Therapeutic outcomes of cryotherapy versus transpupillary diode laser photocoagulation for threshold retinopathy of prematurity.

INTRODUCTION: We undertook this study to compare the clinical outcomes in patients treated for threshold retinopathy of prematurity (ROP) with transpupillary diode laser photocoagulation versus transscleral cryotherapy. METHODS: A retrospective chart review was performed of patients treated for threshold ROP at our institution between 1988 and 1997. Cryotherapy was used to treat patients before 1992, and diode laser was used thereafter. One hundred fifteen eyes of 63 patients underwent cryotherapy, and 130 eyes of 70 patients underwent laser treatment. Because strong concordance exists between fellow eyes treated for ROP, statistical analysis was done for right eye outcomes only. Demographics, short-term complications, and treatment parameters were compared on the entire cohort of patients. Structural outcomes were compared between a group of 79 cryotreated eyes (39 OD, 40 OS) and a group of 113 laser-treated eyes (56 OD, 57 OS). Mean cycloplegic refraction was compared between a group of 38 cryotreated eyes (18 OD, 20 OS) and a group of 90 laser-treated eyes (46 OD, 44 OS). Visual acuity for preverbal and nonverbal children was estimated and converted to a Snellen visual acuity equivalent. Geometric mean visual acuity was then compared between a group of 44 cryotreated eyes (22 OD, 22 OS) and a group of 92 laser-treated eyes (47 OD, 45 OS). Patients were included in each outcome analysis if adequate documentation was present in the patient record. RESULTS: Demographics and short-term complications were not significantly different between the 2 groups. In the statistical group, 22 of 39 right eyes (56.4%) in the cryotherapy group versus 49 of 56 right eyes (87.5%) in the laser group had resolution of ROP after treatment (P = .0008). Mean spherical equivalent cycloplegic refraction at 12 months of age and over the follow-up period was not significantly different between the cryotherapy and laser groups. Estimated geometric mean visual acuity in the cryotherapy group was 20/103 and in the laser group was 20/49 at 12 months of age (P= .0099). CONCLUSIONS: Diode laser photocoagulation was associated with a better long-term structural outcome and visual acuity compared with cryotherapy for the treatment of threshold ROP. Refractive error was not significantly different between the 2 groups over an equivalent follow-up period.     

Refractive outcome following diode laser versus cryotherapy for eyes with retinopathy of prematurity.

The refractive error in 15 eyes with threshold retinopathy of prematurity treated with diode laser photocoagulation was compared with 25 eyes with the same disease severity treated by cryotherapy. Myopia was present in 40% (six eyes) of the first group ranging from -1.50 to -3.50 dioptres; while 92% (23 eyes) showed myopia which ranged from -0.50 to -8.00 dioptres in the cryotherapy group. Sixty per cent (nine eyes) were hypermetropic at less than +3.0 dioptres in the laser group, while only 8% (two eyes) of the cryotherapy group showed hypermetropia. There was no significant difference in astigmatism between the two groups. Eyes with threshold disease treated with diode laser photocoagulation developed significantly less myopia than those treated with cryotherapy (p = 0.0006, two tailed value).     

Combined use of cryotherapy and diode laser photocoagulation for the treatment of threshold retinopathy of prematurity.

PURPOSE: Cryotherapy and indirect laser retinal photoablation are both effective in the treatment of retinopathy of prematurity (ROP). We describe the safety, efficiency, and effectiveness of combined cryotherapy and diode laser photocoagulation to treat threshold ROP. METHODS: Records of patients developing threshold ROP from January 1, 1996 through December 31, 1998, were retrospectively reviewed to identify those treated with combined cryotherapy and photocoagulation and followed up for at least 45 days postoperatively. Diode laser was used to ablate posterior avascular retina, and cryotherapy was used for anterior retina. Data reviewed included ocular and systemic complication rates, treatment duration, number of laser burns, most recent fundus examination, visual acuity, and refraction. RESULTS: In 13 patients, 23 eyes received combined treatment. No intraoperative complications occurred. Mean duration of anesthesia and treatment was 35 +/- 8 minutes/eye. A mean of 117 +/- 84 laser burns/eye were applied. In 20 of 23 eyes (87.0%), anatomic outcome was favorable at last examination. In 13 of 16 eyes (81.3%), functional (visual acuity) outcome was favorable (visual acuity better than 20/200) at 1 year. At 6 months or later, 14 of 16 eyes (87.5%) measured were myopic, of which 5 (31.3%) were highly myopic (> 6 diopters). CONCLUSIONS: The effectiveness of treating ROP with combined cryotherapy and diode laser photocoagulation compares with that of either modality alone. By decreasing the number of laser applications, combined therapy may be faster and technically easier for eyes with very posterior ROP. This may decrease the number of complications seen when either excessive cryotherapy or laser retinal photoablation is used.     

