Laser-treated Eyes Research Articles

Refractive errors in infants with retinopathy of prematurity treated using laser or anti-vascular endothelial growth factor monotherapy

Background: Infants treated for retinopathy of prematurity (ROP) could develop visually significant refractive errors. In this study, we report pre-treatment refractive errors in premature infants with treatment-requiring ROP treated using laser or anti-VEGF monotherapy and compare the components of post-treatment refractive error values between the two treatment groups at different follow-up timepoints.
 Methods: In this retrospective cohort study, we analyzed 360 eyes of 181 premature infants with treatment-requiring ROP who were referred to Farabi Eye Hospital, Tehran, Iran between March 2020 and April 2021. Of the 360 eyes, 195 received laser monotherapy (laser treatment group) and 165 received an intravitreal anti-VEGF injection (anti-VEGF therapy group). All included eyes underwent pre- and post-treatment cycloplegic refraction. Cycloplegia was induced for each infant by instilling a mixed eye drop containing 1% tropicamide, 2.5% phenylephrine, and 0.5% tetracaine (in equal volumes) in each eye three times at five-minute intervals. Cycloplegic refraction was performed 30 minutes after the third instillation.
 Results: The mean (standard deviation [SD]) gestational age (GA) and birth weight (BW) of the infants were 29.0 (2.0) weeks and 1241.0 (403.0) g, respectively. The male-to-female ratio in the entire study cohort was 107 (59.1%) / 74 (40.9%), whereas the ratios in the anti-VEGF therapy group and laser treatment group were 47 (56.6%) / 36 (43.4%) and 60 (61.2%) / 38 (38.8%), respectively. The pre-treatment assessment revealed that 218 (60.6%) eyes were hyperopic, 112 (31.1%) were myopic, and 30 (8.3%) were emmetropic. In the anti-VEGF therapy group, 87 (52.7%) eyes were hyperopic, 63 (38.2%) were myopic, and 15 (9.1%) were emmetropic. In the laser treatment group, 131 (67.2%) eyes were hyperopic, 49 (25.1%) were myopic, and 15 (7.7%) were emmetropic. The mean (SD) spherical refractive error and spherical equivalent of refractive error (SEQ) at the 1-week, 1-month, and > 6-month post-treatment follow-up timepoints; the mean cylindrical refractive error at the 3-month post-treatment timepoint; and the mean SEQ at the time of ROP regression were significantly different between the treatment groups (all P < 0.05). The rate of anisometropia increased significantly from 3.4% at baseline to 9.2% at the 6-month post-treatment follow-up timepoint (P < 0.05).
 Conclusions: In this study, the most common pre-treatment refractive status of all included eyes with treatment-requiring ROP and eyes in each treatment group was hyperopia, followed by myopia and emmetropia. At the more than 6-month post-treatment follow-up, cycloplegic refraction revealed that the laser-treated eyes were significantly more hyperopic than the anti-VEGF-treated eyes, a finding similar to the pre-treatment refraction results. Further studies of same cohort with a longer follow-up period and a control group are needed to determine the real-world effect of each treatment modality on the refractive statuses of children treated for ROP.

Electroretinographic Responses in Retinopathy of Prematurity Treated Using Intravitreal Bevacizumab or Laser

Intravitreal injection of bevacizumab (IVB) offers advantages over laser photoablation for treatment of type 1 retinopathy of prematurity (ROP). However, retinal function has not, to date, been quantitatively compared following these interventions. Therefore, electroretinography (ERG) was used compare retinal function among eyes treated using IVB or laser, and control eyes. In addition, among the IVB-treated eyes, ERG was used to compare function in individuals in whom subsequent laser was and was not required. Prospective clinical cohort study. ERG was used to record dark- and light-adapted stimulus/response functions in 21 children treated using IVB (12 of whom required subsequent laser in at least 1 eye for persistent avascular retina [PAR]). Sensitivity and amplitude parameters were derived from the a-wave, b-wave, and oscillatory potentials (OPs), representing activity in photoreceptor, postreceptor, and inner retinal cells, respectively. These parameters were then referenced to those of 76 healthy, term-born controls and compared to those of 10 children treated using laser only. In children with treated ROP, every ERG parameter was significantly below the mean in controls. However, these significant ERG deficits did not differ between IVB- and laser-treated eyes. Among children treated using IVB, no ERG parameter was significantly associated with dose or need for subsequent laser. Retinal function was significantly impaired in treated ROP eyes. Function in IVB-treated eyes did not differ from that in laser-treated eyes. Functional differences also did not distinguish those IVB-treated eyes that would subsequently need laser for PAR.

