Wavefront-guided laser in situ keratomileusis retreatment for consecutive hyperopia and compound hyperopic astigmatism

PURPOSE: To evaluate the efficacy, predictability, and safety of wavefront-guided laser in situ keratomileusis (LASIK) using the Visx CustomVue excimer laser (Advanced Medical Optics) in eyes with consecutive hyperopia and compound hyperopic astigmatism after LASIK. SETTING: Stanford University School of Medicine, Department of Ophthalmology, Stanford, California, USA. METHODS: This retrospective analysis included 19 eyes of 16 patients who had wavefront-guided LASIK for consecutive hyperopia and compound hyperopic astigmatism after initial LASIK surgery. Primary outcome variables, including uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), higher-order aberration (HOA) analysis, and spherical equivalence, were evaluated at 1 and 3 months. Nine eyes of 7 patients were available for all visits. RESULTS: The mean patient age was 51.7 years +/- 3.77 (SD) (range 44 to 55 years). The mean preoperative manifest refractive spherical equivalent (MRSE) was 0.99 +/- 0.32 diopters (D) (range 0.50 to 1.50 D) and the mean 3-month postoperative MRSE, -0.04 +/- 0.66 D (range -1.50 to 0.75 D). At 1 month, 57.9% of eyes had a UCVA of 20/20 or better and 78.9% of 20/25 or better; 84.2% were within +/-1.00 D of emmetropia. At 3 months, 66.7% of eyes had a UCVA of 20/20 or better and 88.9% of 20/25 or better; 88.9% were within +/-1.00 D of emmetropia. No eye lost 2 or more lines of BSCVA at 1 or 3 months. CONCLUSION: Wavefront-guided LASIK was an effective, predictable, and safe procedure for consecutive hyperopia and compound hyperopic astigmatism after LASIK.     

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.     

Effect of pterygium surgery on corneal topography

PURPOSE: To evaluate the effect of successful pterygium surgery on corneal topography. METHODS: Computerized corneal topography was performed on 20 eyes with pterygium before and 3 months after successful excision and limbo-conjunctival autograft surgery. Corneal shape, corneal spherical power, simulated keratometric astigmatism, surface regularity index (SRI), and surface asymmetry index (SAI) were assessed before and after surgery. Pre- and postoperative uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and manifest refraction spherical equivalent (MRSE) were also evaluated. RESULTS: Changes in corneal shape were mainly a decrease in midline corneal flattening. Corneal spherical power was 41.65+/-3.29 diopters (D) (mean +/- SD) preoperatively and 44.58+/-1.55 D postoperatively (p=0.04). Simulated keratometric astigmatism was 5.47+/-3.45 D preoperatively and 1.79+/-1.52 D postoperatively (p=0.0005). SRI was 1.39+/-0.93 preoperatively and 1.10+/-0.57 postoperatively (p=0.03). SAI was 1.17+/-1.09 preoperatively and 0.75+/-0.73 postoperatively (p=0.02). UCVA was 0.31+/-0.33 preoperatively and 0.52+/-0.32 postoperatively (p=0.04). BSCVA was 0.73+/-0.20 preoperatively and 0.89+/-0.16 postoperatively (p=0.008). MRSE was -0.54+/-3.29 D preoperatively and -1.30+/-3.05 D postoperatively (p=0.45). CONCLUSIONS: Corneal topographic changes caused by the pterygium are almost reversible after surgical treatment. Successful pterygium surgery significantly reduces topographic astigmatism, SRI, SAI, and corneal flattening. However, precise prediction of these refractive changes is not always accurate.     

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.     

