Intracorneal ring segment implantation for the management of keratoconus: safety and efficacy

PURPOSE: To assess the safety and efficacy of intracorneal ring segment (Intacs, Addition Technology, Inc.) implantation in the management of keratoconus. SETTING: Department of Ophthalmology and Ophthalmic Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran. METHODS: This prospective case series comprised 30 keratoconic eyes (22 patients) with a clear central cornea that had Intacs implantation. All patients were contact-lens intolerant. The main outcome measures were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refraction, keratometry, and pachymetry. Patients were examined before Intacs implantation as well as 1 week and 1, 3, and 6 months postoperatively. RESULTS: The mean age of the 5 women and 17 men was 25.9 years +/- 5.29 (SD). The mean UCVA improved from 0.60 +/- 0.311 logMAR preoperatively to 0.29 +/- 0.20 logMAR 6 months postoperatively (P<.001) and the mean BSCVA, from 0.25 +/- 0.16 logMAR to 0.13 +/- 0.14 logMAR, respectively (P<.001).The mean spherical equivalent improved from -6.93 +/- 3.52 diopters (D) preoperatively to -3.23 +/- 2.81 D at 6 months and the mean refractive cylinder, from -4.65 +/- 1.85 D to -3.90 +/- 1.70 D, respectively. The mean keratometry decreased from 49.84 +/- 3.58 D preoperatively to 47.90 +/- 3.58 D postoperatively (P<.001). Three eyes had ring exposure, and 1 eye had bacterial keratitis and ring exposure. CONCLUSION: Intacs implantation appeared to be effective in improving UCVA and BSCVA in patients with mild to moderate keratoconus and contact-lens intolerance.     

Modified intracorneal ring segment implantations (INTACS) for the management of moderate to advanced keratoconus: efficacy and complications

PURPOSE: To evaluate the safety and efficacy of modified intracorneal ring segment implantation (INTACS) in the management of moderate and advanced keratoconus (KCN). METHODS: A modified procedure of intracorneal ring segment (INTACS) implantation was performed in eyes with moderate to advanced keratoconus that were intolerant to contact lens or spectacle correction. The main outcome measures were uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), refraction, and keratometry. The preoperative values were compared with the values 6 and 12 months postoperatively. RESULTS: Implantation was performed on 20 eyes of 15 patients; 9 were female and 6 were male. The mean age was 30.2 years (SD +/- 5.44; range, 23-40). At the 6-month follow-up, UCVA improved from 20/154 (SD +/- 0.11) preoperatively to 20/28 (SD +/- 0.21) postoperatively (P < 0.05); BCSVA improved from 20/37 (SD +/- 0.21) preoperatively to 20/22 (SD +/- 0.13) postoperatively (P < 0.05). Spherical refractive error improved from -3.38 D (SD +/- 3.12) to -1.15 D (SD +/- 1.84); cylindrical refractive error improved from -3.75 (SD +/- 2.04) preoperatively to -1.21 (SD +/- 0.84) postoperatively (P < 0.05); average keratometry decreased from 49.50 D (SD +/- 1.64) preoperatively to 46.35 D (SD +/- 1.50) postoperatively. The changes remained stable to the 12-month follow-up. There was 1 case of anterior chamber perforation. There were 6 eyes that had ring exposure secondary to corneal thinning over the implants 3-6 months postoperatively, and a dense corneal infiltrate developed in 1 patient at 7 months postoperatively. CONCLUSIONS: The procedure appears to be effective in improving UCVA and BSCVA of patients with clinical keratoconus. In our small study group, however, there were significant (6/20) postoperative problems with regards to thinning and ring exposure.     