Investigating the factors affecting myopia in retinopathy of prematurity after laser treatment

BackgroundWe investigated the effect of the number of laser shots applied on the myopic variables to elucidate the mechanism of myopia development in laser-treated retinopathy of prematurity (ROP) eyes.MethodsA total of 33 eyes of 17 infants with ROP who underwent laser treatment were included in the analysis. Cycloplegic retinoscopic refraction testing was carried out and the spherical equivalent (SE) was calculated. Relationships between SE and various variables (including the number of laser shots applied) were examined. In addition, an age-matched control group without ROP was prepared and ocular structural parameters were compared.ResultsAlthough there was no statistical difference in axial length (AL) between two groups (p = 0.88), SE was significantly more myopic in the ROP group (p < 0.001). SE was associated with AL, corneal refraction (CR), and crystalline lens power (CLP) in the ROP group. Of these three factors (AL, CR, and CLP), CLP and the number of laser shots applied were significantly correlated (p = 0.003); however, no correlations were observed between the number of laser shots and AL or CR (p = 0.15 and 0.10, respectively). Very similar tendency was observed in the analysis of the difference between right and left eyes in each child.ConclusionsIn laser-treated ROP eyes, AL, CR, and CLP were related to the degree of myopia. Moreover, the number of shots applied also affected the myopic status in laser-treated ROP eyes. Among AL, CR, and CLP, only CLP was correlated with the laser shots applied.

Foveal and Retinal Nerve Fiber Layer Thickness in Children With a History of Retinopathy of Prematurity Treated With Bevacizumab: A Cross-sectional Study

Objectives: This study aimed to investigate the effects of bevacizumab (an anti-VEGF antibody) on the structure of retina such as the thickness of the nerve fiber layer and macula with optical coherence tomography (OCT) in retinopathy of prematurity (ROP) patients. Materials and Methods: This cross-sectional study was conducted in 2021-2022 in Tabriz, Iran to investigate preterm children aged 4-6 years. To this end, a total of 300 eyes of 150 children were assigned to three groups and then were examined by performing Fundus examination of retina, eye refraction test, and OCT imaging. The first group included 100 eyes with a history of ROP and treated with bevacizumab, the second group consisted of 100 eyes with a history of ROP but improved spontaneously, and the third group comprised 100 eyes of preterm children without a history of ROP. Results: Foveal thickness was 235.46 ± 11 µm in the group receiving bevacizumab, 267.70 ± 12 µm in the group with spontaneous improvement of ROP, and 269.48 ± 10 µm in the group with no ROP. Therefore, the mean thickness of the fovea in the group receiving bevacizumab was significantly lower than that in the other two groups. In the group receiving bevacizumab, moreover, the thickness of the nerve layer of the retina was less than that in the other two groups (P&lt;0.005). Conclusions: In sum, a greater understanding of the development of premature fovea was achieved, which may have facilitated identifying the possible clinical and long-term effects of these abnormal changes on adulthood visual acuity. It was recommended that further studies should be carried out to compare laser-treated eyes in order for expanding the scientific understanding of the development of premature fovea and other aspects of ROP, which may have decreased the preventable blindness rate.

