Correlation of Retinal Structure and Visual Function Assessments in Mouse Diabetes Models

PurposeDiabetic retinopathy results in vision loss with changes to both retinal blood vessels and neural retina. Recent studies have revealed that animal models of diabetes demonstrate early loss of visual function. We explored the time course of retinal change in three different mouse models of diabetes in a longitudinal study using in vivo measures of retinal structure (optical coherence tomography [OCT]) and visual function (optomotor and pupillary responses).MethodsOCT analysis of retinal microstructure, optokinetic response as a measure of visual acuity, and pupillary response to light stimulation were compared among the db/db, Ins2^Akita, and streptozotocin (STZ)-induced mouse models of diabetes at 1.5, 3, 6, and 9 months of diabetes.ResultsThe db/db, Ins2^Akita, and STZ-induced models of diabetes all exhibited vision loss and retinal thinning as disease progressed. Both structural changes and functional measures were significantly correlated with the blood glucose levels. Despite this, vision loss and retinal thinning were not consistently correlated, except for the inner retinal layer thickness at 6 months of diabetes.ConclusionsThis longitudinal study compiled structural measures and functional outcome data for type 1 and 2 diabetes mouse models commonly used for diabetes studies and demonstrated an overall decline in retinal-related health in conjunction with weight change and blood glucose alterations. The relationship between the structural change and functional outcome could be correlative but is not necessarily causative, as retinal thinning was not sufficient to explain visual acuity decline.     

Higher Serum Uric Acid Levels Are Associated With an Increased Risk of Vision-Threatening Diabetic Retinopathy in Type 2 Diabetes Patients

PurposeTo investigate the association between serum uric acid (SUA) levels and vision-threatening diabetic retinopathy (VTDR) in patients with type 2 diabetes.MethodsThis cross-sectional study evaluated 3481 patients with type 2 diabetes from four communities in China between 2016 and 2019. VTDR was defined as severe nonproliferative, proliferative diabetic retinopathy, or clinically significant macular edema evaluated by fundus photography and optical coherence tomography. Potential association between SUA and VTDR was examined using multivariable logistic regression. Sub-group analyses based on sex were constructed.ResultsA total of 305 participants had VTDR. Both higher SUA (odds ratio [OR], 1.22 per 100 µmol/L; 95% confidence interval [CI], 1.04–1.44; P = 0.013) and hyperuricemia (OR, 1.47; 95% CI, 1.07–2.04; P = 0.019) were positively associated with VTDR after adjustment for relevant covariates. Compared with those in the lowest SUA quartile, participants in the third (OR, 1.60; 95% CI, 1.07–2.39; P = 0.022) and fourth (OR, 2.05; 95% CI, 1.37–3.08; P = 0.001) sex-specific SUA quartiles showed a significantly increased risk of VTDR after adjustment. No sex-related difference was observed.ConclusionsHigher SUA levels were associated with an increased risk of VTDR in patients with type 2 diabetes in both sexes, although females seemed to be more sensitive to high SUA than males. Prospective cohort studies are needed to verify SUA as a biomarker for predicting the risk of VTDR. Whether decreased SUA levels could decrease the risk of VTDR also requires further investigation.     

Anemia and Diabetic Kidney Disease Had Joint Effect on Diabetic Retinopathy Among Patients With Type 2 Diabetes

PurposeWhether the association between diabetic kidney disease (DKD) and diabetic retinopathy (DR) in patients with type 2 diabetes mellitus (T2DM) is leveraged by anemia remains unclear. This study is to evaluate the joint effect of DKD and anemia on DR.MethodsData were collected from electronic medical records of 1389 patients with T2DM in the Yiwu Central Hospital of Zhejiang Province from 2018 to 2019. Based on retinal examination findings, patients were classified as without diabetic retinopathy (non-DR), non-proliferative diabetic retinopathy (NPDR), and proliferative diabetic retinopathy (PDR). Odds ratio (OR) from multinomial logistic regression models adjusting for potential risk factors of DR were used to evaluate associations of DKD, renal function measures, and anemia with risk of NPDR and PDR. Path analysis was performed to help understand the association of DKD and hemoglobin (Hb) with DR.ResultsThe study included 901 patients with non-DR, 367 patients with NPDR and 121 patients with PDR. Both high DKD risk and abnormal renal function measures were significantly associated with PDR. Anemia was associated with increased risk of NPDR (OR = 1.75, 95% confidence interval [CI] = 1.18–2.58) and PDR (OR = 3.71, 95% CI = 2.23–6.18). DKD severity and anemia had joint effect on NPDR (OR = 2.29, 95% CI = 1.32–3.96) and PDR (OR = 11.31, 95% CI = 5.95–21.51). These associations were supported by path analysis.ConclusionsDKD severity, abnormal estimated glomerular filtration rate (eGFR), and urinary albumin/creatinine ratio (UACR) were associated with increased risk of DR in patients with T2DM, and anemia had joint effect on these associations. Improving Hb level may decrease the risk of DR in patients with T2DM.     