Combined treatment with laser photocoagulation and cryotherapy for threshold retinopathy of prematurity

PURPOSE: To report the structural, functional, and refractive outcome, safety, and effectiveness of combined cryotherapy and diode laser indirect photocoagulation in the treatment of threshold retinopathy of prematurity (ROP). METHODS: Medical records of patients developing threshold ROP between 1995 and 2003 were reviewed to identify those with combined treatment and followed up for at least 4 years postoperatively. A total of 94 patients (172 eyes) received combined treatment. Data consisted of grade of ROP pre- and postoperatively, most recent fundus examination, birthweight, visual acuity, complications, and refraction. Diode laser was used to ablate posterior avascular retina, and cryotherapy was used for anterior retina. RESULTS: A total of 149 (87%) eyes responded to combined treatment and they had favorable anatomic outcome at last examination. In 131 eyes (76%), functional outcome was favorable (visual acuity better than 20/200) at last examination. Perioperative complications included hemorrhages in 26% of eyes, which resorbed spontaneously. Mean duration of treatment was 31 minutes/eye. At final visit (4 to 12 years), 115 eyes (66.8%) refracted were myopic, of which 26 (22.5%) had high myopia over -6 diopters. CONCLUSIONS: Combined cryotherapy and diode laser photocoagulation for ROP in our patients resulted in regression of threshold ROP with relatively successful structural and functional outcomes. Combined therapy may be faster and useful for eyes with very posterior ROP. This may decrease the number of complications occurring when excessive cryotherapy or laser photoablation must be used in zone 1 ROP.     

Long term functional and structural outcomes of laser therapy for retinopathy of prematurity

AIMS: To assess the long term functional and structural outcomes of premature babies who received diode laser photocoagulation for threshold retinopathy of prematurity (ROP). METHODS: 25 patients (43 eyes) treated with laser were recalled for assessment at a mean follow up of 11 years. A further seven patients (14 eyes) with subthreshold ROP, which had regressed spontaneously without laser treatment, were also examined. All children underwent distance acuity, near acuity, contrast sensitivity (CS), and colour vision assessments followed by a dilated fundal examination and cycloplegic autorefraction. RESULTS: The laser treated eyes had a mean distance visual acuity of 0.37 logMAR, a mean near visual acuity of 0.39 logMAR, a mean contrast sensitivity of 1.49 log CS units, and a mean spherical equivalent of -2.10D. An unfavourable distance visual acuity outcome occurred in five eyes (13.5%). An unfavourable near visual acuity outcome was also noted in the five eyes (13.5%) with poor distance visual outcome. 7% had an unfavourable structural outcome. On comparison with the control group, there was no significant difference in near acuity, CS, refraction, or colour vision between the two groups. However, there was a statistically significant difference in terms of distance visual acuity (p = 0.03). CONCLUSIONS: Laser treated eyes with favourable structural outcome have a good visual outcome. The results show a long term benefit from diode laser photocoagulation in preserving distance and near vision in eyes with threshold ROP.     

