Astigmatism and biometric optic components of diode laser-treated threshold retinopathy of prematurity at 9 years of age

Purpose

To assess the prevalence of astigmatism and its relationship with biometric optic components in preterm school children with diode laser-treated threshold retinopathy of prematurity (ROP).

Methods

A prospective, cross-sectional study in which cycloplegic keratometry, refraction, and ultrasound biometric measurement of optic components were performed on 24 consecutive preterm children with diode laser-treated threshold ROP at the age of 9 years. The study results were compared with data on 1021 age-matched full-term control children from a national survey.

Results

The laser-treated eyes had a mean astigmatism of 3.47 D, with a mean spherical equivalent of −4.49 D. Of the 46 eyes studied, 98% of eyes showed astigmatism ≥0.5 D and 50% had high astigmatism (>3.0 D). Most astigmatic eyes (97.7%) showed with-the-rule astigmatism, with the mean plus cylinder axis at 89.30^o. Further correlation analysis showed the astigmatism in refraction was highly correlated with the corneal astigmatism (r=0.921, P<0.001) and the vertical corneal curvature (r=0.405, P=0.005). There was significantly steeper vertical corneal curvature (P=0.003) and flatter horizontal corneal curvature (P=0.031) in eyes with laser-treated ROP when compared with age-matched full-term controls. The eyes with laser-treated ROP also show significantly thicker lens (3.93 mm) and shallower anterior chamber depth (ACD; 2.92 mm) than full-term controls (P<0.001).

Conclusions

There is significantly higher prevalence and greater magnitude of astigmatism in eyes with laser-treated threshold ROP compared with full-term controls. The steeper vertical corneal curvature component contributes to the increased astigmatism in eyes with laser-treated ROP.     

Diode laser treatment of pre-threshold and threshold retinopathy of prematurity

Purpose: Retinopathy of prematurity (ROP) is a sight‐threatening condition of premature infants. This study aimed to investigate the efficacy of diode laser photocoagulation in the treatment of pre‐threshold and threshold ROP. Methods: A retrospective review was conducted of patients who underwent diode laser treatment for ROP by one author (GAG) from 1992 to 2000. During this time, 2137 babies <1500 g birthweight or <32 weeks post‐conception age were examined. Results: Seventy‐six eyes in 40 infants (20 male, 20 female) were treated for ROP. Treatment was performed on average at 37 weeks post‐conception age (range 31?50 weeks, SD = 3.2). The number of burns per eye for the first session of laser ranged between 193 and 1937 (mean 933), with power ranging from 200 to 1000 mW (mean 484). Eighteen (45.0%) of these 40 infants underwent a second session of laser (mean number of burns 683, range 167?1618), which was performed in 29 (38.2%) of the 76 eyes that initially underwent laser treatment. Complete regression was observed in 61 eyes (80.3%), occurring on average at 39 weeks post‐conception age (range 35?45, SD = 2.2). Six (7.9%) eyes progressed to stage IVA disease, two (2.6%) to stage IVB and three (3.9%) to stage V ROP. In the latter part of the study as the number of laser burns per eye increased it was found that the number of patients requiring a second session of laser treatment decreased, with no adverse outcomes observed in the last 3 years of the study. At last follow up, the average refractive error in the treated eyes was ?0.40 D spherical equivalent (range ?12.75 D to +4.25 D, SD = 3.0). The degree of myopia induced showed no significant correlation with the number of laser burns administered. Conclusion: Diode laser treatment is able to stop progression of ROP in the majority of cases.     

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     

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.     

Treatment of retinopathy of prematurity in extremely premature infants over an 18‐year period

