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PubMedDate not supplied

Contrast sensitivity after posterior chamber phakic intraocular lens implantation for high myopia.

PURPOSE: To evaluate contrast sensitivity after posterior chamber phakic intraocular lens (PIOL) implantation for the correction of high myopia. METHODS: Twenty eyes of ten patients had a posterior chamber phakic intraocular lens (Staar ICL) implanted to correct high myopia. Mean preoperative myopia was -14.10+/-2.70 D. Follow-up was 24 months for all patients. Contrast sensitivity was tested with best spectacle-corrected visual acuity preoperatively and 3, 6, 12, 18, and 24 months postoperatively. RESULTS: Contrast sensitivity increased after surgery in all spatial frequencies. Normal values were achieved for low and intermediate spatial frequencies (3 and 6 c/deg). However, in spite of the improvement, values were still below normal for high spatial frequencies (12 and 18 c/deg). When the first postoperative examination was not considered, there were no statistically significant differences in contrast sensitivity values at different postoperative periods. CONCLUSION: Contrast sensitivity increased after posterior chamber phakic intraocular lens implantation (Staar ICL) in all spatial frequencies when compared to preoperative contrast sensitivity (best spectacle-corrected).

Adult↗
PubMedDate not supplied

Results of laser in situ keratomileusis for myopia of -10 to -19 diopters with a Technolas 217 laser.

PURPOSE: To evaluate the effectiveness, predictability, and safety of laser in situ keratomileusis (LASIK) for correcting myopia greater than -10.00 D. METHODS: Sixty-five eyes of 37 patients with myopia greater than -10.00 D underwent LASIK. Patients were evaluated on day 1, 1 week, 1, 3, and 6 months after surgery. Parameters evaluated were uncorrected visual acuity (UCVA) and best spectacle-corrected visual acuity (BSCVA), residual refractive error, regression of correction, and presence of any complication. RESULTS: Mean preoperative BSCVA was 0.745 +/- 0.234, which improved to 0.8070 +/- 0.237 postoperatively. The average preoperative UCVA was 0.022 +/- 0.02; postoperative UCVA at 6 months was 0.536 +/- 0.255. UCVA of 20/40 or better was achieved in 58% (38 eyes) and 20/20 or better in 26% (17 eyes). The average refractive error before LASIK was -12.64 +/- 2.16 D (range -10.00 to -19.00 D). Mean residual refractive error 1 week following LASIK was -0.63 +/- 1.36 D, which regressed to a mean -1.78 +/- 2.08 D at the end of 6 months. Nineteen eyes (29%) were within +/-0.50 D of intended refractive correction. CONCLUSION: LASIK was partially effective in the correction of high myopia. An initial overcorrection may be programmed to offset the effect of refractive regression.

Adult↗
PubMedDate not supplied

Nomogram adjustment of laser in situ keratomileusis for myopia and myopic astigmatism with the Alcon LADARVision system.

PURPOSE: To evaluate the visual and refractive results of conventional (non-wavefront) laser in situ keratomileusis (LASIK) for treatment of myopia and myopic astigmatism using the Alcon LADARVision 4000 excimer laser system and nomogram adjustment techniques. METHODS: A retrospective analysis of 499 eyes that had LASIK for myopia and myopic astigmatism was performed. Preoperative manifest spherical equivalent refraction ranged from -0.43 to -6.00 D and preoperative astigmatism ranged from 0 to -4.75 D. Patients were evaluated during 3 months following surgery. RESULTS: One month after surgery, 72% of eyes examined (298/415 eyes) had uncorrected visual acuity (UCVA) of 20/20 or better. Three months after surgery, 83% of eyes examined (216/261 eyes) had UCVA of 20/20 or better. One and three months after surgery, 82% and 83% of eyes, respectively, were within +/-0.50 D of attempted correction; 97% of eyes were within +/-1.00 D at both 1 and 3 months. No eye lost more than 1 line of best spectacle-corrected visual acuity (BSCVA) at 3 months after surgery. At the 3-month examination, 83% of eyes had UCVA better than or equal to preoperative BSCVA. CONCLUSIONS: Conventional LASIK to correct myopia and myopic astigmatism was safe and effective using the Alcon LADARVision 4000 excimer laser system. Outcomes were substantially improved throughout development of an accurate nomogram, derived from continually updated regression analysis of previous refractive results.

