Diabetic retinopathy in pregnancy: a population-based study of women with pregestational diabetes

Progression of diabetic retinopathy in women with pregestational diabetes during pregnancy and postpartum

BACKGROUND

Diabetic retinopathy (DR) may worsen during pregnancy, but its course in the postpartum remains poorly understood. Understanding the natural history of DR during and after pregnancy can help determine when sight-threatening DR treatment should be administered.

METHODS

A prospective longitudinal cohort study recruited pregnant women with pre-existing type 1 (T1D) or type 2 diabetes from two tertiary Diabetes Antenatal Clinics in Melbourne, Australia. Eye examination results in early pregnancy, late pregnancy, and up to 12-months postpartum were compared to determine DR changes. Two-field fundus photographs and optical coherence tomography scans were used to assess DR severity.

RESULTS

Overall, 105 (61.4%) women had at least two eye examinations during the observation period. Mean age was 33.5 years (range 19-51); 54 women (51.4%) had T1D; 63% had HbA1c <7% in early pregnancy. DR progression rate was 23.8% (95% CI 16.4-32.6). Having T1D (RR 4.96, 95% CI 1.83-13.46), pre-existing DR in either eye (RR 4.54, 95% CI 2.39-8.61), and elevated systolic blood pressure (adjusted RR 2.49, 95% CI 1.10-5.66) were associated with increased risk of progression. Sight-threatening progression was observed in 9.5% of women. Among the 19 eyes with progression during pregnancy, 15 eyes remained stable, three eyes progressed, and only one eye regressed in the postpartum.

CONCLUSIONS

Nearly 1 in 4 women had DR progression from conception through to 12-months postpartum; almost half of these developing sight-threatening disease. DR progression occurring during pregnancy was found to predominantly remain unchanged, or worsen, after delivery, with very few eyes spontaneously improving postpartum.

Update on diabetic retinopathy during pregnancy

Diabetes mellitus (DM) leads to several vascular and neurological complications, including diabetic retinopathy (DR). As the population ages, health problems in certain groups, including children and pregnant women, are drawing more and more attention. Pregnancy is one of the independent risk factors for the development and progression of DR. Pregnancy-induced changes may contribute to or worsen DR, which can cause a tremendous burden on public health. It is essential for pregnant women with DR and their offspring to minimize the risk of vision loss from DR in this population and adverse outcomes by understanding the development and processes behind this process. Thus, we have updated the recent situation of epidemiology, evolution characteristics, risk factors, pathophysiology, pregnancy outcomes for a better understanding of the latest status of DR, helping to improve maternal and neonatal pregnancy outcomes, and promoting health for women with DR.

Current Trends in Diagnosis and Treatment Approach of Diabetic Retinopathy during Pregnancy: A Narrative Review

Diabetes mellitus during pregnancy and gestational diabetes are major concerns worldwide. These conditions may lead to the development of severe diabetic retinopathy during pregnancy or worsen pre-existing cases. Gestational diabetes also increases the risk of diabetes for both the mother and the fetus in the future. Understanding the prevalence, evaluating risk factors contributing to pathogenesis, and identifying treatment challenges related to diabetic retinopathy in expectant mothers are all of utmost importance. Pregnancy-related physiological changes, including those in metabolism, blood flow, immunity, and hormones, can contribute to the development or worsening of diabetic retinopathy. If left untreated, this condition may eventually result in irreversible vision loss. Treatment options such as laser therapy, intravitreal anti-vascular endothelial growth factor drugs, and intravitreal steroids pose challenges in managing these patients without endangering the developing baby and mother. This narrative review describes the management of diabetic retinopathy during pregnancy, highlights its risk factors, pathophysiology, and diagnostic methods, and offers recommendations based on findings from previous literature.

Relationship between Biochemical Pathways and Non-Coding RNAs Involved in the Progression of Diabetic Retinopathy

Diabetic retinopathy (DR) is a progressive blinding disease, which affects the vision and quality of life of patients, and it severely impacts the society. This complication, caused by abnormal glucose metabolism, leads to structural, functional, molecular, and biochemical abnormalities in the retina. Oxidative stress and inflammation also play pivotal roles in the pathogenic process of DR, leading to mitochondrial damage and a decrease in mitochondrial function. DR causes retinal degeneration in glial and neural cells, while the disappearance of pericytes in retinal blood vessels leads to alterations in vascular regulation and stability. Clinical changes include dilatation and blood flow changes in response to the decrease in retinal perfusion in retinal blood vessels, leading to vascular leakage, neovascularization, and neurodegeneration. The loss of vascular cells in the retina results in capillary occlusion and ischemia. Thus, DR is a highly complex disease with various biological factors, which contribute to its pathogenesis. The interplay between biochemical pathways and non-coding RNAs (ncRNAs) is essential for understanding the development and progression of DR. Abnormal expression of ncRNAs has been confirmed to promote the development of DR, suggesting that ncRNAs such as miRNAs, lncRNAs, and circRNAs have potential as diagnostic biomarkers and theranostic targets in DR. This review provides an overview of the interactions between abnormal biochemical pathways and dysregulated expression of ncRNAs under the influence of hyperglycemic environment in DR.