One or 2 Intacs segments for the correction of keratoconus

PURPOSE: To evaluate the effect of implanting 1 or 2 intracorneal rings (Intacs, KeraVision) as a device to correct, stabilize, and/or improve the best corrected visual acuity in patients with clear cornea keratoconus oriented by the preoperative corneal topography pattern. SETTING: Vissum/Instituto Oftalmológico de Alicante, Miguel Hernandez University, Alicante, Spain. METHODS: In this prospective comparative consecutive study, Intacs segments were implanted in 26 keratoconic eyes with clear central corneas of 19 consecutive patients (9 women and 10 men). Corneas were divided into 2 groups according to the topographic pattern of the cone. Group I included keratoconus not crossing the 180 degrees meridian and Group II included keratoconus crossing the 180 degrees meridian. The Intacs were horizontally placed through a lateral clear corneal incision. According to the corneal topography 1 segment was implanted 0.45 mm inferior in Group I, and 2 segments were implanted, 1 0.25 mm superior and the other 0.45 mm inferior, in Group II. All cases completed a minimum follow-up of 1 year. Differences between preoperative and postoperative uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, and keratometry were clinically and statistically evaluated. RESULTS: Spherical equivalent error and refractive astigmatism were significantly reduced. The mean keratometric values were reduced following Intacs insertion in both groups. At the end of the first year of the postoperative follow-up, Group I (1 segment) had an improvement in mean UCVA to 20/50 (0.4 +/- 0.22 decimal value), which was statistically significant when compared to the preoperative UCVA of 20/100 (0.2 +/- 0.13 decimal value) (P=.011). Mean BSCVA was 20/32 (0.62 +/- 0.24 decimal value), which was also statistically significant when compared to the preoperative BSCVA, which was 20/50 (0.4 +/- 0.21 decimal value) (P=.002). In Group II (2 segments), UCVA after 1 year was 20/63 (0.34 +/- 0.17 decimal value), which was statistically significant when compared to the preoperative UCVA of 20/400 (0.06 +/- 0.02 decimal value) (P=.001). Mean BSCVA was 20/32 (0.62 +/- 0.27 decimal value), which was significantly better than the preoperative UCVA of 20/50 (0.38 +/- 0.22 decimal value) (P=.001). In 4 eyes, the inferior segment was removed because of partial extrusion during the postoperative follow-up. CONCLUSIONS: Treatment of keratoconus with 1 or 2 Intacs segments oriented by the preoperative corneal topography used in this study proved to be effective in decreasing the corneal steepening and astigmatism and improving BSCVA. Further follow-up is needed to determine the final effect of Intacs on the progression of the corneal disease.     

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.     

Treating keratoconus with intacs corneal ring segments

PURPOSE: To assess the safety and efficacy of Intacs inserts for the treatment of mild to moderate keratoconus. METHODS: In a nonrandomized prospective clinical trial, 50 eyes of 37 patients with mild to moderate keratoconus were implanted with asymmetrical pairs of Intacs segments. Patients were interviewed and observed preoperatively and 24 hours, 1 week, 1, 3, 6, and 12 months postoperatively. Main outcome measures were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refraction, satisfaction with vision and trouble with vision, Visual Function-7 score, and surgically induced change in corneal astigmatism. RESULTS: Of the 50 operations performed, 92% were successful. Mean follow-up was 6.3 +/- 3.2 months. In 4 (8%) eyes, both Intacs segments were removed. In addition, 7 refractive adjustments in 7 eyes were performed successfully to improve visual and surgical outcome. Both BSCVA and UCVA improved throughout follow-up. Visual functioning index improved from 61.6 +/- 21.1 to 80.8 +/- 22.5, and the percentage of satisfaction with vision improved from 24.3% to 87.5% at 12 months. Vector analysis of astigmatism correction showed that the mean change in corneal astigmatism was 2.9 +/- 2.9 D at 6 months postoperatively. By selecting patients in whom astigmatism correction was best (index of success >0.5), an analysis was performed to determine individual factors important in successful surgery. Preoperatively these 11 (22%) eyes did not differ significantly from the remaining eyes and the only significant value was low K readings in the flat axis. CONCLUSIONS: Asymmetric Intacs placement improves BSCVA and UCVA and reduces astigmatism in patients with mild to moderate keratoconus. The procedure of Intacs placement is safe and effective. The change in astigmatism correction is unpredictable.     