Adult↗
PubMedDate not supplied

Comparison of conventional and OATz ablation profiles for laser in situ keratomileusis to correct myopia up to -10.00 diopters.

PURPOSE: To compare results of laser in situ keratomileusis (LASIK) using two different ablation profiles for correction of myopia between -0.50 and -10.00 D with the Nidek NAVEX system. METHODS: In a prospective nonrandomized study, 249 myopic eyes (151 patients) had LASIK for correction of myopia. The Nidek MK-2000 micro-keratome and the Nidek NAVEX excimer laser system were used in all eyes. Conventional LASIK was performed in 112 eyes of 64 patients with a 6.0-mm ablation zone and 7.5-mm transition zone (conventional group). LASIK with the Nidek OATz ablation profile was performed in 137 eyes of 87 patients, with variable ablation and transition zones (OATz group). Mean baseline manifest refraction was -4.11 +/- 1.83 D in the conventional group and -5.45 +/- 2.27 D in the OATz group. Baseline best spectacle- corrected visual acuity was 20/20 or better in 83.9% of eyes in the conventional group and 81.0% of eyes in the OATz group. RESULTS: Mean follow-up was 3.6 months (range 3 to 8 mo). At last follow-up, manifest refraction was within +/-0.50 D of emmetropia in 86% of eyes (within +/-1.00 D in 99.1%) in the conventional group and 94.2% of eyes (within +/-1.00 D in 100%) in the OATz group. Uncorrected visual acuity was 20/40 or better in all eyes. No eyes in either group lost 2 or more lines of BSCVA. CONCLUSIONS: The Nidek NAVEX system was safe and predictable in correcting myopia up to -10.00 D with the OATz ablation profile. OATz LASIK was similar to conventional LASIK in both refractive and visual outcomes.

Adolescent↗
PubMedDate not supplied

Combined flap undersurface and bed LASIK for high myopia.

PURPOSE: To discuss the predictability, stability, and safety of LASIK for high myopia using laser treatment on both the flap undersurface and bed (both-sided LASIK). METHODS: One hundred twenty-one eyes of 63 patients underwent flap undersurface and bed LASIK for high myopia. Postoperative uncorrected visual acuity (UCVA), refraction, and topography were evaluated up to 12 months. The safety and injury indices in both-sided LASIK were compared with that of conventional LASIK. RESULTS: In both-sided LASIK, the largest diopter correction on the undersurface of the corneal flap was -6.00 diopters (D), correlating to an ablation of 44.62 microm. The mean thickness of residual corneal stroma bed was 283.87+/-19.83 microm after the laser treatment. Postoperative UCVA was close to the preoperative best spectacle-corrected visual acuity (BSCVA). The mean BSCVA was significantly better (P<.05) than preoperatively at each time point (1 week, 1, 3, and 6 months, and 1 year) after surgery. Postoperative corneal topography was normal in all cases. The safety and injury indices for conventional LASIK in both-sided LASIK eyes were calculated by programming the excimer laser as though conventional treatments would be performed to calculate the theoretical bed ablation. The safety factor of both-sided LASIK was higher than that calculated for conventional LASIK (P<.05); the injury index was lower than that calculated for conventional LASIK (P<.05). CONCLUSIONS: Surgery on high myopia by both-sided LASIK is safe and effective.

Adolescent↗
PubMedDate not supplied

LASIK for myopia with the Zeiss meditec MEL 80.