Continuous glucose monitor use in type 2 diabetes mellitus in pregnancy and perinatal outcomes: a systematic review and meta-analysis

OBJECTIVE

This study aimed to assess whether continuous glucose monitor use in type 2 diabetes mellitus in pregnancy is associated with improved perinatal outcomes.

DATA SOURCES

We searched Ovid MEDLINE, Scopus, ClinicalTrials.gov, and Cochrane library from inception through May 9, 2022.

STUDY ELIGIBILITY CRITERIA

We included all studies that compared continuous glucose monitor use with fingerstick glucose monitoring in women with type 2 diabetes mellitus.

METHODS

The initial search yielded 2463 unique citations that were screened in Covidence by 2 independent reviewers. Study types included randomized controlled trials, cohort studies, and cross-sectional studies. Our outcomes of interest were macrosomia or large-for-gestational-age infants, hemoglobin A1c, cesarean delivery, hypertensive disorders of pregnancy including preeclampsia, gestational age at delivery, and neonatal hypoglycemia.

RESULTS

Three randomized controlled trials met the inclusion criteria. We performed random-effects meta-analyses of estimates from 2 studies without risk of significant bias and reported summary adjusted odds ratios and 95% confidence intervals. Meta-analysis of 56 women with continuous glucose monitor use and 53 control women without continuous glucose monitor use showed that there was no difference in the incidence of large-for-gestational-age infants between continuous glucose monitor users and standard-of-care controls (odds ratio, 0.78; 95% confidence interval, 0.34-1.78) with an I2 of 0%. In addition, there was no difference in the development of preeclampsia between continuous glucose monitor users and standard-of-care controls (odds ratio, 1.63; 95% confidence interval, 0.34-7.22) with an I2 of 0%.

CONCLUSION

Continuous glucose monitor use was not associated with improved perinatal outcomes as assessed by large-for-gestational-age infants and preeclampsia. This review is limited by the small amount of data available for this population, and further research is needed.

Risk factors for the development or progression of diabetic retinopathy in pregnancy: Meta‐analysis and systematic review

BACKGROUND

Diabetic retinopathy (DR) is the leading cause of blindness in the working-age population, and it increases in severity during pregnancy.

METHODS

Systematic review of literature from PubMed, Cochrane Library and Web of Science using keywords 'diabetic retinopathy' and 'pregnancy' and 'progression' from inception to 2021 was completed. Included studies were (1) peer-reviewed observational studies addressing progression/development of DR in pregnancy, (2) provided the number of diabetic patients that developed/progressed in DR during pregnancy, and (3) included differential data on variables between progression and non-progression groups. This was applied by two independent researchers and referred to a third researcher as necessary. Twenty-seven of the original 138 studies met this criterion. Data were pooled and analysed using fixed-effects in meta-analysis.

RESULTS

From 27 studies, 2537 patients were included. Pre-eclampsia [Risk Ratio (RR) 2.62 (95% CI = 1.72, 4.00)] and hypertension treatment during pregnancy [RR 2.74 (95% CI = 1.72, 4.00)] were significantly associated with the development/progression of DR. HbA1c at baseline [MD 0.82 (95% CI = 0.59, 1.06)], duration of diabetes [mean difference (MD) 5.97 (95% CI = 5.38, 6.57)], and diastolic blood pressure at baseline [MD 3.29 (95% CI = 0.46, 6.12)] were all significantly higher in the progression group while only mean birth weight [MD -0.17 (95% CI = -0.31, -0.03)] was significantly higher in the non-progression group.

CONCLUSIONS

This study fills a gap in the literature and provide physicians with more information on the risk factors associated with the progression of DR in pregnancy and how to counsel this vulnerable patient population appropriately.

Prevalence and severity of diabetic retinopathy in pregnant women with diabetes-time to individualize photo screening frequency

AIMS

To evaluate the prevalence and severity of diabetic retinopathy including macular oedema in pregnant women with diabetes and to identify women in whom the frequency of retinal screening can be reduced to minimize the burden of health care visits.

METHODS

A cohort study of 348 women with pre-existing diabetes were routinely screened with retinal photo in early (12 weeks) and late pregnancy (27 weeks). Diabetic retinopathy was classified in five stages in accordance with National Danish Guidelines based on the eye with the highest retinopathy level. Sight-threatening retinopathy was defined as the presence of proliferative retinopathy and/or clinically significant macular oedema (CSMO).

RESULTS

Retinopathy was present in 52% (116/223) vs. 14% (17/125), with sight-threatening retinopathy in 16% (35/223) vs. 6% (7/125) of women with type 1 and type 2, respectively. Women without retinopathy in early and late pregnancy were characterized by shorter diabetes duration (p < 0.0001 and p = 0.008) and predominance of type 2 diabetes. Amongst the 50% (175/348) of the cohort having no retinopathy in early pregnancy and HbA1c<53 mmol/mol (7.0%), none developed sight-threatening retinopathy and 94% (165/175) remained without any retinopathy during pregnancy. Development of sight-threatening retinopathy was mainly observed in women with retinopathy in early pregnancy. Treatment for sight-threatening retinopathy was given to a minority (2.7 and 2.4%, respectively).

CONCLUSION

Good glycaemic control and no retinopathy was seen in a large proportion of women in early pregnancy and none of these women developed sight-threatening retinopathy. The frequency of retinal screening can probably be safely reduced during pregnancy in these women.

