Laser Treatment For Threshold Retinopathy Of Prematurity Research Articles

Refractive status, biometric components, and functional outcomes of patients with threshold retinopathy of prematurity: systemic review and a 17-year longitudinal study.

To assess the long-term refractive status, visual outcome, astigmatism, and the change in biometric optic components in older adolescents up to age 17years with threshold retinopathy of prematurity (ROP) treated with diode laser. A retrospective, longitudinal study in which cycloplegic refraction, keratometry, and the biometric measurement of optic components were performed on 28 consecutive preterm eyes with laser-treated threshold ROP at age 17years. The study results were statistically analysed and compared with age-matched full-term control. All patients with ROP had myopia (average spherical equivalent of - 6.35 D, ranges from - 1.25 to - 12.38 D), and 12 eyes (43%) were highly myopic (spherical equivalent < - 6.0 D). Threshold ROP eyes exhibited a significantly poorer visual acuity (P < 0.001), greater cylinder refractive error (P < 0.001), higher corneal astigmatism (P < 0.001), and flatter horizontal corneal curvature (P = 0.01) compared with age-matched controls. Biometric optic components analysis revealed a significant shallower anterior chamber depth (P < 0.001), thicker lens (P < 0.001), and shorter axial length (P = 0.021) in laser-treated ROP eyes compared with age-matched controls. In this 17-year longitudinal study, a higher prevalence of myopia and astigmatism was observed in laser-treated threshold ROP eyes compared with age-matched control eyes. Myopia and astigmatism in laser-treated ROP eyes typically progress through adolescence after school age. Therefore, we recommend that preterm patients with laser-treated threshold ROP should attend regular follow-up not only for refractive status but also for structural change of anterior segment until their adolescence.

Long‐term biometric optic components of diode laser‐treated threshold retinopathy of prematurity at 9 years of age

To assess quantitatively the biometric optic components and its relationship with refractive status in preterm school children with diode laser-treated threshold retinopathy of prematurity (ROP). A prospective, cross-sectional study in which ultrasound biometric measurement of optic components and cycloplegic refraction 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 1021 age-matched full-term control children from a national survey. The eyes with laser-treated ROP showed statistically significantly thicker lens (3.94 versus 3.39 mm), steeper vertical corneal curvature (7.47 versus 7.67 mm) and shallower anterior chamber depth (ACD) (2.91 versus 3.58 mm) than age-matched full-term controls, but no difference in axial length (23.32 versus 23.24 mm). The laser-treated eyes had a mean spherical equivalent (SE) of -4.49 D compared with mean SE of -0.44 D in controls. Of 46 eyes studied, 93% of eyes were myopic and 28.3% with high myopia (<-6.0 D) compared with the 32% prevalence of myopia in controls. In preterm children, younger gestational age tended to correlate with shallower ACD (r = 0.352) and thicker lens (r = -0.298); lower birth weight tended to correlate with shallower ACD (r = 0.372) and steeper cornea (r = 0.360). There were higher prevalence and greater magnitude of myopia in preterm children. The significantly thicker lens, steeper corneal curvature and shallower anterior chamber depth are the major factors contributing to the development of myopia in preterm school children with laser-treated threshold ROP.

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

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). 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. 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). 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.

Current Role of Cryotherapy in Retinopathy of Prematurity: A Report by the American Academy of Ophthalmology

To evaluate the role of cryotherapy in the current treatment of retinopathy of prematurity (ROP). Literature searches of PubMed and the Cochrane Library were conducted on December 2, 2009, for articles published after 1984. The searches included all languages and retrieved 187 relevant citations. Thirteen articles were deemed relevant to the assessment question and were rated according to the strength of evidence. Four articles reported results from 2 large multicenter randomized clinical trials, and the remaining 9 articles reported results of 3 small randomized trials that directly compared cryotherapy and laser. Neither of the multicenter randomized clinical trials was a direct comparison of cryotherapy with laser. These studies were used to evaluate the comparative trials based on treatment criteria, study populations, and clinical results. Higher percentages of poor structural and functional outcomes generally were seen in eyes treated with cryotherapy compared with eyes undergoing laser treatment. Higher rates of systemic complications and myopia also were identified after treatment with cryotherapy. Despite a relative paucity of level I evidence directly comparing cryotherapy and laser treatment for threshold ROP, the literature suggests that neonatal facilities should gain access to laser technology and laser-trained ophthalmic staff to achieve better outcomes for treatment of the disease.