Late changes in refraction, pachymetry, visual acuity, and corneal topography after penetrating keratoplasty

PURPOSE: To analyze the late changes in refraction, corneal topography, and pachymetry after penetrating keratoplasty. METHODS: We have retrospectively analyzed data of 64 eyes of 56 patients with a clear corneal graft and no other ocular diseases. The eyes were examined soon and several years after all sutures were removed, at 19.5 +/- 3.1 months and 76.8 +/- 25.2 months, respectively, after keratoplasty. All eyes were examined using the EyeSys 2000 videokeratograph and the Tomey SP2000 ultrasonic pachymeter. Corneal surface regularity was studied using the indices provided by the Holladay Diagnostic Summary (ie, asphericity coefficient Q; corneal uniformity index CU; predicted corneal acuity PCA). Irregular astigmatism was quantified using semimeridian data from videokeratographs (refractive power symmetry index). RESULTS: Visual acuity increased by an average of 0.35 +/- 0.93 lines (P = 0.002) between the 2 examinations, whereas no significant changes in refraction and videokeratoscopy (ie, power, indices, and irregular astigmatism) were observed (P > or = 0.08). Central corneal thickness significantly increased from 542 +/- 31 microm to 572 +/- 38 microm (P < 0.001). Change in BSCVA did not significantly correlate with the change in refraction, in topographic indices, or in irregular astigmatism (rs < or = 0.13; P > or = 0.16). CONCLUSION: Late after penetrating keratoplasty, best corrected visual acuity shows a small but statistically significant improvement, whereas refraction and corneal surface regularity are stable. This late improvement in visual acuity is not explained by current techniques.     

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.     

Hyperopic laser in situ keratomileusis in eyes with previous radial keratotomy

PURPOSE: To assess the safety and efficacy of hyperopic laser in situ keratomileusis (LASIK) in eyes with previous radial keratotomy (RK). SETTING: Zale Lipshy University Hospital Laser Center for Vision, University of Texas Southwestern Medical Center, Dallas, Texas, USA. METHODS: Thirty-eight eyes of 25 patients were treated with LASIK for secondary hyperopia after RK using a Visx Star S2, S3, S4, or LADARVision excimer laser. Retreatment was done in 7 eyes. The main outcome measures were manifest refraction spherical equivalent (MRSE), uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), predictability of treatment, and complications. RESULTS: Preoperative mean MRSE was +2.39 diopters (D) +/- 1.28 (SD) (range +0.87 to +6.00 D). At the last visit (25 eyes with minimum follow-up of 12 months, including retreatments), the mean follow-up was 23.3 +/- 7.3 months (range 12 to 34 months), the mean MRSE was +0.11 +/- 0.71 D, and the UCVA was 20/40 or better in 24 eyes (96%). Although no significant change in the mean MRSE was observed, the postoperative mean refractive cylinder showed a gradual increase over the follow-up period. No eye lost more than 2 lines of BSCVA. CONCLUSIONS: Laser in situ keratomileusis was a safe and effective treatment with good predictability for the correction of consecutive hyperopia after RK. Cylindrical errors were difficult to correct, and astigmatic correction tended to regress over time. Retreatments are safe when old flaps were relifted.     

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.     

Topography-guided custom retreatments in 27 symptomatic eyes

PURPOSE: To evaluate the use of topography-guided ablations for refractive irregularities induced by previous surgery. METHODS: This prospective, non-comparative trial comprised 27 symptomatic eyes with a history of LASIK for myopia that underwent topography-guided treatment with the ALLEGRETTO WAVE system. Pre- and postoperative refraction, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), corneal asphericity (Q value), low contrast sensitivity, and patient's subjective assessment of improvement were measured. RESULTS: Preoperative data were sphere -0.84 +/- 1.37 diopters (D), cylinder -1.55 +/- 0.78 D, UCVA 20/49 +/- 0.22, BSCVA 20/32 +/- 0.15, and Q value 1.46 +/- 0.79. Postoperative data at mean 6-month follow-up were: sphere -0.61 +/- 0.81 D, cylinder -0.53 +/- 0.58 D, UCVA 20/25 +/- 0.21 (P < .01), BSCVA 20/21 +/- 0.14 (P < .001), and Q value 1.07 +/- 0.89. Contrast sensitivity scores improved by 70%. No loss of BSCVA occurred in any patient. CONCLUSIONS: Topography-guided treatments may be effective in correcting the quality of vision. It should be viewed as a possible two-step procedure due to spherical adjustment that may change refraction unpredictably.     

