Wavefront-guided photorefractive keratectomy for myopia and myopic astigmatism

PURPOSE: To evaluate the results of wavefront-supported customized ablation (WASCA) in eyes treated with photorefractive keratectomy (PRK) to correct spherical myopia and myopic astigmatism. METHODS: One-hundred fifty eyes of 104 patients (mean age 33.4 +/- 4.4 years) were included in the study. An Asclepion Shack-Hartmann wavefront aberrometer was used to assess lower and higher order refractive aberrations of eyes, and customized PRK treatments were carried out using the Asclepion-Meditec MEL 70 G-Scan excimer laser. Follow-up time was 6 months. RESULTS: The mean preoperative spherical equivalent refraction was -4.02 +/- -1.04 D, and mean uncorrected visual acuity (UCVA) was 0.06 +/- 0.02. Postoperatively, mean UCVA was 1.04 (better than 20/20), mean best spectacle-corrected visual acuity was 1.22 (20/16), and average spherical equivalent refraction was -0.12 D; 98.6% (148 of 150 eyes) were within +/-0.50 D of intended refraction, and 100% were within +/-1.00 D. Concerning safety, in 71.1% of eyes (107 of 150) BSCVA was the same as preoperatively, and in 8.2% (11 of 150) it increased by two or more Snellen lines. None of the eyes lost two or more lines of BSCVA. The root mean square value for higher order aberrations increased 1.4 times following PRK. CONCLUSIONS: WASCA-guided PRK was efficacious, safe and predictable; BSCVA may be improved by the WASCA method compared to results achievable with a traditional PRK technique, in spite of an increase in the root mean square value for higher-order aberrations.     

Long-term outcomes of photorefractive keratectomy in eyes with previous epikeratophakia for keratoconus

PURPOSE: To determine the long-term safety and effectiveness of photorefractive keratectomy (PRK) in the treatment of refractive errors after epikeratophakia (EP) for keratoconus. METHODS: Ten patients (14 eyes) who had refractive errors after EP for keratoconus received PRK surgery. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refractive error, corneal astigmatism, pachymetry, corneal topography, and complications were monitored. RESULTS: Mean follow-up after PRK was 63.4 +/- 19.8 months. Mean spherical equivalent was -5.5 +/- 3.9 D before PRK, -0.9 +/- 0.5 D at 1 month after PRK, and -1.5 +/- 1.0 D at 3 years. Mean astigmatism was 4.2 +/- 2.1 D before PRK, 1.2 +/- 0.5 D at 1 month after PRK, and 1.5 +/- 0.6 D at 3 years. Thirteen (93%) eyes had an UCVA <20/40, and 12 (86%) had a BSCVA of 20/40 or better before PRK. At 1 year, the UCVA was 20/40 or better in 8 (57%) eyes, and the BSCVA was 20/40 or better in all eyes. Mean central corneal thickness was 749 +/- 35 microm before PRK and 621 +/- 56 mum at 3 years. During the follow-up period, haze (grade no more than 1.0) was observed in 2 eyes. No immune rejection episode or recurrent keratoconus was found. CONCLUSIONS: PRK appears to be reliable and safe for the correction of residual ametropia after EP for keratoconus, and the visual acuity can remain stable after PRK for a long time.     

Wavefront-supported photorefractive keratectomy: 12-month follow-up

PURPOSE: To evaluate safety, efficacy, predictability, and stability of wavefront-supported photorefractive keratectomy (PRK) for correction of myopia and myopic astigmatism, with 12-month follow-up. METHODS: Thirty eyes of 23 patients with myopia less than -8.00 D (mean -3.76 +/- 1.90 D) and cylinder less than -3.50 D (mean -0.81 +/- 0.71 D) were selected. Aberrometry measurements were taken with the Asclepion aberrometer in order to perform customized wavefront-supported PRK. Eyes were treated with the Asclepion MEL 70 excimer laser and were followed for 12 months. RESULTS: UCVA of 20/16 or better was achieved by 47% (14 eyes) at 1 month, 67% (20 eyes) at 3 months, 77% (23 eyes) at 6 months, 90% (27 eyes) at 9 months, and 83% (25 eyes) after 1 year. No eye lost more than 1 line of BSCVA at 3, 6, 9, or 12 months. Two eyes (7%) gained more than 2 lines 1 month postoperatively, and 13% (4 eyes) gained more than 2 lines at 6, 9, and 12 months postoperatively. BSCVA of 20/10 or better was achieved in nine eyes (30%) at 1 and 12 months. Visual acuity under low contrast at 3 and 12 months after PRK was unchanged in 87% (26 eyes). Visual acuity under glare remained unchanged at 3 months after PRK in 86% (26 eyes) and at 12 months in 83% (25 eyes). CONCLUSION: Excimer laser wavefront-supported PRK with the Asclepion MEL 70 laser was safe and effective for the treatment of myopia and myopic astigmatism. Daylight visual acuity and mesopic visual acuity outcomes remained stable over 1 year.     

