataract surgery technique.
• Corneal and scleral tunnel incisions are used in small-incision cataract surgery.
• Assessing postoperative corneal thickness is important for evaluating surgical outcomes.

Purpose of the Study:

• To evaluate changes in corneal thickness (pachymetry) after phacoemulsification using clear corneal incisions versus superior scleral tunnel incisions.
• To compare the effects of these two small-incision techniques on corneal hydration and thickness at four weeks post-surgery.

Main Methods:

• Prospective study of 174 eyes undergoing phacoemulsification with either clear corneal (124 eyes) or scleral tunnel (50 eyes) incisions.
• Corneal thickness was measured using Orbscan II topography before and four weeks after surgery.
• Difference pachymetry maps were analyzed to assess changes in midperipheral and central corneal thickness, as well as at the incision site.

Main Results:

• Both clear corneal and scleral tunnel techniques showed a slight increase in mean midperipheral and central corneal thickness four weeks post-surgery.
• Corneal thickness at the incision meridian was significantly higher than the average midperipheral thickness in both groups.
• No statistically significant differences in corneal thickness were observed between the corneal and scleral tunnel groups.

Conclusions:

• Small-incision phacoemulsification, whether via corneal or scleral tunnels, has a minimal and comparable impact on corneal thickness four weeks after surgery.
• Time-dependent pachymetry subtraction maps are valuable tools for monitoring corneal dynamics postoperatively.
• Both surgical approaches appear safe regarding short-term corneal hydration changes.