Haze after laser in situ keratomileusis in eyes with previous photorefractive keratectomy.

In cases with previous photorefractive keratectomy (PRK), there is a risk of developing severe haze after laser in situ keratomileusis (LASIK). We report 3 patients (4 eyes) who developed severe haze after LASIK treatment for residual myopia following PRK. Both PRK and LASIK procedures were performed using the VISX 20/20 excimer laser. We report the grade of haze, amount of regression, and visual acuity after the patients were treated with topical steroids. In 2 eyes, the uncorrected visual acuity was 1.0 after 1 year with grade I haze. In the other 2 eyes, there was a residual refractive error, and the best spectacle-corrected visual acuity was 0.7 with grade II haze.

Laser in situ keratomileusis for treatment of residual myopia after photorefractive keratectomy.

PURPOSE: To evaluate the results of laser in situ keratomileusis after photorefractive keratectomy. METHODS: Eighty eyes of 80 patients with residual myopia after photorefractive keratectomy were reoperated with laser in situ keratomileusis. The study was retrospective. Laser in situ keratomileusis was performed using the automated corneal shaper microkeratome and Chiron Technolas 217-C d1 excimer laser. Data measured after laser in situ keratomileusis included uncorrected visual acuity, best-corrected visual acuity, refraction, haze, pachymetry, and keratometry. The follow-up was at least 12 +/- 1.6 months (range, 12 to 15 months). RESULTS: After laser in situ keratomileusis the mean spherical equivalent was -0.24 diopters +/- 0.78. (range, -3 to +1.5) at 12 months, and the mean uncorrected visual acuity was 0.76 diopters +/- 0.24 (range, 0.1 to 1). Sixty-five eyes (81.3%) had various degrees of haze after laser in situ keratomileusis. One eye (1.2%) lost 2 lines of best-corrected visual acuity. CONCLUSIONS: Laser in situ keratomileusis enhancement may be a good alternative to correct residual myopia and astigmatism after primary photorefractive keratectomy. Corneal haze is a common problem in these eyes, and the treatment after laser in situ keratomileusis enhancement should be the same as the treatment after primary photorefractive keratectomy.

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.

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). CONCLUSION: 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.

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.

Retreatment after laser in situ keratomileusis.

OBJECTIVE: To evaluate the effectiveness, predictability, and safety of laser in situ keratomileusis (LASIK) retreatment for correcting residual myopia. DESIGN: Retrospective noncomparative case series. PARTICIPANTS AND INTERVENTION: Fifty-nine consecutive eyes (43 patients) underwent LASIK retreatment at 3 or 6 months after the primary LASIK procedure. Lifting the corneal flap and reablating the stromal bed with a VISX 20/20 excimer laser was the procedure used for LASIK enhancement. MAIN OUTCOME MEASURES: The following parameters were studied before and after retreatment: visual acuity, refraction, videokeratography, applanation tonometry, and corneal thickness. Complications after LASIK enhancement also were evaluated. Follow-up was 12 months. RESULTS: Before retreatment, only 3.38% of eyes (2 of 59) had an uncorrected visual acuity of 0.5 (20/40) or better, and after retreatment, this percentage increased to 60% (30 of 50) at 6 months and 61.8% (34 of 55) at 12 months. After reoperation, mean best-corrected visual acuity improved by half a line over the values before retreatment. The preretreatment refraction of -2.92 +/- 1.22 diopters (D) (mean +/- standard deviation) decreased significantly to -0.44 +/- 0.80 D at 6 months and to -0.61 +/- 0.82 D at 12 months (P < 0.001). In 82% of eyes (41 of 50) at 6 months and 81.8% (45 of 55) at 12 months, the spherical equivalent was within 1.00 D of emmetropia. There was a significant regression of effect (0.38 D) between 3 and 12 months (P < 0.01). Postretreatment refraction was related to the original refraction before the primary LASIK, the preretreatment refraction, and the ablation diameter used. Although no vision-threatening complications were found, epithelial ingrowth and flap melting were more common after than before LASIK retreatment, with 31% of eyes at 12 months with epithelial ingrowth and 10.9% with flap melting. However, LASIK enhancement improved decentration and night-vision problems. CONCLUSIONS: LASIK retreatment was an effective and predictable procedure for correcting residual myopia. Epithelial ingrowth and flap melting were more frequent after than before LASIK retreatment, whereas decentration and night-vision symptoms improved.

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 procedures.

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.

Correcting simple myopic astigmatism with the excimer laser.

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.

Effect of topical antioxidant therapy on experimental infectious keratitis.

