Journal of refractive and corneal surgery

Publisher: International Society of Refractive Keratoplasty

Description

Discontinued in 1994. Continued by the Journal of Refractive Surgery (1995) (1081-597X).

  • Impact factor
    0.00
  • 5-year impact
    0.00
  • Cited half-life
    0.00
  • Immediacy index
    0.00
  • Eigenfactor
    0.00
  • Article influence
    0.00
  • Other titles
    Journal of refractive and corneal surgery
  • ISSN
    1081-0803
  • OCLC
    30372788
  • Material type
    Periodical
  • Document type
    Journal / Magazine / Newspaper

Publications in this journal

  • Journal of refractive and corneal surgery 01/1998; 10(4):466.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Photorefractive keratectomy (PRK) was performed on 98 consecutive normal myopic eyes with the Summit OmniMed laser System. The minimum follow-up was 3 months and 31 were followed for 6 months. Preoperative myopia ranged from -1.25 to -12.00 D. The myopic eyes were divided into 4 groups according to the amount of myopia: group 1 (-1.25 to -3.00 D), 17 eyes; group 2 (-3.12 to -6.00 D), 42 eyes; group 3 (-6.12 to -9.00 D), 29 eyes and group 4 (> 9.00 D), 10 eyes. In group 1 mean uncorrected visual acuity was 0.87 at 3 months, 1.0 at 6 months and all of the eyes were within 0.50 D of the attempted correction. In group 2 mean uncorrected visual acuity was 0.76 at 3 months, 0.87 at 6 months and 92.3% of the eyes were within 0.50 D of the attempted correction. In group 3 mean uncorrected visual acuity was 0.65 and 0.66 at 3 and 6 months respectively and 77.8% of eyes were within 0.50 D of the attempted refractive correction. In group 4, mean uncorrected visual acuity was 0.46 and 0.7 at 3 and 6 months, respectively, and 100% were within 0.50 D of the attempted correction. Two eyes lost 2 lines and 4 eyes gained 2 or more lines of their preoperative best spectacle corrected visual acuity. Three eyes exhibited steroid induced rise in intraocular pressure that was controlled with topical timolol. No serious complications occurred. Despite the short follow-up, photorefractive keratectomy with the 193 nm excimer laser appears to be an effective and safe treatment for the correction of myopia.
    Journal of refractive and corneal surgery 01/1994; 10(2 Suppl):S231-4.
  • Journal of refractive and corneal surgery 01/1994; 10(5):587-8.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Single and double deepening of the peripheral part of radial keratotomy incisions are used to increase the refractive effect. Single peripheral deepening was performed in 52 eyes of 36 patients and double peripheral deepening in 19 eyes of 14 patients who received radial keratotomy. In the single peripheral deepening group, the mean change in refractive power was 4.01 diopters (D); 53.8% of eyes were within +/- 1.00 D of emmetropia; residual myopia was greater than -1.00 D in 46.2% of eyes; 65.4% of eyes achieved an uncorrected visual acuity greater than or equal to 20/40. In the double peripheral deepening group, the mean change in refractive power was 5.07 D; 52.6% of eyes wee within +/- 1.00 D of emmetropia; residual myopia was greater than -1.00 D in 47.4% of eyes; 89.4% of eyes achieved an uncorrected visual acuity greater than 20/40. The difference in mean dioptric change between the standard radial keratotomy groups and the single and double peripheral deepening groups was 0.53 D and 0.47 D, respectively. Considering the limited additional dioptric change compared with the standard radial keratotomy surgical technique and the increased rate of complications, we think that peripheral deepening in radial keratotomy should be avoided.
    Journal of refractive and corneal surgery 01/1994; 10(6):621-4.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Photorefractive keratectomy (PRK) has been used to treat myopia in human eyes since 1988. We evaluated corneal ablation depth after excimer laser myopic photorefractive keratectomy with the Summit Technology ExciMed UV200LA laser. Preoperative refraction was: mean 9.58 diopters (D) +/- 2.01, (range 6 to 17). We used ultrasound pachometry (1640 m/sec) in 40 eyes of 33 patients. Mean follow-up was of 49.5 weeks (range 16 to 76). The measurement of the corneal thickness showed a reduction of the initial thickness followed by an inconsistent increase caused by wound healing and tissue proliferation. The data showed no direct correlation between diopters of refractive correction and the change in corneal thickness.
