Rhegmatogenous retinal detachment after LASIK for myopia of up to -10 diopters: 10 years of follow-up.

BACKGROUND: The aim of this work was to characterize rhegmatogenous retinal detachment (RRD) in over 22,000 eyes after laser-assisted in situ keratomileusis (LASIK) for the correction of myopia ≤ -10.00 diopters (D), its characteristics, and its frequency at 10 years of follow-up. METHODS: This is a retrospective single-center interventional non-comparative case series. A total of 22,296 myopic eyes that underwent surgical correction of myopia ≤ -10.00 D were included. LASIK for the correction of myopia was performed in all eyes. Patients were followed for 10 years after LASIK. The clinical charts of patients that developed rhegmatogenous retinal detachment (RRD) after LASIK were reviewed. RESULTS: A total of 11,594 (52%) eyes came back for follow-up after LASIK at 10 years. Twenty-two eyes (19 patients) developed a RRD after LASIK at 10 years. Rhegmatogenous retinal detachments occurred between 1 month and 10 years (mean: 31.6 ± 39.3 months) after LASIK. Eyes that developed a RRD had from -1.50 to -9.75 D of myopia (mean: -4.81 ± 2.2 D) before LASIK. The frequency of RRD after LASIK determined in our study was 0.05% (11/22,296) at 1 year, 0.15% (18/11,371) at 5 years, and 0.19% (22/11,594) at 10 years. CONCLUSIONS: Rhegmatogenous retinal detachment after LASIK for the correction of myopia ≤ -10.00 D is infrequent. The risk of RRD after LASIK is very low if you screen patients, and do prophylactic treatment as performed in this study. RRD, if managed promptly, will result in good vision. We recommend that patients scheduled for refractive surgery undergo a very thorough dilated indirect funduscopy with scleral depression and treatment of any retinal lesion predisposing to the development of a RRD before LASIK surgery should be performed.

Corneal perforation during laser in situ keratomileusis after hyperopic electrothermal keratoplasty.

PURPOSE: To report a corneal perforation during laser in situ keratomileusis (LASIK) after previous electrothermokeratoplasty. DESIGN: Interventional case report. METHODS: A 49-year-old man presented with primary hyperopia in the right eye and residual hyperopia after electrothermokeratoplasty in the left eye. His refraction was +4.00 in the right eye and +7.00 -3.00 x 135 degrees in the left eye, with a central pachymetry of 535 microm and 549 microm, respectively. Phacoemulsification with intraocular lens (IOL) insertion in the right eye and a two-step keratophacorefractive procedure with a piggyback IOL insertion and LASIK in the left eye were proposed. RESULTS: Postoperative refraction was -0.50 -0.50 x 150 degrees 20/20 in the right eye. Postphacoemulsification refraction was -4.75 -4.25 x 135 degrees in the left eye. Laser in situ keratomileusis was performed in the left eye, 4 months later, with uneventful astigmatic laser ablation. During the myopic ablation, a sudden outcome of aqueous humor in one of the temporal corneal scars was observed. CONCLUSIONS: Unpredictably thin areas after electrothermokeratoplasty may lead to unexpected corneal perforation during LASIK. The available pachymetry systems may be unreliable after electrothermal keratoplasty.

Anterior uveitis after laser in situ keratomileusis.

PURPOSE: To report a case series of anterior uveitis after laser in situ keratomileusis (LASIK) and the incidence of anterior uveitis at a mean of 3 years. SETTING: Centro Medico Docente La Trinidad and Clinica Oftalmologica Centro Caracas, Caracas, Venezuela. METHODS: Five refractive surgeons and 18488 eyes that had surgical correction of a mean ametropia of -2.23 diopters (D) (range -10.25 to +4.25 D) participated in the study; 74.3% of the eyes were myopic. Laser in situ keratomileusis was performed in all eyes. Patients were followed for a mean of 36 months (range 6 to 48 months) after LASIK. The clinical charts of patients who developed uveitis after LASIK were reviewed. The mean preoperative intraocular pressure (IOP) was 15.2 mm Hg (range 12 to 19 mm Hg). The mean corneal ablation depth was 37.47 micro m (range 12 to 98 micro m). In the immediate postoperative period, all patients received a combination of topical dexamethasone and tobramycin. RESULTS: Thirty-five eyes (18 patients) developed anterior uveitis after LASIK. Signs and symptoms appeared a mean of 20.7 days (range 17 to 28 days) postoperatively and 5.08 days (range 2 to 8 days) after withdrawal of topical steroid and antibiotic agents. Eyes that developed LASIK-related uveitis had a mean preoperative spherical equivalent of -2.32 D (range -7.00 to +4.25 D). Intraocular pressure dropped to a mean of 8.0 mm Hg (range 4 to 12 mm Hg) at the onset of uveitis (P <.0001). The LASIK-related anterior uveitis resolved and IOP returned to baseline after a mean of 3 days on topical steroid and cycloplegic agents. Laboratory and immunology (including human leukocyte antigen-B27) tests were negative in 15 of 18 patients (83.33%). The incidence of uveitis after LASIK was 0.18%. CONCLUSIONS: Anterior uveitis after LASIK is infrequent. It may be due to uveal trauma during surgery with disruption of normal anterior-chamber-associated immune deviation, decreased antiinflammatory cytokines, and increased proinflammatory cytokines. Further studies are needed to investigate the mechanisms of this association.