Results of photorefractive keratectomy in keratoconus suspects at 4 years

PURPOSE: We studied the long-term results of photorefractive keratectomy (PRK) in keratoconus suspects detected by videokeratography (TMS). METHODS: Bilateral inferior corneal steepening was detected in 6 candidates for PRK presenting with moderate myopia or astigmatism. Mean follow-up was 44.5 +/- 4.4 months (range, 38 to 54 mo). Mean spherical equivalent refraction was -5.18 +/- 1.60 D (mean sphere, -4.73 D; mean cyclinder, -0.92 D) which was stable for at least the preceding year. The quantitative measurement of inferior corneal steepening (I-S value) was greater than +1.60 (mean, 1.83 +/- 0.11) in all eyes. An Aesculap Meditec Mel 60 excimer laser was used for the PRK procedures and mean follow-up was 44.5 months. Postoperative pachymetric measurements were also performed in 6 eyes. RESULTS: Postoperative uncorrected visual acuity was 20/20 in 8 eyes (66.6%) and 20/32 or better in all eyes with a mean postoperative spherical equivalent refraction of -0.70 +/- 0.74 D (mean sphere, -0.63 D; mean cyclinder, -0.39 D). Five eyes (41.6%) were within +/- 0.50 D spherical equivalent refraction. Inferior steepening was associated with thinning of the inferior cornea which was statistically significantly thinner than the superior thickness (Student's t-test, P < .05). There were no wound healing problems or any sign that the excimer laser adversely affected the cornea during follow-up. CONCLUSIONS: Photorefractive keratectomy seems to be a safe procedure for reducing or eliminating myopia or astigmatism in keratoconus suspect eyes-most probably forme fruste keratoconus-with a stable refraction, but this may be different in eyes with early keratoconus, known to be a progressive disease.     

Photorefractive keratectomy for post-penetrating keratoplasty myopia and astigmatism

PURPOSE: To determine the safety, effectiveness, and predictability of photorefractive keratectomy (PRK) for the correction of myopia and astigmatism after penetrating keratoplasty. SETTING: Gazi University, Medical School, Department of Ophthalmology, Ankara, Turkey. METHODS: Photorefractive keratectomy was performed in 16 eyes of 16 patients with postkeratoplasty myopia and astigmatism who were unable to wear glasses due to anisometropia and were contact lens intolerant. They were examined for uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and corneal transplant integrity before and after surgery. RESULTS: The mean follow-up after PRK was 26.0 months +/- 15.7 (SD) (range 12 to 63 months). The mean preoperative spherical equivalent refraction of -4.47 +/- 1.39 diopters (D) was -3.39 +/- 1.84 D (P >.05) at the last postoperative visit and the mean preoperative cylinder of -5.62 +/- 2.88 D was -3.23 +/- 1.70 D (P <.05); refractive regression correlated with the amount of ablation performed. The BSCVA decreased in 3 eyes (18.8%), and the UCVA decreased in 2 (12.5%). Six eyes (37.5%) had grade 2 to 3 haze, which resolved spontaneously in 4 eyes within a relatively long time but caused a decrease in BSCVA in 2 (12.5%). Two of the eyes (12.5%) had a rejection episode after PRK and were successfully treated with topical steroids. CONCLUSIONS: Photorefractive keratectomy to correct postkeratoplasty myopia and astigmatism appears to be less effective and less predictable than PRK for naturally occurring myopia and astigmatism. Corneal haze and refractive regression are more prevalent, and patient satisfaction is not good.     