Inter-Eye Agreement in Measurement of Retinal Vascular Fractal Dimension in Patients with Type 1 Diabetes Mellitus

Purpose: To investigate inter-eye agreement in retinal vascular fractal dimension (F_D) in patients with type 1 diabetes.

Methods: In a cross-sectional study, both eyes were exained in 178 patients with type 1 diabetes. All vessels in a zone 0.5–2.0 disc diameters from the optic disc were traced and F_D calculated with the box-counting method using SIVA-Fractal semiautomatic software. The modified Early Treatment Diabetic Retinopathy Study (ETDRS) scale was used to grade diabetic retinopathy (DR). Pitman’s test of difference in variance was used to calculated inter-eye agreement in F_D according to level of DR.

Results: Mean age and duration of diabetes was 37.0 years and 29.5 years, respectively, and 49.4% of participants were male. Mean F_D of right and left eyes was 1.4540 and 1.4472, respectively. F_D did not differ between eyes in patients with no or non-proliferative DR (NPDR) in both eyes. This was true for patients with the same level of DR in both eyes (n = 74, p = 0.73), as well as for patients in which the ETDRS level of DR between the eyes differed by 1 (n = 43, p = 0.99) or more (n = 9, p = 0.53). In patients treated for proliferative DR in one eye, F_D was significantly lower in this eye compared to the other (n = 10, p = 0.03).

Conclusion: F_D did not differ significantly between the two eyes of patients with no DR or NPDR, despite differences in severity of DR.     

Palpebral Fissure Response to Phenylephrine Indicates Autonomic Dysfunction in Patients With Type 1 Diabetes and Polyneuropathy

PurposeThe superior and inferior tarsal muscles are sympathetically innervated smooth muscles. Long-term diabetes often leads to microvascular complications, such as, retinopathy and autonomic neuropathy. We hypothesized that diabetes induces (1) sympathetic paresis in the superior and inferior tarsal muscles and that this measure is associated with (2) the severity of diabetic retinopathy, (3) the duration of diabetes, and (4) autonomic function. In addition, association between the severity of retinopathy and autonomic function was investigated.MethodsForty-eight participants with long-term type 1 diabetes and confirmed distal symmetrical polyneuropathy were included. Palpebral fissure heights were measured bilaterally in response to topically applied 10% phenylephrine to the right eye. The presence of proliferative diabetic retinopathy (PDR) or nonproliferative diabetic retinopathy and disease duration were denoted. Time and frequency derived heart rate variability parameters obtained from 24-hour continuous electrocardiography were recorded.ResultsThe difference in palpebral fissure heights between phenylephrine treated and untreated eyes (∆PFH) was 1.02 mm ± 0.29 (P = 0.001). The ∆PFH was significantly lower in the PDR group (0.41 mm ± 0.43 vs. 1.27 mm ± 1.0), F(1,35) = 5.26, P = 0.011. The ∆PFH was lower with increasing diabetes duration, r(37) = −0.612, P = 0.000. Further, the ∆PFH was lower with diminished autonomic function assessed as total frequency power in electrocardiogram (r = 0.417, P = 0.014), and sympathetic measures of very low (r = 0.437, P = 0.010) and low frequency power (r = 0.384, P = 0.025).ConclusionsThe ∆PFH is a simple ambulatory sympathetic measure, which was associated with the presence of PDR, disease duration, and autonomic function. Consequently, ∆PFH could potentially be an inexpensive and sensitive clinical indicator of autonomic dysfunction.     