Background: To report the efficacy of laser diode therapy in the treatment of retinopathy of prematurity (ROP) in extremely premature (EP) infants over an 18‐year period. Design: Retrospective study. Participants: One hundred twenty‐eight eyes in 66 infants treated between 23 and 25.6 weeks. Methods: Five hundred fifty‐four infants between 23 and 25.6 weeks gestational age (GA) were admitted to The Royal Brisbane and Women's Hospital Neonatal Intensive Care Unit (NICU) between 1992 and 2009. Three hundred seventy‐three patients survived to undergo screening, 304 were diagnosed with ROP, and 66 infants required diode laser therapy. Main Outcome Measures: Success of treatment, visual and refractive outcomes. Results: One hundred twenty‐eight eyes from 66 infants (18.8% of those screened) underwent laser treatment with a mean GA of 24.3 weeks and mean birth weight of 711.4g. Fifty‐six eyes were treated at pre‐threshold disease, and 72 eyes at threshold disease. Over the study period, the number of laser spots and regression rate of ROP increased, while the frequency of re‐treatment decreased. At 40 weeks, 119 eyes had regressed ROP (93%), two advanced to stage 4a, three to stage 4b and four to stage 5. Aggressive posterior ROP (AP‐ROP) occurred in 15 eyes (11.7% of those treated). Forty‐three patients (65%) were followed up for a mean of 56.5 months. The number of laser spots correlated well with subsequent refractive error but poorly with corrected visual acuity. Conclusions: In EP infants, laser diode therapy is an effective technique to halt the progression of ROP in most cases. AP‐ROP is uncommon, even in this subgroup of extremely premature infants.     

Dopamine use is an indicator for the development of threshold retinopathy of prematurity

AIM: To assess whether treatment of premature infants with dopamine is a risk factor for development of retinopathy of prematurity (ROP). METHODS: A retrospective case series analysis of two groups was utilised with a minimum follow up of 6 months. Clinical profiles and patient risk factors were identified along with an evaluation of ROP progression and an analysis of clinical outcome. All infants were seen in a single community neonatal intensive care unit (NICU). 41 consecutive high risk infants were identified during a 36 month period whose birth weight was less than 1000 grams and who remained in the NICU without transfer until at least 28 days of age. Dilated indirect ophthalmoscopy fundus examinations were performed on all infants to identify the degree of and progression to threshold ROP. RESULTS: 18 of 41 infants were treated with dopamine for hypotension. The group of infants requiring dopamine differed statistically from the non-dopamine treated group by having a slightly higher birth weight, a greater incidence of hypotension and colloid treatment, and in manifesting more advanced respiratory disease. Within the dopamine treated group, 12 of 18 infants (67%) reached prethreshold ROP and seven infants (39%) reached threshold ROP requiring laser treatment. In contrast, only three of the infants (13%) who did not require dopamine for hypotension progressed to prethreshold (p = 0.001) and only one of these infants (4%) progressed to threshold ROP (p = 0.02). Logistic regression analysis among other variables demonstrated that dopamine use and gestational age are important factors in this low birthweight population for predicting the development of threshold ROP (dopamine use: adjusted odds ratio = 119.88, p = 0.0061; gestational age: adjusted odds ratio = 0.061, p = 0.0043). CONCLUSIONS: Dopamine use in low birthweight infants may therefore be a risk factor for the development of threshold ROP. More vigilant screening of high risk infants requiring dopamine therapy for systemic hypotension may be warranted.     

Cataract in retinopathy of prematurity – A review

Preterm babies with retinopathy of prematurity (ROP) can become blind if they do not receive appropriate timely intervention. The presence of cataract in these individuals in addition to visual deprivation amblyopia, also delays proper screening, adequate treatment, and makes follow-up assessment difficult. Anatomical differences in these infants and amblyopia management, especially in unilateral cataract, are other important concerns, and hence, management of these cases with cataract and ROP is challenging. In this review, studies where ROP cases were associated with cataract, were evaluated with a focus on preterm individuals less than 6 months age. Preterm babies are at increased risk of developing cataract because of systemic factors. In addition, those with ROP may have cataract associated with retinal detachment or treatment received. The type of cataract, risk factors, and pathophysiology associated with each cause varies. This review highlights these different aspects of cataract in ROP including causes, pathophysiology, types of cataracts, and management. The management of these cases is critical in terms of the timing of cataract surgery and the challenges associated with surgery and posterior segment management for ROP. Anatomical differences, preoperative retina status, pupillary dilatation, neovascularization of iris in aggressive posterior ROP, fundus examination, amblyopia, and follow-up are various important aspects in the management of the same. The preoperative workup, intraoperative challenges, postoperative care, and rehabilitation in these individuals are discussed.     

