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Biomedical subjects

I Lipshitz

Publications and source records attributed to I Lipshitz.

29 records · Page 2Linked to original sources
PubMedDate not supplied

Cutting the cornea with a waterjet keratome.

BACKGROUND: Waterjet cutting is an advanced technology. It consists of a cutting tool that uses a very thin stream of ultra-high-pressure water forced at high velocity through a very small nozzle, creating a very sharp knife. We report on the first experimental use of waterjet technology to reshape the cornea. METHODS: The system was used in vitro on 10 bovine eyes, and in vivo on 10 albino rabbit eyes. Using the waterjet keratome (Lipshitz-Bass knife, LBK) lamellar corneal incisions were performed. Histological examinations were performed. RESULTS: A waterjet stream was found to be capable of incising corneas at relatively low energy levels (4000 PSI). Good surface quality could be obtained, and there was no collateral damage to the remaining portion of the cornea, lens, or retina. In the in vivo experiments, the epithelium healed within 48 hours. CONCLUSIONS: These preliminary experiments suggest that waterjet technology can be an effective instrument for reshaping the cornea.

Animals↗
PubMedDate not supplied

Influence of patient age on photorefractive keratectomy for myopia.

BACKGROUND: To determine whether the outcomes of photorefractive keratectomy (PRK) for myopia are age-dependent. METHODS: The influence of age on PRK outcomes was analyzed for one eye of each of 72 patients divided into two groups: 39 patients (18 to 26 years) and 33 patients (35 to 54 years). The influence of the amount of preoperative myopia (low myopia less than -4.00 diopters (D); moderate to high myopia -4.00 or more D) was also evaluated. All patients were followed for at least 1 year, and all underwent cycloplegic refractions. RESULTS: One year after PRK, the average refraction was -0.15 D in the younger group and +0.38 D in the older group. The achieved refraction was higher than the attempted by +1.00 D or more only in eyes with moderate to high myopia (-4.00 to -10.00 D); 11.54% (3 eyes) of the younger group and in 34.78% (8 eyes) of the older group. CONCLUSIONS: After PRK for myopia, patients between the ages of 35 and 54, with moderate to high myopia, obtained more refractive change with the same intended dioptric correction compared to younger patients with moderate to high myopia. Attempted correction should be adjusted according to age and amount of myopia.

Accommodation, Ocular↗
PubMedDate not supplied

Patient satisfaction after 5.0-mm photorefractive keratectomy for myopia.

PURPOSE: To examine patient satisfaction following photorefractive keratectomy (PRK) in a large number of subjects. METHODS: We used a questionnaire to examine overall patient satisfaction in 173 patients (173 first-operated eyes) at least 1 year after they had undergone PRK. Mean preoperative spherical equivalent refraction was -7.05 +/- 3.73 D (range, -1.50 to -15.00 D). Fifty-one patients had unilateral surgery and 122 had bilateral surgery, 60 of whom had follow-up of 1 year for both eyes. Visual and refractive results, the use of corrective lenses, and subjective side effects were also studied. RESULTS: Eighty percent of 173 patients reported they were satisfied or very satisfied with the surgical outcome, while 19.7% reported they were dissatisfied. The average satisfaction score was 7.92 +/- 2.22 out of a possible 10. After PRK, 77.5% reported improvement or great improvement in their general quality of life; 16.8% were very disturbed by subjective visual symptoms. Of the 51 bilateral patients, 85% required no corrective lenses after surgery. Patients who had bilateral operations were more satisfied than those who had unilateral ones. Statistically significant associations were found between patient satisfaction and initial refraction: as preoperative refraction increased, percentage of satisfied or very satisfied patients decreased. CONCLUSION: Patient satisfaction after PRK was generally high, but subjective visual symptoms remain a problem.

Adult↗
PubMedDate not supplied

Comparison of photorefractive keratectomy on one eye and laser in situ keratomileusis on the other eye of the same patient.

OBJECTIVE: The aim of this study was to compare the results of excimer laser photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) in the same patient. METHODS: All consecutive patients who underwent PRK in one eye and LASIK in the second eye using the same excimer laser (Nidek EC-5000) and had at least 12 months of follow-up were included in this retrospective study (N = 23). Uncorrected and spectacle-corrected visual acuity, final spherical equivalent refraction, and degree of haze were compared. RESULTS: Mean postoperative spherical equivalent refraction in the group of eyes that underwent PRK was +0.73 D (range, -5.50 to +3.50 D). Mean postoperative spherical equivalent refraction in the group of eyes that underwent LASIK was +0.07 D (range, -1.25 to +3.50 D) (P = .046). CONCLUSION: In our study, eyes treated with LASIK had better results than eyes treated with PRK.

Adult↗
PubMedDate not supplied

Bilateral comparison of photorefractive keratectomy for myopia using two excimer lasers.