Refractive outcome of premature infants with or without retinopathy of prematurity at 2 years of age: A prospective controlled cohort study

This study evaluated the extent to which refractive morbidity is correlated to preterm birth or retinopathy of prematurity (ROP) itself, or both, and examined the risk factors associated with refractive errors in a cohort of preterm infants with and without ROP compared with full-term infants. This longitudinal, prospective, controlled cohort study enrolled 109 infants, including 74 preterm and 35 full-term infants. Infants were divided into the following groups: no ROP, regressed ROP, laser-treated threshold ROP, and full-term. Cycloplegic refraction was determined at 6 and 24 months’ corrected age. Multiple regression models, analysis of variance (ANOVA) with post hoc comparisons, paired t test, and the χ2 test were used for data analysis. ROP status was highly predictive of significant refractive errors in preterm infants. Eyes with laser-treated threshold ROP had significant myopia at both ages (mean spherical equivalent [MSE] in right eye at both refractions −0.72, −1.21 diopters [D]), astigmatism (MSE −1.62, −1.80 D), and anisometropia (MSE 0.82, 1.02 D; ANOVA p < 0.05), and increased refractive errors across ages (paired t test p < 0.05). Eyes with regressed ROP (MSE + 0.35 D) and eyes without ROP (MSE + 0.78 D) were less hyperopic than the controls (MSE + 1.60 D) before 1 year (post hoc comparisons p < 0.05). After 1 year, however, hyperopic status, astigmatism, and anisometropia were similar to eyes with regressed ROP (MSE + 0.38 D, astigmatism −0.94 D, anisometropia 0.32 D), eyes without ROP (MSE + 0.35 D, astigmatism −0.51 D, anisometropia 0.31 D) and the controls (MSE + 0.72 D, astigmatism −0.59 D, anisometropia 0.50 D) by post hoc comparisons (p > 0.05). Thus, the persistent hyperopic status across ages in patients with regressed ROP and in patients without ROP differed significantly (paired t test p > 0.05) from that in the full-term infants, with a reduction in hypermetropia noted for the first 2 years of life (paired t test p < 0.05). The incidence and magnitude of significant refractive errors increased with severe ROP and with age. Although the emmetropization process of preterm birth, including regressed ROP and no ROP, differed from full-term birth in early infancy, we found no differences in the refractive status after 1 year in patients with regressed ROP and in patients without ROP, who were at risk of developing ametropia similar to that of full-term patients. Therefore, apart from laser-treated ROP, children with regressed ROP and without ROP can likely be observed with a verbal vision screening at 3–4 years of age.

Oxygen Saturation in Premature Infants at Risk for Threshold Retinopathy of Prematurity

We aimed to determine if oxygen saturation, desaturations, and saturation variability play a role in progression of retinopathy of prematurity (ROP) and need for laser treatment. This was a retrospective case-control study. We performed chart review of premature infants in a university hospital neonatal intensive care unit consecutively examined for ROP between May 2000 and December 2001. We compared birthweight, postmenstrual age, and oxygen saturation for 3 weeks before laser treatment for threshold ROP in group 1 (n=19) (average weight at treatment 2508 grams) and group 2 (n=18) before they reached 2500 grams. Outcome measures were retinopathy progression and need for treatment. Adjusting for birthweight and postmenstrual age, known predictors of ROP progression, we found that babies requiring laser treatment (group 1) had lower average daily oxygen saturation levels in the study period, significantly on 5/20 days (25%). These babies had saturations below 95% on 18/20 days (90%). Babies not requiring laser (group 2) had saturations below 95% on 2/20 days (10%). The last day on which pretreatment saturations differed significantly was 2 days before laser. Group 1 had more desaturations below 80% (6.0±3.2) than group 2 (3.2±1.2), p=0.0002 (independent samples t tests). Saturations varied more for individual group 1 infants. Decreased oxygen saturation as early as 3 weeks and as late as 2 days before laser, increased number of desaturations, and saturation variability were seen in babies eventually requiring laser treatment for ROP.