    Journal of refractive and corneal surgery 01/1994; 10(2 Suppl):S211-6.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Beginning in March 1992, 176 eyes from 176 patients underwent photorefractive keratectomy with the Summit Technology Eximed UV200LA. This study was designed to evaluate the efficacy of this method.
    Journal of refractive and corneal surgery 01/1994; 10(2 Suppl):S199-205.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Map-dot-fingerprint epithelial changes of the cornea have been reported to occur as a consequence of trauma or surgical procedures, such as radial keratotomy. We describe a case of dot-like changes in the corneal epithelium following excimer laser photorefractive keratectomy for the correction of myopia. Because the lesions were located centrally, possibly reducing visual acuity, the epithelium was removed mechanically. Dot-like changes recurred in the same areas 4 weeks after epithelial debridement. Best spectacle-corrected visual acuity improved from 20/200 to 20/100 and remained stable thereafter. Photorefractive keratectomy can lead to abnormal regeneration of epithelium basement membrane, possibly resulting in dot-like changes of corneal epithelium.
    Journal of refractive and corneal surgery 01/1994; 10(3):357-9.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Clinical results show that photorefractive keratectomy (PRK) offers good predictability, efficacy, and safety. However, its potential risks on the human corneal endothelium are poorly known. We report the results of a prospective study conducted to evaluate the corneal endothelium changes after photorefractive keratectomy. Preoperative and serial postoperative specular microscopy was performed in 14 eyes undergoing excimer laser photorefractive keratectomy. The endothelium was analyzed for a variety of parameters, including cell density, coefficient of variation in cell size, and hexagonality. The follow-up was 6 months. The mean cell density was unchanged from 2463 cells/mm2 to 2498 cells/mm2 at 6 months after photorefractive keratectomy. The coefficient of variation of cell size (polymegathism) changed from 0.303 to 0.280 at 1 month, to 0.293 at 3 months, and to 0.290 at 6 months after surgery. The changes in this parameter were statistically significant when comparing pre- versus 1 month postoperative values. The hexagonality was unchanged from 72.08% at baseline to 73.35% at 6 months. No endothelial abnormalities were found after photorefractive keratectomy. Our results suggest a cell migration from the peripheral to central cornea after photorefractive keratectomy in contact lens wearing patients prior to photorefractive keratectomy.
    Journal of refractive and corneal surgery 01/1994; 10(2 Suppl):S194-8.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Intrastromal corneal rings (ICRs) often exhibit small deposits in association with their suture holes. We assessed the morphology of four such deposits. Four ICRs, explanted from nonfunctional human eyes, were examined by scanning electron microscopy and transmission electron microscopy. The surface of the suture hole deposits consisted of a disorganized convolution of collagenous lamellae. Within individual lamellae, however, the collagen fibrils tended to orientate parallel with one another. The deposits consisted of an amorphous material interspersed with curved cellular processes, collagen fibrils of variable diameter, and proteoglycan macromolecules. We propose that the mechanism which regulates stromal remodeling is amended in the region of the ICR suture holes. Due to their location, suture hole deposits have no optical significance; however, evaluation of their morphology provides insights into the wound-healing properties of the corneal stroma following ICR insertion.
