Pascual Claramonte

Laser in situ keratomileusis to correct high myopia

Purpose: To evaluate the effectiveness, predictability, and safety of laser in situ keratomileusis (LASIK) in 143 eyes with myopia from 8.00 to 20.00 diopters (D). Setting: Alicante Institute of Ophthalmology, University of Alicante School of Medicine, Alicante, Spain. Methods: This prospective study comprised 143 eyes (94 patients) that had LASIK with the Chiron Automated Corneal Shaper and the VISX 20/20 excimer laser using a multizone profile and a sutureless hinged corneal flap technique. Results: Uncorrected visual acuity was 20/40 or better in 45.0% of eyes 3 months postoperatively and in 46.4% at 6 months. Best corrected visual acuity (BCVA) improved by 0.07 at 3 and 6 months and was stable after 3 months. Mean spherical equivalent was ‐13.19 diopters (D) ± 2.89 (SD) preoperatively and +0.51 ± 1.63 D at 3 months and +0.18 ± 1.66 D at 6 months postoperatively. At 3 months, spherical equivalent was within 1.00 D of emmetropia in 57.5% of all eyes, 71.0% of eyes with a baseline refraction from ‐8.00 to ‐11.99 D (n = 59), 44.4% with a baseline refraction from ‐12.00 to ‐15.99 D (n = 54), and 53.0% of eyes with a baseline refraction from ‐16.00 to ‐20.00 D (n = 30). The respective 6 month percentages were 60.0, 72.4, 46.0, and 50.0%. The regression of effect was similar in all groups (approximately 0.50 D) between 1 and 3 months, although the high myopia group had further regression. Significant corneal steepening and an increase in corneal thickness occurred between 1 and 3 months. Flap thickness was always less than predicted with both the 130 and 160 &mgr;m plates, and achieved laser ablation was deeper than programmed. The relationships between postoperative refraction and preoperative keratometry and postoperative refraction and the difference in achieved versus programmed ablation were significant. Complications at 6 months included epithelial ingrowth, corneal flap melting, decentered ablation, and irregular astigmatism with loss of BCVA, although none was vision threatening. Conclusion: In this study, LASIK was effective and predictable in the correction of high myopia but was more accurate for myopia up to 12.00 D. Current surgical algorithms must be modified to improve predictability in higher corrections. Longer follow‐up is necessary to evaluate long‐term incidence of vision‐threatening complications.

Near vision restoration with refractive lens exchange and pseudoaccommodating and multifocal refractive and diffractive intraocular lenses: Comparative clinical study

Purpose: To evaluate near visual performance after implantation of a pseudoaccommodating intraocular lens (IOL) (Crystalens® AT‐45, eyeonics) or a multifocal IOL (refractive model, AMO Array®; diffractive model, AcriTec TwinSet) after lens surgery. Settings: Instituto Oftalmológico de Alicante, Miguel Hernandez University, Alicante, Spain. Methods: Forty patients were included in this prospective clinical comparative study. The patients were divided into 3 groups according to the type of IOL implanted. Group 1 included 24 eyes (12 patients) implanted with the Crystalens IOL; Group 2, 32 eyes (16 patients) with the Array IOL, and Group 3, 24 eyes (12 patients) with the TwinSet IOL. Bilateral phacoemulsification and IOL implantation were performed in all patients, and the follow‐up was 1 year. The postoperative main visual outcome evaluations were uncorrected and best corrected distance and near visual acuities, mean add for near, and best distance‐corrected near acuity. Results: In Group 1, the mean uncorrected near acuity was 20/40 preoperatively and 20/25 after 1 year. The mean preoperative best distance‐corrected near acuity was 20/32 and 20/25 after 1 year. In Group 2, the mean uncorrected near acuity was 20/40 and 20/25, respectively. The mean preoperative best distance‐corrected near acuity was 20/32 and 20/25 after 1 year. In Group 3, the mean uncorrected near acuity was 20/63 preoperatively; after 1 year, it was approximately 20/25. The mean best distance‐corrected near acuity was 20/50 and 20/25, respectively. A neodymium:YAG laser capsulotomy was performed for posterior capsule opacification when required, with no change in the refractive outcome. Conclusions: Implantation of multifocal and pseudoaccommodating IOLs provides adequate near vision restoration. The TwinSet IOL provided faster recovery of near vision than the other 2 IOLs. The Crystalens IOL provided less postoperative visual phenomena with favorable near vision. The Array IOL achieved the most comfortable distance and near vision.

Complications of photorefractive keratectomy for myopia: two year follow-up of 3000 cases.