Treated threshold stage 3 versus spontaneously regressed subthreshold stage 3 retinopathy of prematurity: a study of motility, refractive, and anatomical outcomes at 6 months and 36 months

AIM: To compare the visual acuity (VA), spherical equivalent refractive error, motility, and anatomical outcomes in children with treated regressed threshold stage 3 retinopathy of prematurity (ROP) and those with spontaneously regressed subthreshold stage 3 ROP. METHOD: 6 month and 3 year data collected from infants examined between 1989 and 1999 with regressed stage 3 ROP, with or without treatment were retrospectively reviewed. RESULTS: 85 infants were included in this study. 40 eyes received cryotherapy, 81 eyes laser photocoagulation, and 34 eyes had spontaneously regressed subthreshold stage 3 ROP. Grating acuity score > or =2 cycles/degree (c/d) at 6 months was predictive of optotype acuity > or =6/9 in 69% of eyes and a score <2 c/d at 6 months was predictive of acuity < 6/9 in 88% of eyes. Eyes with subthreshold stage 3 ROP were twice as likely to have VA of 6/9 or better at 36 months than the treated eyes. The mean spherical equivalent refractive error at 36 months was -6.5 dioptres (D) (-21.5D to +1.38D) in cryotherapy treated eyes, -2.4D (-13D to +4D) in the laser group, and -0.22D (-9D to +2.25D) in the subthreshold group. Eyes within the treated groups were more myopic than the eyes within the spontaneously regressed group (p = 0.005). At 36 months, 42 out of the 85 infants (that is, 49%) had strabismus (44% in the cryotherapy group, 26% in the laser group, and 25% in the subthreshold group). There was a statistically significant association between the presence of strabismus and anisometropia (p = 0.016) and strabismus and intraventricular haemorrhage (IVH) (p = 0.005). There was a statistically significant difference in the incidence of strabismus between mild and moderate and severe grade IVH (p = 0.01). Eight out of 40 eyes in the cryotherapy group and six out of the 81 eyes in the laser group developed macular ectopia. None of the eyes in the spontaneously regressed group had macular dragging. CONCLUSIONS: In this study, the grating acuity at 6 months was a good predictor of the 3 year optotype acuity in all groups. Eyes with spontaneously regressed subthreshold stage 3 ROP were associated with better vision at 3 years of age and a lesser degree of myopia compared to the treated groups. Strabismus developed predominantly in the treated groups and was frequently associated with neurological damage and/or anisometropia. The spontaneously regressed subthreshold stage 3 group had a better anatomical outcome compared to the groups in which the retinopathy regressed following treatment.     

Randomized comparison of diode laser photocoagulation versus cryotherapy for threshold retinopathy of prematurity: seven-year outcome.

PURPOSE: To report the structural and functional outcomes at a minimum of 7 years postmenstrual age after randomized treatment of threshold retinopathy of prematurity with laser ablation or cryotherapy. METHODS: Nineteen patients were entered into a prospective, randomized protocol, in which one eye received cryotherapy, while the other eye received diode laser photocoagulation. Asymmetric eyes were randomly assigned. Two patients have died, and seven were no longer available for 7-year outcome examinations, leaving 10 children for analysis. RESULTS: Six males and four females with a mean birthweight of 631 g and a mean gestational age of 24.8 weeks were examined. Eight were symmetrical cases and treated in both eyes. Of these, there were six concordant and two discordant structural outcomes. The laser-treated eyes had the favorable outcome in each instance. The geometric mean visual acuity of the paired eyes after laser photocoagulation was 20/33, and after cryotherapy it was 20/133 (P =.03). The mean refractive error was -6.50 diopters after laser photocoagulation and -8.25 diopters after cryotherapy (P =.27), although one of the cryotherapy eyes could not be refracted because of phthisis. CONCLUSIONS: Laser photocoagulation appears to be associated with a structural and functional outcome at least as good as cryotherapy 7 years after therapy. Visual acuity and refractive error data suggest that laser photocoagulation may have an advantage over cryotherapy.     

A comparison of laser photocoagulation with cryotherapy for threshold retinopathy of prematurity at 10 years: part 1. Visual function and structural outcome