To test the effect that the treatment with topical antioxidants may have on corneal infection, we have studied the effect of topically applied antioxidants, such as dimethylthiourea 0.5% (DMTU) and dismutase superoxide 0.2% (SOD), on infectious experimental keratitis caused by Staphylococcus aureus. We have quantified the results of the incubated corneas in ex vivo as well as in in vivo treated with antioxidants by using the luminol amplified chemiluminescence technique (LAC). The evaluation of corneal inflammation was performed calculating the average inflammatory index obtained from the clinical observation of the corneal secretion, corneal edema and ciliary injection. The evolution of the corneal infiltration was evaluated by means of computerized planymetry. The antioxidants used in this study demonstrated a significant reduction of the LAC values when compared with a control group both in the in vivo as well as in ex vivo studies. No significant differences in the clinical evaluation of the average inflammatory index were observed between the study and the control groups. However, a significant increase in the corneal infiltration was registered in the antioxidant treated group (p < 0.001) evaluated by computerized planymetry. Our results indicate that the use of antioxidants as antiinflammatory drugs may have a potential negative influence on the course of infectious keratitis.

Antioxidant therapy in the treatment of experimental acute corneal inflammation.

To ascertain the effectiveness of topical antioxidant therapy on acute corneal inflammation, we have studied the effectiveness of topical treatment with a saline solution and with antioxidants such as 0.2% superoxide dismutase and 0.5% dimethylthiourea (DMTU) in a controlled experimental study. The evolution of the inflammatory process was evaluated by a multimodel approach, including computer-assisted planimetry of the corneal ulcer and infiltrate, ultrasonic pachymetry, luminol-amplified chemiluminescence and the study of corneal transparency by direct spectral spectrophotometry transmittance. The experimental model was a corneal ulcer created by a 60-second application of 1 N sodium hydroxide. Topical treatment with DMTU was shown to significantly improve all parameters tested, while superoxide dismutase reduced only the corneal ulcers. Antioxidant topical therapy with DMTU was shown to be efficient in reducing the inflammatory reaction that occurs during acute corneal inflammation. This suggests that antioxidant therapy could be considered as a complementary treatment in the pharmacological modulation of acute corneal inflammation.

Topical treatment of experimental acute corneal inflammation by dexamethasone and nonsteroidal drugs.

In this study, we have correlated the relative effectiveness of nonsteroidal anti-inflammatory drugs versus corticosteroids in the topical treatment of acute corneal inflammation. The authors have studied the effect of 1 drop every 6 h of flurbiprofen 0.03%, indomethacin 1%, diclofenac 0.1% and dexamethasone 0.1% in an experimental model of corneal alkali burn. The objective parameters used to evaluate the corneal inflammatory response were Luminol-enhanced chemiluminescence, ultrasonic pachymetry and computer-assisted analysis of the area of the corneal ulceration. Indomethacin 1% showed statistically significant effects on the improvement of all the parameters tested in the study. No such effect was demonstrated for flurbiprofen 0.03% or diclofenac 0.1%. We can conclude that indomethacin 1% is an effective drug in the treatment of experimental acute corneal alkali-burn inflammation.

Accuracy of the potential acuity meter in predicting the visual outcome in cases of cataract associated with macular degeneration.

In order to ascertain the accuracy and specificity of the Potential Acuity Meter (PAM) in the preoperative evaluation of likely postoperative visual acuity in cases of cataract associated with age-related macular degeneration (ARMD), we studied the results in 130 cases, 54 of whom had preoperatively proved or suspected ARMD associated with a cataract. All of them were operated with extracapsular extraction and implantation of an intraocular lens (IOL), and final visual acuity was established when all the patients were visited three months postoperatively. A positive linear correlation was found between normal ocular fundus and PAM prediction (r = 0.77), and in the group of patients with preoperatively confirmed ARMD (r = 0.77). No difference was found between the preoperative PAM estimation and the final visual acuity in both groups. The PAM prediction was less accurate in cases with doubtful preoperative ARMD (r = 0.58) for whom showed PAM the highest score of false negatives in favor of the final visual acuity. Our results show that PAM is a reliable clinical technique for the prediction of visual results after cataract surgery in cases with preoperatively proved or doubtful macular pathology. To the best of our knowledge, this is the first report regarding the sensitivity and specificity of the PAM in diseased or suspicious maculas associated with cataract.

Treatment of experimental acute corneal inflammation with inhibitors of the oxidative metabolism.

The authors studied the effect of topical 2% 6-aminonicotinamide and 0.1% adenosine on an experimental model of acute corneal inflammation. Luminol-enhanced chemiluminescence (LAC), as an indirect measurement of free-radical release, and computer-assisted planimetry of the corneal ulcer and its infiltrate were performed both ex vivo and in vivo on the fifth day following the induction of experimental alkali burn keratitis. The authors proved that both drugs significantly inhibited LAC both ex vivo and in vivo and that such treatments had also a significant beneficial effect on the evolution of the corneal ulcer and its infiltrate. To the best of the authors' knowledge, this finding had not been previously reported in experimental corneal inflammation and may indicate that treatment with inhibitors of the oxidative metabolism could offer a new approach in the pharmacological modulation of acute corneal inflammation.