Myopia and astigmatism in retinopathy of prematurity after treatment with cryotherapy or laser photocoagulation

Retinopathy of Prematurity-Targeting Hypoxic and Redox Signaling Pathways

Retinopathy of prematurity (ROP) is a proliferative vascular ailment affecting the retina. It is the main risk factor for visual impairment and blindness in infants and young children worldwide. If left undiagnosed and untreated, it can progress to retinal detachment and severe visual impairment. Geographical variations in ROP epidemiology have emerged over recent decades, attributable to differing levels of care provided to preterm infants across countries and regions. Our understanding of the causes of ROP, screening, diagnosis, treatment, and associated risk factors continues to advance. This review article aims to present the pathophysiological mechanisms of ROP, including its treatment. Specifically, it delves into the latest cutting-edge treatment approaches targeting hypoxia and redox signaling pathways for this condition.

The Male to Female Ratio in Treatment-Warranted Retinopathy of Prematurity: A Systematic Review and Meta-analysis

Importance

Literature and anecdotal evidence suggest a relationship between male sex and retinopathy of prematurity (ROP). It is not known whether a difference, if present, is sex-related pathophysiologic predisposition or sex difference in meeting ROP screening criteria.

Objective

To evaluate the association of sex with the development of treatment-warranted ROP.

Data Sources

PubMed, Embase, and Web of Science databases were searched from 2000 to 2022. The search strategy used keywords including retinopathy of prematurity or ROP or retrolental fibroplasia and treatment or anti-VEGF or bevacizumab or ranibizumab or aflibercept or conbercept or laser or cryotherapy and gender or sex or male or female and medical subject headings terms.

Study Selection

All studies reporting on treatment with anti-vascular endothelial growth factor, laser photocoagulation, and/or cryotherapy for ROP were identified. Studies reporting sex distribution in the treatment group were included in the meta-analysis. Exclusion criteria included case reports, case series of fewer than 10 treated patients, systematic reviews, conference abstracts, letters to the editor, animal studies, and non-English records.

Data Extraction and Synthesis

Two reviewers independently screened and extracted the data following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The proportions of treated male and female infants were combined using random-effects meta-analysis.

Main Outcomes and Measures

Numbers and percentages of male and female infants treated for ROP.

Results

Of 11 368 identified studies, 316 met inclusion criteria, yielding a total of 31 026 treated patients. A higher percentage of male infants were treated for ROP (55% [95% CI, 0.54%-0.55%]), with low heterogeneity between studies (I2 = 34%; P < .001). Thirty-eight studies reported sex distribution in the screened population (170 053 patients; 92 612 [53%] male vs 77 441 [47%] female). There was no significant difference in the odds of receiving treatment between screened male and female infants (pooled odds ratio, 1.04 [95% CI, 0.91-1.18]; P = .67).

Conclusions and Relevance

More male infants are treated for ROP than female infants. This could be due to a known relative pathophysiological fragility of preterm male infants in addition to a difference in ROP screening rates, with more male infants meeting the criteria than female infants. These findings have implications for future studies and may prompt more careful clinical monitoring of male neonates.

Retinopathy of prematurity: a review of epidemiology and current treatment strategies

Retinopathy of prematurity (ROP) is among the most common causes of childhood blindness. Three phases of ROP epidemics have been observed worldwide since ROP was first described in the 1940s. Despite advances in neonatal care, the occurrence of ROP and associated visual impairment has been increasing somewhere on Earth and remains difficult to control. Conventional treatment options for preventing ROP progression include retinal ablation using cryotherapy or laser therapy. With the emergence of anti-vascular endothelial growth factor (anti-VEGF) treatment for ocular diseases, the efficacy and safety of anti-VEGF therapy for ROP have recently been actively discussed. In the advanced stage of ROP with retinal detachment, surgical treatment including scleral buckling or vitrectomy is needed to maintain or induce retinal attachment. At this stage, the visual outcome is usually poor despite successful anatomical retinal attachment. Therefore, preventing ROP progression by timely screening examinations and treatment remains the most important part of ROP management.