Clear lens extraction with intraocular lens followed by photorefractive keratectomy or laser in situ keratomileusis

OBJECTIVE: To study photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK) after clear lens extraction (CLE) with intraocular lens (IOL) implantation for hyperopia or astigmatism. DESIGN: Retrospective, noncomparative interventional case series. PARTICIPANTS: Sixty-five eyes (55 subjects) had CLE with posterior chamber IOL implants for hyperopia up to 12.25 diopters (D); 31 eyes were retreated with PRK, and 34 eyes were retreated with LASIK for residual ametropias. INTERVENTION: For PRK and LASIK, the refractive surgery was performed with the slit-scanning excimer laser Nidek EC-5000, Nidek Co., Tokyo, Japan. MAIN OUTCOME MEASURES: Manifest refraction, best-spectacle and uncorrected Snellen visual acuity, haze, and halos were evaluated before surgery and at 1, 3, 6, and 12 months postoperative. RESULTS: Forty-seven eyes were evaluated at the 12-month postoperative examination: 96% of these eyes had spherical equivalents (SE) within +/-2 D of emmetropia, 79% of eyes had SE within +/-1 D of emmetropia and 51% of eyes had SE within +/-0.50 D of emmetropia. Eighty-five percent of the eyes at 12 months postoperative had uncorrected visual acuity of 20/40 or better, and 46% of eyes had uncorrected visual acuity of 20/20 or better. Eighty-seven percent of the eyes at 12 months postoperative had uncorrected visual acuity within 1 Snellen line of their initial best spectacle-corrected visual acuity (BSCVA) before all treatment. No eye lost 2 Snellen lines of BSCVA at 3, 6, or 12 months after PRK or after LASIK. CONCLUSIONS: IOL implantation for CLE, although an invasive technique, resulted in better refractive outcomes without laser-related clinical complications after PRK or LASIK adjustment.     

Photorefractive keratectomy for myopia with a 15 Hz repetition rate

PURPOSE: To evaluate excimer laser photorefractive keratectomy (PRK) for myopia using a repetition rate of 15 Hz instead of 10 Hz. SETTING: The Cornea and Laser Eye Institute, Teaneck, and Department of Ophthalmology, UMDNJ-New Jersey Medical School, Newark, New Jersey, USA. METHODS: Photorefractive keratectomy using a 15 Hz repetition rate was performed in 23 eyes of 14 patients by a single surgeon at 1 center. The attempted corrections ranged from -2.8 diopters (D) to -5.5 D. Preoperative and postoperative uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), predictability, corneal haze, and subjective glare/halo were evaluated over 6 months. RESULTS: At 6 months, UCVA was 20/32 or better in all eyes and at least 20/20 in 14 eyes (73.7%). Two eyes (10.5%) lost 2 or more Snellen lines of BSCVA; postoperative BSCVA was at least 20/25 in 100% of eyes and 20/20 or better in 95.0%. Fifteen eyes (78.9%) were within +/-0.5 D of attempted correction, and 19 (100%) were within +/-1.0 D. Mean spherical equivalent refraction was -4.62 D preoperatively, +0.15 D at 1 month, -0.09 D at 3 months, and -0.37 D at 6 months. At 6 months, 4 eyes (21.0%) had no corneal haze and 14 (73.7%) had trace subepithelial haze. Fifteen eyes (78.9%) had no glare/halo effect at 6 months, and 4 (21.0%) had minimal glare/halo effect. CONCLUSIONS: Clinical outcomes after excimer laser PRK for myopia using an increased repetition rate of 15 Hz were good and similar to those in studies conducted with a 10 Hz repetition rate.     

Eight-year follow-up of photorefractive keratectomy for myopia

PURPOSE: We evaluated 8-year results of excimer laser photorefractive keratectomy (PRK) for myopia in terms of stability and late complications. METHODS: Ninety-two myopic eyes of 55 patients were treated with a single-step method using an Aesculap-Meditec MEL 60 excimer laser with a 5.0-mm ablation zone. Treated eyes were divided into three groups according to preoperative refraction: low myopes (< or = -6.00 D), medium myopes (-6.10 to -10.00 D), and high myopes (>-10.00 D). RESULTS: Change in myopic regression stabilized in all myopia groups within 12 months, although a small myopic shift occurred up to 8 years after PRK. Mean change in refraction between 2 and 8 years was -0.42 +/- 0.48 D for low myopes, -0.37 +/- 0.34 D for medium myopes, and -0.41 +/- 0.50 D for high myopes. The percentage of eyes within +/- 1.00 D of emmetropia 8 years after PRK was 78.3% in the low myopia group, 68.8% in the medium myopia group, and 57.1% in the high myopia group. One eye lost 2 lines of best spectacle-corrected visual acuity due to irregular astigmatism. In 13.0% of eyes, a residual trace corneal haze was observed, which had no effect on visual acuity. Apart from the loss of 2 lines of BSCVA in one eye, there were no other late complications during the study period. CONCLUSIONS: The mean change in refraction between 2 and 8 years was less than -0.50 D, regardless of preoperative refraction, and may be attributed to natural age-related refractive change. The appearance of residual corneal haze after 8 years correlated with the amount of myopic correction. PRK was a safe and stable surgical procedure in this group of patients.     