Introduction of diabetic retinopathy screening into an antenatal clinic: Impact on maternal screening and diagnosis rates

Pregnancy is a risk factor for the development and progression of diabetic retinopathy (DR) in women with pre-gestational diabetes. However, a minority of pregnant women with diabetes adhere to retinal screening recommendations. The introduction of an onsite retinal camera at our tertiary maternity hospital significantly increased the proportion of women who received at least one retinal screen during pregnancy (93.0% vs 54.3%, P < 0.001) and the identification of both DR and DR progression. We conclude that the use of a retinal camera in similar clinics is a feasible option to improve DR screening and diagnosis rates in pregnancy.

Maternal serum proteomic profiles of pregnant women with type 1 diabetes

Despite improvement in the care of diabetes over the years, pregnancy complicated by type 1 diabetes (T1DM) is still associated with adverse maternal and neonatal outcomes. To date, proteomics studies have been conducted to identify T1DM biomarkers in non-pregnant women, however, no studies included T1DM pregnant women. In this study serum proteomic profiling was conducted in pregnant women with T1DM in the late third trimester. Serum samples were collected from 40 women with T1DM and 38 healthy controls within 3 days before delivery at term pregnancy. Significant differences between serum proteomic patterns were revealed, showing discriminative peaks for complement C3 and C4-A, kininogen-1, and fibrinogen alpha chain. Quantification of selected discriminative proteins by ELISA kits was also performed. The serum concentration of kininogen-1 was significantly lower in women with T1DM than in controls. There were no significant differences in serum concentrations of complement C3 and complement C4-A between study groups. These data indicate that pregnant women with T1DM have a distinct proteomic profile involving proteins in the coagulation and inflammatory pathways. However, their utility as biomarkers of pregnancy complications in women with T1DM warrants further investigation.

Planned vaginal and planned cesarean delivery outcomes in pregnancies complicated with pregestational type 1 diabetes - A three-year academic tertiary hospital cohort study

Background

Finland has the world’s highest incidence of 62.5/100000 of diabetes mellitus type 1 (DM1) with approximately 400 (1%) DM1 pregnancies annually. Pregnancies complicated by DM1 are accompanied with increased risk for perinatal morbidity and mortality. Timing and mode of delivery are based on the risk of complications, yet the data on labor induction is limited. The aim of this study was to compare delivery outcomes in planned vaginal (VD) and planned cesarean deliveries (CD) in late preterm and term DM1 pregnancies, and to evaluate the feasibility of labor induction.

Materials and Methods

Pregnant women with DM1, live singleton fetus in cephalic presentation ≥34 gestational weeks delivering in Helsinki University Hospital between January 1st 2017 and December 31st 2019 were included. The primary outcome were the rates of adverse maternal and perinatal outcome. The study population was classified according to the 1980-revised White’s classification. Statistical analyses were performed by IBM SPSS Statistics for Windows.

Results

Two hundred four women were included, 59.8% (n = 122) had planned VD. The rate of adverse maternal outcome was 27.5% (n = 56), similar between the planned modes of delivery and White classes. The rate of perinatal adverse outcome was 38.7% (n = 79), higher in planned CD (52.4% vs. 29.5%;p = 0.001). The most common adverse perinatal event was respiratory distress (48.8% vs. 23.0%;p <  0.001). The rate of adverse perinatal outcome was higher in White class D + Vascular compared to B + C (45.0% vs. 25.0%, OR after adjustment by gestational age 2.34 [95% CI 1.20–4.50];p = 0.01). The total rate of CD was 63.7% (n = 130), and 39.3% (n = 48) in planned VD. Women with White class D + Vascular more often had emergency CD compared to White Class B + C (48.6% vs. 25.0%;p = 0.009). The rate of labor induction was 51%, being 85.2% in planned VD. The rate of VD in induced labor was 58.7% (n = 61) and the rate of failed induction was 14.1% (n = 15).

Conclusion

Planned VD was associated with lower rate of adverse perinatal outcome compared to planned CS, with no difference in the rates of adverse maternal outcome. Induction of labor may be feasible option but should be carefully considered in this high-risk population.

Gestational and pregestational diabetes in pregnant women with cystic fibrosis

As cystic fibrosis transmembrane regulator (CFTR) modulator therapies offer greater longevity and improved health quality, women living with cystic fibrosis (CF) are increasingly pursuing pregnancy. Maternal risks for pregnant women with CF largely depend on a woman's baseline pulmonary and pancreatic function, and the majority of CF pregnancies will successfully end in live births. Diabetes, either gestational or pre-existing cystic fibrosis-related diabetes (CFRD), is highly prevalent in women with CF, affecting 18 to 62% of pregnancies in recent CF center reports. In addition to the rising incidence of CFRD with age, gestational diabetes is also more common in women with CF due to lower insulin secretion, higher insulin resistance, and increased hepatic glucose production as compared to pregnant women without CF. Diabetes occurring during pregnancy has important implications for maternal and fetal health. It is well established in women without CF that glycemic control is directly associated with risks of fetal malformation, neonatal-perinatal mortality, cesarean delivery and need for neonatal intensive care. Small studies in women with CF suggest that pregnancies affected by diabetes have an increased risk of preterm delivery, lower gestational age, and lower fetal birth weight compared to those without diabetes. Women with CF preparing for pregnancy should be counseled on the risks of diabetes and should undergo routine screening for CFRD with oral glucose tolerance testing (OGTT) if not already completed in the past six months. Glycemic control in those with pre-gestational CFRD should be optimized prior to conception. Insulin is preferred for the management of diabetes in pregnant women with CF via multiple daily injections or insulin pump therapy, and continuous glucose monitors (CGM) can be useful in mitigating hypoglycemia risks. Women with CF face many unique challenges impacting diabetes care during pregnancy and would benefit from support by a multidisciplinary care team, including nutrition and endocrinology, to ensure healthy pregnancies.