PURPOSE: To prospectively evaluate a new high-speed, small spot-scanner laser for the correction of myopia and myopic astigmatism. METHODS: Seventy-six consecutive eyes with myopia and myopic astigmatism between -1.00 and -8.25 diopters (D) and up to -2.75 D astigmatism underwent LASIK treatment using the MEL 80 laser (Carl Zeiss Meditec, Jena, Germany). Parameters evaluated were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), residual refractive error, regression of correction, and aberrometry. RESULTS: Mean preoperative BSCVA was 20/20, which improved to 20/18 postoperatively. Postoperative UCVA was 20/20 at 1 month and 20/18 at 1 year. Uncorrected visual acuity > or = 20/20 was achieved in 58 (83%) of 70 eyes at 1 month and in 60 (88%) of 68 eyes at 1 year. The average refractive error before LASIK was -4.41 +/- 1.98 D. The mean residual refractive error was 0.14 +/- 0.31 D at 1 month and 0.13 +/- 0.30 D at 1 year. At 1-month and 1-year follow-up, respectively, 66 (94%) of 70 eyes and 65 (96%) of 68 eyes were within +/- 0.50 D of intended refractive correction. No eye lost two lines. At 1 month 17% of eyes and at 1 year 13% of eyes gained two lines or more. Between 1-month and 1-year follow-up, 100% of eyes were stable. Mean root-mean-square high order aberration changed from 0.20 microm preoperatively to 0.28 microm postoperatively. CONCLUSIONS: The MEL 80 is effective and safe in the treatment of myopia and myopic astigmatism.

Adolescent↗
PubMed2006

Rhegmatogenous retinal detachment after LASIK for myopia.

PURPOSE: To report the characteristics and incidence of rhegmatogenous retinal detachment in myopic eyes after LASIK. METHODS: The medical records of 49 patients with rhegmatogenous retinal detachment after LASIK were reviewed. The incidence of rhegmatogenous retinal detachment after LASIK was determined and potential risk factors were evaluated. RESULTS: LASIK was performed on 59,424 eyes with spherical equivalent refraction (SE) ranging from -0.75 to -26.50 diopters (D) (mean: -6.10 +/- 3.5 D). Forty-nine eyes developed rhegmatogenous retinal detachment between 1.5 and 76 months (mean: 27.3 +/- 21.7 months) after LASIK. The mean preoperative refractive error in these eyes was -8.6 +/- 3.9 D. Mean age of these patients was 38.2 +/- 11.2 years. Thirty-five (71.4%) patients were male. The cumulative incidence of rhegmatogenous retinal detachment was 0.082% (95% confidence interval [CI]: 0.061-0.109), and the yearly incidence was 0.032% (95% CI: 0.023-0.042) after LASIK. The most frequent location of the retinal breaks was the superior temporal quadrant (22.7%). Male sex, older age, and higher preoperative myopia were significantly related to the incidence of rhegmatogenous retinal detachment after LASIK (P<.001). CONCLUSIONS: Based on the results of this study, following the treatment of high-risk peripheral retinal lesions, LASIK did not appear to be an additional risk factor for the development of rhegmatogenous retinal detachment after LASIK in our patients; however, patients should be informed of the possibility of this complication as a consequence of myopia. Patients who are male, older in age, and have high myopia preoperatively may be at increased risk.

Adolescent↗
PubMed2006

Topographic- and wavefront-guided customized ablations with the NIDEK-EC5000CXII in LASIK for myopia.

PURPOSE: To assess refractive outcomes, changes in the total higher order root mean square (RMS) aberration, and changes in higher order wavefront aberrations after LASIK for myopia and myopic astigmatism with the NIDEK Advanced Vision Excimer Laser platform (NAVEX) using either an aspheric or topography-based or whole eye wavefront ablation algorithm. METHODS: This was a retrospective study of 1459 eyes that underwent LASIK for myopia and myopic astigmatism. The mean preoperative spherical equivalent refraction was -4.68 diopters (D) (range: -0.50 to -9.63 D) with astigmatism up to -4.50 D. Treatments were classified into three categories depending on the type of ablation algorithm used--optimized aspheric transition zone (OATz) denoted eyes that underwent aspheric treatment zones; customized aspheric treatment zone (CATz) denoted eyes that underwent customized ablations based on corneal topography; and OPDCAT denoted eyes that underwent customized ablation based on the whole eye wavefront profile. Follow-up data are reported at 3 months (69%) and 12 months (17%) postoperatively. RESULTS: Three months after LASIK, the predictability (10.5 D from target refraction) was 80% for OATz, 91% for CATz, and 76% for OPDCAT. Of all eyes, 96% were within +/- 1.0 D of intended refraction 3 months postoperatively and 100% after 12 months (87% +/- 0.5 D). In the aspheric and custom groups, a notable improvement of uncorrected visual acuity was noted between 3 and 12 months after LASIK. No eye lost >1 line of best spectacle-corrected visual acuity. Mean higher order RMS increased in all groups. CONCLUSIONS: The data support that the treatment of myopia and myopic astigmatism is safe and effective with NAVEX. Customized ablation based on corneal topography rather than on total wavefront error was more predictable.

