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PURPOSE: To evaluate the safety of the corneal inlay removal procedure and the reversibility of visual acuities, corneal topography, and corneal biomicroscopy changes in a series of cases. METHODS: Ten cases implanted with one of three versions of the AcuFocus Kamra Inlay (ACI 7000, 7000T, and 7000PDT; AcuFocus, Inc., Irvine, CA) were followed for a minimum of 6 months after corneal inlay removal. RESULTS: The reason for removal was related to subjective dissatisfaction with visual symptoms (8 of 10 patients) such as night glare, photophobia, starburst, blurry vision, and halos. One case of removal was related to inadvertent thin flap and the final case was related to insufficient near vision. Mean uncorrected distance visual acuity (UDVA) and uncorrected near visual acuity (UNVA) was 0 ± 0.1 logMAR (Snellen 20/20) and 0.5 ± 0.2 logMAR (Snellen 20/40), respectively, preoperatively and 0.1 ± 0.1 logMAR (Snellen 20/25) and 0.5 ± 0.1 logMAR (Snellen 20/63), respectively, 6 months after corneal inlay removal. Mean corrected distance visual acuity (CDVA) and corrected near visual acuity (CNVA) was 0 ± 0.1 logMAR (Snellen 20/20) and 0 ± 0.1 logMAR (Snellen 20/20), respectively, preoperatively and 0 ± 0.1 logMAR (Snellen 20/20) and 0.1 ± 0.1 logMAR (Snellen 20/25), respectively, 6 months after corneal inlay removal. Mean root mean square (RMS) higher-order aberration (HOA) was 0.50 ± 0.12 (range: 0.30 to 0.70) preoperatively and 0.69 ± 0.14 (range: 0.48 to 0.95) 6 months after corneal inlay removal ( P < .8). Weak positive correlation was found between Δt Implant-Removal (Δt I-R), RMS spherical, coma, and HOA at 6 months (Δt I-R vs RMS spherical was r = 0.2, r 2 = 0.5, P < .7; Δt I-R vs RMS coma was r = 0.8, r 2 = 0.6, P < .3; and Δt I-R vs HOA r = 0.8; r 2 = 0.6, P < .9). CONCLUSION: This study suggests that after removal of the corneal inlay, corneal topography and corneal aberrometry are not permanently affected. In more than 60% of patients, CNVA, CDVA, UNVA, and UDVA were similar to the preoperative value. [ J Refract Surg. 2013;29(8):550–556.]

Purpose: To compare the effect of femtosecond thin-flap LASIK and photorefractive keratectomy (PRK) on postoperative endothelial cell density. Methods: In a prospective, randomized, contralateral, single-center clinical trial, 25 patients (mean age: 30±5 years [range: 21 to 38 years]) underwent PRK in one eye and thin-flap LASIK in the fellow eye for the correction of myopia using a wavefront-guided platform. The central corneal endothelial cell density was measured using the NIDEK Confoscan 4 preoperatively, and at 1 and 3 months postoperatively. Changes in endothelial cell density were analyzed over time between the two refractive techniques. Results: In PRK, the average preoperative endothelial cell density was 3011±329 cells/mm 2 , which decreased to 2951±327 cells/mm 2 at 1 month ( P =.5736) and 2982±365 cells/mm 2 at 3 months ( P =.6513). In thin-flap LASIK, the average preoperative endothelial cell density was 2995±325 cells/mm 2 , which decreased to 2977±358 cells/mm 2 at 1 month ( P =.5756) and 2931±369 cells/mm 2 at 3 months ( P =.4106). No statistically significant difference was found between the two groups at 1 ( P =.7404) or 3 ( P =.3208) months postoperatively. Conclusions: No statistically significant change was noted in endothelial cell density following either PRK or thin-flap LASIK for the treatment of myopia. Furthermore, no statistically significant difference was found between the two groups out to 3 months postoperatively, indicating that thin-flap LASIK is as safe as PRK with regards to endothelial health. [ J Refract Surg . 2009;25:1098–1102.]

BACKGROUND: Variation in healing response has been noted after excimer laser photorefractive keratectomy (PRK). METHODS: A retrospective analysis of 116 eyes that underwent PRK for myopia was performed. Standard surgical protocol and postoperative corticosteroid treatment were followed for all eyes. Scattergrams of achieved correction versus attempted correction at 6 months after surgery were analyzed. Subepithelial corneal haze was compared with refractive outcome. RESULTS: Three healing responses were observed. Normal responders (84.5%) showed a hyperopic overcorrection at 1 month with a gradual regression toward plano and good refractive outcome. Inadequate responders (11.2%) showed a pronounced early hyperopic overcorrection (greater than 1.50 diopters [D]) with minimal regression at 6 months. Aggressive responders (4.3%) displayed an early overcorrection with rapid regression toward myopia. Clear to trace subepithelial corneal haze was present at 6 months in 96% of normal and inadequate responders. Aggressive responders had more pronounced subepithelial haze at 6 months. CONCLUSION: Variation in the amount of subepithelial healing response occurs after excimer laser PRK. Abnormal healing responses may be detected early in the postoperative period by correlation of refractive error with the amount of subepithelial haze. [J Refract Surg. 1995;11:341-347.]