    Journal of refractive and corneal surgery 01/1994; 10(2):142-8.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Many radial keratotomy surgeons advocate bilateral simultaneous surgery, in which there is an inherent, although rare, risk of bilateral sight-threatening complications such as microbial keratitis. This study was designed to evaluate the refractive outcomes of simultaneous and non-simultaneous radial keratotomy performed by a single surgeon. We retrospectively compared the results of radial keratotomy performed simultaneously (both eyes operated on the same day, 20 patients) versus non-simultaneously (right and left eyes operated on different days, 71 patients) by a single surgeon. Both eyes had the same surgical procedure, including clear zone diameter and number of incisions. The refractive results of bilateral simultaneous and non-simultaneous surgery were largely equivalent for all parameters analyzed except one. The variability of the difference in postoperative refractive error between right and left eyes was less for those patients undergoing simultaneous surgery (p = .0008). Our data suggest that performing radial keratotomy as a bilateral simultaneous procedure increases the symmetry of the refractive effect. In view of recent reports of sight-threatening risks such as bilateral microbial keratitis following bilateral keratotomy, however, the potential risks and benefits of bilateral surgery should be carefully considered before operating on both eyes on the same day.
    Journal of refractive and corneal surgery 01/1994; 10(5):545-9.
  • [Show abstract] [Hide abstract]
    ABSTRACT: We designed an excimer laser keratomileusis delivery system to increase the regularity of the refractive cut surface and allow greater precision in the level and shape of the ablated zone. A parallel faced corneal disc was produced by microkeratectomy from six human eyes and surgical keratectomy in 12 beagle corneas. A 193-nanometer excimer laser that was used to project an oval beam onto the corneal disc was rotated on a flat surface to ensure overlapping of the ovally ablated areas between pulses. Electron microscopy of eye bank lenticules demonstrated a circular smooth regularly concave ablation zone. Histological examination of nine clear corneas confirmed thinning of the stroma without fibroblastic reaction and no epithelial hypertrophy. Mean preoperative corneal power of 43.15 +/- 2.18 decreased postoperatively to 33.61 +/- 2.34. The new technique of excimer laser keratomileusis has the advantage of a cut surface smoother and the clear zone is devoid of the stepwise concavity and irregularity seen in diaphragm based photoablation delivery systems.
    Journal of refractive and corneal surgery 01/1994; 10(5):575-81.
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to assess the role of surgeons' skill on the final results of photorefractive keratectomy (PRK) in the correction of myopia. We evaluated the results of 160 consecutive unilateral treatments performed by four surgeons in a multicenter study group, with a one year follow up. Eighty-eight patients were males (55%) and 72 females (45%). Mean age was 33.7 years (median = 33, standard deviation = 10.22, range 18-65). Attempted correction ranged between -1.50 and -15.00 D. All the eyes received topical corticosteroid therapy postoperatively. At the one year follow up, we evaluated the following: uncorrected visual acuity lines gained and refractive error (spherical equivalent) as parameters of efficacy and predictability; best spectacle corrected visual acuity loss and corneal clarity as safety parameters. We also examined the centration or decentration of the ablation zone. In order to draw up a kind of learning curve, the mean values for each parameter were calculated by arbitrarily grouping the first 10 cases of each surgeon in the first group (40 patients), the second 10 cases in the second group (40 patients) and so on. We found that increase in uncorrected visual acuity, final refractive error and corneal clarity appeared to improve as the surgeon became more experienced, while loss of best spectacle corrected visual acuity was not significantly influenced by increased surgical experience. We think experience with photorefractive keratectomy in at least 40 eyes is necessary to obtain best results.
    Journal of refractive and corneal surgery 01/1994; 10(2 Suppl):S188-93.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Overcorrection, regression and haze are some side-effects found after excimer laser photorefractive keratectomy (PRK) for high myopia. A new method attempts to avoid photoablation through Bowman's layer, using the stroma to flatten the cornea without use of a microkeratome. Manual surgical instruments such as the diamond blade, spatula, Pierce forceps, and Vannas scissors are used to remove a disc of anterior cornea. Minimal topical corticosteroids are used, avoiding the complications of prolonged corticotherapy. Six eyes underwent manual excimer laser keratomileusis-in-situ. Postoperatively, the epitheliums in these eyes initially were dry and excoriated. By the twentieth day, however, the eyes had re-epithelialized and recovered. The optical effect is the same as when keratomileusis is used. No more than three-fourths of the pre-existing myopia was used in the program as some undercorrection was desired.
    Journal of refractive and corneal surgery 01/1994; 10(2 Suppl):S255-7.