Purpose: To evaluate the results and complications of photorefractive keratectomy (PRK) for myopia. Setting: Alicante Institute of Ophthalmology, University of Alicante, Spain. Methods: This prospective study evaluated the results and complications of the first 3000 cases of PRK performed with a VISX Twenty‐Twenty excimer laser. Myopia ranged from −1.0 to −14.0 diopters (D) and astigmatism, from −1.0 to −5.0 D. Follow‐up was 2 years. Results: Ten eyes (0.7%) lost two or more lines of best corrected visual acuity 1 year after surgery. Retreatment for undercorrection or regression was done in 7.41% in the low myopia group and 38.69% in the high myopia group. Central islands, which could be detected only on videokeratoscopy, occurred frequently but influenced the refractive and visual outcomes in few cases. Severe haze was present in 17 eyes only after 1 year follow‐up. There were no cases of progressive hyperopia. Other complications such as eccentric ablation producing astigmatism (n = 15), delayed re‐epithelialization, or recurrent corneal erosion were rare. Conclusion: There were few complications after PRK in 3000 eyes. With proper patient selection, PRK can be considered relatively safe compared with other refractive orocedures.

Relationship between anterior chamber depth, refractive state, corneal diameter, and axial length.

PURPOSE Phakic intraocular lenses are being used increasingly to correct refractive errors. We studied the relationship between anterior chamber depth, refractive state of the eye, spherical equivalent refraction, axial length of the globe, corneal diameter, and keratometry. METHODS Two hundred eleven eyes of 211 patients were enrolled. All eyes underwent the same protocol with a complete ocular examination that included slit-lamp microscopy, intraocular pressure, objective and subjective refraction, calculation of the spherical equivalent refraction, corneal pachymetry, anterior chamber depth, axial length of the globe, and keratometry. All results were analyzed statistically using SPSS statistics software. Correlations between different parameters were studied using the Pearson correlation test. RESULTS The anterior chamber depth was found to correlate significantly with both the average corneal diameter and the axial length of the globe (0.744, 0.531, P < .01) and was also found to correlate through an inverse relation with both age and spherical equivalent refraction (-0.391, -0.623, P < .01). Corneal thickness and keratometric power did not correlate with the anterior chamber depth. CONCLUSION Most parameters (axial length, corneal diameter, spherical equivalent refraction, patient age) affected anterior chamber depth and should be considered carefully when planning refractive procedures that employ phakic intraocular lenses.

Photorefractive keratectomy for pediatric myopic anisometropia

Purpose: To evaluate the visual results of excimer laser photorefractive keratectomy (PRK) to treat pediatric patients with amblyopic myopic anisometropia in whom conventional amblyopia treatments have failed. Setting: Instituto Oftalmológico de Alicante, University of Alicante, Spain. Methods: Six patients aged 5 to 7 years with amblyopic myopic anisometropia were treated by PRK in the more myopic eye using a VISX Twenty‐Twenty excimer laser. Minimum preoperative refraction in the amblyopic eyes ranged from −4.00 to −13.00 diopters and best corrected visual acuity (BCVA), from 20/40 to 20/400. All cases completed a minimum of 2 years follow‐up of antiamblyopic treatment. Results: After PRK, preoperative BCVA was maintained without optical correction and complementary refraction resulted in increased BCVA in every case. One patient with high myopia developed severe haze. There were no other significant complications. Conclusion: Our results indicate’ that PRK may be an alternative for the correction of pediatric myopic anisometropia and an important aid in treating amblyopia. When other therapies have failed, using PRK in children of the ages in this study must be carefully evaluated; however, our results suggest a beneficial effect.

Laser in situ keratomileusis to correct residual myopia after cataract surgery

PURPOSE To evaluate the effectiveness, predictability, and safety of laser in situ keratomileusis (LASIK) for correcting residual myopia after cataract surgery with intraocular lens implantation. METHODS Twenty-two eyes of 22 patients underwent LASIK for the correction of residual myopia after cataract surgery. LASIK was carried out using the Chiron Automated Corneal Shaper and the NIDEK EC-5000 excimer laser. In all eyes, the follow-up was 12 months. RESULTS Before LASIK, 1 eye (4.5%) had an uncorrected visual acuity of 0.5 or better; 12 months after LASIK, 10 eyes (45.4%) achieved this level of visual acuity and 0 eyes achieved 1.00 or better. Before LASIK, mean refraction was -2.90 +/- 1.80 D; 12 months after LASIK it decreased significantly to 0.40 +/- 0.60 D (P < .01). In 18 eyes (81.8%) at 12 months after LASIK, spherical equivalent refraction was within +/-1.00 D of emmetropia; 11 eyes (50%) were within 0.50 D. No vision-threatening complications occurred. CONCLUSION LASIK with the Automated Corneal Shaper and Nidek EC-5000 excimer laser was an effective, predictable, stable, and safe procedure for correcting residual myopia after cataract surgery. No intraocular lens or cataract incision related complications occurred when LASIK was performed at least 3 months after phacoemulsification.