Duration of Diabetes and Screening Coverage for Retinopathy Among Patients With Type 2 Diabetes

Aims: Despite reporting of the Wisconsin Epidemiologic Study of Diabetic Retinopathy¹ and the Diabetic Retinopathy Awareness Program² that diabetes duration was a significant predictor for adherence to vision care guidelines, reports of estimates of screening coverage for diabetic retinopathy taking into account diabetes duration have been lagging. This article estimates considering diabetes duration, the prevalence of diabetic retinopathy and screening coverage for diabetic retinopathy among type 2 diabetic patients. Methods: As part of a treatment program at a High-Resolution Diabetes Center in Spain, type 2 diabetic patients attending the center from January 2003 to January 2005 were invited to participate in the study. Data on age, sex, and diabetes were recorded into a questionnaire, as was information about previous eye examinations. Polaroid® photographs were taken of the eye fundus with the poorest visual acuity using a nonmydriatic retinal camera. Results: A total of 217 type 2 diabetic patients entered the program. The average age and duration of diabetes was 60.9 years and 7 years, respectively. Screening coverage for diabetic retinopathy was higher in those with a longer duration of diabetes (χ² = 36.5; p = 0.001). Fifty percent of patients had developed some retinopathy within the first 5 years after the diagnosis of the disease, but only 26.1% had received a previous fundus examination. Conclusions: These results argue for screening programs for people with type 2 diabetes mellitus focused on the subgroup of patients with diabetes duration of 5 years or less.     

Association of Skin Intrinsic Fluorescence with Retinal Microvascular Complications of Long Term Type 1 Diabetes in the Wisconsin Epidemiologic Study of Diabetic Retinopathy

Objective: To determine the association between skin intrinsic fluorescence (SIF), a noninvasive measure of advanced glycation endproducts and oxidative stress in skin, and retinal microvascular complications of long duration type 1 diabetes, proliferative diabetic retinopathy (PDR) and macular edema.

Methods: A cross-sectional cohort study of persons with type 1 diabetes in the Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR) who participated in a 32-year follow-up examination in 2012–2014. Subjects underwent a physical examination, answered a health questionnaire, and had fundus photographs taken. SIF was measured on the underside of the left forearm near the elbow with the SCOUT DS^® skin fluorescence spectrometer. Two representative SIF measures were used for these analyses: SIF01 excited by an LED centered at 375?nm with correction factors K_x = 0.6 and K_m = 0.2 and SIF15 excited by an LED centered at 456?nm with correction factors K_x = 0.4 and?K_m = 0.9.

Results: The 414 participants had mean diabetes duration of 42.2 years (standard deviation 6.8 years, range 32.9–67.9 years). PDR was statistically significantly associated (p < 0.05) with both SIF measures in multivariate models including other relevant factors (odds ratio [OR] = 1.17 for SIF01 and 1.20 for SIF15).

Conclusion: Skin intrinsic fluorescence measures are independently associated with PDR in the WESDR. Incidence information is needed to evaluate whether there is a causal relationship.     

2型糖尿病患者肾功能相关指标与发生视网膜病变的相关性

目的:研究2型糖尿病患者肾功能相关指标与视网膜病变发生的相关性,指导糖尿病视网膜病变早期诊断及治疗.方法:选取2014-03/2015-12间就诊的明确诊断为2型糖尿病的295例患者.根据眼底表现情况,分为DR组和非DR组,对比分析两组患者一般资料、肾功能相关指标,基于差异性分析探讨肾功能相关指标与糖尿病患者发生视网膜病变发生相关性.结果:与非DR组相比,DR组24h尿蛋白定量、尿微量白蛋白/血肌酐比值、血肌酐、血尿素氮、血尿酸明显高于非DR组,差异具有统计学意义;两组内生肌酐清除率、肾小球滤过率差异不具有统计学意义.结论:24h尿蛋白定量、尿微量白蛋白/血肌酐比值、血肌酐、血尿素氮、血尿酸与DM患者发生DR具有相关性,而内生肌酐清除率、肾小球滤过率与DM患者发生DR无相关性.     

Risk Factors for Proliferative Diabetic Retinopathy in African Americans with Type 2 Diabetes

Purpose: To assess personal and demographic risk factors for proliferative diabetic retinopathy in African Americans with type 2 diabetes.

Methods: In this prospective, non-interventional, cross-sectional case-control study, 380 African Americans with type 2 diabetes were enrolled. Participants were recruited prospectively and had to have either: (1) absence of diabetic retinopathy after ≥10 years of type 2 diabetes, or (2) presence of proliferative diabetic retinopathy when enrolled. Dilated, 7-field fundus photographs were graded using the Early Treatment Diabetic Retinopathy Study scale. Covariates including hemoglobin A_1C (HbA_1C), blood pressure, height, weight and waist circumference were collected prospectively. Multivariate regression models adjusted for age, sex and site were constructed to assess associations between risk factors and proliferative diabetic retinopathy.