Phototherapeutic keratectomy with mitomycin C for corneal haze following photorefractive keratectomy for myopia

PURPOSE: To evaluate the safety and efficacy of phototherapeutic keratectomy (PTK) with single application of mitomycin C for patients with severe corneal haze following photorefractive keratectomy (PRK) for high myopia. METHODS: Eight eyes of seven patients were treated with PTK and intraoperative topical application of mitomycin C (0.02%) for severe corneal haze (grade 3) following PRK for myopia. RESULTS: All patients' visual performance improved significantly. Mean preoperative visual acuity (20/200 for both UCVA and BSCVA) improved significantly to 20/33 (0.6) and 20/30 (0.7) for UCVA and BSCVA, respectively. Six eyes (85.7%) had improved UCVA to 20/40 or better and gained five or more lines of UCVA. The corneal haze score decreased from grade 3 initially (for all eyes prior to PTK and mitomycin C) to a final mean haze score of 0.3 (range 0 to 0.5). Mean final spherical equivalent refraction achieved was -1.30 +/- 1.60 D (range -3.75 to +1.25 D). One eye gained only three lines of visual acuity due to regression and residual haze. No adverse effects related to the use of mitomycin C were recorded. CONCLUSION: PTK with a single intraoperative application of mitomycin C was safe and effective in reducing corneal haze and improving visual acuity in patients with severe corneal haze following PRK.     

Customized photoastigmatic refractive keratectomy using combined topographic and refractive data for myopia and astigmatism in eyes with forme fruste and mild keratoconus

PURPOSE: To examine the outcomes of photoastigmatic refractive keratectomy using corneal and refractive parameters for myopia and astigmatism in eyes with forme fruste and mild keratoconus. SETTING: Private practice, Melbourne, Australia. METHODS: Photoastigmatic refractive keratectomy was performed with a Star 1 or Star 2 laser (Visx) in 45 eyes with forme fruste or mild keratoconus using the Alpins vector planning technique. Inclusion requirements were best corrected visual acuity (BCVA) 20/40 or better, no slitlamp signs of keratoconus, mean keratometry less than 50.00 diopters (D), and corneal and refractive stability for at least 2 years. RESULTS: Thirty-two eyes had follow-up of 5 years and 9 eyes, of 10 years. Preoperatively, the mean refractive astigmatism was -1.39 DC +/- 1.08 (SD) (range 0.45 to -5.04 DC) and the mean corneal astigmatism was 1.52 +/- 1.18 D (range 0.35 to 4.75 D) by manual keratometry and 1.70 +/- 1.42 D (range 0.32 to 5.32 D) by topography. Twelve months postoperatively, the mean refractive astigmatism was -0.43 +/- 0.40 D and the mean corneal astigmatism was 1.05 +/- 0.85 D by keratometry and 1.02 +/- 0.83 D by topography. At 12 months, the uncorrected visual acuity was 20/20 or better in 56% of eyes and 20/40 or better in all eyes. The BCVA was 20/20 or better in 89% of eyes and 20/30 or better in all eyes. Seven eyes had a loss of BCVA, and 16 eyes had a gain. There were no cases of keratoconus progression. CONCLUSIONS: Photoastigmatic refractive keratectomy in eyes with forme fruste and mild keratoconus was safe and effective for myopia and astigmatism in carefully selected patients with refractive and corneal stability. The incorporation of the corneal astigmatism data into the applied treatment parameters may improve visual and total astigmatism results.     