Neuroprotective effect of the calcium channel blocker nilvadipine on retinal ganglion cell death in a mouse ocular hypertension model

We investigated whether nilvadipine has a neuroprotective effect on retinal ganglion cells (RGCs) in a mouse model of ocular hypertension (OH) that expresses cyan fluorescein protein (CFP) in RGCs. OH was induced in the right eyes of Thy1-CFP transgenic mice using a laser. Nilvadipine or vehicle treatment began simultaneously with OH modeling and was administered intraperitoneally once daily for 8 weeks. Intraocular pressure (IOP) in both the laser- and non-treated eyes was measured weekly with the microneedle method, and calculations were performed to estimate the pressure insult in each eye. Using a retinal whole mount, the number of RGCs was counted at week 9. Laser-treated eyes showed a significant increase in IOP (p < 0.01), and the pressure insult did not differ between the drug-treated groups. Over time, laser treatment produced a significant decrease in the number of RGCs in the vehicle-treated groups, but this effect was attenuated by nilvadipine treatment. The pressure insult and RGC survival rate were significantly negatively correlated in the vehicle-treated group (y = -0.078 x + 107.8, r = 0.76, p < 0.001), but not in the nilvadipine-treated group (y = -0.015 x + 99.9, r = 0.43, p = 0.128). Nilvadipine was a potent neuroprotective agent for RGCs in our mouse model of OH and may have potential for protection against glaucoma. This model is useful as a screening tool for drugs with retinal protective effects.

Corneal topography in preterm children aged 2 years to 12 years with or without retinopathy of prematurity.

To evaluate corneal topography in full-term and preterm children with or without retinopathy of prematurity (ROP). We enrolled children aged from 2 years to 12 years between January 2019 and May 2021 in the following four groups: full-term (group 1), premature without ROP (group 2), untreated premature with ROP (group 3), and laser-treated and/or intravitreal injection (IVI) of anti-vascular endothelial growth factor (VEGF)-treated premature with ROP (group 4). Corneal topography was measured with the Galilei Placido-dual Scheimpflug analyzer G4 every half year, and was compared among the groups using generalized estimating equation models at approximately 7 years of age. We included 77, 178, 45, and 131 participants in groups 1, 2, 3, and 4, respectively. The mean (standard deviation) number of visits per patient was 2.9 (1.4). Compared with full-term eyes, premature eyes demonstrated steeper anterior corneal curvature (p = 0.016 and p = 0.008 for the mean and steep K, respectively), higher anterior and posterior corneal astigmatism (p = 0.036 and p = 0.016, respectively), and thinner thinnest pachymetry (p < 0.001). The laser-treated ROP eyes displayed steeper anterior corneal curvature (p = 0.040 for steep K) and higher anterior corneal astigmatism (p = 0.005) than the IVI-treated eyes. Moreover, they exhibited high cone location and magnitude index (1.96) reaching the cut-off for detecting keratoconus (1.82). The premature status led to greater corneal ectasia, and laser treatment for ROP caused further corneal steepness. Higher anterior corneal astigmatism was associated with laser treatment. The ROP pathology and IVI anti-VEGF treatment exerted a marginal effect on corneal topography.

Refractive outcomes in infants treated for retinopathy of prematurity

Background: Infants treated for retinopathy of prematurity (ROP) can develop visually significant refractive error. However, the degree of refractive error may differ between laser treatment and intravitreal anti-vascular endothelial growth factor (anti-VEGF) injection. We reviewed studies that investigated refractive error outcomes of treatment in premature infants with ROP.&#x0D; Methods: In this narrative review, a literature search was carried out in PubMed/MEDLINE from 01/01/2000 to 20/10/2022 without language restrictions, using the following keywords: “anti-VEGF,” “ROP” or “prematurity retinopathy,” and “laser.” We included comparative studies on refractive error outcomes of intravitreal anti-VEGF and laser treatments, a combination of both modalities simultaneously or sequentially, and two anti-VEGF agents.&#x0D; Results: The initial search yielded 164 records. We reviewed the titles and abstracts of the retrieved papers and the reference list of published systematic reviews and meta-analyses, meta-analyses, or reviews on our topic. Thirty-three records fulfilled our inclusion criteria, which included refractive outcomes in 4350 eyes of 2359 participants treated for ROP. Based on the reported refractive outcomes, we divided the studies into four categories: 1) those that revealed a higher rate of refractive error in the laser-treated eyes than in the anti-VEGF-treated eyes; 2) those that revealed no significant difference in refractive outcomes between the two treatment modalities; 3) those that revealed a higher rate of refractive error in the anti-VEGF-treated eyes or compared refractive outcomes between two anti-VEGF agents; and 4) those that reported refractive outcomes in the eyes that received combined simultaneous or sequential treatment with laser after initial anti-VEGF treatment. We also summarized the refractive outcomes of all included primary studies in each category.&#x0D; Conclusions: This study showed that the laser-treated eyes experienced more myopic shift. However, the refractive outcomes in premature infants of laser treatment, anti-VEGF treatment, and a combination of both modalities simultaneously or sequentially were often contradictory. This variability resulted from obvious differences in the sample size, different follow-up durations, or inhomogeneous study or treatment designs. Further well-designed prospective trials on refractive outcomes and the trend of changes in the refractive status over long-term follow-ups in the eyes treated with ROP are necessary to identify consensus results concerning real-world refractive outcomes of each treatment modality or simultaneous or sequential combination of both modalities, to suggest a safe and effective treatment option for eye care professionals.