OBJECTIVE: To assess visual and structural outcomes after laser photocoagulation and transscleral cryotherapy for threshold retinopathy of prematurity (ROP) after 10 years. DESIGN: Extended follow-up of a randomized controlled clinical trial. PARTICIPANTS: One hundred eighteen eyes from 66 patients were randomly assigned to receive either cryotherapy or laser photocoagulation for threshold ROP. Forty-four eyes from 25 patients were examined for 10-year follow-up evaluations. INTERVENTION: Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuity, slit-lamp, and fundus examination; fundus photography; and B-scans (eyes with retinal detachments) were performed. Patients' histories were taken to elicit past amblyopia therapy. Based on fundus photographs, independent observers graded the degree of retinal dragging as none, mild, moderate, or severe. MAIN AND SECONDARY OUTCOME MEASURES: Best-corrected ETDRS visual acuity (BCVA). The degree of dragging was determined clinically and photographically. In addition, the presence of strabismus or amblyopia and/or any history of treatment for amblyopia were noted accordingly. RESULTS: Eyes treated with laser had a mean BCVA of 20/66 (Snellen equivalent), whereas cryotherapy-treated eyes had a mean BCVA of 20/182 (Snellen equivalent) (P = 0.015, n = 42). Compared with eyes treated with cryotherapy, eyes treated with laser photocoagulation were 5.2 times more likely to have a 20/50 or better BCVA (95% confidence interval, 1.37-19.8, n = 42). Eyes treated with cryotherapy were 7.2 times (95% confidence interval, 1.54-33.6, n = 33) more likely to develop retinal dragging compared with laser treatment. By linear regression analysis, ETDRS visual acuity was inversely proportionate to the degree of retinal dragging in both laser (r = -0.637, P = 0.006) and cryotherapy (r = -0.517, P = 0.040) treated eyes. Among the 21 patients with favorable outcomes in both eyes, 13 had strabismus (62%) and 6 had received amblyopia therapy (29%). Ptosis, loss of cilia, and cortical cataract were among probable treatment-related complications that were noted in this study. CONCLUSIONS: Overall, laser-treated eyes had better structural and functional outcome compared with eyes treated with cryotherapy.     

Koagulationstherapie bei Frühgeborenenretinopathie

PURPOSE: To analyze and compare the anatomical and functional outcome following cryotherapy or laser therapy for ROP. METHODS: Between April 1991 and February 2002, 127 eyes with ROP (65 patients) were treated after threshold ROP was reached. Ten additional eyes with zone I disease were treated with prethreshold. All patients were followed up until a stable retinal situation occurred. RESULTS: An "unfavorable outcome," as described in the Cryo ROP study, occurred in 1 of 91 (1%) eyes with laser treatment and in 3 of 46 (6.5%) eyes with cryotherapy. Temporal dragging of vessels was noticed in 6 of 91 eyes (6.6%) with laser treatment vs 7 of 46 eyes (15.2%) with cryotherapy, respectively. Visual acuity > or =20/25 was achieved in 39.2% in eyes with laser therapy and in 17.6% with cryotherapy (p<0.05). CONCLUSION: A strict screening protocol and treatment at onset of threshold disease results in an excellent anatomical and functional outcome. The results of laser therapy were superior over cryotherapy, indicating that laser treatment is the therapy of choice.     

Refractive outcome in eyes with retinopathy of prematurity treated with cryotherapy or diode laser: 3 year follow up.

AIMS: To compare the refractive error 1 to 3 years after cryotherapy or diode laser treatment for threshold retinopathy of prematurity. METHODS: Twenty six infants treated with diode laser and 17 infants treated with cryotherapy underwent cycloplegic refraction during follow up. RESULTS: After 3 years of follow up, 94.1% of patients had myopia (right eye if bilateral) following cryotherapy and 45.5% of patients had myopia following diode laser treatment. The difference between the two proportions was 48.7% (95% confidence interval 17.8 to 80.1, p = 0.004). In the cryotherapy group 55% of patients were highly myopic (> -6.00 dioptres) while in the laser group there were no high myopes. CONCLUSIONS: In the diode laser group there were significantly fewer myopes than in the cryotherapy group up to 3 years after the procedure. There was no trend towards increasing myopia in the laser treated group and the refraction in these eyes stabilised after 1 year. In the cryotherapy group there was a significant increase in the degree of myopia between year 1 and year 3 of follow up (p = 0.02). Diode laser treatment is thought to be as effective as cryotherapy, and has the added benefit of reducing myopia, in the treatment of ROP.     