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.     

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.     

Laser intrastromal keratoplasty--case report

PURPOSE: To evaluate the feasibility of correcting high hyperopia by means of intrastromal implantation of a laser shaped corneal lenticule prepared from a human donor eye. METHODS: A female patient with high hyperopia and irregular astigmatism resulting from multiple laser in situ keratomileusis procedures and lamellar keratoplasty underwent laser intrastromal keratoplasty. Her preoperative uncorrected visual acuity (UCVA) was 20/300 and best spectacle-corrected visual acuity (BSCVA) was 20/100 with a refraction of +8.00 -1.00 x 130 degrees. Corneal topography showed a highly irregular corneal surface. Central corneal thickness was 398 microm. Lenticule preparation included mechanical de-epithelialization of a human donor eye, keratectomy with a microkeratome, user-designed software combining a photorefractive keratectomy (PRK) treatment for +8.00 D sphere, an ablation zone of 7.0 mm, and a circumferential cut (internal diameter of 6.5 mm) for tissue ablation. Implantation involved re-lifting the flap, positioning the lenticule onto the corneal bed, and repositioning of the flap. RESULTS: The operation was uneventful as was the early postoperative follow-up. BSCVA improved to 20/50 with +1.00 -2.25 x 120 degrees at 2 months postoperatively. Corneal topography showed a more regular cornea with increased curvature in all meridians. Central corneal thickness increased to 600 microm. CONCLUSION: Laser intrastroma keratoplasty may be an option for correcting high hyperopa and irregular astigmatism in eyes with a thin corneal bed.     

Prospective, paired comparison of laser in situ keratomileusis and laser epithelial keratomileusis for myopia less than -6.00 diopters

PURPOSE: To compare visual and refractive results, contrast sensitivity, and tear stability after laser in situ keratomileusis (LASIK) in one eye and laser epithelial keratomileusis (LASEK) in the fellow eye for low myopia. METHODS: Patients diagnosed with low myopia, with a maximum difference of 1 D between their two eyes, were randomly assigned to receive LASEK on one eye and LASIK on the other eye. A total of 64 eyes of 32 patients with a mean age of 26.83 +/- 5.33 years were included in the study. Preoperative myopia ranged from -1.00 to -6.00 D. Follow-up was 6 to 12 months. Uncorrected (UCVA) and best spectacle-corrected visual acuity (BSCVA), Schirmer test results, tear break-up time, corneal asphericity, corneal uniformity index, predicted corneal acuity, and contrast sensitivity values were compared with preoperative values. A Wilcoxon test was used for statistical comparisons and a P-value less than .05 was considered significant. RESULTS: At 6 months after surgery, there was no statistically significant difference in UCVA, BSCVA, spherical and cylindrical refractive error, Schirmer test, or tear break-up time between groups. Contrast sensitivity values in the LASIK eyes were lower in comparison to preoperative values, but there was no change in the LASEK group. CONCLUSIONS: Based on 6-month results, LASEK for low myopia was safe and effective with predictable results, offered early refractive stability, and may be considered an alternative for LASIK.     