Results: Proliferative diabetic retinopathy was associated with longer duration of diabetes (odds ratio, OR, 1.62, p < 0.001), higher systolic blood pressure (OR 1.65, p < 0.001) and insulin use (OR 6.65, p < 0.001) in the multivariate regression analysis. HbA_1C was associated with proliferative diabetic retinopathy in the univariate analysis (OR 1.31, p = 0.002) but was no longer significant in the multivariate analysis.

Conclusions: In this case-control study of African Americans with type 2 diabetes, duration of diabetes, systolic hypertension and insulin use were strong risk factors for the development of proliferative diabetic retinopathy. Interestingly, HbA_1C did not confer additional risk in this cohort.     

1型糖尿病患者视网膜病变与肾功能的关系

目的：探讨1型糖尿病患者视网膜病变与肾功能的相关性。

方法：选取2016-09/2018-05在我院眼科和内分泌科门诊及住院的1型糖尿病患者110例,根据眼底情况分为无糖尿病视网膜病变(NDR)组35例、非增生期糖尿病视网膜病变(BDR)组35例和增生期糖尿病视网膜病变(PDR)组40例,同时选取健康体检者40例作为对照组,分别记录受检者的一般情况,并检测尿白蛋白/尿肌酐比值、肾小球滤过率、血清肌酐、血尿素氮、胱抑素C、尿α1-微球蛋白和尿β2-微球蛋白等指标。

结果：四组受检者尿白蛋白/尿肌酐比值、肾小球率过滤、血清肌酐、血尿素氮、胱抑素C、尿α1-微球蛋白、尿β2-微球蛋白检测值有明显差异(均P<0.05),糖尿病患者尿白蛋白/尿肌酐比值、血清肌酐、血尿素氮、胱抑素C、尿α1-微球蛋白、尿β2-微球蛋白明显升高,肾小球滤过率显著下降(均P<0.05)。糖尿病患者视网膜病变程度与尿白蛋白/尿肌酐比值呈正相关(r_s =0.498,P<0.05),与肾小球滤过率呈负相关(r_s=-0.481,P<0.05)。PDR组患者大量尿蛋白(尿白蛋白/尿肌酐比值>300mg/g)发病率为67.5%,肾功能不全(肾小球滤过率<60mL/min)发病率高达65.0%。

结论：1型糖尿病患者视网膜病变与肾功能关系密切,肾功能异常患者糖尿病视网膜病变发生风险高,检测肾功能有助于预测其发生发展。     

Risk evaluation for diabetic retinopathy in Chinese renal-biopsied type 2 diabetes mellitus patients

AIM: To investigate diabetic retinopathy (DR) prevalence in Chinese renal-biopsied type 2 diabetes mellitus (T2DM) patients with kidney dysfunction, and to further evaluate its relationship with diabetic nephropathy (DN) incidence and the risk factors for DR development in this population. METHODS: A total of 84 renal-biopsied T2DM patients were included. Fundus and imaging examinations were employed for DR diagnosis. Demographic information and clinical measures along with renal histopathology were analyzed for comparisons between the DR and non-DR groups. Risk factors on DR development were analyzed with multiple logistic regression. RESULTS: DR prevalence was 50% in total. The incidences of DN, non-diabetic renal disease (NDRD) and mixed-type pathology were 47.6%, 19.0% and 33.3% in the DR group respectively, while 11.9%, 83.3% and 4.8% in the non-DR group. Systolic blood pressure, ratio of urinary albumin to creatine ratio, urinary albumin, 24-hours urinary protein, the incidence and severity of DN histopathology were found statistically increased in the DR group. Multiple logistic regression analysis showed histopathological DN incidence significantly increased the risk of DR development [odds ratio (OR)=21.664, 95% confidential interval (CI) 5.588 to 83.991, P<0.001 for DN, and OR=45.475, 95%CI 6.949 to 297.611, P<0.001 for mixed-type, respectively, in reference to NDRD)], wherein DN severity positively correlated. CONCLUSION: Renal histopathological evidence indicates DN incidence and severity increases the risk of DR development in Chinese T2DM patients inexperienced of regular fundus examinations.     

