This research focuses on four cases of patients having undergone eximer laser photorefractive surgery who were diagnosed with adenoviral keratoconjunctivitis during the postoperative period and who later developed epidemic keratoconjunctivitis (EKC)-like keratitis. Two of the patients had undergone laser-assisted subepithelial keratectomy (LASEK), one had undergone laser in situ keratomileusis and one had photorefractive keratectomy. After the surgery adenoviral keratoconjunctivitis and recurrent late-developing EKC-like keratitis were observed in the patients. Recurrent late-developing EKC-like keratitis occurred in one of the patients, who had received LASEK as many as three times. The others had only one or two episodes.The corneal infiltrates of keratitis mainly occurred in the central cornea. Successful resolution of recurrent late-developing EKC-like keratitis was achieved through the use of topical steroids without sequelae and the final best-corrected visual acuity was as good as the base line. These keratitis infiltrates have been presumed to represent an immune response to the suspected adenoviral antigens deposited in corneal stroma during the primary adenoviral infection. Previous reports argued that patients with a history of adenoviral ketatoconjunctivitis were succeptible to adenoviral keratoconjunctivitis becoming reactivated; however, in our research, our patients had their first adenoviral infections after the eximer laser photorefractive surgery and reactivation was confirmed. We recommend that attention be paid to adenoviral infection after laser refractive operations, because these patients seem to have more frequent recurrences.
Adenovirus Infections, Human/diagnosis/drug therapy/*etiology ; Adult ; Conjunctivitis, Viral/diagnosis/drug therapy/*etiology ; *Corneal Surgery, Laser ; Eye Infections, Viral/diagnosis/drug therapy/*etiology ; Female ; Glucocorticoids/therapeutic use ; Humans ; Keratectomy, Subepithelial, Laser-Assisted ; Keratitis/diagnosis/drug therapy/*etiology ; Keratomileusis, Laser In Situ ; Lasers, Excimer/therapeutic use ; Photorefractive Keratectomy ; *Postoperative Complications ; Recurrence ; Young Adult

PURPOSE: The corneal change induced by refractive procedures influence both the postoperative refractive status and the ocular spherical aberration (SA). We evaluated changes in corneal SA after three types of surface ablation: phototherapeutic keratectomy (PTK), myopic photorefractive keratectomy (PRK), and myopic wavefront-guided laser epithelial keratomileusis (LASEK). METHODS: Twenty-six eyes (25 patients) were subjected to PTK 26 eyes (14 patients) to PRK, and 34 eyes (17 patients) to wavefront-guided LASEK. Corneal SA was measured with the iTrace in all patients both preoperatively and 6 months postoperatively. RESULTS: Six months after surgery, mean corneal SA was -0.173 +/- 0.171 micrometer in the PTK group, 0.672 +/- 0.200 micrometer in the PRK group, and 0.143 +/- 0.136 micrometer in the wavefront-guided LASEK group. The mean difference between the preoperative and postoperative corneal SA (DeltaSA) was -0.475 micrometer in the PTK group, 0.402 micrometer in the PRK group, and -0.143 micrometer in the wavefront-guided LASEK group. CONCLUSIONS: Surgically induced changes in corneal SA vary with procedure. The prediction of the pattern of SA change induced by various surface ablation procedures may be helpful for developing future surgical procedures.
Adult ; Aged ; Corneal Dystrophies, Hereditary/*surgery ; Corneal Wavefront Aberration/*surgery ; Female ; Follow-Up Studies ; Humans ; Keratomileusis, Laser In Situ/*methods ; Male ; Middle Aged ; Myopia/*surgery ; Photorefractive Keratectomy/*methods ; Prospective Studies ; Treatment Outcome