Prevalence of diabetic retinopathy in women with pregestational diabetes during pregnancy and the postpartum

BACKGROUND

Diabetic retinopathy (DR) may be affected by pregnancy. The majority of prevalence data regarding DR in pregnancy predate the advent of contemporary guidelines for diabetes management during pregnancy. This study reports DR prevalence and associated risk factors in women with pregestational diabetes during pregnancy and the postpartum in Australia.

METHODS

A total of 172 pregnant women with type 1 (T1DM) or type 2 diabetes diagnosed pre-pregnancy were prospectively recruited from two obstetrics hospitals in Melbourne (November 2017-March 2020). Eye examinations were scheduled in each trimester, at 3-, 6-, and 12-months postpartum. DR severity was graded from two-field fundus photographs by an independent grader utilising the Airlie House Classification. Sight-threatening DR (STDR) was defined as the presence of diabetic macular oedema or proliferative DR.

RESULTS

Overall, 146 (84.9%) women had at least one eye examination during pregnancy. The mean age was 33.8 years (range 19-51), median diabetes duration was 7.0 years (IQR 3.0-17.0), 71 women (48.6%) had T1DM. DR and STDR prevalence during pregnancy per 100 eyes was 24.3 (95% CI 19.7-29.6) and 9.0 (95% CI 6.1-12.9); while prevalence in the postpartum was 22.2 (95% CI 16.5-29.3) and 10.0 (95% CI 5.4-17.9), respectively. T1DM, longer diabetes duration, higher HbA1c in early pregnancy, and pre-existing nephropathy were significant risk factors.

CONCLUSIONS

The prevalence of DR in pregnant women was similar to the non-pregnant diabetic population in Australia. One in nine participants had STDR during pregnancy and the postpartum, highlighting the need to optimise DR management guidelines in pregnancy given the significant risk of vision loss.

[Features of retinal blood flow in pregnant women with carbohydrate metabolism disorders]

Studying the condition of retinal blood flow in pregnant women with disorders of carbohydrate metabolism contributes to early detection of diabetic retinopathy (DR), which is necessary for timely treatment and preservation of high visual functions.

PURPOSE

To study retinal blood flow in pregnant women with disorders of carbohydrate metabolism using optical coherence tomography angiography (OCTA) in order to determine the criteria for manifestation and progression of DR.

MATERIAL AND METHODS

The study examined 203 pregnant women in the third trimester: 24 - with type 1 and 2 diabetes (T1D and T2D), 143 - with gestational diabetes (GD), and 36 apparently healthy women with physiological pregnancy that comprised the control group. OCTA imaging was performed on RTVue XR Avanti ("Optovue", USA) system using HD Angio Retina 6.0 mm² scan protocol. The whole image vessel density (wiVD), foveal vessel density (FVD), and foveal avascular zone (FAZ) area in the superficial capillary plexus were studied.

RESULTS

FVD was significantly lower in pregnant women with diabetes than in pregnant women with GD and in the control group, prompting an assumption that retinal microvascular regulation changes because of chronic disturbances of carbohydrate metabolism in such patients and due to development of microangiopathy. Statistically significant increase in FAZ area and decrease in wiVD were revealed in patients with DR compared to data from the group of pregnant women with diabetes but without DR, in the absence of differences in FVD. In 2 patients with T1D and no ophthalmoscopic signs of DR, OCTA revealed areas of nonperfusion in the posterior pole of the eye.

CONCLUSION

OCTA can help identify areas of retinal nonperfusion in the posterior pole of the eye in pregnant women with diabetes and no ophthalmoscopic signs of DR, and determine objective indications for timely retinal laser coagulation.

Rates of diabetic retinopathy screening in pregnant patients with type 1 and type 2 diabetes in a predominantly Indigenous Central Australian population

BACKGROUND

Pregnancy is a risk factor for the progression of diabetic retinopathy (DR) in women with pre-gestational diabetes. Australian screening guidelines recommend DR screening in the first trimester of pregnancy. The rates of DR screening in pregnant patients with pre-gestational diabetes are unknown in Australia.

AIM

To determine the rates of DR screening in pregnant women with pre-gestational diabetes at Alice Springs Hospital Diabetes Antenatal Care and Education (DANCE) clinic.

MATERIALS AND METHODS

Retrospective review of women with pre-gestational diabetes who attended the DANCE clinic between July 2016 and June 2020.