BACKGROUND: A new experimental surgical technique to correct spherical hyperopia by steepening of the central corneal curvature was performed on human cadaver eyes. METHODS: Ten eyes were used in the study. All were pretreated with glycerin to ensure a uniform corneal thickness between .55 and .65 mm on ultrasonic pachometry. A constant intraocular pressure of approximately 30 to 40 mm Hg was maintained in each eye by the injection of saline into the vitreous cavity. This was verified by pneumotonometry. A vertical blade diamond knife was set at 100% of the thinnest of four paracentral readings. Each eye underwent preoperative computed topography. One set of five eyes had 12 incisions made following a 5.75-millimeter diameter Mendez hexagonal marker that included unconnected T incisions at each junction (ie, "Hex T" pattern). The other set of five eyes had four arcuate incisions made following a 6-millimeter diameter zone marker; each incision was 60° in arc. Immediately after surgery, computed topography was repeated. RESULTS: The hexagonal keratotomy set of eyes had an average steepening of the cornea of 0.80 D with a range of -1.05 to +4.38 D. The arcuate keratotomy set had an average steepening of +2.12 D with a range of + 1.27 to +3.27 D. CONCLUSIONS: This study suggests arcuate keratotomy may be a more effective procedure in the correction of spherical hyperopia when compared with hexagonal keratotomy. The amount of corneal steepening achieved in a cadaver eye model may not be the same as when performed in vivo. (Refract Corneal Surg 1993;9:388-391.)

PURPOSE: To compare the measured difference and degree of cyclotorsion in eyes undergoing customized laser ablation between the time of wavefront measurement and laser refractive surgery. METHODS: The degree of cyclotorsion was measured in 1019 consecutive eyes of 732 patients who underwent wavefront-guided corneal ablation for the treatment of myopia with or without astigmatism with the Alcon LADARVision excimer laser. Prior to obtaining the wavefront measurement, the horizontal axis of each eye was marked. Cyclotorsional alignment was measured on the supine patient prior to beginning the laser. RESULTS: The predominant trend was for excyclotorsion. The total range of torsion in degrees was 0.5? to 17.5? (mean: 4.05?2.9?). Cyclotorsion >2? occurred in 68% of all eyes. In the right eyes, 83% excyclotorted, 14% incyclotorted, and 3% displayed no torsion. In the left eyes, 62% excyclotorted, 34% incyclotorted, and 4% exhibited no torsion. In a subset of 112 patients undergoing simultaneous bilateral surgery, 46% displayed bilateral excyclotorsion and 1.7% displayed bilateral incyclotorsion. CONCLUSIONS: In this study, the majority of eyes had a low to moderate amount of cyclotorsion observed with the change of orientation from seated to supine position. Excyclotorsion was the predominant pattern. Proper registration prior to wavefront-guided corneal ablation is essential for proper correction of astigmatism and higher order aberrations to achieve optimal visual outcomes. [J Refract Surg. 2005;21:S772-S774.]

A 48-year-old man had symptoms of monocular diplopia following photorefractive keratectomy (PRK) for residual myopia after radial keratotomy. The cornea was characterized by a ring of subepithelial haze. A new type of corneal topography analysis that depicts areas of focal optical micro irregularity was used to diagnose the etiology of the optical symptoms. [Ophthalmic Surg Lasers 1996;27:315-317.]

Photorefractive keratectomy (PRK) was performed on 91 eyes of 71 patients who had previous radial keratotomy, radial combined with astigmatic keratotomy or astigmatic keratotomy alone (refractive keratotomy). Residual myopia, prior to photorefractive keratectomy, ranged from -1.50 to -8.00 D (mean -3.62) and cylinder from 0 to 2.25 D (mean 0.78). Uncorrected visual acuity was 20/40 or better in 89.7% at one year. At the 12 month follow-up 75.9% of patients were within +/- 1.00 D of intended correction. [J Refract Corneal Surg. 1994;10:S235S238.1

The holmium:YAG laser can be used to perform corneal collagen shrinkage and treat refractive errors. Studies are underway for the treatment of hyperopia by shrinking collagen in the peripheral cornea, which produces central and paracentral steepening. There is initial overcorrection followed by a regression of effect postoperatively, which appears to stabilize 4 to 6 months postoperatively. Refinement of current nomograms and definition of the amount of expected regression will enhance its accuracy. The holmium:YAG laser may be superior to radial thermokeratoplasty with a hot needle. Nearly 100 years ago, Lans was the first to report that heating of the cornea could induce collagen shrinkage with resultant corneal curvature changes.1 Various collagen shrinkage procedures have evolved since then. To date, the most wellknown form of collagen shrinkage involves the hot needle and a technique developed by Fyodorov to do radial thermokeratoplasty for hyperopia.2 This article will review the current state of holmium:YAG laser technology and the advantages it may provide over radial thermokeratoplasty. (Refract Corneal Surg (suppl) 1993;9:S134-S137.)

Phototherapeutic keratectomy (PTK) with the excimer laser has been shown to be effective in removing anterior corneal pathology and smoothing surface irregularities. Blocking agents are important in PTK. The techniques we present seek to balance therapeutic effect and refractive error change. Successful PTK depends on thorough preoperative assessment and attention to intraoperative detail. Clinical research has demonstrated that the excimer laser is an effective tool, not only for correcting myopic refractive errors,1,2 but also for treating various types of anterior corneal pathology.35 We present our PTK techniques that reflect recent refinements. (Refract Corneal Surg (suppl) 1993;9:S81-S85.)

The visual and refractive results of two surgical procedures for the correction of aphakia were compared restrospectively. One hundred eyes underwent secondary anterior chamber intraocular lens implantation and 43 eyes had epikeratophakia. The visual recovery after epikeratophakia was delayed compared with that following lens implantation, especially in persons over 60 years of age, and the refractive errors were less predictable. After 6 months, 90% of Pseudophakie eyes had visual acuities equal to or within one line of preoperative best-corrected acuity, compared with only 66% of eyes after epikeratophakia. Patient age is an important consideration in selecting the optimal procedure for visual rehabilitation of the contact lens-intolerant aphakic patient.