Effect of foveal morphology on visual acuity in 4–6-year-old children with retinopathy of prematurity: a J-CREST study

Laser therapy is the most effective treatment considered for retinopathy of prematurity (ROP). We compared the foveal morphology of the retina in eyes with a history of ROP to that of full-term children. This cross-sectional comparative study included 74 patients with a history of ROP, aged 4–6 years. Among them, 41 underwent laser treatment for ROP. The clinical findings and retinal morphology in these patients were compared to that of 33 patients who had spontaneous ROP regression and 30 age-matched full-term controls. All the patients with ROP had 20/40 or better best-corrected visual acuity (BCVA). The foveal thickness was significantly thicker in laser-treated ROP eyes than in regressed ROP eyes and controls. The outer nuclear layer was significantly thicker, and the inner segment (IS) of the photoreceptors and the inner retinal layer were significantly thicker in the laser-treated ROP eyes than that in the control eyes. In the patients with ROP and controls, better BCVA was associated positively with deeper foveal depression, which was associated with a later gestational age. Our results suggest that prematurity and laser treatment affect the foveal morphology and BCVA.

Refractive outcomes following unilateral laser treatment for type 1 retinopathy of prematurity

To compare refractive outcomes of infants with type 1 retinopathy of prematurity (ROP) in whom one eye was treated with laser and the fellow eye spontaneously regressed. The medical records of infants who underwent IVB and laser treatment for type 1 ROP or aggressive posterior-ROP between January 2016 and December 2019 were retrospectively evaluated. Infants in whom ROP in the fellow eye regressed and for whom refractive data was available in the record were included in the study. Refractive outcomes of unilaterally treated infants were assessed. A total of 283 cases were reviewed: of these, 17 experienced spontaneous regression in the fellow eye and were included. All unilateral laser-treated eyes had type 1 ROP in zone Ⅱ. The median age at treatment was 40 weeks' postmenstrual age (IQR, 39-41). The mean spherical equivalent at the last examination was 2.1 ± 2.5 D in treated eyes and 2.50±1.4 D in nontreated eyes, at a mean age of 25.0 ± 9.1 months (P = 0.378). Ofthe 7 infants who underwent fluorescein angiography, the median of the ratio of the length of the temporal retinal vascularization to the optic disk-to-fovea distance was 3.71 (3.22-3.79) in treated and 4.28 (3.90-4.49) in untreated eyes, at a median age of 18 months (P = 0.018). In laser-treated eyes with peripheral zone Ⅱ ROP and with advanced treatment age, wedidnot observe a significant myopic change compared to the fellow untreated eye.

Long-term Visual and Refractive Outcomes of Argon Laser-treated Retinopathy of Prematurity.

