Pupil size affects coma value in certain eyes

Nov 13, 2014

When compared with eyes of normal axial length, high-myopic pseudophakic eyes with posterior staphyloma had significantly less internal coma and less coma variations during mydriasis, according to recently published research.

When compared with eyes of normal axial length, high-myopic pseudophakic eyes with posterior staphyloma had significantly less internal coma and less coma variations during mydriasis, according to research published in Eye.

The researchers studied 60 eyes: 40 in highly myopic cataract patients with posterior staphyloma and 20 in cataract patients with normal axial length.

They found that the high-myopic pseudophakic eyes with posterior staphyloma had significantly lower values of internal coma - both under 4 mm and 6 mm pupil sizes - at 1 month after phacoemulsification and IOL implantation compared to eyes with normal axial length.

The high-myopic pseudophakic eyes with posterior staphyloma also had significantly lower internal total higher-order aberrations and third-order aberrations at 6-mm pupil size.

In addition, the researchers found statistically significant differences between the two groups in the variation from 4- to 6-mm pupil sizes for:

  • internal coma
  • internal third-order aberrations

  • internal total higher-order aberrations
  • ocular coma aberrations.

Strehl ratio increased significantly in high-myopic eyes and decreased slightly in normal axial length eyes after mydriasis, and modular transfer functions were found to vary in a statistically significant manner between the two groups at frequencies of 15, 30, 45 and 60 cycles/degree.

To read an abstract of the study, click here.

x