Photorefractive keratectomy in megalophthalmos anterior

PURPOSE: To evaluate the results of photorefractive keratectomy (PRK) for the correction of myopia and myopic astigmatism in megalophthalmos anterior. METHODS: Four eyes of two brothers with megalophthalmos anterior were treated with PRK. In patient 1, best spectacle-corrected visual acuity (BSCVA) was 20/20 in both eyes with a refraction of -4.50 -4.50 x 180 degrees in the right eye and -3.75 -3.00 x 175 degrees in the left eye. In patient 2, BSCVA was 20/25 in both eyes with a refraction of -4.25 x 166 degrees in the right eye and +0.50 -4.00 x 175 degrees in the left eye. RESULTS: Topographic map, slit-lamp, ultrasound biomicroscopy, and postoperative course (no progression), supported with vectorial analysis, demonstrated megalophthalmos anterior. During 24-month follow-up, mild haze was observed and BSCVA was maintained. CONCLUSIONS: Myopia and astigmatism are often observed in this type of nonprogressive corneal dysgenesis. Based on this fact and our results, we recommend PRK in cases of megalophthalmos anterior.     

Ferrara intracorneal ring segments for keratoconus

PURPOSE: To assess the outcome of Ferrara intracorneal ring segments for keratoconus. SETTING: Private practice and university hospital, Porto Alegre, Brazil. METHODS: In this retrospective noncomparative interventional case series, 51 keratoconus eyes of 47 patients that had Ferrara intracorneal ring segment implantation were reviewed. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), central corneal curvature, corneal astigmatism, surface regularity index, surface asymmetry index, and complications were analyzed. RESULTS: At a mean follow-up of 13.0 months +/- 8.7 (SD), the BSCVA improved in 86.4% of eyes, was unchanged in 1.9%, and worsened in 11.7%. The UCVA improved in 86.4% of eyes, was unchanged in 7.8%, and worsened in 5.8%. The mean spherical equivalent (SE) was reduced from -6.08 +/- 5.01 diopters (D) to -4.55 +/- 5.71 D and the mean refractive astigmatism, from -3.82 +/- 2.13 D to -2.16 +/- 2.07 D. The mean central corneal curvature was reduced from 48.76 +/- 3.97 D to 43.17 +/- 4.79 D. Eyes with central keratoconus had statistically significantly better results than eyes with inferior keratoconus in topographic astigmatism, SE, and refraction cylinder. Penetrating keratoplasty was avoided in 38 eyes (74.5%) during the follow-up. Intracorneal ring segment decentration occurred in 2 eyes (3.9%), segment extrusion in 10 eyes (19.6%), bacterial keratitis in 1 eye (1.9%) with segment extrusion, and a disciform keratitis in 1 eye (1.9%). CONCLUSION: Implantation of Ferrara intracorneal ring segments in patients with keratoconus was a safe and reversible procedure that led to stable results and avoided or delayed PKP in many cases.     

Corneal suture for the correction of hyperopia following radial keratotomy

PURPOSE: To report the visual and refractive changes observed after double concentric corneal suture to correct hyperopic shift after radial keratotomy (RK). METHODS: This retrospective consecutive case series comprised 17 eyes (15 patients) that underwent two concentric corneal sutures (modified Grene Lasso suture) to correct hyperopic shift after RK. All surgeries were performed by the same surgeon between 2000 and 2003. RESULTS: The mean time after RK was 11.6 +/- 3.2 years. The mean follow-up was 20.3 +/- 11.3 months. The spherical equivalent refraction was reduced from a preoperative mean of +4.38 +/- 2.87 diopters (D) to -0.54 +/- 2.59 D at last postoperative follow-up (P < .001). No statistically significant difference was observed in mean refractive astigmatism before and after the corneal suture (P = .15). Before surgery, no eye presented with best spectacle-corrected visual acuity (BSCVA) > or = 20/20. At final follow-up, 3 (17.6%) eyes attained this level. Seven (41.2%) eyes improved their BSCVA by > or = 2 Snellen lines. One (5.9%) eye lost 2 Snellen lines of BSCVA. CONCLUSIONS: Corneal suture can be used to correct RK-induced hyperopia, improving the corneal asphericity in an attempt to stabilize these corneas. It appeared to be effective even for high degrees of hyperopia and in cases with associated irregular astigmatism or open incisions.     