Advances in understanding and management of retinopathy of prematurity

The understanding, diagnosis, and treatment of retinopathy of prematurity have changed in the 70 years since the original description of retrolental fibroplasia associated with high oxygenation. It is now recognized that retinopathy of prematurity differs in appearance worldwide and as ever smaller and younger premature infants survive. New methods are being evaluated to image the retina, diagnose severe retinopathy of prematurity, and determine windows of time for treatment to save eyes and improve visual and neural outcomes. New treatments to promote physiologic retinal vascular development, vascular repair, and inhibit vasoproliferation by regulating proteins involved in vascular endothelial growth factor, insulin-like growth factor, or erythropoietin signaling. Reducing excessive oxidative/nitrosative stress and understanding progenitor cells and neurovascular and glial vascular interactions are being studied.

Refractive Error in Patients with Retinopathy of Prematurity after Laser Photocoagulation or Bevacizumab Monotherapy

PURPOSE

To evaluate the refractive development of premature infants with retinopathy of prematurity (ROP) after treatment with laser photocoagulation or intravitreal injection of bevacizumab (IVB).

METHODS

The medical records of patients with ROP treated between 2003 and 2012 who underwent yearly follow-ups were retrospectively reviewed. Patients with residual ROP abnormalities were excluded. The cycloplegic refraction at 3 years of age, assessed using an autorefractometer, was recorded.

RESULTS

In total, 54 eyes from 54 patients were enrolled. Patients were divided into 4 groups: group 1, including 14 eyes of 14 patients treated with laser therapy; group 2, 15 eyes of 15 patients treated with IVB; group 3, 13 eyes of 13 patients with non-type 1 ROP under conservative follow-up, and group 4, 12 eyes of 12 premature patients without ROP. The mean spherical equivalent at 3 years of age was -1.71 ± 1.27 dpt in group 1, -1.53 ± 2.20 dpt in group 2, 0.63 ± 1.37 dpt in group 3, and 0.41 ± 1.95 dpt in group 4. The mean refractive error differed significantly among the 4 groups (p < 0.001). Patients in groups 1 and 2 were more prone to myopia compared with those in groups 3 and 4. Furthermore, patients with type 1 ROP treated by laser photocoagulation (group 1) and those treated by IVB (group 2) had similar refraction (p = 1).

CONCLUSIONS

The results of this study suggest that treatment-demanding ROP eyes are susceptible to more severe myopia with age compared with eyes without ROP or those with spontaneously regressed ROP. In addition, the myopic status between laser and IVB treatment did not differ statistically.

Long term refractive and structural outcome following laser treatment for zone 1 aggressive posterior retinopathy of prematurity

AIM

To report the long term refractive, visual and structural outcome post-laser for zone 1 aggressive posterior retinopathy of prematurity (AP-ROP).

MATERIALS AND METHODS

A retrospective analysis was performed of refractive status of premature infants with zone 1 AP-ROP who underwent laser photocoagulation from 2002 to 2007 and followed up till 2013. Once the disease regressed, children were followed up six monthly with detailed examination regarding fixation pattern, ocular motility, nystagmus, detailed anterior segment and posterior segment examination, and refractive status including best corrected visual acuity.

RESULTS

Forty-eight eyes of 25 infants were included in the study. Average follow-up was 6.91 years (range, 3.8-9.5years) after laser treatment. Astigmatism was noted in 43 out of 48 eyes (89.6%). Two eyes had simple myopia whereas three eyes had no refractive error.

CONCLUSION

After successful laser treatment for zone 1 retinopathy of prematurity (ROP), 94% of our cases developed refractive error. Although most had a favorable anatomical and visual outcome, long-term follow-up even after a successful laser treatment in ROP was necessary.

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.

Short-term effect of cryotherapy on human scleral tissue by atomic force microscopy

This study investigated the inflammatory effect of cryotherapy application on collagen matrix network in human infant sclera. Donor scleral tissues taken from three infant patients divided into five groups: control group, sham-treated group, and three cryotreated groups. In the cryotherapy groups, the sclera was treated for 5 s, 10 s, and 20 s with -80°C freezing by a cryosurgical system. The cryotreated reactions were examined using double histological analysis with hematoxylin-eosin and Masson's trichrome, and atomic force microscopy analysis to quantify the diameter and D-banding of collagen fibrils. The infant scleral tissues treated with cryotherapy showed a significantly increased collagen density associated with inflammatory response (p < 0.05), increased fibril diameter (p < 0.005) compared to the scleral tissues in the control group. The results directly suggest that the cryotherapy affects the morphology of scleral collagen.

