The Experts below are selected from a list of 15576 Experts worldwide ranked by ideXlab platform
Dimitri T. Azar - One of the best experts on this subject based on the ideXlab platform.
-
Intrastromal epithelial accretion follows deep excimer annular Keratectomy.
Cornea, 1996Co-Authors: Sandeep Jain, Wallace Chamon, Walter J. Stark, William R. Green, Robert A. Prendergast, Dimitri T. AzarAbstract:The purpose of this study was to evaluate corneal reepithelialization and wound healing following annular excimer Keratectomy. Two sets of experiments were performed on 35 rabbit eyes. In the first set of experiments, experiment I, deep Fresnel excimer Keratectomy was performed, with a 6-mm outer and 3-mm inner diameter. Animals were sacrificed at 1, 5, 12, and 16 weeks, and corneas were examined by light and electron microscopy. In experiment II, the central epithelium was left intact, and superficial and deep mid-peripheral excimer annular keratectomies were performed measuring 6 mm in outer and 3 mm in inner diameter. Animals were sacrificed at 1 week, and corneas were examined by light microscopy. Following deep Fresnel excimer Keratectomy (experiment I), corneas showed stromal edema in the central 3-mm zone. Intrastromal islands of epithelial cells with PAS positive basement membrane-like structures were seen histologically at 1 week. Electron microscopy showed loss of stromal collagen in areas adjacent to epithelial islands; in areas distant from the epithelial islands, the stromal collagen appeared normal. The overlying central stroma sloughed after 5 weeks. Anterior stromal scarring was observed. In experiment II (mid-peripheral annular Keratectomy), intrastromal epithelial accretion was present in corneas with deep annular Keratectomy but not in superficial annular Keratectomy. Intrastromal epithelial accretion follows deep excimer annular Keratectomy and is associated with adjacent stromal degradation.
-
Objective Measurement of Corneal Light Scattering after Excimer Laser Keratectomy
Ophthalmology, 1996Co-Authors: Richard E. Braunstein, Sandeep Jain, Walter J. Stark, Russell L. Mccally, Patrick J. Connolly, Dimitri T. AzarAbstract:Purpose: To obtain objective measurements of corneal light scattering after excimer laser Keratectomy, and to evaluate the relation of light scattering to clinical haze grading and visual acuity. Methods: The authors measured best-corrected visual acuity, subjective clinical haze grade, and corneal light-scattering index in patients undergoing photorefractive Keratectomy (PRK) (n = 26) and phototherapeutic Keratectomy (n = 8), preoperatively and postoperatively at 1, 3, 6, 9, and 12 months or later. Corneal light scattering was correlated with visual acuity and clinical haze grade. Results: Corneal light scattering increased after PRK and was reduced after phototherapeutic Keratectomy. Corneal light-scattering index showed a stronger positive correlation with logMAR visual acuity ( r = 0.57) than clinical haze grading ( r = 0.34). Corneal light-scattering index ( P P Conclusions: Excimer laser surgery affects corneal light scattering. Ablations with depths greater than 80 μm produce significantly higher levels of haze than those less than 80 μm. Objective measurement of corneal light scattering may be useful in monitoring the outcome of excimer Keratectomy.
-
Corneal light scattering after laser in situ keratomileusis and photorefractive Keratectomy
American journal of ophthalmology, 1995Co-Authors: Sandeep Jain, Wallace Chamon, Johnny M. Khoury, Dimitri T. AzarAbstract:Purpose To compare corneal light scattering after laser in situ keratomileusis and photorefractive Keratectomy in rabbit eyes. Methods For laser in situ keratomileusis, a 5-mm, −10-diopter spherorefractive resection was performed on the stromal bed under a corneal flap. Corneal light scattering was objectively measured for 12 weeks, and compared to corneal light scattering after photorefractive Keratectomy (5 mm, −10 diopters). Results Corneal light scattering was significantly lower in the laser in situ keratomileusis group than in the photorefractive Keratectomy group at all time points after surgery (P Conclusions In this experimental study, laser in situ keratomileusis resulted in significantly less corneal light scattering than photorefractive Keratectomy.
Ahmet Demirok - One of the best experts on this subject based on the ideXlab platform.
-
Comparison of visual and refractive results after transepithelial and mechanical photorefractive Keratectomy in myopia.
International ophthalmology, 2017Co-Authors: Yusuf Yildirim, Onur Olcucu, Neşe Alagöz, Alper Agca, Yalcin Karakucuk, Ahmet DemirokAbstract:Purpose To compare postoperative visual outcomes and higher-order aberrations (HOAs) following transepithelial photorefractive Keratectomy (t-PRK) and mechanical photorefractive Keratectomy (m-PRK).