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.     

Retinopathy of prematurity: postmenstrual age at threshold in a transitional economy is similar to that in developed countries

Background: To analyse the timing of threshold disease in infants requiring treatment for retinopathy of prematurity in a transitional economy. Methods: Design: Retrospective, observational, cohort study. Setting: National Hospital of Paediatrics, Hanoi, Vietnam. Study population: Premature infants in the Neonatal ward requiring laser treatment for threshold retinopathy of prematurity. Main outcome measures: Chronological age and postmenstrual age at treatment. Results: From January 2002 to November 2004, 42 infants from the National Hospital of Paediatrics required laser surgery for threshold retinopathy of prematurity. The mean ± standard deviation (SD) of birth weight was 1369 ± 184 g (range 1000–1700); the mean ± SD of gestation at birth was 30 ± 1.8 weeks (range 27–34); and the mean ± SD of postmenstrual age at which treatment occurred in these infants was 36.2 ± 2.5 weeks (range 31.4–42). A further 58 infants were transferred from other hospitals for laser surgery between January 2004 and October 2004. The mean ± SD of birth weight was 1325.5 ± 237.2 g (range 800–1900); the mean ± SD of gestation at birth was 30 ± 1.7 weeks (range 28–35); and the mean ± SD of postmenstrual age at which treatment was given in these infants was 36.3 ± 2.3 weeks (range 32.71–44.3). Discussions: Despite the relative maturity of the gestation of these infants compared with infants in developed countries who develop severe retinopathy of prematurity, the timing of treatment for threshold disease appears to be related to postmenstrual age.     

1型阈值前期和阈值期早产儿视网膜病变血小板参数分析

目的　观察不同时间段１型阈值前期和阈值期早产儿视网膜病变（ｒｅｔｉｎｏｐａｔｈｙｏｆｐｒｅｍａｔｕｒｉｔｙ,ＲＯＰ）患儿血小板相关参数的变化,分析其与ＲＯＰ发生发展的内在联系。方法收集我院新生儿病房２０１３年１月至２０１４年１２月诊治的早产儿临床资料,纳入早产儿分为１型阈值前期与阈值期ＲＯＰ组和对照组,对照组出生孕周与ＲＯＰ组匹配,眼底筛查未见明显ＲＯＰ病变,并对两组矫正胎龄为３２～３３周、３６～３７周、４０～４１周、４４～４５周者的血小板平均体积（ｍｅａｎｐｌａｔｅｌｅｔｖｏｌｕｍｅ,ＭＰＶ）和血小板计数（ｐｌａｔｅｌｅｔｃｏｕｎｔｓ,ＰＣ）进行比较。结果　与对照组相比,ＲＯＰ组患儿３６～３７周和４０～４１周的ＭＰＶ［（１０．８６±１．８７）ｆＬ、（１０．１２±１．４５）ｆＬ,（１０．７４±１．６６）ｆＬ、（１０．１７±１．５２）ｆＬ］显著增加（均为Ｐ＜０．０５）;３２～３３周和４４～４５周ＭＰＶ［（１０．１８±１．５４）ｆＬ、（１０．３７±１．９１）ｆＬ,（１０．５６±１．２１）ｆＬ、（１０．４２±０．９７）ｆＬ］差异均无统计学意义（均为Ｐ＞０．０５）。与对照组相比,ＲＯＰ组患儿３２～３３周、３６～３７周、４０～４１周、４４～４５周的ＰＣ［（２８８．００±１４３．２５）×１０９Ｌ－１、（２９１．００±１１３．２７）×１０９Ｌ－１,（２７７．２３±９２．８８）×１０９Ｌ－１、（２６５．４９±１０２．１３）×１０９ Ｌ－１,（３０６．００±１７１．８３）×１０９Ｌ－１、（２８４．００±１４３．５６）×１０９Ｌ－１,（３１１．４３±１３１．２４）×１０９ Ｌ－１、（３０３．６２±９４．５５）×１０９Ｌ－１］差异均无统计学意义（均为Ｐ＞０．０５）。进一步进行多因素Ｌｏｇｉｓｔｉｃ回归分析,结果显示ＭＰＶ与１型阈值前期和阈值期ＲＯＰ发生相关。结论　ＭＰＶ的变化可能与ＲＯＰ的病情严重程度和检查时间的差异相关;ＭＰＶ增高是１型阈值前期和阈值期ＲＯＰ发生的高危因素,活化的血小板在１型阈值前期和阈值期ＲＯＰ的发生发展中发挥重要作用。     