Ferrara intrastromal corneal ring segments for severe keratoconus

PURPOSE: Intrastromal Ferrara ring segments were inserted in eyes with severe keratoconus to evaluate safety and efficacy of this procedure. METHODS: Intrastromal Ferrara ring segments were placed in 36 eyes of 35 patients with severe keratoconus, who were evaluated after 12 months of follow-up. All patients had highly disabling visual acuity, contact lens intolerance, and a previous indication for penetrating keratoplasty. Statistical analysis included preoperative and postoperative uncorrected visual acuity, best spectacle-corrected visual acuity, manifest refraction, anterior chamber depth, keratometry, and pachymetry. RESULTS: No patient had a loss of visual acuity. Uncorrected visual acuity improved in 28 eyes (77.78%) and best spectacle-corrected visual acuity improved in 29 eyes (80.56%). Spherical equivalent refraction decreased from -7.29 +/- 3.12 D to -4.80 +/- 3.04 D at 12 months after Ferrara intrastromal ring segment implantation. Corneal topography and ultrasound biomicroscopy showed corneal flattening, demonstrated by thinning of the central cornea and a reduction in anterior chamber depth. Segment decentration occurred in one eye (2.7%), asymmetric positioning of the segments in two eyes (5%), inadequate depth in two eyes (5%), migration of the segments in two eyes (5%), segment extrusion in five eyes (13.8%), conjunctivitis in one eye (2.7%), bacterial keratitis in one eye (2.7%), and hydrops in one eye (2.7%). CONCLUSIONS: With these early results, Ferrara intrastromal ring segments appear to be an alternative for the treatment of severe keratoconus.     

Videokeratography in conductive keratoplasty

PURPOSE: We used EyeSys videokeratography to evaluate corneal shape changes induced by conductive keratoplasty, a procedure that utilizes radio frequency energy to alter corneal shape to correct hyperopia. METHODS: Follow-up data were available for 19 eyes (out of 24 eyes of 13 patients). Preoperative spherical hyperopia ranged from +0.75 to +3.25 D with astigmatism <0.75 D. Manifest refractive spherical equivalent refraction (MRSE), uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), topographical parameter predicted corneal acuity (PCA), corneal uniformity index (CU Index), regular astigmatism, total astigmatism, average simulated keratometry (Avg Sim K), effective refractive power, and asphericity were measured preoperatively and at 6 and 12 months postoperatively. RESULTS: Twelve months postoperatively, mean PCA, CU Index, and BSCVA were maintained at preoperative levels. Mean UCVA (LogMAR) improved from 0.53+/-0.21 to 0.10+/-0.19 (P<.05) with a mean MRSE change from +1.62+/-0.76 D to -0.06+/-0.84 D (P<.05) from preoperative to 12 months postoperative. Mean asphericity increased +0.044+/-0.24 D (P>.05), mean Avg Sim K increased 1.88+/-0.72 D (P<.05), mean effective refractive power increased 1.71+/-0.79 D (P<.05), mean cylinder (cycloplegic refraction) increased 0.19+/-0.36 D (P<.05), mean regular astigmatism increased 0.25+/-0.49 D (P>.05), and mean irregular astigmatism decreased 0.01+/-0.13 D (P>.05) from preoperative to 12 months after conductive keratoplasty. CONCLUSIONS: Avg Sim K and effective refractive power changes support the refractive results; 12-month postoperative maintenance of BSCVA, PCA, and CU Index suggest the procedure is safe. Conductive keratoplasty induced a slight regular astigmatism in some eyes, which decreased with time. The increase in mean corneal asphericity indicated possible induction of central and peripheral cornea changes.     

Artisan phakic iris claw intraocular lens for high primary and secondary hyperopia