Structural and functional results of indirect diode laser treatment for retinopathy of prematurity from 1999 to 2003 in Kuwait

Purpose

The purpose was to report the structural, visual, and refractive outcomes of infants treated for retinopathy of prematurity (ROP) with laser and to identify the risk factors for unfavorable outcomes.

Materials and methods

The charts of infants with severe ROP treated by diode laser in a tertiary center during the period April 1999 to November 2003 were reviewed. Treated infants were followed up for fundus examination, visual acuity assessment, and cycloplegic refraction. Data regarding ocular risk factors, like zones of ROP and the extent of extraretinal proliferations, and data regarding various systemic risk factors were collected. A minimum follow up of 6 months was needed for inclusion in the study of structural outcome. A minimum follow up of 24 months was needed for the study of visual and refractive outcomes. The outcomes measured were: rate of unfavorable structural outcome, unfavorable visual outcome (visual acuity < 20/40), and high myopia (myopia ≥ 5 diopters). The ocular and systemic risk factors were studied for their significance in the development of unfavorable outcomes.

Results

Two hundred seventy eyes of 148 infants were treated for severe ROP, out of which 20 eyes (7.4%) had unfavorable structural outcome. Visual data were available for 149 eyes of 81 infants, of which 70 eyes (47%) had unfavorable visual outcome. Refractive data were available for 131 eyes of 72 infants, and high myopia was present in 23 (17.6%) eyes. Zone I disease was the significant risk factor for unfavorable structural (P < 0.0001), unfavorable visual outcome (P = 0.03), and for high myopia (P < 0.0001). Lower post-conceptional age at treatment was significant for unfavorable structural outcome (P = 0.03) and high myopia (P < 0.0001). Presence of sepsis (P = 0.029) and extraretinal proliferation ≥ 6 hours were significant for unfavorable structural outcome (P = 0.002).

Conclusion

ROP in zone I was the most significant risk factor for all the unfavorable outcomes. Laser-treated ROP infants need long term follow up.

An updated study of the use of bevacizumab in the treatment of patients with prethreshold retinopathy of prematurity in taiwan

PURPOSE

To investigate the effectiveness and complications associated with the use of bevacizumab, an anti-vascular endothelial growth factor agent, in the treatment of prethreshold retinopathy of prematurity (ROP).

DESIGN

A multicenter, retrospective case series.

METHODS

Data from patients who had received intravitreal bevacizumab (IVB) injections for the treatment of ROP were collected from 4 medical centers in Taiwan. The main outcome measures were the regression of ROP and the complications that were associated with the IVB injections.

RESULTS

In total, 162 eyes from 85 patients were included in the study. After receiving IVB injections, 143 eyes (88%) exhibited ROP regression. Fourteen eyes (9%) required additional laser treatment for ROP regression after the absence of a positive response to the IVB injections. Three eyes (2%) progressed to stage 4 ROP and required vitrectomies to reattach the retinas. Two eyes (1%) received 1 additional IVB injection to decrease persistent plus disease. All of the eyes (100%) had attached retinas after the various treatments that they received. The major ocular complications that were associated with IVB injections included vitreous or preretinal hemorrhage in 2 eyes (1%); cataract in 1 eye (1%); and exotropia in 1 eye (1%). No notable systemic complications related to the IVB injections were observed.

CONCLUSIONS

IVB injection seems to be an effective and well-tolerated method of treating prethreshold ROP. Laser therapy may still be required as a backup treatment for patients who do not respond to an IVB injection or for those in whom ROP worsens after an IVB injection.

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.

Astigmatism in the Early Treatment for Retinopathy Of Prematurity Study: findings to 3 years of age

PURPOSE

To examine the prevalence of astigmatism (> or =1.00 diopter [D]) and high astigmatism (> or =2.00 D) at 6 and 9 months corrected age and 2 and 3 years postnatal age, in preterm children with birth weight of less than 1251 g in whom high-risk prethreshold retinopathy of prematurity (ROP) developed and who participated in the Early Treatment for Retinopathy of Prematurity (ETROP) Study.

DESIGN

Randomized, controlled clinical trial.

PARTICIPANTS

Four hundred one infants in whom prethreshold ROP developed in one or both eyes and who were randomized after they were determined to have a high risk (> or =15%) of poor structural outcome without treatment using the Risk Management of Retinopathy of Prematurity (RM-ROP2) program. Refractive error was measured by cycloplegic retinoscopy. Eyes with additional retinal, glaucoma, or cataract surgery were excluded.