Aqueous Humor Biomarkers of Retinal Glial Cell Activation in Patients With or Without Age-Related Cataracts and With Different Stages of Diabetic Retinopathy

PurposeTo clarify the expression of biomarkers of retinal glial cell activation in the aqueous humor (AH) of patients with and without age-related cataracts (ARCs) at different stages of diabetic retinopathy (DR).MethodsPatients were stratified by the presence of ARCs and then grouped by the presence of diabetes mellitus (DM), nonproliferative DR (NPDR), proliferative DR (PDR), and controls. Water channel aquaporin 1 (AQP1), water channel aquaporin 4 (AQP4), inwardly rectifying potassium channel 4.1 (Kir4.1), and glial fibrillary acidic protein (GFAP) were assayed in AH samples by ELISAs.ResultsWe enrolled 82 patients. The AQP1 concentration was higher in AH from cataract control patients than in control patients without cataracts (P < 0.05). The APQ1 concentration was also higher in patients with DM, NPDR, and PDR than in controls (P < 0.05). The concentrations of AQP4 and GFAP were significantly increased in patients with NPDR and PDR (P < 0.05) but not in patients with DM. Kir4.1 concentration was significantly decreased in patients with NPDR and PDR (P < 0.05), but the decrease in patients with DM did not reach significance. There were no differences in AQP4, Kir4.1, and GFAP between patients with and without ARCs.ConclusionsIncreased AQP1 in AH may be a biomarker for ARCs in patients without diabetes and a biomarker for retinal glial cell activation in patients with diabetes without cataracts. AQP4, Kir4.1, and GFAP levels in AH suggested that retinal glial cell activation was affected by the progression of DR.     

Dysbiosis in the Gut Microbiome in Streptozotocin-Induced Diabetes Rats and Follow-Up During Retinal Changes

PurposeTo analyze the gut bacterial microbiome of streptozotocin-induced diabetic rats and rats with retinal changes.MethodsInduction of diabetes was confirmed by an increase in blood sugar (>150 mg/dL), and the progression of diabetes with retinal changes was assessed by histology and immunohistochemistry of retinal sections. Microbiomes were generated using fecal DNA, and the V3–V4 amplicons were sequenced and analyzed by QIIME and R.ResultsDysbiosis in the gut microbiome of diabetic rats and diabetic rats with retinal changes was observed at the phylum and genus levels compared with the control rats. Heat-map analysis based on the differentially abundant genera indicated that the microbiomes of controls and diabetic rats separated into two distinct clusters. The majority of the microbiomes in diabetic rats with retinal changes also formed a distinct cluster from the control rats. β-diversity analysis separated the microbiome of control rats from the microbiome of diabetic rats and diabetic rats with retinal changes, but the microbiomes of diabetic rats and diabetic rats with retinal changes showed an overlap. Functional analysis indicated that the enhanced inflammation in diabetic rats showing retinal changes could be ascribed to a decrease in anti-inflammatory bacteria and an increase in pathogenic and proinflammatory bacteria.ConclusionsThis study showed that the gut bacterial microbiome in diabetic rats with retinal changes was different compared with control rats. The results could help develop novel therapeutics for diabetics and diabetic individuals with retinal changes.     

Associations Between Peripapillary Retinal Nerve Fiber Layer and Choroidal Thickness With the Development and Progression of Diabetic Retinopathy

PurposeTo evaluate the role of the peripapillary retinal nerve fiber layer (pRNFL) and peripapillary choroidal thickness (pCT) in the development and progression of diabetic retinopathy (DR).MethodsThis is a cohort study based on the baseline and 2-year follow-up data of the Guangzhou Diabetic Eye Study. Patients with type 2 diabetes mellitus between the ages of 30 and 80 years were recruited from communities in Guangzhou. DR was graded by seven-field fundus photography after dilation of the pupil. pRNFL and pCT were measured via swept-source optical coherence tomography.ResultsA total of 895 patients were included in the study; of these, 748 did not have DR at baseline and 147 had DR at baseline. During the 2-year follow-up, 80 developed DR (10.7%), and 11 experienced DR progression (7.5%). After adjusting for confounding factors, a higher risk of incident DR was strongly associated with a lower average thickness of the pRNFL (risk ratio [RR] per 1 SD, 0.55; 95% confidence interval [CI], 0.42–0.72; P < 0.001) and average pCT (RR per 1 SD, 0.49; 95% CI, 0.34–0.70; P < 0.001). Adding both metrics to the DR prediction model significantly improved the discriminant ability of the model for incidences of DR (area under the curve increased by 15.38% from 0.673 to 0.777; P < 0.001).ConclusionsNeurodegeneration shown by the thinning of pRNFL and impaired choroidal circulation shown by the thinning of pCT are independently associated with DR onset, and assessing both metrics can improve the risk assessment for DR incidences.     