Demographic Changes and Response to Laser Treatment in Threshold Retinopathy of Prematurity: 10-Year Experience

To evaluate the outcome of indirect diode laser treatment for threshold retinopathy of prematurity (ROP) and to report demographic changes observed over 10 years. Retrospective chart review and statistical analysis of 111 eyes of 61 infants treated for threshold ROP between 1991-2001 at a single academic institution. Ninety-six 111(86%) eyes showed regression of neovascularization after laser treatment. Fourteen (13%) eyes had zone 1 disease and 97 (87%) eyes had zone 2 disease. Thirty-six percent of eyes with zone 1 disease progressed to stage 4 or 5 disease despite treatment, whereas 10% of the zone 2 eyes progressed. Based on multivariate logistic regression, zone and female gender were found to be predictive of progression, whereas birth weight was predictive of zone. Between 1991 and 2001, a significant trend toward lower mean gestational age at time of birth (Pearson correlation = -0.35, P = .0041) was found. However, progression rates to stage 4 and 5 disease following laser treatment were similar for infants born before and after 1997 (P = .0796). Regression of neovascularization was noted in 86% of eyes following laser treatment for threshold ROP. Zone was predictive of progression to stage 4 or 5 despite treatment. Premature infants being treated for threshold ROP tended to be born at an earlier gestational age and with lower birth weights over time, but progression rates to more severe stages did not increase following laser treatment, suggesting that optimal treatment can yield favorable ocular outcomes.

Long-term visual outcomes of laser-treated threshold retinopathy of prematurity: a study of refractive status at 7 years

To assess the long-term visual outcomes and refractive status in patients with diode laser-treated threshold retinopathy of prematurity (ROP), and to investigate the causes of impaired visual function. A total of 60 eyes of 30 consecutive patients with diode laser-treated threshold ROP were recalled for assessment at the age of 7 years or more. There were 38 eyes (65.5%) achieving 6/12 or better vision, however, an unfavourable visual outcome (6/60 or worse) occurred in four eyes (6.9%). One eye (1.7%) had unfavourable structural outcome. Of these 60 laser-treated eyes, 46 eyes (77.0%) were myopic, the overall mean spherical equivalent was -3.87 D. Anisometropia (>or=1.5 D) was also noted in 14 patients (46.7%). Strabismus was present in nine patients (30.0%). Perinatal neurological events of intraventricular haemorrhage (IVH) were identified in eight children (26.7%), periventricular leucomalacia (PVL) in eight children (26.7%), and cerebral palsy (CP) in four children (13.3%). There was a statistically significant association of the presence of strabismus with PVL (P=0.002). The presence of anisometropia was a significant risk factor associated with poor visual outcome of 6/15 or worse in laser-treated ROP (P=0.002). The majority of patients with diode laser-treated threshold ROP had favourable anatomical and visual outcomes. However, anisometropia, advanced refractive error, strabismus, and perinatal neurological events remain important causes of impaired visual function. Long-term follow-up is very important for early detection and timely treatment of these ocular morbidities.

Argon laser photocoagulation for retinopathy of prematurity: long-term outcome

To assess the visual, refractive, ocular structural, and neurodevelopmental outcome in a group of children who were screened, treated with laser photocoagulation for threshold retinopathy of prematurity (ROP), and followed up at our institution. The 21 survivors of a cohort of 23 children were recalled at the age of 5 years or more. They underwent a full ophthalmologic examination. A paediatric neurologist and/or developmental paediatrician performed a neurodevelopmental assessment and a neuropsychologist performed psychological testing. A total of 30 eyes (71.4%) had a best-corrected visual acuity (BCVA) of 20/40 or better. In all, 26 (62%) eyes were myopic; the overall mean spherical equivalent was -4.95 D. No eye had Stage 4 findings and only one eye (2.4%) progressed to stage 5 despite photocoagulation. In total, 14 patients (66.6%) showed evidence of stereopsis. Strabismus was seen in six patients (28.5%) and nystagmus in three (14.3%). Periventricular leukomalacia (PVL) was identified in five patients (23.8%), cerebral palsy (CP) in seven (33.3%), and intraventricular haemorrhage (IVH) in 13 (62%). Cerebral palsy and IVH associated strongly with visual acuity of less than 20/40 (P=0.009 and 0.047). There was also a strong association between visual acuity of 20/40 or above and a better cognitive outcome (P=0.013). Retinal scarring and detachment are relatively rare causes of visual morbidity 5 years or more after laser treatment for threshold ROP, but the neurological sequelae of extreme prematurity and amblyopia remain important causes of impaired visual function.