RESULTS

There were 146 pregnancies in 144 individual women included in this review. There were 93% (n = 134) who identified as Aboriginal but not Torres Strait Islander. DR screening was performed in 23 (16%) pregnancies, in which DR was present in six (26%) and no retinal abnormality was found in 17 (74%). Of seven (5%) women who had a history of DR, only three had a screen during the pregnancy period. The location of the DR screen included Alice Springs Hospital (17%, n = 4), Alice Springs general practice clinics (35%, n = 8) and remote NT community clinics outside of Alice Springs (39%, n = 9). The trimesters in which women received their DR screens were: trimester 1, 45%, n = 10; trimester 2, 39%, n = 9; trimester 3, 17%, n = 4.

CONCLUSION

The minority of pregnant women who attend the DANCE clinic at Alice Springs Hospital received DR screening in adherence with national guidelines.

Adverse pregnancy outcomes in women with diabetes-related microvascular disease and risks of disease progression in pregnancy: A systematic review and meta-analysis

BACKGROUND

The rise in the global prevalence of diabetes, particularly among younger people, has led to an increase in the number of pregnant women with preexisting diabetes, many of whom have diabetes-related microvascular complications. We aimed to estimate the magnitude of the risks of adverse pregnancy outcomes or disease progression in this population.

METHODS AND FINDINGS

We undertook a systematic review and meta-analysis on maternal and perinatal complications in women with type 1 or 2 diabetic microvascular disease and the risk factors for worsening of microvascular disease in pregnancy using a prospective protocol (PROSPERO CRD42017076647). We searched major databases (January 1990 to July 2021) for relevant cohort studies. Study quality was assessed using the Newcastle-Ottawa Scale. We summarized the findings as odds ratios (ORs) with 95% confidence intervals (CIs) using random effects meta-analysis. We included 56 cohort studies involving 12,819 pregnant women with diabetes; including 40 from Europe and 9 from North America. Pregnant women with diabetic nephropathy were at greater risk of preeclampsia (OR 10.76, CI 6.43 to 17.99, p < 0.001), early (<34 weeks) (OR 6.90, 95% CI 3.38 to 14.06, p < 0.001) and any preterm birth (OR 4.48, CI 3.40 to 5.92, p < 0.001), and cesarean section (OR 3.04, CI 1.24 to 7.47, p = 0.015); their babies were at higher risk of perinatal death (OR 2.26, CI 1.07 to 4.75, p = 0.032), congenital abnormality (OR 2.71, CI 1.58 to 4.66, p < 0.001), small for gestational age (OR 16.89, CI 7.07 to 40.37, p < 0.001), and admission to neonatal unit (OR 2.59, CI 1.72 to 3.90, p < 0.001) compared to those without nephropathy. Diabetic retinopathy was associated with any preterm birth (OR 1.67, CI 1.27 to 2.20, p < 0.001) and preeclampsia (OR 2.20, CI 1.57 to 3.10, p < 0.001) but not other complications. The risks of onset or worsening of retinopathy were increased in women who were nulliparous (OR 1.75, 95% CI 1.28 to 2.40, p < 0.001), smokers (OR 2.31, 95% CI 1.25 to 4.27, p = 0.008), with existing proliferative disease (OR 2.12, 95% CI 1.11 to 4.04, p = 0.022), and longer duration of diabetes (weighted mean difference: 4.51 years, 95% CI 2.26 to 6.76, p < 0.001) compared to those without the risk factors. The main limitations of this analysis are the heterogeneity of definition of retinopathy and nephropathy and the inclusion of women both with type 1 and type 2 diabetes.

CONCLUSIONS

In pregnant women with diabetes, presence of nephropathy and/or retinopathy appear to further increase the risks of maternal complications.

Pregnancy and the eye

PURPOSE OF REVIEW

The aim of this study was to summarize common eye changes that may occur during pregnancy, and how pregnancy may affect preexisting eye conditions such as glaucoma and diabetic retinopathy. Challenges and complexities surrounding the treatment of these eye conditions during pregnancy are also highlighted.

RECENT FINDINGS

Refractive changes are common and may persist in the postpartum in patients with keratoconus. Although new medical and surgical glaucoma treatments are available, their safety in pregnancy is unknown. Limited use of topical and systemic glaucoma therapies is recommended, with a preference for selective laser trabeculoplasty as first line treatment in appropriate cases. The impact of pregnancy on diabetic retinopathy remains unclear. Although anti-vascular endothelial growth factor agents are first-line treatment for sight-threatening diabetic retinopathy, their effect on the developing foetus remains unknown and are therefore best avoided in the first and second trimesters. Noninfectious uveitis tends to become less active during pregnancy, allowing the potential tapering of systemic therapy and the use of local topical or injected corticosteroid treatment for active disease as required.

SUMMARY

Significant changes can occur to the eye during pregnancy, wherein the optimal treatment for many ocular conditions remains uncertain, highlighting the need for further research to develop clear recommendations that best balance the need to preserve the mother's sight, and the health of the developing foetus. The need for preconception planning, and collaborative multidisciplinary care between the obstetrician, physician, ophthalmologist and paediatrician is paramount.