PurposeIn this case–control study, we measured visual acuity, objective refraction, ocular biometric parameters, and strabismus in premature cases classified according to the following categories: argon laser-treated retinopathy of prematurity (ROP), untreated spontaneously regressed ROP, no ROP, and full-term controls.MethodsCases with a history of prematurity at six years of age were categorized into the following groups: patients with a history of treated type 1 ROP using argon laser (group I), untreated spontaneously regressed ROP (group II), and no history of ROP (group III). Group IV included age-matched healthy full-term controls. Funduscopy was performed for all the cases and the control group.Results In total, 24 eyes of 12 laser-treated ROP cases, 186 eyes of 93 spontaneously regressed ROP patients, 74 eyes of 37 premature cases with no history of ROP, and 286 eyes of 143 controls were included in the study. The mean spherical equivalent in the treated cases was not significantly different from that in the untreated cases and patients in group III. However, the average cylindrical power was significantly different among the groups (P 0.004). Furthermore, anisometropia (1.5 diopters) was diagnosed with a higher rate in the treated cases (P = 0.03). The corneal curvature of the laser-treated eyes was significantly steeper and the axial length was significantly shorter than those in the other groups (P 0.002 and P 0.001, respectively, for multivariate analysis). Strabismus was found in three treated patients (25%). Additionally, there were three treated eyes (12.5%) diagnosed with macular dragging.ConclusionPremature cases including those who had a history of argon laser-treated ROP and those with untreated spontaneously regressed ROP showed acceptable long-term visual and refractive outcomes along with a fairly low rate of ocular disorders.

Endothelial Glycocalyx Morphology in Different Flow Regions of the Aqueous Outflow Pathway of Normal and Laser-Induced Glaucoma Monkey Eyes.

Glycocalyx morphology was examined in the trabecular outflow pathway of monkey eyes with and without experimental glaucoma. Laser burns were administered along ~270 degrees of the trabecular meshwork (TM) of one eye (n = 6) or both eyes (n = 2) of each monkey until intraocular pressure remained elevated. Portions of the TM were not laser-treated. Unlasered eyes (n = 6) served as controls. Enucleated eyes were perfused at 15 mmHg to measure the outflow facility, perfused with fluorescein to evaluate the outflow pattern, perfusion-fixed for glycocalyx labeling, and processed for electron microscopy. Coverage and thickness of the glycocalyx were measured in the TM, Schlemm’s canal (SC), collector channels (CCs), intrascleral veins (ISVs), and episcleral veins (ESVs) in non-lasered regions and high- and low-flow regions of controls. Compared to controls, laser-treated eyes had decreased outflow facility (p = 0.02). Glycocalyx thickness increased from the TM to ESVs in non-lasered regions and controls (p < 0.05). Glycocalyx coverage was generally greater distally in non-lasered regions (p < 0.05). In lasered regions, TM, SC, and CCs were partly to completely obliterated, and ISVs and ESVs displayed minimal glycocalyx. Whether the glycocalyx is decreased in the trabecular outflow pathway of human glaucomatous eyes warrants investigation.

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.

Cataract progression after Nd:YAG laser iridotomy in primary angle-closure suspect eyes

Background/AimsProphylactic laser peripheral iridotomy (LPI) is performed in primary angle-closure suspect (PACS) eyes to prevent acute angle-closure attacks. However, accelerated cataractogenesis is a potential risk of the procedure that may...

Longitudinal Change of Refractive Error in Retinopathy of Prematurity Treated With Intravitreal Bevacizumab or Laser Photocoagulation

To compare progression of myopia and refractive error in former premature infants with retinopathy of prematurity (ROP) treated using intravitreal bevacizumab (IVB) or laser. Retrospective clinical cohort study. We identified premature infants with ROP treated using IVB from 2011 to 2020 and compared their longitudinal cycloplegic refraction data to that of infants with ROP treated using laser during the same timeframe. A subset of infants treated using IVB also underwent additional treatment using laser. We included cycloplegic refractions from 789 cumulative visits over a median 3.2 years. We used a linear mixed-effects model with a log decay function to evaluate how refraction changed with age after treatment. In aggregate, the model estimated a significant (P < .001) trend in refraction-from slight hyperopia to relatively more myopic states. However, progression in laser-treated eyes was significantly (P < .001) more rapid, regardless of treatment with IVB. The number of laser spots resulted in increased myopic progression by approximately 0.16 diopters per 100 laser spots. Both ROP stage and zone had a significant effect on myopic progression, with more severe disease resulting in faster myopic progression. Random effects, including individual subject variation with nested variance for left and right eye, accounted for 86.4% of the remaining variance not explained by age and treatment. Laser treatment for severe ROP increases the trend to severe myopia. In our sample, IVB did not affect myopic progression but did substantially reduce the amount of consequent laser required to treat ROP. The effect of laser persists after accounting for differences in ROP stage and zone.