Development of unilateral corneal ectasia after PRK with ipsilateral preoperative forme fruste keratoconus

PURPOSE: To describe clinical and topographic features of keratectasia after photorefractive keratectomy (PRK) in a patient with abnormal preoperative topography. METHODS: A 25-year-old man underwent uneventful bilateral PRK for moderate myopia of -5.75 -1.75 x 95 in the right eye and -7.50 -1.25 x 80 in the left eye with best spectacle-corrected visual acuity (BSCVA) of 20/25 in both eyes. Preoperative corneal thickness was 500 microm in the right eye and 460 microm in the left eye. The total calculated ablation depth was 70 microm in the right eye and 100 microm in the left eye. Preoperative corneal topography revealed forme fruste keratoconus in the right eye with an inferior-superior ratio of 4. RESULTS: Five years postoperatively, the patient developed unilateral inferior keratectasia in the right eye with refraction of +0.50 -5.50 x 90, BSCVA of 20/100, and central corneal thickness of 481 microm with inferior corneal thickness of 374 microm. CONCLUSIONS: This case report adds to the growing body of evidence in the ophthalmic literature suggesting that patients with preoperative forme fruste keratoconus or early keratoconus may develop clinically significant progression of corneal ectasia after PRK.     

Twelve-year follow-up of photorefractive keratectomy for low to moderate myopia

PURPOSE: To evaluate long-term safety and stability in a group of myopic patients who underwent photorefractive keratectomy (PRK) > or =12 years ago. METHODS: Myopic PRK was performed on 120 eyes of 80 patients using the Summit UV200 excimer laser with a 5-mm ablation zone. Of the original group, most of whom were followed for > or =2 years (mean 2.6 +/- 1.7 years), 34 patients (58 eyes) returned at 12 years (mean 12.7 +/- 0.79 years) and had refractive stability, refractive predictability, best spectacle-corrected visual acuity (BSCVA), corneal haze, and subjective patient symptoms, such as glare/halos, recorded. RESULTS: Preoperative mean refractive spherical equivalent (MRSE) ranged from -1.75 to -7.25 diopters (D) and astigmatism from 0.00 to 1.50 D. All eyes underwent a change in manifest refraction over 12 years. At 2 years, MRSE was -0.27 +/- 0.55 D and at 12 years was -0.58 +/- 0.72 D. In 87.9% of eyes, the level of preoperative BSCVA was maintained or improved, whereas 34.5% of eyes gained one line, and 12.1% lost one line of BSCVA. Uncorrected visual acuity > or = 20/20 was noted in 67% of eyes, whereas 62.1% were within +/- 0.50 D of emmetropia. Trace haze was noted in 17.2% of eyes at 12 years. One patient had a rhegmatogenous retinal detachment, but this was unlikely due to the PRK procedure. With respect to the small optical zone, 14 (41.1%) patients had night visual problems, particularly halos, which were severe in 2.7%. All patients questioned stated they would have the procedure done again. CONCLUSIONS: Photorefractive keratectomy with the Summit UV200 excimer laser effectively reduced myopia and showed good refractive stability from year 2 to 12 with good patient satisfaction.     

Randomized prospective comparison of visian toric implantable collamer lens and conventional photorefractive keratectomy for moderate to high myopic astigmatism

PURPOSE: To compare the Visian Toric Implantable Collamer Lens (TICL), a toric phakic intraocular lens (IOL), and photorefractive keratectomy (PRK) in the correction of moderate to high myopic astigmatism. METHODS: This prospective, randomized study consisted of 43 eyes implanted with the TICL (20 bilateral cases) and 45 eyes receiving PRK with mitomycin C (22 bilateral cases) with moderate to high myopia (-6.00 to -20.00 diopters [D] sphere) measured at the spectacle plane and 1.00 to 4.00 D of astigmatism. All patient treatment and follow-up occurred at the Naval Medical Center San Diego. Study follow-up was 1 day, 1 week, 1, 3, 6, and 12 months postoperative. RESULTS: Mean best spectacle-corrected visual acuity (BSCVA), change in BSCVA, proportion of cases with improvement of 1 or more lines of BSCVA, proportion of cases with BSCVA and uncorrected visual acuity (UCVA) 20/12.5 or better, proportion of cases with BSCVA and UCVA 20/16 or better (6 months, 88% vs 54%, P=.002), and predictability +/-1.00 D (6 months, 100% vs 67%, P<.001) were all significantly better in the TICL group than the PRK group at all time periods studied postoperatively. Similarly, contrast sensitivity, tested at both the 5% photopic level and the 25% mesopic level, was significantly better at all postoperative time points in the TICL group. Mean spherical equivalent refraction was closer to emmetropia (0.28+/-0.41 vs 0.76+/-0.86, P=.005), and predictability +/-0.50 D and stability of manifest refraction (+/-0.50 D and +/-1.00 D) were significantly better in the TICL group at all postoperative visits through 6 months. Mean astigmatism correction at 6 months was not significantly different between the two groups (0.52+/-0.33 vs 0.46+/-0.35, P=.450). CONCLUSIONS: The TICL performed better than PRK in all measures of safety (BSCVA), efficacy (UCVA), predictability, and stability in this comparison, supporting the TICL as a viable alternative to existing refractive surgical treatments.     