Involution of threshold retinopathy of prematurity after diode laser photocoagulation

Objective To characterize the process of involution of threshold retinopathy of prematurity after transpupillary diode laser photocoagulation. Design Retrospective case series. Participants Neonates with threshold retinopathy who underwent diode laser photocoagulation of the peripheral avascular retina. Methods A retrospective chart review was done of the weekly examination records of infants treated for threshold disease. Features that were studied included the presence of residual stage 3 neovascularization, plus disease, and development of retinal detachment (RD). Main outcome measures Timing of full involution and/or development of an RD. Results Of 262 eyes of 138 infants treated, full involution without RD was seen in 8%, 43%, 64%, 73%, and 86% of eyes at postoperative weeks 1, 2, 3, 4, and 9±3, respectively. Retinal detachments were diagnosed cumulatively in 0%, 1.5%, 4.2%, 6.5%, and 14% of eyes at weeks 1, 2, 3, 4, and 9±3, respectively. Conclusions Full involution of laser-treated threshold retinopathy of prematurity required more than 2 weeks in more than half of treated eyes. Most RDs were not detected until ≥3 weeks after treatment.

Retinal features predictive of progressive stage 4 retinopathy of prematurity.

To determine the retinal features predictive of progressive stage 4 retinopathy of prematurity (ROP) after laser treatment for threshold ROP. Retrospective review of 72 eyes of 37 infants after laser treatment for threshold ROP between 1993 and 2002. Retinal features were abstracted from examinations made within 1 week of development of stage 4A ROP or 2 weeks after laser treatment in eyes with regressed threshold disease. Predictive features of progressive stage 4 ROP were determined using a generalized estimating equation model to account for within-subject variability. The generalized estimating equation showed that vitreous state, ridge elevation of six or more clock hours, and two or more quadrants of plus disease predicted progressive retinal detachment, whereas two or more quadrants of neovascularization did not. Progressive stage 4 ROP requiring surgical intervention was predicted by the absence of clear vitreous, ridge elevation of six or more clock hours, and two or more quadrants of plus disease, but not by neovascularization. These results may be useful in the management of eyes after laser treatment for threshold ROP.

Retinopathy of prematurity in infants with birth weights greater than 1250 grams

Purpose To determine whether severe retinopathy of prematurity (ROP) occurs in infants whose birth weights exceed 1250 g. Methods We retrospectively reviewed the medical records of 1118 premature infants with birth weights > 1250 g, who were referred for screening examinations for ROP, to determine the severity of ROP observed. We then cross-tabulated these data with each infant’s estimated gestational age and birth weight. Finally, we applied currently recommended screening guidelines retrospectively to determine whether they would have identified infants who had developed severe disease and who were subsequently treated. Results Stage 3 ROP was detected in infants with estimated gestational ages up to and including 32 weeks and birth weights up to and including 1874 g. A total of 26 of the participants received laser treatment for threshold ROP. Seven of these infants would not have been referred for screening according to current guidelines. Conclusions Current screenings guidelines may fail to detect severe ROP in larger, more mature infants.

Features associated with surgical outcome in patients with stages 4 and 5 retinopathy of prematurity.