Morphological changes to Schlemm's canal and the distal aqueous outflow pathway in monkey eyes with laser-induced ocular hypertension

Though roughly 30–50% of aqueous outflow resistance resides distal to Schlemm's canal (SC), the morphology of the conventional outflow pathway distal to SC has not been thoroughly evaluated. This study examined the morphological changes along proximal and distal aspects of the conventional aqueous outflow pathway and their association with decreased outflow facility in an experimental model of glaucoma in cynomolgus macaques. Nd:YAG laser burns were made to 270–340 degrees of the trabecular meshwork (TM) of one eye (n = 6) or both eyes (n = 2) of each monkey to induce ocular hypertension. Distinct regions of the TM were left unlasered. Contralateral eyes (n = 5) were not lasered and were utilized as controls. Monkeys were sacrificed ≥58 months after their last laser treatment. All eyes were enucleated and perfused at 15 mmHg for 30 min to measure outflow facility. Two pairs of eyes were also perfused with fluorescein to examine segmental outflow. All eyes underwent perfusion-fixation for 1 h. Anterior segments were cut into radial wedges and processed for light and electron microscopy. Width, height, and cross-sectional area (CSA) of SC were compared between high- and low-flow regions of control eyes, and between non-lasered regions of laser-treated eyes and control eyes. Number and CSA of intrascleral veins (ISVs) were compared between non-lasered and lasered regions of laser-treated eyes and control eyes, and between high- and low-flow regions of control eyes. Scleral collagen fibril diameter was compared between control eyes and lasered and non-lasered regions of laser-treated eyes. Median outflow facility was significantly decreased in laser-treated eyes compared to control eyes (P = 0.02). Median CSA and height of SC were smaller in high-flow regions than low-flow regions of control eyes (P < 0.05). Median width of SC was not significantly different between high- and low-flow regions of control eyes (P > 0.05). Median CSA, width, and height of SC were not different between non-lasered regions and control eyes (P > 0.05). SC was partially or completely obliterated in lasered regions. Median number of ISVs was significantly decreased in lasered regions compared to non-lasered regions (P < 0.01) and control eyes (P < 0.01). Median CSA of ISVs did not differ between these groups (P > 0.05). Median number and CSA of ISVs were not significantly different between high- and low-flow regions of control eyes (P > 0.05). Lasered regions displayed looser scleral stroma and smaller median diameter of collagen fibrils adjacent to the TM compared to non-lasered regions (P < 0.05) and control eyes (P < 0.05). Dense TM, partial to complete obliteration of SC, and a decreased number of patent ISVs may account in part for the decreased outflow facility in monkey eyes with laser-induced ocular hypertension. The significance of changes in scleral structure in laser-treated eyes warrants further investigation.

Refractive outcomes following yttrium aluminum garnet laser (532 nm green laser) in severe retinopathy of prematurity