PURPOSE: The aim of this study was to compare the results of excimer laser photorefractive keratectomy (PRK) in patients who underwent PRK using the Summit Apex (Omnimed) excimer laser in one eye and the Nidek EC-5000 excimer laser in the other. METHODS: All consecutive patients who underwent PRK with the Summit Apex laser (Omnimed) in one eye and the Nidek laser (EC-5000) in the second and had at least 12 months of follow-up were included in this retrospective study (n=30). Uncorrected and spectacle-corrected visual acuity, final spherical equivalent refraction, and grade of subepithelial haze were compared. The average preoperative spherical equivalent refraction of eyes treated with the Summit laser was -6.00 D (range, -2.50 to -8.75 D), and for Nidek-treated eyes it was -5.57 D (range, -2.50 to -8.80 D). RESULTS: Forty-seven percent of Summit-treated eyes and 53% of Nidek-treated eyes had uncorrected visual acuity of 6/6 or better; 61% of Summit-treated eyes and 63% of Nidek-treated eyes had uncorrected visual acuity of 6/7.5 or better; 95% of Summit-treated eyes and 95% of Nidek-treated eyes had uncorrected visual acuity of 6/12 or better (difference not statistically significant). Seventy-three percent of eyes treated with the Summit laser and 80% of eyes treated with the Nidek laser had a postoperative refraction within +/-0.50 D of emmetropia; 97% of Summit-treated eyes and 87% of Nidek-treated eyes had a postoperative spherical equivalent refraction within +/-1.00 D of emmetropia; the difference between the two lasers was not statistically significant. However, the percent of eyes with persistent hyperopia was smaller in the Nidek group after 3 months (P=.0062) and after 6 months (P=.07) than in the Summit group. Videokeratography was not done. CONCLUSION: Both lasers were effective with relatively low side effects. No significant difference was found between the two lasers in postoperative uncorrected visual acuity or refractive outcome. Eyes operated with the Nidek laser had less persistent hyperopia and stabilized earlier.

Adult↗
PubMedDate not supplied

Combined transverse and interrupted radial keratotomy for compound myopic astigmatism.

BACKGROUND: A variety of patterns of keratotomy are used to correct naturally occurring astigmatism. We evaluated straight transverse incisions with interrupted radial incisions (jump radials). METHODS: In 32 human eyes with naturally occurring astigmatism, we used straight transverse incisions with interrupted radial incisions, with or without additional radial keratotomy, to correct compound myopic astigmatism. The range of preoperative refractive astigmatism was 1.00 to 3.50 D. RESULTS: The mean follow-up time was 15 months (range, 12 to 18 months). The average surgically corrected astigmatism was 1.55 +/- 0.29 D. Eighty-seven percent of the eyes achieved less than 1.00 D of astigmatism, and the remaining four eyes retained 1.00 to 1.25 D of astigmatism. CONCLUSION: Combined transverse and interrupted radial incisions are effective in correcting naturally occurring astigmatism.

Adult↗
PubMedDate not supplied

Scraping of epithelium for treatment of undercorrection and haze after photorefractive keratectomy.

We report an easy, safe technique to treat regression and haze after excimer laser photorefractive keratectomy (PRK), in which the hyperplastic epithelium is removed manually. The results of scraping of epithelium in 21 eyes of 20 patients are presented. Mean follow-up time was 3 months (range 1 to 7). The mean spherical equivalent refraction before photorefractive keratectomy was -9.93 +/- 2.95 diopters (D); the mean spherical equivalent refraction before epithelial scraping was -3.82 +/- 2.87 D; after scraping it declined to -2.63 +/- 4.04 D. The uncorrected visual acuity after scraping was 20/50 or better in 6 eyes. In 5 others it was between 20/60 and 20/100, and in 10 eyes it was worse than 20/100. The corrected visual acuity after scraping was 20/30 or better in 8 eyes, between 20/40 and 20/60 in 8 eyes, and between 20/60 and 20/100 in 5 eyes.

Adult↗
PubMedDate not supplied

Astigmatic keratotomy followed by photorefractive keratectomy in the treatment of compound myopic astigmatism.

Eleven eyes of 9 patients that had compound myopic astigmatism were treated by astigmatic keratotomy followed 1 month later by photorefractive keratectomy (PRK). In 9 eyes arcuate incisions were performed, in 1 eye a modified Ruiz procedure was performed, and in 1 eye radial T cuts were done. The mean spherical equivalent was -8.26 +/- 2.51 diopters (D) after the astigmatic keratotomy but before photorefractive keratectomy, and -0.36 +/- 0.93 D after photorefractive keratectomy. The mean cylinder was -3.11 +/- 1.16 D preoperatively, and -0.14 +/- 0.9 D postoperatively. Combined astigmatic keratotomy and photorefractive keratectomy are effective treatments for compound myopic astigmatism.

Adult↗
PubMedDate not supplied

Photorefractive keratectomy for the treatment of myopia after epikeratoplasty: a case report.

An aphakic eye with a +9.00 diopter (D) refraction developed high myopia of -13.00 D after applying epikeratoplasty using a +14.00 D lenticule. We preformed photorefractive keratectomy by excimer laser. The procedure was uneventful, with no postoperative pain. Epithelialization occurred as usual. Recovery of the cornea followed the usual course with initial overcorrection followed by certain regression. After 7 months follow-up the spherical equivalent was -3.25 D and the lenticule was clear. In myopia after epikeratoplasty photorefractive keratectomy is an effective alternative to lenticule exchange.

Aphakia, Postcataract↗
PubMedDate not supplied

Phototherapeutic keratectomy in the treatment of corneal scarring from trachoma.

Trachoma is still one of the world's major blinding diseases. Characteristically, trachoma causes deep scarring of the conjunctiva and tarsus that can result in tear deficiency, trichiasis, and entropion. Another common finding is a diffused corneal opacity that is the end stage of peripheral and central corneal infiltrates. The conventional treatment of the corneal opacities is keratoplasty, which has a guarded prognosis because of severe dryness and trichiasis. We report on our experience in treating patients with corneal trachoma with phototherapeutic keratectomy (PTK) with the excimer laser.

Aged↗