Two-year results of laser treatment for retinopathy of prematurity at a single neonatal intensive care unit

PURPOSE: To present the 2-year results of all patients receiving laser treatment for retinopathy of prematurity (ROP) at a single institution over a 9.5-year period. To establish the frequency of threshold ROP. METHODS: Consecutive case series. All patients who had laser treatment for ROP at The Royal Women's Hospital, Melbourne, Australia, between January 1992 and July 2001 were prospectively recorded in a database. Their medical charts were retrospectively reviewed. Baseline birthweight, gestational age at birth, timing of treatment, and ROP severity at treatment were recorded. The main outcome measures were visual acuity (significantly reduced or not), anatomic outcome and refractive error at 2 years of age (corrected for the degree of prematurity). RESULTS: A total of 107 eyes of 57 babies were treated with laser photocoagulation. Four children did not survive for follow-up, and 2-year follow-up data were available for 38 children (67%, 71 treated eyes). Average duration of follow-up was 26 months. Two-year visual acuity was significantly reduced in 12/71 (17%) treated eyes, and 3/38 children (8%) had significantly reduced vision in both eyes. An anatomical outcome of macular fold or worse was observed in 8/71 eyes (11%). Mean 2-year spherical equivalent refractive outcome was only minimally myopic (-0.6 D). CONCLUSION: Visual, anatomic and refractive outcomes after laser treatment for ROP were favourable, confirming that laser photocoagulation is an effective treatment for severe ROP.     

Three year visual outcome for treated stage 3 retinopathy of prematurity: cryotherapy versus laser

BACKGROUND/AIMS—In the management of retinopathy of prematurity (ROP), several studies have demonstrated laser photocoagulation to be as effective as cryotherapy in reducing the incidence of unfavourable structural outcome. However, few data are available on the functional outcome. The 3 year visual acuity outcome of infants treated with laser or cryotherapy in a neonatal unit is presented.
METHODS—The case notes of 34 infants (64 eyes) treated with cryotherapy, between 1989 and 1992, and 32 infants (59 eyes) treated with laser, between 1992 and 1995, were reviewed.
RESULTS—In the cryotherapy group 69% of eyes had a favourable structural outcome. Of these structurally successful eyes 62.5%, 35.0%, and 33.3% of eyes had visual acuities within normal limits at the 12 month, 24 month, and 36 month corrected age milestones respectively. In the laser group 93% of eyes had a favourable structural outcome. Of these structurally successful eyes 96.4%, 66.7%, and 59.5% of eyes had visual acuities within normal limits at the 12 month, 24 month, and 36 month corrected age milestones respectively.
CONCLUSION—In the management of ROP, when laser photocoagulation induces a structurally successful result, the potential for normal visual acuity development at 3 years is high. Whether the poorer functional outcome of the eyes treated with cryotherapy is an artefact of the historical nature of the study or as a result of an adverse effect of the destructive transcleral application is unknown.

Keywords: retinopathy of prematurity; laser; cryotherapy; visual outcome     

Prospective randomized evaluation of diode-laser and cryotherapy in prethreshold retinopathy of prematurity

PURPOSE: To study the efficacy of indirect diode laser photocoagulation and cryotherapy in prethreshold retinopathy of prematurity (ROP). METHODS: Thirty-six eyes of 18 premature infants less than 34 weeks gestational age and/or less than 1600 g birth weight with prethreshold ROP were prospectively randomized to treatment with either indirect laser photocoagulation or cryotherapy. Prethreshold ROP was defined as any stage of ROP in zone I with plus disease; or stage 3 with three or more contiguous clock hours or five or more total clock hours of involvement of retina in zone II with plus disease but less than threshold disease. Regression of the ROP was assessed for a minimum period of 6 months. RESULTS: Regression of ROP occurred in all 36 eyes (100%) in both groups. CONCLUSIONS: Excellent results are achieved if ROP is treated at the prethreshold stage with both indirect laser photocoagulation and cryotherapy. Although laser has definite advantages, cryotherapy can be considered as an alternative modality of treatment in developing countries due to economic reasons.     

Diode laser photocoagulation for retinopathy of prematurity--outcomes in one-year observation

PURPOSE: To evaluate structural and functional outcomes in one-year old patients, treated for retinopathy of prematurity (ROP) with transpupillary diode laser photocoagulation. MATERIALS AND METHODS: 58 children (116 eyes) 12 months old, after treatment for ROP with diode laser photocoagulation, were examined. Both, functional outcome (visual acuity--basing on the examination with Teller Acuity Card Procedure), and structural outcome were evaluated. The cycloplegic refraction was examined in all cases. RESULTS: We have found good functional outcome in 81.9%, and good structural outcomes in 96.5% of examined eyes. 64.6% of eyes had hyperopic refractive error, and 31% were myopic. CONCLUSIONS: Diode laser photocoagulation is an effective method of treatment for ROP.     