  • [Show abstract] [Hide abstract]
    ABSTRACT: I have previously reported a new technique of suture fixation of a posterior chamber intraocular lens (IOL) to the iris through a limbal incision in the absence of a posterior lens capsule. This study evaluated the results of that technique as an alternative to anterior chamber lens implantation or suturing of a posterior chamber lens through the ciliary sulcus and sclera. The clinical records of 30 consecutive eyes that underwent this procedure between September 1987 and February 1991 were studied retrospectively. Four sutures were attached to four holes in the optic of a posterior chamber IOL. Two sutures on straight needles were passed through a superior limbal wound, to the pupil, reaching the inferior iris to be tied onto this iris. The two upper sutures on curved needles were passed through the pupil and going to the superior iris and then tied. An anterior vitrectomy was done in the pupil in 18 (60%) eyes. The mean postoperative follow-up time was 40 months (range, 24 to 66 months). Nineteen eyes (63%) had visual acuities of 20/40 or better; and 10 eyes (33%) had visual acuities between 20/50 and 20/80. The remaining eye had persistent cystoid macular edema, proven by fluorescein angiography, with 20/100 visual acuity. No serious anterior segment complications occurred. There was mild pigment dispersion on the IOL in four eyes. Four eyes needed timolol drops to lower the intraocular pressure. This technique offers a viable alternative to transscleral fixation of a posterior chamber IOL via a limbal approach.
    Journal of refractive and corneal surgery 01/1994; 10(5):565-70.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Currently used corneal refractive procedures do not offer a perfect solution for high hyperopia. This article proposes clear lens extraction and intraocular lens (IOL) implantation for the correction of high hyperopia. Extracapsular clear lens extraction and posterior chamber IOL implantation was performed in 10 normally sighted eyes of five patients with a hyperopic spherical equivalent refraction between +7.88 and +9.75 D. The follow-up period was 18 months. Mean uncorrected visual acuity improved from count fingers to 20/25. All eyes saw 20/30 or better without correction. Postoperative correction ranged from -0.37 to +0.50 diopters (mean, 0.01). The mean endothelial cell loss percentage at 18 months was 11.2% +/- 1.87% (range, 8% to 13%). The excellent results of contemporary cataract surgery, the reduced morbidity, patient satisfaction, as well as accuracy and rapid stability of the refraction suggest that clear lens extraction and IOL implantation are useful refractive procedures for the correction of high hyperopia.
    Journal of refractive and corneal surgery 01/1994; 10(2):117-21; discussion 122-4.
  • [Show abstract] [Hide abstract]
    ABSTRACT: 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.
    Journal of refractive and corneal surgery 01/1994; 10(2 Suppl):S290-2.
  • [Show abstract] [Hide abstract]
    ABSTRACT: The most effective management of the pain that follows excimer laser photorefractive keratectomy (PRK) appears to be the use of topical nonsteroidal anti-inflammatory agents. A bandage contact lens for 2 days after photorefractive keratectomy is additive to pain relief. The helpfulness of patching was not confirmed. Surprisingly, drops of local anesthetic were not an efficacious means of managing the pain. This was possibly because they were not used frequently enough. The findings showed trends, but were not statistically significant.
    Journal of refractive and corneal surgery 01/1994; 10(2 Suppl):S222-5.
  • [Show abstract] [Hide abstract]
    ABSTRACT: To compare the levels of prostaglandin E2 (PGE2) in corneal tissue after 193-nanometer excimer laser keratectomy and mechanical keratectomy with a microkeratome. Four rabbits underwent 193-nanometer excimer laser phototherapeutic keratectomy on one eye, and lamellar keratectomy with the microkeratome on the fellow eye. The corneas were harvested at 10 hours after the treatment and quantitated for PGE2 levels using an enzyme-linked immune assay. Control levels of PGE2 in untreated corneas were obtained from a previous study. Unoperated control corneas had low levels of PGE2 (1.79 +/- 1.0 pg/mL). Both surgical techniques resulted in a significant (p < .01) increase in PGE2. Corneas ablated mechanically with the microkeratome had an average PGE2 level of 15.48 +/-5.36 pg/mL, which represented an 8.6-fold increase compared to control; there was an additional 330% mean increase in PGE2 concentration in the laser-ablated corneas (51.29 +/- 36.08 pg/mL) compared to the corneas treated with mechanical lamellar keratectomy (p = .014). Mechanical and photochemical superficial keratectomies induce production of an inflammatory mediator, PGE2. The 193-nanometer excimer laser irradiation causes a greater increase of PGE2 production in the corneal tissue than does keratectomy with the microkeratome; this observation may support a role for cyclo-oxygenase inhibitors in postoperative therapy.