Interface Corneal Edema Secondary to Steroid-induced Elevation of Intraocular Pressure Simulating Diffuse Lamellar Keratitis

PURPOSE To describe interface corneal edema secondary to steroid-induced elevation of intraocular pressure (IOP) following LASIK. METHODS Retrospective observational case series. Diffuse interface edema secondary to steroid-induced elevation of IOP was observed after LASIK simulating diffuse lamellar keratitis (DLK) in 13 eyes. Mean patient age was 31.4 +/- 5.3 years. Patients were divided into two groups according to provisional misdiagnosis: DLK group (group 1) comprised 11 eyes and infection group (group 2) comprised 2 eyes (microbial keratitis). Mean follow-up was 8.1 +/- 0.5 weeks. RESULTS In the DLK group, typical diffuse haze was confined to the interface and extended to the visual axis, impairing vision in all eyes. Provisional diagnosis was late-onset DLK and topical steroids were started. Repeat examination showed elevated IOP as measured at the corneal center and periphery using applanation tonometry (mean 19.1 mmHg and 39.5 mmHg, respectively), causing interface edema with evident interface fluid pockets. Steroids were stopped and topical anti-glaucoma therapy was started. The interface edema decreased and at the end of follow-up the corneal transparency was restored and IOP dropped to normal values. The infection group demonstrated a microbial keratitis-like reaction and underwent flap lifting and interface wound debridement and biopsy with administration of fortified antibiotics and steroids. After elevated IOP was detected, steroids and antibiotics were stopped and topical anti-glaucoma therapy was started, resulting in the resolution of the interface edema. CONCLUSIONS Interface fluid syndrome secondary to steroid-induced elevation of IOP might develop in steroid responders after LASIK with a misleading clinical picture simulating DLK or infectious keratitis. Management includes stopping topical steroids and starting topical antiglaucoma therapy.

Photorefractive keratectomy for residual myopia after cataract surgery

PURPOSE To evaluate the effectiveness, predictability, and safety of photorefractive keratectomy (PRK) for correcting residual myopia and myopic astigmatism after cataract surgery with intraocular lens implantation. SETTING Refractive Surgery and Cornea Unit, Instituto Oftalmológico de Alicante, Alicante, Spain. METHODS Thirty consecutive eyes (30 patients) had PRK for residual myopia after cataract surgery. Surface PRK with a VISX Twenty-Twenty excimer laser was used in all patients. Follow-up was 1 year. RESULTS Before PRK, no eye had an uncorrected visual acuity (UCVA) of 20/40 or better. Twelve months after PRK, 16 eyes (53.33%) had a UCVA of 20/40 or better. After PRK, best corrected visual acuity (BCVA) improved 1 line or more in 14 eyes (46.66%) over the preoperative values, and 15 eyes (50.00%) had the same BCVA as before PRK. Mean pre-PRK refraction of -5.00 diopters (D) +/- 2.50 (SD) decreased significantly to -0.25 +/- 0.50 D at 12 months (P < .001). At 12 months, the spherical equivalent was within +/- 1.00 D of emmetropia in 27 eyes (90.00%). No vision-threatening complications occurred. CONCLUSION Photorefractive keratectomy was an effective, predictable, and safe procedure for correcting residual myopia and myopic astigmatism after cataract surgery.

Correcting simple myopic astigmatism with the excimer laser

Abstract For one year we followed 46 eyes that had photoastigmatic refractive keratectomy with an excimer laser to correct simple myopic astigmatism. Mean preoperative cylinder was −2.50 ± 0.70 diopters (D); mean preoperative best corrected visual acuity was 20/25 ± 1 Snellen line. Mean postoperative refraction one year after surgery was −0.5 ± 0.2, and mean uncorrected visual acuity was 20/25 ± 1 Snellen line. In all eyes, the final axis of the residual cylinder was ±5 degrees around the preoperative axis. Uncorrected visual acuity equaled best preoperative acuity in 24 eyes. Eight eyes gained one line of best corrected visual acuity, six gained more than one line, and eight lost one line. No patient lost more than one line of uncorrected visual acuity. No significant complications such as haze, halos, eccentric ablation, or hypercorrection were observed.

Choroidal neovascularization in myopic eyes after photorefractive keratectomy

Purpose: To evaluate the incidence, characteristics, and results of treatment of choroidal neovascularization (CNV) in myopic eyes corrected by photorefractive keratectomy (PRK). Setting: University Miguel Hernández, Instituto Oftalmológico de Alicante, Alicante, Spain. Methods: This study was of the incidence of CNV in 5936 consecutive eyes that had PRK for the correction of myopia. Mean follow‐up was 38.5 months ± 17.4 (SD). Results: Extrafoveal CNV developed in the right eye of a 44‐year‐old woman 26 months after PRK for the correction of −12.00 diopters (D) of myopia. The follow‐up after PRK was 38 months. Best corrected visual acuity (BCVA) before PRK was 20/40 (spherical equivalent [SE] −12.00 D). After PRK, BCVA was 20/32 SE −1.75 D). The CNV was treated by direct argon‐green laser photocoagulation and did not recur in the subsequent 12 months). After CNV treatment, BCVA was 20/32 (SE −2.25 D). Conclusions: The incidence of CNV after PRK for myopia was low. Choroidal neovascularization is a possible complication in myopic eyes, and the risk exists before PRK. After PRK, the risk of CNV in myopic patients did not increase.