Changes of posterior corneal astigmatism and tilt after myopic laser in situ keratomileusis.

PURPOSE: The purpose of this study was to assess the changes of posterior corneal astigmatism and tilt after laser in situ keratomileusis (LASIK) and to correlate these changes with the amount of correction and the residual stromal bed thickness. METHODS: This prospective nonrandomized (self-controlled) comparative trial included 57 eyes from 14 females and 15 males, whose mean age (+/- standard deviation [SD]) at the time of surgery was 33 +/- 9 years (range, 19-53), with a spherical equivalent (SEQ) of -1.00 to -15.50 (mean, -5.07 +/- 2.81) diopters (D). All LASIK procedures were accomplished with the Keratom II Coherent-Schwind excimer laser and the Moria Model One microkeratome (150-microm head). Subjective refractometry, Orbscan slit-scanning corneal topography analysis, and pachymetry were performed before and 3 months after LASIK for myopia (n= 35; -1.00 to -15.50 D [mean, -4.75 +/- 3.07]) or myopic astigmatism (n= 22; sphere, 0.00 to -9.75 D [mean, -4.75 +/- 2.36]; cylinder, -0.75 to -3.50 D [-1.68 +/- 0.86]). Intended ablation depth ranged from 12 to 108 (mean, 48 +/- 22) microm. Topographic raw data were decomposed into a set of Zernike polynomials as published in detail previously, and parameters for detection of asymmetric mechanical deformation of the cornea were derived. Posterior corneal astigmatism and tilt before and after LASIK were compared, and changes in these variables were correlated with the SEQ change (DeltaSEQ) and the residual corneal bed thickness (RBT). RESULTS: The RBT after LASIK ranged from 186 to 373 (mean, 280 +/- 42) microm. Overall, astigmatism (0.19 +/- 0.07 D/0.22 +/- 0.13 D; p= 0.80) and tilt (3.58 +/- 0.35 degrees /3.65 +/- 0.48 degrees; p= 0.61) did not change significantly by 3 months after LASIK. In eyes with RBT < or =250 microm, the average change in astigmatism (0.05 +/- 0.11 versus 0.01 +/- 0.13 D; p= 0.46) and tilt (0.21 +/- 0.45 degrees versus 0.04 +/- 0.55 degrees; p= 0.30) was not greater than in eyes with RBT > 250 microm. Change in astigmatism (p= 0.19) and tilt (p= 0.56) did not correlate with the RBT during LASIK. CONCLUSIONS: Zernike decomposition of topographic height data discloses that no significant asymmetric mechanical deformation of the posterior corneal curvature occurs after myopic LASIK. Further studies with long-term follow-up are needed to clarify whether this symmetry of the posterior corneal surface can indeed be preserved over time after LASIK if the RBT is < 250 microm.

Consideration of the posterior corneal curvature for assessment of corneal power after myopic LASIK.

PURPOSE: To evaluate the effect of a separate measurement of the anterior and posterior corneal surface to calculate the total refractive power of the cornea after myopic laser in situ keratomileusis (LASIK). METHODS: A total of 39 eyes of 21 patients (aged 33 +/- 9 years) were included in this prospective, non-randomized, comparative study. These involved 19 myopic corrections (- 3.5 +/- 1.6 dioptres) and 23 refractive corrections of myopic astigmatism (sphere: - 3.7 +/- 1.6 D, cylinder: - 1.2 +/- 0.4 D). All procedures were accomplished with the Keratom II). Coherent-Schwind excimer laser and the Moria Model One) microkeratome (150 micro m head) at the Medical Education Centre, La Trinidad, Caracas, Venezuela. Subjective refractometry, Bausch & Lomb) keratometry and Orbscan) slit-scanning corneal topography analysis were performed before and 3 months after LASIK. Corneal power was assessed directly using keratometry (K1) and Orbscan videokeratography (T1). Corneal power was calculated using the preoperative keratometric (K2, 'gold standard', clinical history method) or topographic power (T2, clinical history method) and spherical equivalent change. A composite value was derived from the Orbscan anterior and posterior surface power and central pachymetry (T3). RESULTS: Three months postoperatively, corneal power ranged in a descending order from T1 (42.33 +/- 1.78 D), K1 (40.82 +/- 2.20 D), K2 (40.42 +/- 2.36 D), T2 (40.03 +/- 2.51 D) to T3 (38.78 +/- 2.23 D). On average, T1 exceeded the gold standard by 1.9 D and the gold standard exceeded T3 by 1.6 D. K2, T1, T2 and T3 correlated significantly with K1 (r = 0.975, p < 0.001; r = 0.909, p < 0.001; r = 0.963, p < 0.001; r = 0.853, p < 0.001, respectively). The differences T1-K2 (r = - 0.699, p < 0.001) and T3-K2 (r = - 0.499, p = 0.001) correlated highly inversely and K1-K2 correlated borderline inversely (r = - 0.325, p = 0.043) with the intended refractive correction. CONCLUSION: After myopic LASIK, refractive corneal power is overestimated by direct keratometric and especially videokeratoscopic measurements. The higher the intended refractive correction, the greater is this error. A separate measurement of both refractive surfaces of the cornea tends to underestimate but may enhance accuracy of the total refractive corneal power if the history of the patient is unknown.