-
Diamond burr superficial Keratectomy with mitomycin C for corneal scarring and high corneal astigmatism after pterygium excision
Clinical Ophthalmology, 2013Co-Authors: Engin Bilge Ozgurhan, Necip Kara, Aydin Yildirim, Zeynep Alkin, Ercument Bozkurt, Ahmet DemirokAbstract:Background The purpose of this paper is to report the successful treatment of corneal scarring and high corneal astigmatism secondary to previous pterygium surgery with diamond burr superficial Keratectomy using mitomycin C. Methods Four patients with corneal scarring and high corneal astigmatism related to previous pterygium surgery underwent diamond burr superficial Keratectomy with application of mitomycin C. Anterior segment photography and corneal topographic analysis were obtained preoperatively and postoperatively in all patients. Results Six months after surgery, corneal astigmatism and corneal aberrations were reduced in all patients. A clear cornea was achieved in all cases. No complications were noted during the follow-up period. Conclusion Diamond burr superficial Keratectomy with application of mitomycin C is a potentially effective and simple procedure for treating patients with corneal scarring and high corneal astigmatism secondary to previous pterygium surgery.
James J Salz - One of the best experts on this subject based on the ideXlab platform.
-
Refractive keratotomy after photorefractive Keratectomy.
Journal of refractive surgery (Thorofare N.J. : 1995), 1999Co-Authors: Amir H Kolahdouz-isfahani, James J SalzAbstract:BACKGROUND The current surgical procedures available for the treatment of residual myopia and/or astigmatism after photorefractive Keratectomy (PRK) include refractive keratotomy, laser in situ keratomileusis (LASIK), repeat PRK, or photorefractive astigmatic Keratectomy (PARK). In this study, we investigate the safety and efficacy of refractive keratotomy for the correction of residual myopia and/or astigmatism after PRK. METHODS Ten eyes of 9 patients underwent refractive keratotomy after excimer laser photorefractive Keratectomy using the Lindstrom nomogram. PRK procedures were performed using the VISX 20/20 system by one surgeon. RESULTS All eyes except one obtained an uncorrected visual acuity of 20/40 or better. One eye developed significant haze following PRK with myopic astigmatic regression and underwent refractive keratotomy to correct the residual refractive error. This patient was also the only patient who lost 2 lines of spectacle-corrected visual acuity secondary to corneal haze. CONCLUSION This study demonstrates that refractive keratotomy can reduce residual astigmatism and myopia that may be present following excimer laser photorefractive Keratectomy. Our results suggest there is no need to change the refractive keratotomy nomograms for eyes that have previously undergone PRK.
-
Retrospective comparison of photorefractive Keratectomy and radial keratotomy.
Journal of refractive surgery (Thorofare N.J. : 1995), 1995Co-Authors: Jeffrey C Hong, James J SalzAbstract:BACKGROUND The efficacy and predictability of photorefractive Keratectomy and radial keratotomy become increasingly relevant. This retrospective study compares one surgeon's experience with photorefractive Keratectomy and radial keratotomy over a 3-year period from 1990 to 1993. METHODS Photorefractive Keratectomy was performed on 103 eyes of 76 patients that met the inclusion criteria for the phase IIb, phase III, and phototherapeutic Keratectomy studies as delineated by the United States Food and Drug Administration. Radial keratotomy was performed on 117 eyes of 81 patients with up to 9.00 diopters (D) of myopia. RESULTS In the photorefractive Keratectomy group, 83% of the eyes achieved uncorrected visual acuity of at least 20/40; 37% saw 20/20; 88% had a refraction within 1.00 D of emmetropia, and 63% within 0.50 D of emmetropia. For the radial keratotomy group, 85% of the eyes achieved an uncorrected visual acuity of 20/40 or better; 27% saw 20/20; 88% had a refraction within 1.00 D of emmetropia; and 55% within 0.50 D of emmetropia. There were no serious complications, and only one single eye in each of the photorefractive Keratectomy and radial keratotomy groups lost two lines or more of spectacle-corrected visual acuity. CONCLUSION Photorefractive Keratectomy and radial keratotomy are both effective procedures, and result in similar refractive outcomes for myopia of -1.00 to -9.00 D.
-
Traumatic corneal abrasions following photorefractive Keratectomy.
Journal of refractive and corneal surgery, 1994Co-Authors: James J SalzAbstract:BACKGROUND During excimer laser photorefractive Keratectomy, central Bowman's layer and superficial stroma are removed. A potential disadvantage of this technique is whether proper epithelization of the cornea will occur in the event of a corneal abrasion. A potential advantage of photorefractive Keratectomy over radial keratotomy in the event of blunt trauma is the presumably sound structural integrity of the cornea following superficial removal of stroma in photorefractive Keratectomy compared to the weakened cornea following deep incisions in radial keratotomy. METHODS We report two patients who sustained corneal abrasions from blunt trauma to the eye and orbit following photorefractive Keratectomy--one following a fist injury and the other following a karate kick. RESULTS In both patients, the corneal abrasions healed without incident and without recurrent erosions and both corneas remained intact. CONCLUSIONS Corneal abrasion following trauma in two patients who has undergone photorefractive Keratectomy healed as expected in a normal cornea. Although it is uncertain whether the trauma in these patients would have been sufficient to rupture radial keratotomy incisions, as would be expected from a superficial photorefractive Keratectomy, the corneas remained intact following blunt trauma.