Excimer laser refractive correction of myopia after episcleral buckling for rhegmatogenous retinal detachment

PURPOSE: To evaluate the long-term effects of excimer laser treatment for ametropia after surgical treatment of rhegmatogenous retinal detachment (RRD) with scleral buckles. SETTING: Helsinki University Eye Hospital, Helsinki, Finland. METHODS: Ten patients (10 eyes) who had 1 or more surgeries for RRD followed by refractive surgery for myopia were retrospectively enrolled in this study and were examined after excimer laser refractive surgery. Photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK) was performed using a Star S2 excimer laser system (Visx). The best spectacle-corrected visual acuity (BSCVA), refraction, degree of anisometropia, and topographical changes were evaluated before and after the surgeries. RESULTS: All patients were free of asthenopic symptoms after refractive surgery. At the end of the follow-up, a mean of 67 months +/- 14 (SD) after refractive surgery, 6 patients were within +/-1.0 diopter of the intended correction. Compared with previously reported cohorts of myopic patients, the achieved refraction in patients who previously had a scleral buckling procedure was worse. The postoperative refraction was stable, and corneal topography did not show induced scar formation, keratectasia, or irregular astigmatism. After refractive surgery, the BSCVA improved 1 Snellen line in 3 patients and 2 lines in 1 patient. One patient lost 1 Snellen line and another patient lost 2 lines. Four patients showed no changes. New retinal complications were not observed. CONCLUSIONS: In the long-term, PRK and LASIK were safe methods for the treatment of myopia in RRD patients after scleral buckling. The predictability of myopic LASIK/PRK may be worse than generally reported in myopic cohorts.     

Five-year follow-up of photorefractive keratectomy for myopia

PURPOSE: To analyze long-term results of photorefractive keratectomy (PRK) for myopia and myopic astigmatism. METHODS: This retrospective study included 15 eyes of 8 patients who were examined annually for 5 years after PRK. The Nidek EC-5000 laser with an ablation zone of 5.0 mm was used. Evaluations included spherical equivalent manifest refraction, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), corneal haze, and corneal astigmatism calculated by Fourier analysis of videokeratography data. RESULTS: A tendency toward myopic regression was most evident within the first postoperative year, with manifest refraction changing from +0.80 +/- 1.62 D at 1 week to -0.45 +/- 0.70 D at 1 year postoperatively (P = .007). Regression continued after the second postoperative year. There was a statistically significant difference between manifest refraction at 2 years (-0.36 +/- 0.75 D) and 5 years (-1.11 +/- 1.12 D) (P = .002). Postoperative UCVA stabilized from 3 months up to 3 years, but slightly deteriorated at 4 years and thereafter due to the myopic refractive shift. BSCVA remained stable throughout the 5-year follow-up period. Several eyes developed mild corneal haze after surgery, but haze was minimal in the majority of patients by 1 year and continued to fade over time. The asymmetry component of the cornea significantly increased after surgery, with all postoperative values significantly higher than before PRK (P < .05). Higher order irregularity increased after surgery, with a statistically significant difference between preoperative and 1 year postoperative (P < .05), but values after 2 years were not different from preoperative baseline. CONCLUSION: Fifteen eyes with a baseline refraction of -3.00 to -9.00 D had PRK with the Nidek EC-5000 laser and a 5-mm-diameter ablation zone. Myopic regression occurred in the first year, with continued mild regression of approximately -0.75 D between 2 and 5 years. Nevertheless, the results show the procedure was relatively safe and effective in this group.     