PURPOSE: The corneal change induced by refractive procedures influence both the postoperative refractive status and the ocular spherical aberration (SA). We evaluated changes in corneal SA after three types of surface ablation: phototherapeutic keratectomy (PTK), myopic photorefractive keratectomy (PRK), and myopic wavefront-guided laser epithelial keratomileusis (LASEK). METHODS: Twenty-six eyes (25 patients) were subjected to PTK 26 eyes (14 patients) to PRK, and 34 eyes (17 patients) to wavefront-guided LASEK. Corneal SA was measured with the iTrace in all patients both preoperatively and 6 months postoperatively. RESULTS: Six months after surgery, mean corneal SA was -0.173 +/- 0.171 micrometer in the PTK group, 0.672 +/- 0.200 micrometer in the PRK group, and 0.143 +/- 0.136 micrometer in the wavefront-guided LASEK group. The mean difference between the preoperative and postoperative corneal SA (DeltaSA) was -0.475 micrometer in the PTK group, 0.402 micrometer in the PRK group, and -0.143 micrometer in the wavefront-guided LASEK group. CONCLUSIONS: Surgically induced changes in corneal SA vary with procedure. The prediction of the pattern of SA change induced by various surface ablation procedures may be helpful for developing future surgical procedures.
Adult ; Aged ; Corneal Dystrophies, Hereditary/*surgery ; Corneal Wavefront Aberration/*surgery ; Female ; Follow-Up Studies ; Humans ; Keratomileusis, Laser In Situ/*methods ; Male ; Middle Aged ; Myopia/*surgery ; Photorefractive Keratectomy/*methods ; Prospective Studies ; Treatment Outcome

The purpose of this study is to assess the efficacy of the multi-zone cross-cylinder method as compared with the single method for astigmatism correction using LASIK. This prospective study enrolled 40 patients (52 eyes) who underwent the cross-cylinder method using LASIK, and 52 patients (60 eyes) who underwent the single method using LASIK: all patients were given a diagnosis of complex myopic astigmatism from the department of ophthalmology of this hospital between January 2002 and July 2003. Preoperatively, the mean spherical equivalent refraction was .3.85 +/- 1.13 D in the cross-cylinder group and .4.05 +/-1.20 D in the single method group (p = 0.23). The mean cylinder was .2.05 +/-1.58 D in the cross-cylinder group and .1.95 +/-1.12 D in the single method group (p = 0.31). 6 months after treatment the results were a mean spherical equivalent refraction of .0.26 +/-0.30 D in the crosscylinder group and -0.34 +/-0.35 D in the single method group (p = 0.13). The mean cylinder was .0.38 +/-0.29 D in the cross-cylinder group and .0.45 +/-0.30 D in the single method group (p = 0.096). There were no statistically significant differences between the two groups. The mean BCVA was not different from mean preoperative BCVA in both groups (i.e., 0.98 +/-0.10, 0.96 +/-0.25, p = 0.86). Postoperatively, patient complications that included night halo, glare and corneal haze were not noted in either group. In conclusion, the results of cross-cylinder method are no different from the single method for the correction of a complex astigmatism. In the future, studies will have to be conducted to assess the efficacy of the cross-cylinder method in consideration of those factors that can affect the postoperative outcome.
Adult ; Astigmatism/*surgery ; Corneal Stroma/surgery ; Humans ; Keratomileusis, Laser In Situ/*methods ; Myopia/*surgery ; Postoperative Complications ; Prospective Studies

PURPOSE: To compare the changes in posterior corneal curvature using scanning slit topography (Orbscan II) and Scheimpflug imaging (Pentacam) before and after Epi-laser in situ keratomileusis (LASIK) for myopia. METHODS: In a prospective observational case-series study, 20 myopic patients having undergone Epi-LASIK were examined serially with two different devices, Orbscan II and Pentacam, preoperatively and one month postoperatively. Posterior central elevation (PCE) and posterior maximal elevation (PME) were compared between the two devices, and the changes in parameters after Epi-LASIK were analyzed using a difference map. RESULTS: All parameters (preoperative and postoperative PCE and preoperative and postoperative PME) that were measured using the Orbscan II were significantly greater compared to those of the Pentacam (for all p < 0.001). PCE and PME were significantly increased one month postoperatively in the Orbscan II measurements (p < 0.05) but were not significantly increased in the Pentacam measurements. Also, DeltaPCE and DeltaPME, in the difference map obtained by each serial scanning, were significantly greater in the Orbscan II measurements than with the Pentacam (p = 0.012, p = 0.016). CONCLUSIONS: The Pentacam measurements displayed significantly reduced values in all parameters related to posterior corneal elevation compared to those of the Orbscan II. The Pentacam showed no significant change in posterior corneal curvature after Epi-LASIK, based on the difference map.
Adult ; Corneal Topography/*methods ; Female ; Humans ; Keratomileusis, Laser In Situ/*methods ; Male ; Myopia/*surgery ; Prospective Studies ; Treatment Outcome