Sung Huei Tseng - One of the best experts on this subject based on the ideXlab platform.
-
Nocardia brasiliensis keratitis successfully treated with therapeutic lamellar Keratectomy.
Cornea, 1996Co-Authors: Sung Huei Tseng, Jainn-jou ChenAbstract:A 36-year-old man sustained an indolent keratitis following a minor corneal trauma. Nocardia brasiliensis was isolated from cultures of the corneal scrapings. Fortified topical antibiotics, based on in vitro drug sensitivity testing, were intensively applied for weeks without clinical improvement. The patient underwent therapeutic lamellar Keratectomy, which led to a rapid and complete resolution. The site of the Keratectomy reepithelialized within 2 days and became a faint subepithelial haze thereafter. The visual acuity improved to 20/20 and there was no evidence of recurrence during the subsequent follow-up. It appears that lamellar Keratectomy is a valuable treatment alternative for localized chronic nocardial keratitis.
-
Therapeutic lamellar Keratectomy in the management of experimental keratomycosis.
Journal of the Formosan Medical Association = Taiwan yi zhi, 1994Co-Authors: Sung Huei Tseng, K. Y. Tang, Sheau-chiou Chao, Mark Ming-long HsuAbstract:Keratomycosis, a vision-threatening corneal infection, is a challenge to the ophthalmologist because it is often refractory to medical treatment. Surgical Keratectomy may not only debulk the major infectious source but potentiate the intracorneal penetration of the antifungal agents. To evaluate the efficacy of Keratectomy in managing the fungal corneal ulcer, three common keratomycosis models, Candida, Fusarium, and Aspergillus keratitis, were established in 46 eyes of 23 rabbits (each group had 14, 16 and 16 eyes respectively). Within each keratitis group, the infected eyes were randomly divided into equally numbered experimental and control subgroups. The eyes of the experimental subgroups underwent therapeutic lamellar Keratectomy once the typical fungal corneal infection had developed after inoculation. Following Keratectomy, eyes of both the treated and control groups received natamycin eyedrops and were regularly examined biomicroscopically. Our results showed that therapeutic lamellar Keratectomy is beneficial in chronic, indolent keratitis, such as Candida and Fusarium keratitis, where it promoted corneal healing and shortened the duration of treatment required. The procedure is a valuable adjunctive measure for antifungal agents in these two types of keratitis. However, acute keratitis of the Aspergillus group did not benefit from Keratectomy; in these cases, surgery may actually increase the risk of corneal perforation.
James Chodosh - One of the best experts on this subject based on the ideXlab platform.
-
photorefractive Keratectomy for myopia in the setting of thygeson s superficial punctate keratitis
Cornea, 2001Co-Authors: Steven W Fite, James ChodoshAbstract:PURPOSE To describe a patient with Thygeson's superficial punctate keratitis who underwent photorefractive Keratectomy for the correction of myopia. METHODS A 49-year-old woman with unilateral Thygeson's keratitis was examined before and after photorefractive Keratectomy. RESULTS A myopic patient underwent photorefractive Keratectomy in the left eye and gained 20/20 uncorrected visual acuity. Seventeen months after surgery, symptomatic Thygeson's keratitis lesions recurred in the peripheral but not the central cornea. CONCLUSION Photorefractive Keratectomy reliably corrected myopia in a patient with previous Thygeson's keratitis. The recurrence of lesions only in the peripheral untreated cornea suggests that the inflammatory signal in Thygeson's keratitis may reside in the superficial corneal stroma.
-
Photorefractive Keratectomy for myopia in the setting of adenoviral subepithelial infiltrates
American journal of ophthalmology, 1998Co-Authors: Steven W Fite, James ChodoshAbstract:Abstract PURPOSE: To report a patient with persistent subepithelial corneal opacities 18 months after adenoviral keratoconjunctivitis who underwent photorefractive Keratectomy for the correction of myopia. METHODS: Case report, review of medical literature, and slit-lamp photography. RESULTS: The patient underwent photorefractive Keratectomy in each eye, 1 week apart, with ablation of central corneal opacities and resultant best-corrected visual acuity of BE, 20/20. Symptomatic subepithelial stromal infiltrates recurred in the peripheral but not the central cornea of each eye 3 months after laser treatment. CONCLUSIONS: Photorefractive Keratectomy was successful in the correction of myopia and prevented the recurrence of adenoviral subepithelial corneal infiltrates within the laser-treated central cornea.
