We performed eight radial line cuts in anterior radial keratotomy(RK) employing the Russian style and the American style incisions on 103 eyes from August/ 1989 to March/ 1990. To analyze the results of myopic correction according to the size of the central optical zone and the incision length in RK, we chose the central optical zone size according to the degree of myopia (4.0 mm from -1.50D to -2.75D, 3.5mm from -30D to -3.75D and 3.0mm above -4.0D) and measured the length of each of the eight radial incisions of the cornea. The results were as follows: 1. In determining the average length of each corneal incision in RK, the longest was the superior and superior-nasal incision and the shortest was the temporal and inferior-temporal incision, regardless of the central optical zone size. 2. The total length of each of the eight incisions in each eye ranged from the longest at 3.0mm of central optical zone and the shortest at 4.0mm of central optical zone Undoubtedly, total incision length affected clinical results not significantly (p>0.05). 3. Assessing the clinical effect of myopic correction according to the optical zone size, smaller diameter clear zones produce a greater flattening of the cornea than larger ones. 4. The clinical result was not significantly affected by the direction of the incision (p>0.05).
Cornea ; Keratotomy, Radial* ; Myopia

To measure the rate of endothelial cell loss caused by anterior radial keratotomy, twenty one eyes of twelve patients were chosen. Numbers of endothelial cells per mm2 were examined through Keeler Konan wide field specular microscope at the time of preoperative, postoperative 3 month, 6 month, and 1 year. There were only a few changes in numbers of endothelial cells, and the results were statistically significant. Therefore anterior radial keratotomy rarely cause bullous keratopathy due to significant endothelial cell loss.
Endothelial Cells* ; Humans* ; Keratotomy, Radial*

To measure the rate of endothelial cell loss caused by anterior radial keratotomy, twenty one eyes of twelve patients were chosen. Numbers of endothelial cells per mm2 were examined through Keeler Konan wide field specular microscope at the time of preoperative, postoperative 3 month, 6 month, and 1 year. There were only a few changes in numbers of endothelial cells, and the results were statistically significant. Therefore anterior radial keratotomy rarely cause bullous keratopathy due to significant endothelial cell loss.
Endothelial Cells* ; Humans* ; Keratotomy, Radial*

Corneal thickness is of paramount importance in radial keratotomy, The corneal thickness is usually measured before the surgery and it is used to set the length of knife blade for the surgery. But corneal thickness is not monitored during surgery. Some studies report the change of the corneal thickness during surgery and heat from the operating microscope and air current is considered as the factors which affect the corneal thickness during surgery. The purpose of this study is to determine the change in corneal thickness during radial keratotomy in rabbit. The corneal thickness was measured with ultrasonic pachymeter(Vida 55, U.S.A.). Forty-four rabbits(44 eyes) received radial keratotomy and the central corneal thickness was taken just before the operation and immediately, 1 day and 1 week after the operation. Seven rabbits(7 eyes) were served as control and they were exposed to the same operating conditions but no surgery was performed. The corneal thickness was measured at 0 minute, 5 minutes and 10 minutes respectively. The results were as follows: 1) The corneal thickness of the experimental group before the operation and immediately, 1 day and 1 week after the operation were 361.57 +/- 19.63 micrometer, 328.25 +/- 22.97 micrometer, 346.07 +/- 19.36 micrometer and 351.02 +/- 20.94 micrometer respectively. 2) The corneal thickness of the control group at 0 minute, 5 minutes and 10 minutes were 367.29 +/- 48.70 micrometer, 341.29 +/- 66.43 micrometer, and 320.43 +/- 74.20 micrometer respectively. 3) The corneal thickness of experimental group was reduced by 9.07% immediately after surgery than that before the operation, and it was significant statistically(p<0.000). 4) The corneal thickness of experimental group on 1 day and 1 week after operation was reduced by 4.18% and 2.85% than that before operation, and it was significant statistically (p<0.000 respectively). 5) In control group the corneal thickness of 5 minutes and 10 minutes was reduced by 7.60% and 13.54% than that of 0 minute, and it was significant statistically(P-value; 0.033, 0.009 respectively). 6) There was no statistically significant difference between the corneal thickness in experimental and control group at 5 minutes and 10 minutes respectively(p-value; 0.466, 0.816 respectively).
Hot Temperature ; Keratotomy, Radial* ; Ultrasonics

The authors report clinical results of 6 myopic patients(6 eyes) who showed undercorrection following keratomileusis-in-situ and then underwent radial keratotomy to correct the residual myopia. The mean age of patients was 39.2 years, and the mean interval between keratomileusis and radial keratotomy was 19.8 months. The mean refractive error was changed from -7.0D preoperatively to -3.23D after radial keratotomy. 'The average difference of refractive error between treated eye and untreated fellow eye was changed from 5.12D to 1. 63D after radial keratotomy. The mean visual acuity was changed from 0.15 preoperatively to 0.33 after radial keratotomy. In conclusion, radial keratotomy is an useful procedure for correcting undercorrected myopia after keratomileusis in situ.
Humans ; Keratotomy, Radial* ; Myopia* ; Refractive Errors ; Visual Acuity