A Narrative Review of the Complex Relationship between Pregnancy and Eye Changes

Pregnancy is a condition often characterized by changes that occur in different parts of the body. Generally, the eyes suffer several changes during pregnancy that are usually transient but may become permanent at times. This may occur due to the release of placental hormones and those of maternal endocrine glands and fetal adrenal glands. Due to hormonal influences, physiological ocular changes during pregnancy have been shown in Caucasian women, so corneal sensitivity, refractive status, intraocular pressure, and visual acuity may change during pregnancy. Within this review, all studies that referred to physiological aspects and to changes of ocular pathology of pregnancy, the effect of the pregnancy on pre-existing (diabetic retinopathy, neuro-ophthalmic disorders) eye disorders, postpartum ocular changes, the intraocular pressure and the effect of hypotensive ophthalmic medicine during pregnancy, the connection between pregnancy and the neuro-ophthalmic pathology, as well as the role of anesthesia were analyzed.

Diabetic retinopathy and diabetic macular oedema pathways and management: UK Consensus Working Group

The management of diabetic retinopathy (DR) has evolved considerably over the past decade, with the availability of new technologies (diagnostic and therapeutic). As such, the existing Royal College of Ophthalmologists DR Guidelines (2013) are outdated, and to the best of our knowledge are not under revision at present. Furthermore, there are no other UK guidelines covering all available treatments, and there seems to be significant variation around the UK in the management of diabetic macular oedema (DMO). This manuscript provides a summary of reviews the pathogenesis of DR and DMO, including role of vascular endothelial growth factor (VEGF) and non-VEGF cytokines, clinical grading/classification of DMO vis a vis current terminology (of centre-involving [CI-DMO], or non-centre involving [nCI-DMO], systemic risks and their management). The excellent UK DR Screening (DRS) service has continued to evolve and remains world-leading. However, challenges remain, as there are significant variations in equipment used, and reproducible standards of DMO screening nationally. The interphase between DRS and the hospital eye service can only be strengthened with further improvements. The role of modern technology including optical coherence tomography (OCT) and wide-field imaging, and working practices including virtual clinics and their potential in increasing clinic capacity and improving patient experiences and outcomes are discussed. Similarly, potential roles of home monitoring in diabetic eyes in the future are explored. The role of pharmacological (intravitreal injections [IVT] of anti-VEGFs and steroids) and laser therapies are summarised. Generally, IVT anti-VEGF are offered as first line pharmacologic therapy. As requirements of diabetic patients in particular patient groups may vary, including pregnant women, children, and persons with learning difficulties, it is important that DR management is personalised in such particular patient groups. First choice therapy needs to be individualised in these cases and may be intravitreal steroids rather than the standard choice of anti-VEGF agents. Some of these, but not all, are discussed in this document.

Progression of Diabetic Retinopathy and Predictors of Its Development and Progression During Pregnancy in Patients With Type 1 Diabetes: A Report of 499 Pregnancies

OBJECTIVE

Pregnancy has been associated with development and progression of diabetic retinopathy (DR), but incidence of DR remains unclear. We assessed DR progression rate and its predictors during pregnancies in patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

We report the retrospective data from pregnancies in patients with type 1 diabetes followed in Lille, France (1997-2015). Eye examination was performed every 3 months or every month in case of severe nonproliferative retinopathy or progression. Progression was defined by DR degradation (≥1 stage of the Early Treatment Diabetic Retinopathy Study [ETDRS] classification); it included DR development and worsening in patients without and with prepregnancy DR, respectively.

RESULTS

A total of 499 pregnancies in 375 patients were included; prepregnancy retinopathy was present in 30.3%. Progression, development, and worsening rates were 21.8%, 24.4% of those without retinopathy, and 15.9% of those with retinopathy, respectively. Development of sight-threatening retinopathy was rare. Progression mainly occurred in early or midpregnancy. Elevated prepregnancy HbA_1c and duration of diabetes ≥10 years were predictors of DR progression. Among pregnancies with prepregnancy DR, continuous subcutaneous insulin infusion (CSII) tended to decrease the risk of DR progression. Among CSII-treated patients, those with prepregnancy DR had a significantly decreased risk of DR progression. Among the 270 pregnancies of women with any DR during pregnancy who returned for a postpartum ophthalmologic examination, the rate of progression was only 4.1% and the rate of regression was 9.3%.

CONCLUSIONS

This study provides epidemiologic data on progression of retinopathy during pregnancy and will be useful for future guidelines for retinopathy screening.

ADIPS 2020 guideline for pre-existing diabetes and pregnancy

This is the full version of the Australasian Diabetes in Pregnancy Society (ADIPS) 2020 guideline for pre-existing diabetes and pregnancy. The guideline encompasses the management of women with pre-existing type 1 diabetes and type 2 diabetes in relation to pregnancy, including preconception, antepartum, intrapartum and postpartum care. The management of women with monogenic diabetes or cystic fibrosis-related diabetes in relation to pregnancy is also discussed.