LASIK治疗近视散光的临床观察

目的:观察准分子激光原位角膜磨镶术(laser in situ kera-tomileusis,LASIK)治疗近视散光的临床疗效。方法:应用鹰视准分子激光治疗系统对120例234眼近视散光进行LASIK手术治疗。随访12mo,比较手术前后的视力、屈光度、散光及其散光轴位的变化。结果:术后随访12mo,裸眼视力≥术前最佳矫正视力(BCVA)者108例213眼(91%),屈光度在±1.00D以内者112例222眼(94.8%),散光残留平均为-0.52D。结论:LASIK治疗近视散光效果好,稳定性高,安全可靠。     

Longer term visual outcome of eyes with retinopathy of prematurity treated with cryotherapy or diode laser

AIMS—Visual outcome of 66 eyes in 37 patients who had undergone treatment with either cryotherapy or diode laser for threshold retinopathy of prematurity was assessed.
METHODS—17 patients, representing 30 eyes treated with cryotherapy, were examined at between 56 and 98 months corrected age (median 68 months). 20 patients representing 36 eyes treated with diode laser, were examined at between 30 and 66 months corrected age (median 51 months). Structural outcome was categorised as: optimal—flat posterior pole; suboptimal—macular ectopia, optic nerve hypoplasia, retinal fold involving the macula, and retinal detachment involving the macula.
RESULTS—Optimal structural outcome was, in the absence of amblyopia, associated with optimal visual acuity (of 6/12 or better) in all cases, with most eyes achieving a visual acuity of 6/9 or 6/6. Suboptimal structural outcome was invariably associated with suboptimal visual acuity. Amblyopia was present in eight out of 20 cryotherapy treated eyes and in five out of 26 laser treated eyes with an optimal structural outcome. Refractive errors were significantly less in laser treated eyes as was the incidence of anisometropic amblyopia.
CONCLUSION—Eyes treated with either cryotherapy or diode laser for threshold retinopathy of prematurity with optimal structural outcome are associated with development of optimal visual acuity—that is, 6/12 or better. Treatment with either cryotherapy or laser does not in itself reduce the visual potential of these eyes.

Keywords: retinopathy of prematurity; cryotherapy; laser; visual acuity     

Trends in the management of stage 3 retinopathy of prematurity.

AIMS/BACKGROUND: The clinical outcome of 66 consecutive infants with stage 3 retinopathy of prematurity (ROP) is reported. METHODS: Thirty four infants (64 eyes) were treated with cryotherapy and 32 infants (59 eyes) underwent laser photocoagulation. RESULTS: Infants with anterior-mid zone II ROP had a high rate of disease regression whether treated by cryotherapy or laser photocoagulation. Infants with posterior zone II or zone I ROP had a 40% success rate with cryotherapy, and 87.5% when treated with laser photocoagulation. CONCLUSION: Evolving experience and changing management policies in infants with posterior ROP has led to improved results.     

Effect of disagreement between refractive, keratometric, and topographic determination of astigmatic axis on suture removal after penetrating keratoplasty