PURPOSE: To report the long-term results concerning refractive changes after radial keratotomy in 6 eyes of 3 patients. CASE SUMMARY: We observed 3 patients who underwent radial keratotomy over 25 years previously. The positive effect of this surgery on the correction of refractive error decreased with increasing post-surgery time and myopic refractive errors accompanying astigmatism recurred. On average, refractive errors improved to 3.375 diopter (D) and corneal power improved to 2.954 D; in all cases, uncorrected visual acuities were not significantly improved. CONCLUSIONS: The effect of radial keratotomy on the correction of refractive errors decreased with time due to regression; myopic refractive errors recurred in the long-term.
Astigmatism ; Humans ; Keratotomy, Radial* ; Myopia ; Refractive Errors ; Visual Acuity

We had performed eight incision radial keratotomy employing the American technique on 247 eyes of 166 patients from July, 1986 to December, 1987. The clinical results including postoperative uncorrected visual acuity, refractive power, and keratometric power were followed up at 6 months on 92(37.2%) of 247 cases. The results were as follows; 1. The mean postoperative uncorrected visual acuity was 0.595 and 60.9% of all cases had 20/40 or better uncorrected visual acuity. 2. The mean reduction in postoperative refractive power was 3.26 diopters. 3. The mean reduction in postoperative keratometric power was 3.08 diopters. 4. Operative and postoperative complications were visual fluctuation(142 eyes), photophobia(52 eyes), microperforation(7 eyes), transient increase of IOP(5 eyes), changes of peripheral cornea(6 eyes), and one case of postoperative cataract with persistent hypotony and uveitis.
Cataract ; Humans ; Keratotomy, Radial* ; Postoperative Complications ; Uveitis ; Visual Acuity

PURPOSE: To elucidate a proper method of intraocular lens (IOL) power calculation in highly myopic eyes with previous radial keratotomy (RK). METHODS: Five post-RK-surgery eyes with pre-RK-surgery myopia over -10.0 diopters (D) were studied retrospectively. The keratometric values obtained via the clinical history method, the contact lens over-refraction method, conventional keratometry, and Orbscan II were compared to the true keratometric value calculated retrospectively using the SRK/T formula. RESULTS: The mean pre-RK-surgery refractive power was -19.35+/-5.86D (-14.50 ~ -29.50D) and cataract surgery was performed on average 16.6 years after RK. The true keratometric value was closest to that estimated by the contact lens over-refraction method in 1 eye and to the flatter keratometric value between Sim K and the 3mm zone mean Pwr obtained with axial keratometric power map of Orbscan II in 4. CONCLUSIONS: The flatter keratometric value between Sim K and the 3mm zone mean Pwr from Orbscan II was closest to the true post-RK-surgery keratometric value of the central cornea.
Cataract ; Cornea ; Keratotomy, Radial* ; Lenses, Intraocular* ; Myopia ; Retrospective Studies

This study was performed to compare the refractive effect and visual outcome of Excimer laser radial keratotomy(RK) with those of central photorefractive keratectomy(PRK) for myopia correction. The myopic eyes were subdivided into mild(-2.75D), moderate(-3.00 ~ -5.75D) and severe(>-6.00) myopia. In 54 eyes treated with RK 3 eyes(5.6%) were mild, 26 eyes(48.1%) were moderate and 25 eyes (46.3%) were severe myopic eyes. In 518 eyes treated with central PRK 10 eyes(1.9%) were mild, 214(41.3%) were moderate and 294(56.8%) were severe myopic eyes. Mean reduction of refractive power measured with skiascope following RK and central PRK in mild, moderate and severe myopia were 1.42 +/- 0.85D and 3.19 +/- 0.84D, 2.07 +/- 1.75D and 4.66 +/- 1.90D, and 2.54 +/- 2.45D and 7.54 +/- 2.81D, respectively. Mean reduction of keratometric diopter following RK and central PRK in mild, moderate and severe myopia were 2.00 +/- 1.05D and 3.66 +/- 1.03D, 1.90 +/- 1.05D and 4.83 +/- 1.99, and 1.52 +/- 2.54D and 5.58 +/- 3.46D, repectively. Uncorrected visual acuity following RK and central PRK in mild. moderate and severe myopia were 0.73 +/- 0.19 and 0.91 +/- 0.26, 0.43 +/- 0.30 +/- and 0.79 +/- 0.24, and 0.20 +/- 0.13 and 0.66 +/- 0.28, respectively. In conclusion, refractive effect and visual outcome of central photorefractive keratectomy was better than the those of radial keratotomy for correction of myopia; especially high myopic eyes.
Keratotomy, Radial* ; Lasers, Excimer* ; Myopia* ; Photorefractive Keratectomy* ; Visual Acuity

Radial keratotomy has not been used to treat keratoconus. A 20-year-old male with keratoconus underwent a radial keratotomy to achieve satisfactory vision. Immediately after the operation visual acuity was improved, but one year later acute hydrops was developed for unknown reasons. Therefore, the authors report it with review of the literatures.
Edema* ; Humans ; Keratoconus* ; Keratotomy, Radial* ; Male ; Visual Acuity ; Young Adult