Adolescent↗
PubMed2006

Ten-year follow-up of 360 degrees intrastromal corneal rings for myopia.

PURPOSE: To determine the safety, efficacy, and stability of intrastromal corneal rings 10 years after placement for myopia. METHODS: Ten eyes with myopia treated with the placement of 360 degrees complete intrastromal corneal rings with the ends sutured together were evaluated at 10-year follow-up for the following: uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction spherical equivalent (MRSE), induced manifest refractive cylinder, keratometry readings, slit-lamp findings, and ultrasound central pachymetry. Ten-year data were compared to 1-year results to assess visual stability over time. RESULTS: No statistically significant difference was noted between UCVA at 1 year and 10 years. At the 10-year examination, 90% of patients had BSCVA > or = 20/25 and 100% had BSCVA > or = 20/30. There was no statistically significant difference between MRSE at 1 year and 10 years. At the 10-year examination, induced manifest refractive cylinder was >1.00 diopter (D) in 0% of eyes and < or = 0.25 D in 60% of eyes. There was no statistically significant difference between mean central keratometric power at 1-year follow-up compared with 10-year follow-up. No statistically significant difference was noted in central corneal thickness between 1 and 10 years in the eyes studied. CONCLUSIONS: Intrastromal corneal rings are an effective and stable method of correcting mild myopia based on optic parameters.

Adult↗
PubMed1976

[A short observation on the cause of myopia (author's transl)].

The increased excretion of acid mucopolysaccharides in the urine of patients with advanced myopia is indeed relevant for understanding the chemical processes in the sclera during this period, but it does not say anything concerning the genesis of myopia as such. This is due more to an infiltrative malformation of the eyeball and the optic nerve. The behaviour of the connective tissue can also be due to infiltration, or contrariwise induced from parenchyma at the appropriate time. Hence therapeutic possibilities can hardly be deduced from the chemistry of the sclera. Abnormally small corneas in people with high myopia point to a genetic connection between such eyes and "true" microphthalmos with orbital cyst.

Humans↗
PubMed1998

Spherical and aspherical photorefractive keratectomy and laser in-situ keratomileusis for moderate to high myopia: two prospective, randomized clinical trials. Summit technology PRK-LASIK study group.

