Visual Outcomes and Aberrometric Changes With Topography-Guided Photorefractive Keratectomy Treatment of Irregular Astigmatism After Penetrating Keratoplasty

Abstract

Twelve months postoperatively, the BSCVA improved significantly, the lines of vision increased, and astigmatism, corneal best-fit sphere, mean keratometry, corneal thickness, corneal root mean square total, and corneal spherical aberrations decreased. TG-PRK with MMC is a good alternative for correcting post-PKP cases with irregular astigmatism with elevated higher-order aberrations.

Intrastromal corneal ring segments followed by PRK for postkeratoplasty high astigmatism: prospective study

“…16–21 Although 5 published studies of PRK for PKA compared favorably with ours, our subjects' initial corrected vision was significantly worse. 14,22–35…”

Aberrometric, Keratometric, and Visual Outcomes After Trans-Epithelial Topography-Guided Phototherapeutic Keratectomy for the Treatment of Irregular Corneas

“…Six cases (19.4%) presented haze, which resolved without visual sequelae, and only 1 case with recurrent herpetic keratitis. Similarly, Bandeira e Silva et al 18 reported significant improvements (80% of patients) in the BCVA of 15 postkeratoplasty eyes after TG-PRK. Additionally, twelve months postoperatively the lines of vision increased, and astigmatism, corneal best-fit sphere, mean keratometry, corneal thickness, corneal total RMS, and corneal SA decreased.…”

“…They obtained a mean reduction of 1.52 um in total RMS. 18 Rajan et al, 15 and Camellin et al 16 also reported decreases in total coma and SA. Ghoreishi et al, 8 studied TE-TG-PRK in 22 eyes with irregular astigmatism post-radial keratotomy (RK).…”

“…Only few groups have studied aberrometric changes with TG-PRK for irregular astigmatism after keratoplasty. [15][16][17][18][19] In our study, not only post-keratoplasty patients were included. In our cohort there was a significant decrease in coma from 1.25±1.17 preoperative to 0.84±0.71 at 6 months (P<0.01); these changes remained stable at final follow-up.…”

“…[1][2][3][4][5][6][7] Most cases of irregular astigmatism are secondary to corneal causes, and TG treatments have been used in these cases with satisfactory results. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]20,21 When the aberrations exist at the level of the cornea, the information provided by the topographer is then transferred to a laser platform, which subsequently plans a treatment based on the specific irregularity and higher order aberrations of that specific cornea. The regularizing procedure itself may induce some refractive shift that will further need to be corrected.…”