Nonmydriatic Photographic Screening for Diabetic Retinopathy in Pregnant Patients with Pre-Existing Diabetes in a Safety Net Population: 1 Year Results from the Diabetic Retinopathy in Pregnant Patients Study

Background: Pregnant patients with pre-existing diabetes mellitus (DM) are at increased risk for development or progression of existing diabetic retinopathy (DR). A quality improvement project was initiated to improve DR screening during pregnancy at a safety net hospital. This article highlights the utility and generalizability of our telemedicine-based screening model. Materials and Methods: In April 2018, we implemented a photographic retinal screening system in the Maternal Fetal Medicine (MFM) clinic at Santa Clara Valley Medical Center in San Jose, CA. The system is intended to screen all pregnant patients with pre-existing diabetes (type 1 and 2). Retinal images are automatically uploaded to a secure server and interpreted by a retina specialist (C.K.P.). Results: A total of 71 pregnant patients with pre-existing DM were seen in the MFM clinic during the study period. Sixty-six of 71 patients (93.0%) were screened compared with 69.1% in the year prior. Of the 64 patients screened with readable images 11 (17.2%) had DR, whereas 53 did not. Forty-nine of the 64 (74.2%) patients screened underwent screening using the new nonmydriatic system in the MFM clinic. Only 7 out of 47 (14.9%) patients with readable images in the MFM clinic required referral to the ophthalmology clinic. Conclusion: Our model for DR screening in pregnant patients in safety net hospitals is effective in improving screening rates and expediting evaluation and treatment for those in need. This system can prevent irreversible vision loss in pregnant patients and provides an effective framework for ophthalmic care in a safety net hospital system.

Need for less tight glucose control in early pregnancy after embryogenesis due to high risk of maternal hypoglycaemia in women with pre-existing diabetes can be compensated by good control in late pregnancy

AIM

Poor glucose control is associated with adverse outcomes in pregnancies with pre-existing diabetes. However, strict glucose control increases the risk of severe hypoglycaemia, particularly in the first trimester. Therefore, we aimed to investigate whether less tight glucose control in the first trimester determines adverse outcomes or can be compensated for by good control in late pregnancy.

METHODS

Retrospective data were collected from 517 singleton pregnancies complicated by pre-existing diabetes delivering between 2010 and 2017. Three hundred and thirty-six pregnancies fulfilled the inclusion criteria of having available HbA_1c values either pre-conception or in the first trimester (65% type 1 diabetes, 35% type 2 diabetes).

RESULTS

Higher HbA_1c values in the first trimester were associated with increasing rates of large for gestational age (LGA) neonates, preterm delivery or neonatal intensive care unit admissions. Multiple regression analysis demonstrated third trimester HbA_1c , type 1 diabetes, multiparity and excess weight gain, but not first trimester HbA_1c , to be independently predictive for LGA. Pre-eclampsia and third trimester HbA_1c increased the risk for preterm delivery. If HbA_1c was ≤ 42 mmol/mol (6.0%) in the third trimester, rates of adverse outcomes were not significantly higher even if HbA_1c targets of ≤ 48 mmol/mol (6.5%) had not been met in the first trimester. Good first trimester glucose control did not modify the rates of adverse outcomes if HbA_1c was > 42 mmol/mol (6.0%) in the third trimester.

CONCLUSIONS

Less tight glycaemic control, for example due to high frequency of severe hypoglycaemia in the first trimester, does not lead to increased adverse neonatal events if followed by tight control in the third trimester. Besides glycaemic control, excess weight gain is a modifiable predictor of adverse outcome.

Management of pregestational diabetes mellitus: a comparison of guidelines

Background: Pregestational diabetes is associated with adverse maternal and neonatal outcomes. The aim of this study was to summarize and compare evidence-based recommendations on pregestational diabetes and to focus especially on issues related to the management of this entity.Materials and methods: A descriptive review of three recently published national guidelines on pregestational diabetes was conducted: the American Diabetes Association on "Diabetes in Pregnancy: Standards of Medical Care in Diabetes - 2019," the National Institute for Health and Care Excellence on "Diabetes in pregnancy: management from preconception to the postnatal period" and the American College of Obstetricians and Gynecologists on "Pregestational Diabetes Mellitus." These guidelines were compared according to recommendations on management, during the preconception, antenatal, intrapartum and postpartum period.Results: There were many similar recommendations regarding the preconception counseling, the antepartum assessment by specialists, the glycemic control target levels, the pharmacologic treatment and the postpartum period among the three guidelines. On the other hand, the American Diabetes Association makes no recommendations regarding fetal monitoring and obstetric management during pregnancy and the intrapartum period, while there are several similarities between the other two guidelines.Conclusions: The adoption of an international consensus based on evidence - based guidelines will increase the awareness of the healthcare professionals on the management of pregestational diabetes, leading that way to more favorable perinatal outcomes.

Knowledge and practices of primary care physicians on the current referral system of diabetic retinopathy in Islamabad and Rawal-Pindi, Pakistan

AIM

To assess the current knowledge and practices in diabetic eye care and referral system regarding diabetic retinopathy (DR) in health centers of Islamabad and Rawal-Pindi.

METHODS

A cross-sectional study was carried out in 4 government and private health centers in Rawalpindi-Islamabad from May 2018 to Oct. 2018. A total of 38 Primary Care Physicians (general practitioners, family physicians, and internists) were recruited out of which data for 2 were either not returned, or were missing partially. Data were collected through a 27-item consented & validated, multiple-choice questionnaire based on physician characteristics, knowledge and practice of diabetic eye care and challenges faced due current DR referral system. Descriptive analyses for all variables were performed including, mean and standard deviation. Analytical analyses were also conducted to study association between different study variables.