To present ocular features associated with surgical outcomes in infants with stages 4 and 5 retinopathy of prematurity (ROP). Twenty-two infants (35 eyes) were referred for vitreoretinal surgery for stages 4 and 5 ROP. The following ocular features recorded before the development of retinal detachment requiring surgical intervention were analyzed: clock hour extent of ridge elevation, vitreous state, plus disease, prominent iris vessels, neovascularization, and the presence of exudates. Surgical procedures included scleral buckle, lensectomy-vitrectomy, and lens-sparing vitrectomy. Univariate and multivariate analyses were used to determine features associated with failure to achieve retinal reattachment as the main outcome variable. Of the 35 eyes that underwent at least one surgical procedure, nine had successful retinal reattachment after the first surgery, and 18 achieved it at the end of follow-up. After accounting for the correlation between the eyes, features significantly associated with surgical failure after the first surgery were vitreous haze, hemorrhage, or organization; plus disease; and neovascularization. The presence of exudates was significantly associated with a successful outcome. When eyes were analyzed by stage at the first procedure, vitreous organization and plus disease were associated with failed retinal reattachment in stage 4 eyes, whereas at least 6 clock hours of ridge elevation and plus disease were significant in stage 5 eyes. The need to perform a lensectomy-vitrectomy was associated with a poor surgical outcome. Neither stage nor number of procedures performed was associated with the development of phthisis. Vitreous haze, neovascularization, and plus disease are associated with a poor surgical outcome in eyes that progress after treatment for threshold ROP requiring surgical intervention for retinal detachment. When eyes were divided by stage of ROP at first surgery, plus disease remained a significant variable associated with failed retinal reattachment. Close observation of eyes after laser treatment for threshold ROP is necessary. If neovascularization and plus disease persist and progression of ROP is noted, additional laser should be considered before surgery for retinal detachment. Additional studies with a larger patient sample will be necessary to further define ocular features associated with surgical outcome for ROP.

A comparison of dense versus less dense diode laser photocoagulation patterns for threshold retinopathy of prematurity

ObjectiveTo determine if the density of diode laser photocoagulation for the treatment of zone 1 or zone 2 threshold retinopathy of prematurity (ROP) affects the rate of progression of the disease. DesignRetrospective, nonrandomized, comparative trial (n = 12) and prospective, randomized, clinical trial (n = 46). ParticipantsTwo surgeons treated a total of 107 eyes from 58 patients with zone 1 or zone 2 threshold ROP within 72 hours of diagnosis. The two consecutive groups of patients were treated with two different diode laser photocoagulation patterns between May 1995 and October 1997 and were observed for at least 3 months. InterventionAll patients underwent diode laser photocoagulation of the peripheral avascular retina extending from the ridge of extraretinal proliferation to the ora serrata. One cohort received a near confluent laser pattern, whereas the second cohort received a pattern of laser spots placed 1 to 1.5 burn widths apart. Main outcome measuresAnatomic outcome, rate of progression to stage 4 or 5 retinopathy of prematurity, postoperative complications, and timing and frequency of retreatment. ResultsFor analysis, the retrospective and randomized outcome data were grouped. The rate of progression in the near confluent laser treatment group was 3.6% overall, 0% of zone 1 eyes, and 3.8% of zone 2 eyes. The rate of progression in the less dense treatment group was 29% overall, 44% of zone 1 eyes, and 21% of zone 2 eyes. Mean time to retreatment was 16 days in cohort 1 and 24 days in cohort 2. ConclusionsA dense pattern of diode laser treatment for threshold ROP and prompt retreatment for residual plus disease significantly reduce the rate of progression in eyes with zone 2 disease (P = 0.02) and may be beneficial in eyes with zone 1 disease.

Timing of initial screening examinations for retinopathy of prematurity.

To test a screening protocol for retinopathy of prematurity (ROP) that uses the dual criteria of postconceptional age and chronological age, rather than a single parameter, to determine precisely when to begin eye examinations. We retrospectively reviewed medical records of 179 infants (326 eyes) who had undergone laser treatment for threshold ROP. We entered their chronological and postconceptional ages at treatment into a database and evaluated various screening parameters to determine the combination of criteria that would allow us to safely postpone the initial eye examinations. Screening infants at 7 weeks of chronological age or 34 weeks of postconceptional age (whichever comes first), but not before 5 weeks of chronological age, seems to reliably detect the onset of threshold ROP while reducing the number of unnecessary early examinations. Simultaneously applied dual criteria of chronological age and postconceptional age may be a superior method of determining when to initiate ROP examinations and is preferable to using either chronological age or postconceptional age alone.