BACKGROUND/AIMS: Post-keratoplasty astigmatism can be managed by selective suture removal in the steep axis. Corneal topography, keratometry, and refraction are used to determine the steep axis for suture removal. However, often there is a disagreement between the topographically determined steep axis and sutures to be removed and that determined by keratometry and refraction. The purpose of this study was to evaluate any difference in the effect of suture removal, on visual acuity and astigmatism, in patients where such a disagreement existed. METHODS: 37 cases (from 37 patients) of selective suture removal after penetrating keratoplasty, were included. In the first group "the disagreement group" (n=15) there was disagreement between corneal topography, keratometry, and refraction regarding the axis of astigmatism and sutures to be removed. In the second group "the agreement group" (n=22) there was agreement between corneal topography, keratometry, and refraction in the determination of the astigmatic axis and sutures to be removed. Sutures were removed according to the corneal topography, at least 5 months postoperatively. Vector analysis for change in astigmatism and visual acuity after suture removal was compared between groups. RESULTS: In the disagreement group, the amount of vector corrected change in refractive, keratometric, and topographic astigmatism after suture removal was 3.45 (SD 2.34), 3.57 (1.63), and 2.83 (1. 68) dioptres, respectively. In the agreement group, the amount of vector corrected change in refractive, keratometric, and topographic astigmatism was 5.95 (3.52), 5.37 (3.29), and 4.71 (2.69) dioptres respectively. This difference in the vector corrected change in astigmatism between groups was statistically significant, p values of 0.02, 0.03, and 0.03 respectively. Visual acuity changes were more favourable in the agreement group. Improvement or no change in visual acuity occurred in 90.9% in the agreement group compared with 73.3% of the disagreement group. CONCLUSIONS: Agreement between refraction, keratometry, and topography was associated with greater change in vector corrected astigmatism and was an indicator of good prognosis. Disagreement between refraction, keratometry, and topography was associated with less vector corrected change in astigmatism, a greater probability of decrease in visual acuity, and a relatively poor outcome following suture removal. However, patients in the disagreement group still have a greater chance of improvement than worsening, following suture removal.     

早产儿视网膜病变患儿激光光凝术后视功能和屈光状态

目的　研究早产儿视网膜病变（retinopathy of prematurity,ROP）患儿激光光凝术后视功能和屈光状态。方法　回顾性队列研究。收集我院行二极管激光光凝术治愈的ROP患儿44 例（88眼）,远期随访3 a以上,观察其视力、眼位及屈光状态情况。术后最佳矫正视力（best corrected visual acuity,BCVA）<0.3定义为低视力,术后低视力与出生体质量、孕周、治疗时矫正胎龄、病变区域和激光次数的相关性行Logistic多因素回归分析。结果　44例（88眼）患儿年龄为（4.2±0.8）岁,BCVA≤0.1者2眼,>0.1~0.3者 9眼,>0.3~0.5者14眼,>0.5者63眼。Logistic多因素回归分析显示,术后低视力与出生体质量、孕周、矫正胎龄和激光治疗次数均无相关性（均为P>0.05）,与病变区域有关（P=0.049）。近视性屈光不正29眼,近视度数为-0.25~-10.50 D,其中高度近视（SE≥-5.00 D）8眼;合并散光者44眼,散光度-1.00~-5.00 DC,其中高度散光（≥-2.00 DC）20眼;10例患有斜视,1例有眼球震颤。结论　ROP激光术后大部分患儿有较好的视力,高度近视和斜视是视力损伤的主要原因。     

Prospective contralateral eye study to compare conventional and wavefront‐guided laser in situ keratomileusis

Purpose: To compare outcomes of customized/wavefront guided with conventional ablation in myopic patients with or without astigmatism undergoing laser in situ keratomileusis. Methods: A prospective, comparative, contralateral eye study was performed. Sixty‐eight eyes of 34 myopic patients with similar refractive error in both eyes were included. One eye was randomly selected to undergo conventional and the fellow eye customized ablation. Surgery was performed using the Technolas 217z laser (Bausch & Lomb, Surrey, UK). Uncorrected visual acuity, manifest refractive spherical equivalent (MRSE), astigmatism, aberrometry and contrast sensitivity were recorded pre and 3 months postoperatively. Results: Mean MRSE treated in the conventional and customized groups were 3.77 ± 1.61 dioptres and ?3.83 ± 1.59 dioptres respectively. Three months postoperatively there was no significant difference between the groups in mean MRSE (p = 0.99) or cylinder (p = 0.56). The factor increase in postoperative total higher order aberrations (HOAs) was less in the customized (1.32) compared with the conventional (1.54) treatment group but did not reach statistical significance (p = 0.08). Scotopic contrast sensitivity decreased significantly postoperatively in the conventional but not in the customized treatment group. Conclusion: Visual acuity and refractive error outcomes were similar in both treatment group and no patient preference was observed. Customized ablation was associated with a smaller but not statistically significant postoperative increase in HOAs, better preservation of scotopic contrast sensitivity, quicker treatment time and removal of less corneal tissue.