PURPOSE: We compared laser assisted in situ keratomileusis (LASIK) mode and photorefractive keratectomy (PRK) mode ablation methods in laser subepithelial keratomileusis (LASEK) surgery using the MEL-80 excimer laser. METHODS: All patients were followed up for a minimum of 1 year. The PRK mode group consisted of 46 eyes of 23 patients and the LASIK mode group consisted of 97 eyes of 56 patients. The central corneal thickness (CCT), ablation thickness, manifest refractive error and uncorrected visual acuity were compared preoperatively, 1 month and 1 year postoperatively. Spherical equivalent (SE) of cycloplegic refraction at postoperative 1 month and the uncorrected visual acuity (UCVA) ratios of 1.0 or better at postoperative 1 year were compared between the two groups to evaluate clinical efficacy. RESULTS: The SE of refractive error, CCT and target corneal ablation thickness of the two groups were not significantly different preoperatively. The PRK mode group obtained an actual ablation mean thickness of 82.8% of the target and the LASIK mode group obtained an actual ablation mean thickness of 94.1% of the target at postoperative 1 month. In each group, a statistically significant difference was observed between the actual corneal ablation thickness and target corneal ablation thickness. In the PRK mode group, the mean SE of postoperative 1 month cycloplegic refraction was +0.24 +/- 0.47 D and in the LASIK mode group, +0.87 +/- 0.54 D, indicating a statistically significant difference between the two groups. One year postoperatively, the UCVA ratios of 1.0 or better were 83% in the PRK mode group and 96% in the LASIK mode group, showing a statistically significant difference between the two groups. However, SE of manifest refractive error and CCT in the two groups were not statistically different at postoperative 1 year. CONCLUSIONS: The LASIK mode ablation method showed better results than the PRK mode ablation method in postoperative UCVA prognosis after LASEK surgery using the MEL-80 excimer laser.
Humans ; Keratectomy, Subepithelial, Laser-Assisted* ; Keratomileusis, Laser In Situ* ; Lasers, Excimer* ; Photorefractive Keratectomy ; Prognosis ; Refractive Errors ; Visual Acuity

Surgical modalities to correct hyperopia include photorefractive keratectomy (PRK), laser in situ keratomileusis (LASIK), Ho:YAG laser thermal keratoplasty (LTK), conductive keratoplasty (CK), phakic IOL, and refractive lens exchange. Excimer laser-based techniques, which include LASIK, LASEK, and PRK, are currently the most popular forms of surgery to correct not only myopia and astigmatism but also hyperopia. These techniques have been reported to be safe and effective for both primary surgeries and enhancements. However, various complications related to the flap and loss of best corrected visual acuity associated with a smaller optic zone, decentration, and irregular ablation caused by longer treatment time in high hyperopia over +5 diopter can have adverse effects on visual outcomes. The development of non-excimer laser-based techniques offers viable alternatives for laser vision correction techniques. More recent non-excimer-based thermal refractive techniques include LTK and CK. Earlier forms of thermal techniques showed a lack of predictability and stability, resulting in no further development of them. Recently, CK, a laserless, radiofrequency-based technique, has been approved by the FDA for the correction of low to moderate hyperopia even though the refractive instability has not been solved yet. In high hyperopia, lens approach like phakic IOL or refractive lens exchange instead of corneal surgery is preferred. ICL (Implantable contact lens) and Artisan is the most popular lens model that has well proven clinical results concerning its safety and effectiveness. Accommodative IOL or multifocal IOL could be the solution for pseudophakic presbyopia in refractive lens exchange in the future.
Astigmatism ; Corneal Transplantation ; Hyperopia* ; Keratectomy, Subepithelial, Laser-Assisted ; Keratomileusis, Laser In Situ ; Lasers, Excimer ; Myopia ; Photorefractive Keratectomy ; Presbyopia ; Visual Acuity

OBJECTIVETo observe the influence of flap-on or flap-off Epipolis laser in situ keratomileusis (epi-LASIK) on the release of transforming growth factor-β1 (TGF-β1) in tear fluid and corneal haze formation.

METHODSThirty patients (60 eyes) with myopia underwent epi-LASIK surgery with epithelial flap repositioning (flap-on) in the right eyes and epithelial flap removal (flap-off) in the left eyes. The level of TGF-β1 in tears was measured preoperatively and on days 1, 3, and 7 postoperatively. Corneal haze was graded at 1, 3 and 6 months after surgery.