To assess the refractive outcomes in eyes with severe Retinopathy of prematurity (ROP) after treatment with the frequency-doubled neodymium-doped yttrium aluminum garnet (Nd-YAG) laser 532 nm (green laser) at 1-2 years of age and compare with eyes that underwent spontaneous regression of ROP and to identify the risk factors associated with the refractive outcomes in laser-treated eyes with severe ROP. Infants who underwent laser treatment with green laser were enrolled in Group 1 and those who had spontaneous regression of ROP were enrolled in Group 2. All these children underwent a visual assessment, refraction using 1% cyclopentolate eye drops and indirect ophthalmoscopy at 1-2 years of age. Data regarding the gestational age, sex, birth weight, inborn (born in our institution) or outborn (born outside and referred to us), stage and zone of ROP and laser spots given were obtained from the treatment records. Data were analyzed using SSPS 19.0 software for Windows (SSPS Inc., Chicago, Illinois, USA). A total of 102 infants were enrolled, 51 in each group. Visual acuity ranged from 0.25-1 cycles per cm in both groups. Spherical equivalent (SE) ranged from - 8.25 D to + 5.50 D in Group 1 and -1.00D to +4.00D in Group 2. Group 1 had an incidence of 23.5% Myopia and 33.4% Astigmatism which was significantly more than Group 2. The linear regression model predicted a decrease in the SE by 0.658D if the number of laser spots increased by 1000 (P < 0.001). No other risk factors (gestational age/birth weight) were found to have a significant association with refractive errors in the lasered ROP group. Eyes with laser-treated severe ROP are frequently associated with myopia and astigmatism when compared to spontaneously regressed ROP. The number of laser spots delivered has a direct association with the amount of refractive error.

Refractive outcomes of laser-treated and non-laser-treated retinopathy of prematurity at Hospital Selayang: a 2-year retrospective review

Objective: To compare the refractive outcomes of laser-treated and non-laser-treated retinopathy of prematurity (ROP) infant, at 2 years of age in Hospital Selayang.Methods: Retrospective review involving patients born between 2016 and 2018. They were divided into those who were treated with laser photocoagulation, and those who were observed. Laser treatment was given to infants with threshold and high-risk, pre-threshold disease. Refractive error was identified by cycloplegic refraction at 2 years of age.Results: There were 22 eyes from 11 infants in the laser-treated group, all of which had zone II ROP with plus disease; of these, four had stage 2 ROP and 18 had stage 3 ROP. There were 53 eyes from 28 patients in the non-laser-treated group. The mean birth weight for the laser-treated and non-laser-treated groups was 966.9 ± 92.6 g and 1019.3 ± 282.0 g, respectively (P = 0.398). Mean gestational age for the laser-treated and non-laser-treated groups was 28.2 ± 2.2 weeks and 27.7 ± 2.2 weeks, respectively (P = 0.390). At 2 years, the mean spherical equivalence for the laser-treated and non-laser treated groups was -0.55 ± 2.49 D and +0.17 ± 1.43 D, respectively, although the difference was not statistically significant (P = 0.120). Myopia was commoner in the laser-treated group (six eyes [27%] vs five eyes [9%], P = 0.047), and two eyes from two different infants (10%) from this group also developed high myopia (&gt; -6.00 D). For hypermetropia and astigmatism, there were no statistically significant differences between the groups (all P &gt; 0.05). High myopia was strongly related to the post-conceptual age when receiving laser therapy (P = 0.025). In the laser-treated group, two infants (9%) had amblyopia and one (5%) had exotropia at 2 years of age. None of the eyes developed structural retinal sequelae.Conclusion: Despite successful treatment of ROP, a significant number of laser-treated eyes developed myopia. This highlights the need for long-term refractive screening in these patients.

Assessment of pupillary light reflex using dynamic pupillometry in laser-treated eyes with retinal vein occlusion.