Late clinical characteristics of infants with retinopathy of prematurity and treated with cryotherapy

AIM: To describe the clinical characteristics and late results of patients with retinopathy of prematurity (ROP) treated with “6h cryotherapy”. METHODS: Out of 1252 infants screened for ROP, 52 patients were treated with temporal 6h cryotherapy from 1997 to 2005 were recalled to our clinic. Among these 23 patients were available and 46 eyes of 23 infants were included to evaluate for visual acuity, refractive error, ocular alignment, nystagmus, retinal examination (abnormal branching of retinal vessels, retinal thinning, latis degenerations, tortuosity of vessels, straightening of temporal vessels, narrowing of the angle of vessel in the juxtapapillary entrance, pigment changes, macular heterotopia), optic atrophy and optic disc cupping, axial length at birth and axial length at 1y. RESULTS: The median age at examination was 7 (5-18)y. In 32.6% of patients, the visual acuity was ≤20/200 and the mean best corrected visual acuity was 20/35 as measured with a Snellen chart. Mean spherical refractive error was -1.76±2.69 D. The degree of myopia at the last examination was found to be correlated with the elongation of the eye in the first year of life. Exotropia was present in 17.4% (n=8) of infants and esotropia in 13% (n=6). The most common retinal abnormality was abnormal branching of retinal vessels (82.6%) followed by retinal thinning (52.2%). CONCLUSION: The late clinical outcomes of infants with ROP treated in our clinic with cryotherapy seems to comparable with results of laser treatment.     

Transscleral vs transpupillary diode laser photocoagulation for the treatment of zone II type 1 retinopathy of prematurity: Anatomical and refractive outcomes

Purpose:To compare the anatomical and refractive outcomes of transscleral diode versus transpupillary laser photocoagulation for the treatment of zone II type 1 retinopathy of prematurity (ROP).Methods:In this prospective comparative interventional case series, infants with type 1 ROP in zone II were assigned to either transpupillary or transscleral laser based on the surgeons’ expertise area. The rate of regression, need for retreatment, and structural and biometric outcomes at month 6 were evaluated and compared between the two treatment groups.Results:In total, 209 eyes were enrolled; 145 eyes of 77 infants and 64 eyes of 33 infants and were in transscleral and transpupillary groups, respectively. There was no significant difference in baseline characteristics between the groups. There was no significant difference in retreatment rates (1.6% vs. 3.4%; P = 0.669) and progression to stage 4 (1.6% vs. 2.8%; P = 0.999) between the transpupillary and transscleral groups, respectively. At month 6, the mean spherical equivalent was 0.31 ± 3.57 and 0.44 ± 2.85 diopters, and the axial length was 18.28 ± 6.22 and 18.36 ± 6.87 mm in the transpupillary and transscleral groups, respectively, without a significant difference between groups. There was no significant difference in the rate of myopia (43.8% vs. 33.8%; P = 0.169) and high myopia (4.7% vs. 4.8%; P = 0.965) in transpupillary and transscleral groups at month 6.Conclusion:The transpupillary and transscleral laser photocoagulation routes are both effective in the treatment of zone II type 1 ROP and show no significant differences in anatomical or refractive outcomes in relation to the route chosen.     

急性进展性后部型早产儿视网膜病变的治疗研究进展

急性进展性后部型早产儿视网膜病变(aggressive posterior retinopathy of prematurity,AP-ROP)是一种少见且进展很快的严重性早产儿视网膜病变,可不遵循1~3期的经典病程,而迅速进展为5期病变,最终导致不可逆的视力丧失。目前常用的治疗方式有激光光凝、玻璃体腔内注射抗血管内皮生长因子(VEGF)、玻璃体切除术。本文将从以上三个方面入手,对AP-ROP的治疗方式进行综述。