RESULTSThe mean preoperative spherical equivalent refraction was -4.98∓2.28 D (-2.50 to -7.25 D) in flap-on group and -5.20∓4.02 D (-1.75 to -7.00 D) in flap-off group, showing no significant difference between the two groups (P=0.80). TGF-β1 levels in the tear fluid were similar in the two groups preoperatively (P=0.11) and at 1, 3, and 7 days postoperatively (P=0.55, 0.45, 0.19, respectively). TGF-β1 levels in tears gradually decreased after the first postoperative day in both groups, but were still higher than the preoperative value till the 7th postoperative day. Corneal haze scores in the two groups were similar at 1 month (P=0.98), 3 months (P=0.52), and 6 months (P=0.72) after the operation.

CONCLUSIONFlap-on and flap-off epi-LASIK surgeries do not differ significantly in postoperative TGF-β1 levels in the tear fluid or in the postoperative haze scores. TGF-β1 may play a role in corneal wound healing.

Adult ; Cornea ; surgery ; Epithelium, Corneal ; pathology ; surgery ; Female ; Humans ; Keratomileusis, Laser In Situ ; methods ; Male ; Postoperative Period ; Surgical Flaps ; Tears ; metabolism ; Transforming Growth Factor beta1 ; metabolism ; Young Adult

PURPOSE: The purpose of this study was to investigate the clinical efficacy of an optimized prolate ablation procedure for correcting residual refractive errors following laser surgery. METHODS: We analyzed 24 eyes of 15 patients who underwent an optimized prolate ablation procedure for the correction of residual refractive errors following laser in situ keratomileusis, laser-assisted subepithelial keratectomy, or photorefractive keratectomy surgeries. Preoperative ophthalmic examinations were performed, and uncorrected distance visual acuity, corrected distance visual acuity, manifest refraction values (sphere, cylinder, and spherical equivalent), point spread function, modulation transfer function, corneal asphericity (Q value), ocular aberrations, and corneal haze measurements were obtained postoperatively at 1, 3, and 6 months. RESULTS: Uncorrected distance visual acuity improved and refractive errors decreased significantly at 1, 3, and 6 months postoperatively. Total coma aberration increased at 3 and 6 months postoperatively, while changes in all other aberrations were not statistically significant. Similarly, no significant changes in point spread function were detected, but modulation transfer function increased significantly at the postoperative time points measured. CONCLUSIONS: The optimized prolate ablation procedure was effective in terms of improving visual acuity and objective visual performance for the correction of persistent refractive errors following laser surgery.
Coma ; Humans ; Keratectomy, Subepithelial, Laser-Assisted ; Keratomileusis, Laser In Situ ; Laser Therapy* ; Phosmet* ; Photorefractive Keratectomy ; Refractive Errors* ; Refractive Surgical Procedures ; Treatment Outcome ; Visual Acuity

PURPOSE: We classified the Orbscan anterior elevation maps in normal eyes (under myopic, emmetropic and hyperopic conditions) and in those after myopic refractive surgery. We did this classification to demonstrate how Orbscan anterior elevation maps are useful in screening for the existence and extent of previous myopic refractive surgery. Such a classification can help clinicians interpret preoperative and postoperative topographies. METHODS: We measured for visual acuity and refractive power in 4800 eyes. After a slit-lamp examination, a corneal topography exam was performed with an Orbscan corneal topography system. The eyes were divided into two groups, with Group I representing those who had not had refractive surgery (4438 eyes). Group II included those who had undergone previous refractive surgery to correct myopia (362 eyes). RESULTS: In Group I, the central island type (43.0%) was the most common, followed by the temporal ridge (25.8%), the with-the-rule regular ridge (16.7%), the against-the-rule regular ridge (6.6%), the nasal ridge (4.0%), and the saddle type (2.1%). In Group II, the depressed lake type (69.9%) was most common, followed by the de-centered ablation type (21.3%). The trend line of the postoperative central anterior surface elevation (E) and the ablation power of refractive surgery were calculated. Ablation power of refractive surgery=0.0047 E+0.0083 CONCLUSIONS: This study demonstrates that it is possible to use Orbscan anterior elevation maps to screen for the extent of previous refractory surgery used in the correction of myopia. This study may also be useful in understanding the shapes of Orbscan anterior elevation maps before and after myopic refractive surgery as well as in determining the degree of ablated myopic refractive power and decentration.
Vision Screening/*instrumentation ; Retrospective Studies ; Preoperative Care ; Postoperative Period ; Myopia/*diagnosis/surgery ; *Keratomileusis, Laser In Situ ; Humans ; Equipment Design ; *Corneal Topography ; Cornea/*pathology ; Adult