Arcuate transverse keratotomy remains a useful adjunct to correct astigmatism in conjunction with photorefractive keratectomy

PURPOSE: To retrospectively evaluate the effectiveness of paired, arcuate transverse keratotomy (Arc-T) performed prior to or after photorefractive keratectomy (PRK) to correct low to moderate amounts of natural or laser-induced astigmatism. METHODS: Spherical PRK was performed in 730 eyes for myopia of -1.00 to -7.00 D. PRK with arcuate transverse keratotomy was performed in 150 of these eyes; we studied 123 eyes that did not have PRK enhancement. Arc-T was performed prior to PRK in all 37 study eyes with astigmatism of 1.50 D or more at the preoperative examination. Arc-T keratotomy was performed after PRK in 86 study eyes for residual astigmatism of +0.75 D or more and uncorrected visual acuity of 20/30 or worse. RESULTS: Arc-T before PRK group: PRK was performed at a mean 1.0 +/- 1.5 months after Arc-T. Mean astigmatism decreased from +2.40 +/- 0.6 D (range, 1.00 to 4.00 D) before Arc-T to 0.60 +/- 0.60 D (range, 0 to 2.25 D) after Arc-T (P < .0001). Net change in astigmatism was 1.80 +/- 0.60 D (range, 0.80 to 2.80 D) and mean reduction was 75%. Spherical equivalent refraction changed from -4.10 +/- 1.90 D (range, -0.25 to -8.10 D) to -4.40 +/- 1.80 D after Arc-T (P = .002). Mean change in spherical equivalent refraction after Arc-T was -0.30 +/- 0.50 D (range, -1.10 to +0.40 D). Arc-T after PRK group: Arc-T was performed at a mean 3.5 +/- 1.9 months after PRK. Six months after Arc-T, astigmatism was decreased from +1.50 +/- 0.60 D to 0.40 +/- 0.40 D (P = .04). Net change in astigmatism at 6 months was 1.10 +/- 0.60 D and mean reduction was 74%. Vector change in astigmatism magnitude was 1.30 +/- 0.60 D (range, 0 to 4.00 D) at 6 months and vector change in astigmatism axis was 65 degrees +/- 68 degrees. Spherical equivalent refraction did not change when Arc-T was performed after PRK for eyes with low astigmatism (P = .4). Arc-T retreatment was performed in 6 of 37 (16%) eyes that had Arc-T before PRK and 18 of 86 (21%) eyes that had Arc-T after PRK (P = .12). CONCLUSION: Arcuate transverse keratotomy performed prior to PRK for high astigmatism or after PRK for lower levels of residual astigmatism effectively improved visual outcome. Coupling was less predictable for high levels of astigmatism correction with Arc-T.     

Photorefractive keratectomy with mitomycin C after deep anterior lamellar keratoplasty for keratoconus

PURPOSE: To evaluate the safety and efficacy of photorefractive keratectomy (PRK) with intraoperative mitomycin C (MMC) after deep anterior lamellar keratoplasty (DALK) for keratoconus. METHODS: This was a prospective, noncomparative single-surgeon study. Eyes with compound myopic astigmatism after DALK with a spherical equivalent (SE) between -3 and -10 D were treated by PRK. After ablation, MMC 0.2 mg/mL was placed on the stromal bed for 45 seconds. A 6% undercorrection was planned. RESULTS: The study was completed on 10 eyes of 10 patients. The preoperative mean SE was -4.98 +/- 1.75 (SD) D. At 10 months after surgery, the mean SE was 0.28 +/- 0.61 D, and the mean defocus equivalent was 1.08 +/- 0.58 D. Postoperatively, 9 eyes were within 2 D, 6 were within 1 D, and 1 eye was within 0.5 D of defocus equivalent. The preoperative mean best spectacle-corrected visual acuity (BSCVA) was 0.68 +/- 0.15 D, and at 10 months it was 0.78 +/- 0.13 D. The 95% confidence interval for the mean difference of pre- and postoperative BSCVA was 0.02-0.17 (P < 0.05). No lines of BSCVA were lost. The mean postoperative uncorrected visual acuity was 0.55 +/- 0.1. The safety index was 1.15, and the efficacy index was 0.81. Corneal haze was grade 0 in 8 eyes and grade 0.5 in 2 eyes. Mean epithelialization time was 4.1 +/- 0.99 days. Preoperative mean endothelial cell density was 2320 +/- 184 cells/mm(2), and at 10 months it was 2284 +/- 175 cells/mm(2). CONCLUSIONS: PRK with MMC can safely and effectively correct myopia and regular myopic astigmatism after DALK. Undercorrection should be planned to compensate for the overcorrecting effect of MMC.