PURPOSE: To evaluate the efficacy, predictability, and safety of the Artisan iris claw phakic intraocular lens for the correction of high primary and secondary hyperopia. METHODS: Fifty-seven eyes were divided into two groups: 29 eyes had primary hyperopia (mean refraction 6.06 +/- 1.26 D, and 28 eyes had secondary hyperopia, (mean refraction 5.88 +/- 1.88 D) induced or residual following a previous corneal refractive procedure. Consecutive implantation of the Artisan iris claw phakic intraocular lens was performed. Main outcome measures recorded were BSCVA, UCVA, refraction, and astigmatic change, intraocular inflammation, and endothelial cell loss. RESULTS: Primary hyperopic group: Preoperatively, mean UCVA was 0.4 +/- 0.7 and mean BSCVA was 0.2 +/- 0.6. After implantation, mean UCVA was 0.3 +/- 0.6 and BSCVA was 0.1 +/- 0.6. Mean cycloplegic residual spherical refractive error after surgery was 0.10 +/- 0.57 D (range -1 to +2 D). Mean surgically induced astigmatism was 1.48 +/- 0.89 D. Safety index was 1.11. Efficacy index was 0.83. Secondary hyperopic group: Preoperatively, mean UCVA was 0.5 +/- 0.7 and mean BSCVA was 0.2 +/- 0.6. Postoperatively, mean UCVA was 0.4 +/- 0.7 and mean BSCVA was 0.2 +/- 0.6. Mean cycloplegic residual spherical refractive error was 0.55 +/- 1.49 D. Mean surgically induced astigmatism was 1.85 +/- 1.19 D. Safety index was 1.05. Efficacy index was 0.7. Postoperative iridocyclitis was observed in one eye (3.4%) in the primary group and in three eyes (10.7%) in the secondary group. Overall corneal endothelial cell loss at 1 year of follow-up was 9.4%. CONCLUSION: The Artisan iris claw phakic intraocular lens was reasonably safe and predictable for correcting high hyperopia.     

Intacs implantation using a femtosecond laser for management of keratoconus: Comparison of 306 cases in different stages

PURPOSE: To evaluate the efficacy of intrastromal ring segment (Intacs, Addition Technology, Inc.) implantation and analyze outcomes according to different keratoconus stages. SETTING: Kudret Eye Hospital, Ankara, Turkey. METHOD: In this retrospective noncomparative case series, 306 keratoconic eyes of 255 patients who had Intacs segment implantation were reviewed. Patients were grouped according to the Amsler-Krumeich keratoconus classification (stage II, 155 eyes; stage III, 83 eyes; stage IV, 68 eyes). The uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), central corneal curvature, spherical and cylindrical manifest refractions, and central corneal thickness were analyzed and compared according to keratoconus stage. RESULTS: At a mean follow-up of 10.39 months +/- 5.04 (SD), the BCVA improved in 71.6% of eyes and the UCVA improved in 75.7% of eyes. The mean keratometry (K) decreased from 50.7 diopters (D) to 47.9 D (P<.05); the mean manifest spherical refraction, from -6.04 D to -3.09 D (P<.05); and the mean manifest cylindrical refraction, from -4.11 D to -3.82 D (P>.05). The changes in BCVA and manifest spherical and cylindrical refractions were not statistically different between the different keratoconus stages (P >.05). There was less change in UCVA and more improvement in the mean K value after Intacs treatment in stage IV than in the other stages (P<.05, analysis of variance). CONCLUSIONS: Intacs treatment with a femtosecond laser was effective for management of keratoconus of all stages. Improvement in UCVA may be less in severe keratoconus than in moderate keratoconus.     

Ferrara intracorneal ring implantation and cataract surgery for the correction of pellucid marginal corneal degeneration

We report a case of Ferrara intracorneal ring (Mediphacos) implantation and cataract surgery for the correction of pellucid marginal corneal degeneration. Preoperatively, the patient's uncorrected visual acuity (UCVA) was 0.05 in the right eye and 0.10 in the left eye. The best spectacle-corrected visual acuity (BSCVA) was 0.50 with -2.00 -11.25 x 80 in the right eye and 0.60 with -2.00 -5.50 x 95 in the left eye. One month postoperatively, the UCVA was 0.50 in the right eye and 0.30 in the left eye. The BSCVA was 0.80 with -1.00 in the right eye and 0.60 with -0.75 -1.25 x 160 in the left eye. Ferrara intrastromal rings and cataract surgery resulted in a more regular corneal shape with a reduction in astigmatism for good visual recovery.     