OBJECTIVE: Determine the outcomes of single-zone photorefractive keratectomy (SZPRK), aspherical photorefractive keratectomy (ASPRK), and laser in-situ keratomileusis (LASIK) for the correction of myopia between -6 and -12 diopters. DESIGN: Two simultaneous prospective, randomized, multi-center clinical trials. PARTICIPANTS: 286 first-treated eyes of 286 patients enrolled in one of two studies. In Study I, 134 eyes were randomized to SZPRK (58 eyes) or ASPRK (76 eyes). In Study II, 152 eyes were randomized to ASPRK (76 eyes) or to LASIK (76 eyes). INTERVENTION: All eyes received spherical one-pass excimer laser ablation as part of PRK or LASIK performed with the Summit Technologies Apex laser under an investigational device exemption, with attempted corrections between -6 and -12 diopters. MAIN OUTCOME MEASURES: Data on uncorrected and best spectacle-corrected visual acuity, predictability and stability of refraction, and complications were analyzed. Follow-up was 12 months. RESULTS: At 1 month postoperatively, more eyes in the LASIK group achieved 20/20 and 20/25 or better uncorrected visual acuity than PRK-treated eyes; at the 20/25 or better level, the difference was significant for LASIK (29/76 eyes, 38%) over SZPRK (10/58 eyes, 17%) (P = .0064). At all subsequent postoperative intervals, no difference was seen between treatment groups. Similarly, best corrected visual acuities were better for LASIK than all PRK eyes at 1 month postoperatively, and LASIK was better than SZPRK at 3 months follow-up (e.g., for 20/20 or better at 1 month, LASIK 50/76 eyes (66%) versus SZPRK 24/57 eyes (42%), P = .0066). PRK eyes had a mean loss of BCVA through 6 months, while LASIK eyes had a slight gain of mean BCVA through month 6; at 12 months, both ASPRK groups but not SZPRK continued to have a small mean loss of BCVA (e.g., compared to preoperative, mean BCVA at 12 months for SZPRK was + 0.3, LASIK was +.21, ASPRK I was -0.11, and ASPRK II -0.31 (SZPRK versus ASPRK II, P = .0116). Predictability was better for PRK than LASIK at all follow-up intervals (e.g., for manifest refraction spherical equivalent +/- 1.0 diopters at 6 months, ASPRK I 42/62 eyes (68%) versus LASIK 29/72 eyes (40%), P = .0014%). Stability was slightly but insignificantly less in the LASIK eyes compared to PRK eyes. All visual outcome measures were better for eyes with preoperative myopia between -6 and -8.9 D compared with eyes with myopia between -9 and -12 D. No consistent differences in refractive outcomes or postoperative corneal haze were seen between aspherical and single-zone ablations; haze diminished over 12 months and was judged to be vision-impairing in only one ASPRK eye. Microkeratome and flap complications occurred in 4 eyes, resulting in delay of completion of the procedure in 3 eyes but not causing long-term impairment. CONCLUSIONS: Improvement in uncorrected visual acuity and return of best corrected visual acuity was more rapid for LASIK than PRK, but efficacy outcomes in the longer term through 12 months were similar for all treatment groups. LASIK eyes tended toward undercorrection with the nomogram employed in this study compared to PRK, but the scatter was similar, suggesting little difference between these procedures for most patients by 6 months and thereafter. No consistent advantage was demonstrated between aspherical and single-zone ablation patterns. Predictability was much better for all procedures for corrections of -6 to -8.9 D compared with -9 to -12 D. Sporadic loss of best corrected vision in the PRK eyes not found in the LASIK eyes and other measures of visual function require further study.

Adult↗
PubMed1999

Excimer laser photorefractive keratectomy for high myopia and myopic astigmatism.

BACKGROUND AND OBJECTIVE: To determine the efficacy, safety, and predictability of excimer laser photorefractive keratectomy of high myopia and myopic astigmatism. PATIENTS AND METHODS: 76 eyes of 52 patients with myopia from -8.00 to -23.50 diopters (D) with or without astigmatism up to -5.50D were treated with the VISX 20/20 excimer laser (VISK, Santa Clara, CA) and a multi-zone ablation technique. Visual acuity, manifest refraction, corneal haze, and topography were evaluated at 1 week and 1, 3, 6, 12, and 18 months postoperatively. RESULTS: Postoperative refractions were generally stable after 12 months. At the last follow-up all patients were within - 1.96 D of the intended correction. Eighteen months postoperatively, 68% of patients undergoing photorefractive keratectomy (PRK), and 65% of patients undergoing photo astigmatic refractive keratectomy (PARK), were within 1 D of planned refraction. Furthermore, 87% of patients after PRK and 80% of patients after PARK had a visual acuity of 20/40 or better. CONCLUSIONS: High myopia with or without astigmatism was successfully treated in most of the patients using PRK. The stability of the postoperative refraction during the first 18 months seems to be good. The incidence of adverse effects was low but improvements in the future should further reduce complications, thus increasing the safety of refractive procedures.