    Journal of refractive and corneal surgery 01/1994; 10(4):413-6.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Radial keratotomy reduces myopia by flattening the central cornea, but the mechanism remains a matter of controversy. In this article, we studied the biomechanical behavior of the cornea and its response to radial keratotomy. A human cadaver eye model without corneal epithelium was used in this study. We studied the effects which varying intraocular pressure (IOP) and corneal hydration would have on the keratometric power of unoperated eyes and eyes following radial keratotomy. For nonoperated eyes, first, normal corneal hydration was maintained while the IOP was varied. Second, the IOP was maintained at a constant level of 20 mm Hg while the corneal hydration was changed. The effects of separately varying the IOP and corneal hydration of postoperative eyes following an eight-incision radial keratotomy were studied in a similar fashion. In the nonoperated eye, a very high IOP was associated with a general reduction of corneal astigmatism without significantly affecting the overall keratometric spherical equivalent refraction. A steepening change of less than 0.50 diopters (D) was obtained in all eyes when dehydrating the cornea from 700 +/- 50 microns (centrally) and 830 +/- 70 microns (peripherally), to 495 +/- 25 microns (centrally) and 655 +/- 45 microns (peripherally). Following radial keratotomy, changes in IOP within the physiological range were found to have minimal influence (< 0.50 D) on the radial keratotomy keratometric power. However, after hydrating the cornea with balanced salt solution for 30 minutes, we obtained a mean flattening of 10.00 D. When dehydrating these corneas with topical hyperosmotic solution over a period of 3.5 hours, the flattening reversed to near preoperative values. The change in keratometric power resulting from radial keratotomy was significantly modulated by varying the hydration state of the deepithelialized cornea: the greater the hydration, the flatter the central cornea; therefore, the unpredictable surgical outcomes and diurnal fluctuations observed after radial keratotomy may be affected by applying topical hyperosmotic agents. We hypothesize that the corneal stroma is an inelastic, anisotropic, layered collagen structure that distributes tensile stress unequally throughout its thickness as a function of the amount of hydration. IOP, within physiological levels, did not have a significant effect on corneal flattening.
    Journal of refractive and corneal surgery 01/1994; 10(3):343-51; discussion 351-6.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Corneal neovascularization is a common clinical entity. Although visual acuity is usually impaired and corneal function compromised, there has been only limited success in the clinical management of this condition. We evaluated the efficacy of laser photocoagulation of neovascularization in the rabbit cornea. New vessel formation was provoked by the placement of sutures in the corneas. Rose bengal was injected intravenously and new vessels in the upper part of the corneas were treated with an argon laser. The lower halves were used as controls. Eighteen rabbits were divided into 2 groups. In group A neovascularization was treated 28 days after suture removal, when corneal inflammation had regressed. In group B treatment was performed 3 days after suture removal, when the cornea still exhibited marked inflammation. Postoperatively, the corneas were studied by slit-lamp microscopy, fluorescein angiography, and light, as well as electron microscopy. In group A, treatment led to the immediate occlusion of the vessels and to their gradual disappearance during the course of 3 months. In group B, no occlusion was seen during the 3-month follow-up period. The main histologic findings in the occluded vessels were endothelial cell disruption and degeneration, and the formation of clots. Our results suggest that argon laser photocoagulation using rose bengal is an effective method of occluding corneal new vessels, providing there is no corneal inflammation at the time of treatment.
    Journal of refractive and corneal surgery 01/1994; 10(6):631-9.