Function of the Retinal Pigment Epithelium in Patients With Neurofibromatosis Type 1

PurposeRetinal and choroidal abnormalities in neurofibromatosis type 1 (NF1) remain poorly studied. It has been reported, however, that the function of the retinal pigment epithelium (RPE) in NF1 was abnormal, with a supra-normal Arden ratio of the electro-oculogram (EOG). This study aims to evaluate the function of the RPE, using EOG, first in patients with NF1 compared to controls and second in patients with NF1 with choroidal abnormalities compared to patients with NF1 without choroidal abnormalities.MethodsThis prospective case-control study included 20 patients with NF1 (10 patients with choroidal abnormalities and 10 patients without) and 10 healthy patients, matched for age. A complete ophthalmologic assessment with multimodal imaging, an EOG, and a full-field electroretinogram were performed for each included patient. The main outcome measured was the EOG light peak (LP)/dark trough (DT) ratio.ResultsThe LP/DT ratio was 3.02 ± 0.52 in patients with NF1 and 2.63 ± 0.31 in controls (P = 0.02). DT values were significantly lower in patients with NF1 than in controls (240 vs. 325 µV, P = 0.02), while light peak values were not significantly different (P = 0.26). No difference was found for peak latencies. No significant correlation between the surface and number of choroidal abnormalities and EOG parameters was demonstrated.ConclusionsThis study confirms the dysfunction of the RPE in patients with NF1, involving a lower DT and a corresponding higher LP/DT ratio. We hypothesize that this pattern may be due to a dysregulation of the melanocytogenesis, inducing a disruption in Ca2⁺ ion flux and an abnormal polarization of the RPE.     

Mean Platelet Volume is Associated with Diabetic Macular Edema in Patients with Type-2 Diabetes Mellitus

Aim: To evaluate the effect of the platelet indices on the stage of diabetic retinopathy (DR) and diabetic macular edema (DME). Methods: In this retrospective study, the mean platelet valume (MPV), Plateletcrit (PCT), platelet (PLT), and platelet distribution width (PDW) of 199 diabetic patients and 76 healthy subjects were enrolled. The participants were divided into four groups. The first group was healthy control; the second group consisted of diabetic patients without DR; the third group was nonproliferative DR (NPDR); and the fourth group was proliferative DR (PDR). Results: Significant differences were found only in MPV and PCT values between patients with diabetes and healthy participants (8.6±0.96 fL vs 8.32±0.9 fL, P=0.011, 0.216± 0.58 vs 0.202±0.52, P=0.038). Comparing the groups, a statistically significant difference in MPV values was found between groups 4 and 1 (8.91±.7 fL vs 8.32±0.9 fL P=0.001) and between groups 4 and 3 (8.91±.7 fL vs 8.42±0.9 fL P=0.014). The MPV values of patients with DME were significantly higher than those of diabetic patients without DME (8.87±0.80 fL vs 8.45±0.97 fL). Conclusion: High MPV values may be an important risk factor for the development of PDR and DME in patients with diabetic retinopathy.     

Capillary-free Vascularized Retina in Patients with Aggressive Posterior Retinopathy of Prematurity and Late Retinal Capillary Formation

Purpose

To report the clinical features, clinical course, and treatment outcomes after laser photocoagulation in infants with aggressive posterior retinopathy of prematurity (APROP) and capillary-free zones in vascularized retina.

Methods

Six patients (12 eyes) with APROP and capillary-free zones in vascularized retina were retrospectively reviewed. Twelve eyes of six infants were included and were treated with laser photocoagulation for avascular retina and for capillary-free zones in vascularized retina, except for the posterior pole, and fundus findings were photographically-documented in sequence. In addition, anatomic and visual outcomes were evaluated with complications of APROP.

Results

Among all of the consecutive infants with APROP, capillary-free zones in vascularized retina were demonstrated in 24% of the infants. All of the infants were >27 weeks of gestation age and had birth weights >1,000 g. After laser treatment, 7 eyes (58.3%) had favorable outcomes, and late capillary filling in capillary-free zones of vascularized retina were noted, however 4 eyes (33.3%) progressed to retinal detachment and 1 eye (8.3%) was complicated by a retinal fold-distorting posterior pole. The visual outcomes were associated with anatomic outcomes.

Conclusions

The anatomic outcomes in infants with APROP who had capillary-free zones were comparable to previously reported infants with APROP. The late capillary filling of capillary-free zones in vascularized retina was noted, and angiogenesis was considered to be involved. This process toward normal capillary formation or neovascularization in APROP, might determine its outcome.