Analysis of results related to good and bad outcomes of Intacs implantation for keratoconus correction

PURPOSE: To evaluate factors influencing good and poor outcomes after intracorneal ring segment implantation to correct keratoconus. SETTING: Instituto Oftalmológico de Alicante (Vissum Corporation), University of Miguel Hernandez, Alicante, Spain. METHODS: A retrospective comparative study of the visual outcome, 25 eyes of 21 patients were implanted after intracorneal ring segments (Intacs, Addition Technology) as a method to correct keratoconus. Outcomes were evaluated 6 months after implantation based on the visual results. Group A comprised 20 eyes that gained 3 lines or more of best spectacle-corrected visual acuity (BSCVA) to correct keratoconus, and Group B comprised 5 eyes that lost 1 line of BSCVA. RESULTS: In Group A, the preoperative mean BSCVA was 0.43 (20/50) and the postoperative mean BSCVA, 0.82 (20/20) (P< or =.0001). In Group B, the preoperative mean BSCVA was 0.36 (20/63) and the postoperative mean BSCVA, 0.24 (20/80) (P< or =.02). The preoperative mean sphere power was 3.90 diopters (D) greater in Group B than in Group A (P< or =.007); the mean spherical equivalent was 4.36 D greater (P< or =.007), and the mean K-reading was 6.91 D greater (P< or =.001). The postoperative reduction in spherical dioptric power was 2.11 D (P< or =.027) and the mean spherical equivalent, 2.81 D (P< or =.003), significant only in Group A. The reduction in mean central K-readings was 4.30 D (P< or =.0001) in Group A and 6.19 D (P< or =.014) in Group B. The correlation of the preoperative mean K value to the postoperative BSCVA was significant at the .01 level by the Pearson test (-0.67). In Group A, all eyes (100%) had a mean K-reading < or =53 D. In Group B, 4 eyes (80%) had a mean K-reading > or =55 D. CONCLUSION: Intacs provided better results in visual acuity and corneal topography quality and significantly reduced the spherical equivalent in eyes with keratoconus with relatively low mean K values (< or =53 D) and a relatively low spherical equivalent. In advanced keratoconus (mean K-reading > or =55 D), poor results can be anticipated.     

Evaluation of anterior and posterior surfaces of the cornea using a dual Scheimpflug analyzer in keratoconus patients implanted with intrastromal corneal ring segments

AIM: To evaluate corneal parameters measured with a dual Scheimpflug analyzer in keratoconus patients implanted with intrastromal corneal ring segments (ICRS). METHODS: Fifty eyes of 40 keratoconus patients had Ferrara ICRS implantation from November 2010 to April 2014. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), refraction, keratometry, asphericity, elevation, pachymetry, root mean square (RMS), spherical aberration and coma were studied. All patients were evaluated using a dual Scheimpflug system. RESULTS: The mean follow-up time after the procedure was 12.7mo. The mean UCVA improved from 0.82 to 0.31 (P<0.001); the mean BCVA improved from 0.42 to 0.05 (P<0.0001), the mean spherical refraction changed from -3.06±3.80 D to -0.80±2.5 D (P<0.0001) and the mean refraction astigmatism reduced from -4.51±2.08 D to -2.26±1.18 D (P<0.0001). The changes from preoperative to postoperative, in parameters of the anterior and posterior surface of the cornea, were statistically significant except the elevation posterior at the apex of the cornea and posterior asphericity. CONCLUSION: The implantation of Ferrara ICRS induces changes in both anterior and posterior surfaces of the cornea.     

Intacs for keratoconus and post-LASIK ectasia: mechanical versus femtosecond laser-assisted channel creation