INTERVENTION

Eyes were randomized to receive laser photocoagulation at high-risk prethreshold ROP (early treated [ET]) or to be conventionally managed (CM), receiving treatment only if threshold ROP developed.

MAIN OUTCOME MEASURES

Astigmatism and high astigmatism at each visit. Astigmatism was classified as with-the-rule (WTR; 75 degrees -105 degrees ), against-the-rule (ATR; 0 degrees -15 degrees and 165 degrees -180 degrees ), or oblique (OBL; 16 degrees -74 degrees and 106 degrees -164 degrees ).

RESULTS

The prevalence of astigmatism in ET and CM eyes was similar at each test age. For both groups, there was an increase in prevalence of astigmatism from approximately 32% at 6 months to approximately 42% by 3 years, mostly occurring between 6 and 9 months. Among eyes that could be refracted, astigmatism was not influenced by zone of acute-phase ROP, presence of plus disease, or retinal residua of ROP. Eyes with astigmatism and high astigmatism most often had WTR astigmatism.

CONCLUSIONS

By age 3 years, nearly 43% of eyes treated at high-risk prethreshold ROP developed astigmatism of > or =1.00 D and nearly 20% had astigmatism of > or =2.00 D. Presence of astigmatism was not influenced by timing of treatment of acute-phase ROP or by characteristics of acute-phase or cicatricial ROP. These findings reinforce the need for follow-up eye examinations in infants with high-risk prethreshold ROP.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Effect of peripheral retinal ablation with cryotherapy versus diode laser photocoagulation on axial length in the growing rabbit eye

AIMS

To evaluate and compare the effects of peripheral retinal cryotherapy and diode laser photocoagulation on axial length, anterior chamber depth, and lens thickness in developing rabbit eyes.

METHODS

26 eyes of 6 week old Abbit rabbits were randomly assigned to undergo laser photocoagulation or cryotherapy of the peripheral retina. Eight eyes of four untreated rabbits served as controls. Biometric and intraocular pressure measurements were performed at 0, 5, and 10 weeks after treatment.

RESULTS

Five rabbits died, leaving 10 rabbits (20 eyes) in the study group and two (four eyes) in the control group. Average axial lengths for the control, laser treated, and cryo treated eyes were 15.72 mm, 16.08 mm, and 16.11 mm, respectively, at baseline and 17.48 mm, 18.09 mm, and 19.4 mm, respectively, at 10 weeks after treatment (p = 0.028, paired Wilcoxon test). Anterior chamber depth increased from 2.2 mm to 2.5 mm in both treatment groups, and from 2.14 mm to 2.28 mm in the control group. Lens thickness averaged 5.11 mm in the control group and 5.38 mm in the treatment groups before treatment, and 6.34 mm, 6.31 mm, and 6.38 mm, respectively, 10 weeks after treatment.

CONCLUSIONS

Peripheral retinal cryotherapy causes a significantly greater elongation of the eye compared to diode laser photocoagulation in a rabbit model.

Macular pigmentary changes as a sequelae of retinal hemorrhages in premature infants with retinopathy of prematurity

PURPOSE

We assess the incidence of macular changes in ROP patients with retinal hemorrhages.

PATIENTS AND METHODS

The premature group consisted of 360 children born 32 weeks gestation and/or with weight below 1,500 g. We used the RetCam-120 Digital Retinal Camera to document retinal changes.

RESULTS

Of the 360 premature infants 241 (67%) had no ROP, and 119 (33%) had ROP. Of the preterm infants with ROP retinal hemorrhages were found in 46 (38%) children. Of the newborns with ROP and with retinal hemorrhages, macular pigmentary changes were found in 3 (6%) patients. Of these 3 patients, the first had pre-threshold ROP, the second threshold ROP and had underwent diode laser photocoagulation, and the third patient had stage 2 ROP. In the patients with pre-threshold and threshold ROP retinal hemorrhages appeared 6 weeks after birth and macular pigmentary changes were found 6 months after birth. In the patient with stage 2 ROP hemorrhages appeared 7-8 weeks after birth and macular pigmentary changes were detected 12 months after birth.

CONCLUSIONS

Although macular hemorrhages almost always resorb without complications, our study allows the assumption that retinal hemorrhages may cause macular pigmentary changes in the macula, and thus may lead to deprivation amblyopia. Our results may suggest that the presence of the macular pigmentary changes may be related to the hemorrhage and not to the specific therapy or to the disease.