Photorefractive Keratectomy with Adjunctive Mitomycin C for Residual Error after Laser-Assisted In Situ Keratomileusis Using the Pulzar 213 nm Solid-State Laser: Early Results

Abstract

Purpose. To evaluate the accuracy, efficacy, stability, and safety of photorefractive keratectomy (PRK) enhancement using the Pulzar 213 nm solid-state laser (SSL) with adjunctive Mitomycin C in eyes previously treated with laser assisted in situ keratomileusis (LASIK) with residual error of refraction. Methods. This is a prospective noncomparative case series of 16 eyes of 12 patients who underwent PRK for residual refractive error after primary LASIK. Mitomycin C 0.02% was used after the PRK to prevent haze formation. Outcomes measured were pre- and postoperative manifest refraction spherical equivalent (MRSE), uncorrected (UDVA) and best-corrected distance visual acuity (CDVA), and slit lamp evidence of corneal complications. Results. The mean UDVA improved from 20/70 preoperatively to 20/30 postoperatively. The average gain in lines for the UDVA was 2.38. After six months of followup, the postoperative MRSE within 0.50 D in 56% (9) of eyes and 94% (15) eyes were within 1.0 diopters of the intended correction. No eyes developed haze all throughout the study. Conclusion. PRK enhancement with adjunctive use of Mitomycin C for the correction of residual error of refraction after LASIK using the Pulzar 213 nm solid-state laser is an accurate, effective, and safe procedure.

First Clinical Results of a New Generation of Ablative Solid-State Lasers

“…It should be pointed out that the initially obtained good results described above could be achieved without a nomogram and match the previously reported good safety and efficacy profiles reached with solid-state lasers of other research groups [ 17 , 18 , 24 , 25 , 26 , 27 , 28 ].…”

“…Furthermore, based on the work of Hale and Querry on extinction coefficients of radiation over a large area of the electromagnetic spectrum, Dair and co-workers found less absorption of up to two orders of magnitude for solid-state lasers in Balanced Salt Solution (BSS) and 0.9% Sodium Chloride solution compared to an excimer system [ 19 , 20 ]. While for excimer lasers emitting at 193 nm, tissue hydration control was found to be crucial to achieve target ablation [ 21 , 22 , 23 ], solid-state ablation lasers emitting at longer wavelengths would offer the benefits of being less dependent on the hydration state of the cornea and the humidity of the surgical environment, as well as not using toxic gas and operating silently [ 24 , 25 , 26 , 27 , 28 ].…”

Photorefractive Keratectomy for Residual Myopia after Myopic Laser In Situ Keratomileusis

“…Beerthuizen and Siebelt [ 31 ] reported prolonged grade 1 corneal haze that persisted up to 6 months in 1 eye in their study that included 18 eyes treated with PRK for residual ametropia after LASIK. In another prospective study [ 37 ] on 16 eyes treated with PRK and mitomycin C (50 seconds) for residual error following LASIK, none of the eyes developed corneal haze of any degree during 6-month followup. A study reported that exposure to high ultraviolet radiation level may increase the risk of late-onset corneal haze in eyes with moderate to high myopia [ 38 ].…”

Photorefractive Keratectomy (PRK) Retreatment of Residual Refractive Errors after Laser in Situ Keratomileusis (LASIK)

“…There have been several publications using surface retreatment after LASIK after Carones, most of them including only a limited number of eyes. [9][10][11][12][13][14][15][16][17] Table 2 shows safety and accuracy data in these studies. Our study includes a large number of eyes with at least 24 months follow-up.…”