PURPOSE: To evaluate the efficacy of intracorneal ring segments to treat keratoconus and post-laser in situ keratomileusis (LASIK) keratectasia implanted by using either mechanical dissection or a femtosecond laser. METHODS: Thirty-three eyes of 29 patients had intracorneal ring segments implanted by using mechanical dissection (17 eyes) or a femtosecond laser (16 eyes). Mean follow-up was 10.3 months. Parameters assessed before and after surgery included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refractive spherical equivalent (MRSE), refractive cylinder (RC), best contact lens-corrected visual acuity (BCLVA), and contact lens tolerance. RESULTS: Statistically significant changes occurred for all parameters when we analyzed all 33 eyes as 1 group. Mean UCVA LogMar values improved from 1.0 +/- 0.3 (20/200) to 0.6 +/- 0.4 (20/80) (P < 0.0005). Mean BSCVA changed from 0.3 +/- 0.2 (20/40) to 0.2 +/- 0.2 (20/30) (10%; P < 0.05), and MRSE from -9 +/- 4 to -7 +/- 4 D (P < 0.05; 20%). There was a decrease of 0.5 D or more of RC in 62% of eyes. BCLVA improved from 0.2 +/- 0.2 (20/30) to 0.1 +/- 0.1 (20/25) after surgery (P < 0.02). Contact lens tolerance improved in 81% of eyes. There was no statistically significant difference in outcomes between mechanical dissection and femtosecond laser-assisted techniques. However, although statistical power was adequate to detect changes in clinical parameters as a result of surgery, it was not sufficient to conclusively show such differences between surgical techniques. CONCLUSIONS: For mild to moderate cases of keratoconus and post-LASIK keratectasia, the use of a femtosecond laser for Intacs channel creation seems as effective as mechanical dissection. Future studies are warranted to further evaluate channel creation by a femtosecond laser.     

One-year results of intrastromal corneal ring segment implantation (KeraRing) using femtosecond laser in patients with keratoconus

PURPOSE: To report the results of intrastromal corneal ring segment [ICRS] (KeraRing; Mediphacos, Belo Horizonte, Brazil) implantation using a femtosecond laser (IntraLase Corp, Irvine, California, USA) in keratoconic patients. DESIGN: Retrospective, noncomparative, interventional study. METHODS: Thirty-two keratoconic patients (50 eyes) who underwent ICRS insertion using a femtosecond laser for channel creation and completed at least one year of follow-up were included in this study. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refraction, topographic findings, and adverse events were assessed. RESULTS: No intraoperative complications were demonstrated in this series of patients. At the first postoperative day, segment migration to the incision site was seen in three eyes (6%; early postoperative complication). To avoid melting, we repositioned the migrated segment away from the incision site. Serious second migration was not seen and we did not need to reposition any segment again. At the last postoperative examination, there was a statistically significant reduction in the spherical equivalent refractive error compared with that observed at the examination before implantation (mean +/- standard deviation, -5.62 +/- 4.15 diopters [D; range, -23.62 to 0.50 D] to -2.49 +/- 2.68 D [range, -11.12 to 3.5 D]; P < .001). The UCVA before implantation was 20/40 or worse in 47 eyes (94%; range, counting fingers to 20/30), whereas at the last follow-up examination, 14 (28%) of 50 eyes had a UCVA of 20/40 or better (range, counting fingers to 20/25). Nine eyes (18%) maintained the preimplantation BSCVA, whereas 39 eyes (68%) experienced a BSCVA gain of one to four lines at the last follow-up examination. Only in two eyes (4%; two patients) with advanced keratoconus (stage III) was there a decrease of up to two lines. Despite this deterioration in BSCVA, the patients did not want to remove the ICRSs, because there was an increase of UCVA. No late postoperative complications were observed during the follow-up period. CONCLUSIONS: ICRS (KeraRing) implantation using femtosecond laser for tunnel creation is a minimally invasive procedure for improving visual acuity (both UCVA and BSCVA) in keratoconic patients.     

Limbal relaxing incisions to correct corneal astigmatism during phacoemulsification

PURPOSE: To evaluate the safety and efficacy of limbal relaxing incisions for the correction of corneal astigmatism during phacoemulsification. METHODS: Fifty eyes of 37 patients (mean age 66.5 years, range: 45 to 80 years) with cataract and coexisting topographic astigmatism were included in the study. Eyes were randomly divided into two groups: eyes that underwent cataract surgery with limbal relaxing incisions (cataract LRI group) and eyes that underwent cataract surgery only (control group). All limbal relaxing incisions were performed during phacoemulsification. Best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity (UCVA), and corneal topography were recorded preoperatively and 1, 3, and 6 months postoperatively. RESULTS: A statistically significant improvement in BSCVA was seen in the cataract LRI eyes from 0.9 +/- 0.7 preoperatively to 0.1 +/- 0.1 at 1, 3, and 6 months postoperatively (P < .01). A statistically significant improvement in BSCVA was seen in control eyes from 0.8 +/- 0.6 before surgery to 0.2 +/- 0.2 at 1, 3, and 6 months after surgery (P < .01). No difference in postoperative BSCVA was noted between the groups. A statistically significant reduction in the mean topographic astigmatism was seen in the cataract LRI eyes from 1.93 +/- 0.58 diopters (D) preoperatively to 1.02 +/- 0.60 D 6 months postoperatively (P < .05). The control eyes did not show a statistically significant change in topographic astigmatism. CONCLUSIONS: Limbal relaxing incisions performed during phacoemulsification surgery appear to be a safe, effective, and stable procedure to reduce pre-existing corneal astigmatism.     