Adult↗
PubMed1997

[A preliminary report of microlamellar keratectomy for correction of high myopia].

OBJECTIVE: To evaluate the preliminary results of high myopia corrected by microlamellar keratectomy (MLK). METHODS: 73 eyes of 43 patients with high myopia were treated by MLK. The preoperative refraction ranged from -7.00 to -32.00 D (mean -18.45 +/- 6.18 D). All the operations were performed with a special apparatus made in America for MLK. RESULTS: At 6 months after surgery, in the 73 eyes with complete data, all the uncorrected visual acuity and corrected visual acuity were betterthan or equal to their preoperative ones respectively. Uncorrected visual acuity was better than or equal to the preoperative corrected visual acuity in 51 eyes (71.83%). The correction of refraction in 63 eyes (86.30%) was within +/- 4.00 D of the intended correction. No severe complications occurred during and after operation. The postoperative status of refraction was stable. CONCLUSIONS: MLK is effective in high myopia treatment and has some special advantages compared with radial keratotomy, photorefractive keratectomy, automated lamellar keratoplasty and excimer laser in situ keratomileusis. But the procedure is influenced by several factors, and the predictability of this procedure is merely fair. The authors suggest that this kind of procedure be done with excellent microsurgery equipment, microsurgical skills and much more clinical experiences in managing corneal disorders.

Adolescent↗
PubMedDate not supplied

[Complex method for examining children with false myopia].

The authors propose a complex method for examining children with false myopia. The complex includes routine methods for detecting and evaluating the stability of spasm, measurement of the relative accommodation reserve, ophthalmic tone, and anteroposterior axis of the eye. The method allows differentiation between false and true myopia, evaluates its degree, and helps prescribe etiopathogenetic treatment for ruling out the transfer of false myopia into true (axial).

Accommodation, Ocular↗
PubMedDate not supplied

[Reinforcement of the sclera with new types of synthetic materials in progressive myopia].

The possibility of using a new synthetic material mersilene for scleroplastic operations has been evaluated in experiments and clinical trials were carried out in patients with progressive myopia subjected to sclera fortification. Morphological studies showed the formation of a connective tissue capsule round mersilene; new collagen fibers grow through its cellular structures, thus fortifying the strength of the sclera-graft complex. Clinical results indicate that sclera fortification by a mersilene graft arrested the progress of myopia in almost all (98%) patients by the end of the first year postoperation; by the end of the second year, myopic refraction stabilized in 92% patients. Hence, mersilene transplants are recommended for scleroplasty in progressive myopia.

Adolescent↗
PubMed1999

Seven years experience with LASIK for myopia.

PURPOSE: This paper presents the results of the last seven years with LASIK for the treatment of myopia. METHODS: 4170 eyes of 3163 patients with a mean preoperative spherical equivalent--9.66 diopters were submitted to LASIK. The eyes were divided in three groups according to the preoperative refraction: Group A (-5 to 10D), group B (-10 to 16D) and group C (over -16 D). RESULTS: At one year the percentage of eyes within +/- 1D of emmetropia was the following: group A: 84.4%, group B: 70.8%, and group C: 42.8%. CONCLUSIONS: The method is safe, effective, and predictable especially in the range of myopia between -5 and -15 D of myopia. Predictability could be further improved by secondary procedures.

Follow-Up Studies↗
PubMedDate not supplied

[Clinical variants of glaucoma in patients with acquired high myopia].

Examinations of 88 glaucoma patients with high myopia showed three variants of glaucoma: 1) mixed form with combination of nuclear cataract and lenticular myopia, 2) open-angle form with ischemic background cerebral circulation (ocular circulation deficiency combined with a decrease in linear velocity of the bloodflow in the intracranial collateral cerebral circulation: to 21.8% in the anterior cerebral artery, to 26.1% in the middle cerebral artery, and to cerebral artery (by 8.3%) and in the orbital artery (by 4.2%). Clinical values indicate impeded venous outflow. Differential diagnostic signs of glaucoma in high myopia are defined.

Adult↗