This study aims to evaluate the pupillary light reflex measured with dynamic pupillometry in patients who underwent retinal laser photocoagulation due to unilateral retinal vein occlusion (RVO). A total of 48 patients with unilateral RVO were included in the study. Thirty-four patients had undergone retinal laser photocoagulation while the remaining 14 patients that did not undergo laser treatment were observed for control purposes. Of the laser-treated eyes, 14 eyes (41.2%) had central RVO (CRVO) and 20 eyes (58.8%) had branch RVO (BRVO). Among the 14 patients with RVO without laser treatment, nine eyes (64.3%) had CRVO and five eyes (35.7%) had BRVO. Pupillary light reflexes were assessed with dynamic pupillometry (MonPackOne®; Metrovision, France). The parameters of the eyes with RVO were compared with that of fellow healthy eyes. Mean patient age was 65.8 ± 10.4 years and median time after photocoagulation was 25.5 months. Eyes that received laser photocoagulation had lower pupil contraction amplitude (p = 0.037), prolonged contraction latency (p = 0.027), slower contraction velocity (p = 0.043), and slower dilation velocity (p < 0.001) compared to healthy fellow eyes. Subgroup analysis revealed that eyes with CRVO had lower contraction amplitude (p = 0.013) and slower dilation velocity (p = 0.003), and eyes with BRVO had slower dilation velocity (p = 0.003). Non-laser-treated eyes with RVO revealed no significant difference in any of the pupillary light reflex parameters compared to fellow eyes. Laser-treated eyes with RVO demonstrated changes in pupillary light reflex parameters including reduced contraction amplitude, prolonged contraction latency, and slower contraction and dilation velocities measured with dynamic pupillometry.

THE EVOLUTION OF ISOLATED NEOVASCULAR TUFTS ("POPCORN") IN RETINOPATHY OF PREMATURITY.

To explore the natural evolution of isolated neovascular tufts ("popcorn") in retinopathy of prematurity (ROP) and its significance in the progression of acute ROP. In this retrospective case series, 89 infants (89 eyes) in total having acute ROP were analyzed during serial retinal examinations with a RetCam III wide-angle fundus imaging system, among which 53 eyes were observed to have popcorn and 36 eyes did not. The clinical outcomes of the popcorn (+) group and the popcorn (-) group were compared. Popcorn was located only in Zone II, Stage 2 ROP, primarily in the temporal field (65%). It appeared at a mean postmenstrual age of (37.6 ± 1.3) weeks, disappeared at (41.0 ± 2.2) weeks, and lasted for (2.8 ± 1.1) weeks. The popcorn (+) group had a significantly higher natural regression incidence than the popcorn (-) group (P < 0.05). The laser-treated eyes in the popcorn (+) group had earlier presentations (36.4 ± 0.7 vs. 38.2 ± 1.3 weeks) and shorter existences (1.5 ± 0.5 vs. 3.2 ± 0.9 weeks) of popcorn than the regressed eyes (P < 0.01, respectively). Popcorn is generally a "benign" indicator of the regression of ROP. The early presentation (<postmenstrual age 37 weeks) and short duration of popcorn require further observation.

Foveal thickness, foveal microvasculature, and refractive error in children with asymmetric involvement of retinopathy of prematurity.

To evaluate foveal thickness, foveal microvasculature, and refractive error in children with asymmetric involvement of retinopathy of prematurity who had laser treatment in one eye and spontaneously regressed retinopathy of prematurity in the fellow eye. Totally, 17 children (34 eyes) with a history of asymmetric course of acute Zone II retinopathy of prematurity were assessed. Data on best-corrected visual acuity, refractive status, axial length, anterior chamber depth, and optical coherence tomography angiography findings were analyzed between treated and non-treated fellow eyes. Treated eyes were more myopic than non-treated eyes (mean, -0.09 ± 1.86 diopters vs mean, 0.07 ± 0.98 diopters, p = 0.026). Compared to non-treated eyes, treated eyes had shallower anterior chamber depth (mean, 3.27 ± 0.24mm vs mean, 3.55 ± 0.19mm, p = 0.02). No significant difference was observed regarding optical coherence tomography angiography parameters between two eyes of the children. The mean central foveal thickness was found to be higher in treated eyes than in non-treated eyes (297.46 ± 22.03 vs 275.55 ± 18.45, p = 0.009). Higher number of laser spots were associated with decreased parafoveal superficial capillary plexus vessel density (r = -0.56, p = 0.02) and increased central foveal thickness (r = 0.62, p = 0.008). Our results revealed no difference in optical coherence tomography angiography parameters between laser-treated and non-treated eyes in children with asymmetric involvement of Zone II retinopathy of prematurity except for a higher central foveal thickness in laser-treated eyes. Treated eyes were more myopic than the non-treated eyes. Number of laser applications during treatment had an impact on parafoveal superficial capillary plexus vessel density.