Short-term results of penetrating keratoplasty performed with the Femtec femtosecond laser

PURPOSE: To evaluate the use of the Femtec femtosecond (fs) laser for penetrating keratoplasty (PK) in the treatment of corneal diseases. DESIGN: Prospective, nonrandomized clinical study. METHODS: Nine eyes of nine patients underwent surgery for PK. Five had pseudophakic bullous keratopathy, three had Fuchs dystrophy, and one presented in a keratoconus patient. A Femtec (20/10 PerfectVision; GmbH, Heidelberg, Germany) fs laser was used to create penetrating cuts on donor and recipient corneas. All patients were evaluated for uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), pachymetry, topography, and endothelial cell density (ECD). Scanning electron microscopy (SEM) was performed on corneal tissue after surgery. RESULTS: All eyes were treated successfully without intraoperative complications. The mean follow-up was 6 +/- 3 months. At the last postoperative examination mean BSCVA was 20/69 and there was a significant improvement (P = .08) in both UCVA and BSCVA. Mean astigmatism was 2.9 +/- 1.2 diopters. Mean ECD was 1194 +/- 465 cells/mm(2) with a mean cell loss after surgery of 49.8% +/- 19.8%. SEM displayed smooth rectilinear cut margins and minor remaining tissue bridges. One patient presented a retinal detachment three months after surgery that was successfully treated and two subjects showed an allograft rejection. CONCLUSION: Use of the Femtec fs laser was effective and safe to perform PK. Short-term visual results and refractive results are analogous to conventional PK or other fs laser-assisted PK studies. Longer-term follow-up of additional cases is necessary to precisely quantify the endothelial cell loss after fs surgery.     

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.     

Limbal relaxing incisions for primary mixed astigmatism and mixed astigmatism after cataract surgery

PURPOSE: To evaluate the effect of limbal relaxing incisions (LRIs) in the treatment of primary mixed astigmatism and mixed astigmatism after cataract surgery. SETTING: Department of Ophthalmology, In?nü University, Malatya, Turkey. METHODS: Limbal relaxing incisions were performed to correct astigmatism in 37 eyes of 26 patients with mixed astigmatism. Twenty-four eyes had primary astigmatism, and 13 eyes had astigmatism after cataract surgery. The length, number, and depth of the incisions were determined using the Gills and Gayton nomogram. The manifest refractive astigmatism was measured preoperatively and 1 day, 1 week, and 1, 3, 6, and 12 months postoperatively. Surgically induced astigmatism using the vector method, preoperative and postoperative uncorrected visual acuity (UCVA), and best spectacle-corrected visual acuity (BSCVA) were evaluated. Follow-up was at least 6 months in all cases. RESULTS: The mean preoperative and postoperative refractive astigmatism was 3.31 diopters (D) +/- 1.50 (SD) and 1.59 +/- 1.28 D, respectively (P <.001). The mean absolute change in refractive astigmatism was 1.72 +/- 0.81 D. No patient lost lines of UCVA or BSCVA. The safety index was 1.21 and the efficacy index, 0.88. The mean preoperative and postoperative UCVA was 0.29 +/- 0.22 and 0.54 +/- 0.31, respectively (P =.0001) and the mean BSCVA, 0.61 +/- 0.30 and 0.74 +/- 0.30, respectively (P =.0001). The mean vectorial magnitude was 2.32 +/- 1.36 D at the last follow-up. There were no serious postoperative complications. CONCLUSION: Limbal relaxing incisions are a simple, safe, and effective method to correct primary mixed astigmatism and mixed astigmatism after cataract surgery.