Toric phakic intraocular lens for the correction of hyperopia and astigmatism

PURPOSE: To evaluate the Artisan toric phakic intraocular lens (pIOL) for the correction of hyperopia and astigmatism. SETTING: Department of Ophthalmology, Erasmus MC, Rotterdam, The Netherlands, and Department of Ophthalmology, Sint Truiden, Belgium. METHODS: In this prospective study of 47 eyes of 28 patients with hyperopia and astigmatism, Artisan toric pIOLs were implanted between April 1999 and June 2004. Uncorrected visual acuity (UCVA), best corrected visual acuity, refraction, astigmatism, safety, and predictability were analyzed. Change in astigmatism was analyzed with vector analysis. Refractive cylinders are expressed in minus form. RESULTS: Mean preoperative spherical equivalent was +4.33 diopters (D) +/- 2.26 (SD). Mean follow-up was 11.1 months (range 6 to 36 months). A gain of 1 or more lines in best spectacle-corrected visual acuity (BSCVA) was seen in 36.2%. Safety index and efficacy index after 6 months were 1.06 and 0.87, respectively. The mean postoperative astigmatism at 6 months was 0.19 D at an axis of 144 degrees. At 6 months, about three quarters (76.6%) of the eyes had a UCVA of 20/40 or better. One eye lost 2 lines of BSCVA. In 1 eye, the lens position had to be changed because of a large axis misalignment. No serious complications developed in any of the treated eyes during follow-up. CONCLUSIONS: Artisan toric pIOLs can correct moderate to high hyperopia combined with astigmatism with good refractive results. In this study, there were no serious complications. However, the predictability of the refractive results appeared to be lower than those in the correction of myopia and astigmatism with toric Artisan lenses.     

Mechanized astigmatic arcuate keratotomy with the Hanna arcitome for astigmatism after keratoplasty

PURPOSE: To report the results of correction of post-keratoplasty astigmatism by arcuate keratotomy performed with the Hanna arcitome (Moria). SETTING: Service 5, H?pital des 15-20, Paris VI University, Paris, France. METHODS: Forty eyes operated on for post-keratoplasty astigmatism using the Hanna arcitome were retrospectively studied. Paired symmetrical arcuate keratotomies were performed on the graft button. Mean follow-up was 10.8 months +/- 11.2 (SD). Outcome measures included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and subjective refraction. For statistical analysis, visual acuity data were transformed into logMAR units. The refractive data were analyzed using the Alpins method. RESULTS: By a mean of 10.8 +/- 11.2 months after surgery, the UCVA had improved a mean of 0.28 +/- 0.46 lines, which was significant (P = .013). The BSCVA remained stable. The mean subjective cylinder was 8.84 +/- 3.00 diopters (D) preoperatively and 4.88 +/- 2.50 D postoperatively (P<.001). The changes in postoperative subjective cylinder values correlated with preoperative cylinder values (r(s) = 0.584; P<.0001). The subjective axis was modified by 20 degrees or less in 27 eyes (67.5%). The mean surgically induced astigmatism was 8.07 +/- 3.83 D and the mean correction index, 0.96 +/- 0.46. One microperforation occurred and required suturing. Incisions were off center in 1 case, and 2 patients had an allograft rejection after the procedure. CONCLUSIONS: Arcuate keratotomy performed with the Hanna arcitome was effective in reducing post-keratoplasty astigmatism. The device enabled safer, easier arcuate incisions than with manual techniques. However, predictability and efficacy could be improved by a more accurate nomogram.     

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.     

Conductive keratoplasty for the correction of residual hyperopia after LASIK

PURPOSE: To report the 6-month results concerning efficacy, safety, predictability, and stability of conductive keratoplasty for the correction of residual hyperopia after corneal refractive surgery. METHODS: A total of 35 eyes (26 patients) with residual hyperopia after corneal refractive surgery ranging between +1.00 to +4.75 diopters (D) of spherical equivalent refraction were enrolled in the study and underwent conductive keratoplasty following a modified nomogram. RESULTS: Variables and data were available for all eyes at 6 months postoperatively. A total of 24 (69%) eyes had uncorrected visual acuity (UCVA) of > or = 20/40, and 10 (29%) eyes had UCVA of 20/20. Manifest refractive spherical equivalent was within +/- 0.50 D in 17 (49%) eyes and within +/- 1.00 D in 25 (71%) eyes in cases of previous hyperopic LASIK; the optical zone was significantly increased. CONCLUSIONS: Using a modified nomogram, conductive keratoplasty for correction of residual hyperopia was effective, but predictability was not satisfactory and safety needs to be established.     

Excimer laser retreatment of residual myopia following photoastigmatic refractive keratectomy for compound myopic astigmatism

PURPOSE: To prospectively evaluate the safety, efficacy, and visual performance of excimer laser enhancement following photoastigmatic refractive keratectomy (PARK) with the Summit Apex Plus. SETTING: Stanford University School of Medicine Eye Laser Clinic, Stanford, California, USA. METHODS: As part of a Food and Drug Administration clinical trial, 93 eyes of 56 patients with a mean spherical equivalent (SE) of -4.98 diopters (D) +/- 1.80 (SD) (range -1.75 to -8.50 D) had PARK for compound myopic astigmatism using the Summit Apex Plus excimer laser and a poly(methyl methacrylate) erodible mask. Seventeen eyes with a mean SE of -2.08 +/- 0.76 D required excimer laser refractive keratectomy for residual spherical myopia or compound myopic astigmatism. Patients were prospectively followed 1, 3, 6, 9, and 12+ months after the enhancement procedure. Primary outcome variables included uncorrected visual acuity (UCVA), refraction, vector analysis, best spectacle-corrected visual acuity (BSCVA) under standard ambient conditions (photopic, scotopic, and glare), corneal clarity, and contrast sensitivity function curve under photopic and scotopic conditions. RESULTS: At the last postoperative visit, the mean sphere had been corrected 82% to a residual of -0.29 +/- 1.23 D and mean SE had been corrected 65% to a residual of -0.74 +/- 1.27 D. Eighty-two percent of eyes were within +/-1.0 D of attempted correction. Eighty-eight percent had a UCVA of 20/40 or better. Vector analysis demonstrated a difference vector of within +/-1.0 D in 75% of eyes that had PARK retreatment. There was no significant loss in the contrast sensitivity curve. Late regression associated with corneal haze and loss of BSCVA occurred in 2 eyes (11.7%). CONCLUSIONS: Retreatment following PARK for compound myopic astigmatism results in effective reduction in residual spherical myopia and compound myopic astigmatism. An improvement in UCVA without loss of contrast sensitivity can be expected in most eyes. However, regression, corneal haze, and loss of BSCVA may occur. Further studies are indicated to predict risk factors for these complications.     

Laser in situ keratomileusis for hyperopia with the LADARVision 4000 with centration on the coaxially sighted corneal light reflex

PURPOSE: To analyze the visual acuity, contrast sensitivity, and target deviations in patients who had laser in situ keratomileusis (LASIK) for primary hyperopia with the ablation centered on the coaxially sighted corneal light reflex. SETTING: University-based refractive surgery practice. METHODS: Retrospective review comprised 37 consecutive patients (61 eyes) who had LASIK for hyperopia with the LADARVision 4000 excimer laser (Alcon Laboratories). Preoperative and 3-month postoperative visual acuity and contrast sensitivity, as well as the target deviation, were assessed for each eye. The change in best spectacle-corrected visual acuity (BSCVA), best spectacle-corrected contrast sensitivity (BSCCS), and target deviation from the intended correction were analyzed. RESULTS: Postoperatively, the uncorrected visual acuity (UCVA) was 20/20 or better in 44.4% of eyes. The mean deviation from target was +0.25 diopter (D) +/- 0.82 (SD), with 65.6% of eyes within +/-0.50 D of target. None eye lost 2 or more lines of BSCVA. A loss of 3 or more patches of BSCCS were seen in 6.6% of the eyes and a loss of 4 or more patches, in 1.6%. CONCLUSION: Hyperopic LASIK with LADARVision 4000 with the ablation zone centered on the coaxially sighted corneal light reflex did not adversely affect BSCVA and BSCCS.