RESULTS

Mean scores of knowledge for general practitioners, family physicians, and internists were 41.7%, 42.0% and 46.6% respectively. A lack of knowledge, and suboptimal practices were observed regarding signs, symptoms, screening, testing, evaluation and referral of DR regardless of physicians' specialty, or years in practice. Lack of expertise regarding direct ophthalmoscopy, interpretation of findings, and referral to an ophthalmologist were noted. Physicians who performed consultation and counselling according to patients' needs referred more patients to an ophthalmologist than those who restricted their consultation to a fixed amount of time and had more patients per unit time (P=0.01). Physicians who had taken care of less than 5 number of patients with DR marked less incorrect answers with no significantly greater number or correct answers compared to physicians who had taken care of more than 5 number of patients with DR (P=0.044). An association of more than 5 patients with DR taken care of with more need based patient consultation and counselling was also noted (P=0.017). An evaluation of the current referral system for DR revealed major loopholes in the health care infrastructure, proper guidelines, properly functioning equipment, check and balances, and lack of guidance to physicians regarding acquiring and updating knowledge regarding DR.

CONCLUSION

Lack of updated and adequate knowledge, practices among primary care physicians, and suboptimal diabetic eye care and referral system have contributed to late presentation of DR. Interventions are needed to improve current diabetic eye care, and knowledge and practices of primary care physicians.

Non-mydriatic fundus camera screening with diagnosis by telemedicine for diabetic retinopathy patients with type 1 and type 2 diabetes: a hospital-based cross-sectional study

BACKGROUND

Diabetic retinopathy (DR) is considered the fifth leading cause of visual impairment worldwide and is associated with a huge social and economic burden.

OBJECTIVE

Describe the practicality of non-mydriatic funduscopic screening photography for the detection of DR among patients with type 1 and type 2 diabetes.

DESIGN

Cross-sectional hospital-based study.

SETTING

Diabetes center, Riyadh.

PATIENTS AND METHODS

Between July and December 2017, patients with diabetes and aged ≥18 years were selected by systematic random sampling from the University Diabetes Center. Fundoscopic eye examination was performed using the TRC-NW8 non-mydriatic camera, which performs ocular coherence tomography (OCT) to detect macular edema. Using telemedicine, pictures were graded by a retinal-specialized ophthalmologist using the international clinical DR disease severity scale. Patients were classified according to the type and severity of DR.

MAIN OUTCOME MEASURES

Detection and classification of DR.

SAMPLE SIZE

978 Saudi patients with diabetes.

RESULTS

Of 426 (43.5%) patients with DR, 370 had nonproliferative DR and 55 had proliferative DR. Nineteen (1.9%) had macular edema. The most important risk factors for DR were longer diabetes duration and poor glycemic control. Both older age and insulin use contributed to the higher prevalence of DR and macular edema. DR was more common among type 1 patients at 55.4% compared with 49% among type 2 patients. In addition, more females had macular edema (57.1% versus 42.9% among males). Nine patients with macular edema (47.3%) had hypertension while 154 of 426 patients with DR (36.2%) had hypertension.

CONCLUSION

Non-mydriatic funduscopic screening photography was practical and useful for the detection of DR in patients with type 1 and type 2 diabetes.

LIMITATIONS

Conducted in a single center.

CONFLICT OF INTEREST

None.

[Clinical features of diabetic retinopathy in pregnancy]

INTRODUCTION

Pregnancy is a risk factor for progression of diabetic retinopathy (DR). Despite the common opinion about the regression of DR after childbirth, it is possible for the disease to progress aggressively, which can cause loss of visual functions when treated untimely.

PURPOSE

To present clinical cases with different course of development of DR in pregnant women with type 1 diabetes mellitus (DM1).

MATERIAL AND METHODS

Five pregnant women with DM1 lasting more than 8 years were examined. Glycemic level of all patients was higher than normal (glycated hemoglobin (HbA1c) of more than 6.1%). Ophthalmologic examination was carried out including fundus photography, optical coherence tomography (OCT) of the macular area, Angio-OCT.

RESULTS

The most significant factors in the progression of DR in pregnant women are DR1 compensation, severity and stabilization of DR during the preconception period, presence of a concomitant pathology. Timely detection of signs of progression of DR and therapeutic measures taken during pregnancy, in particular laser coagulation, were shown to stabilize the course of the disease and prevent loss of vision in pregnant women with DM1.

CONCLUSION

Clinical course of DR in pregnancy can vary between absence of manifestation, stabilization, and progression. Progression of DR during pregnancy is determined by a number of factors including compensation of DM during the preconception period and throughout pregnancy, severity and stabilization of retinopathy during the preconception period, and presence of a concomitant pathology. Timely detection of the signs of DR progression and its treatment, in particular laser coagulation of the retina, can help stabilize the course of the disease during pregnancy. The course of DR may be aggressive in some pregnant women involving progression in the postpartum period, which warrants active monitoring of patients with retinopathy after childbirth.

Diabetic Retinopathy and Pregnancy

Purpose: analysis of clinical cases of different course of diabetic retinopathy in pregnancy.

Patients and methods. The article presents 5 clinical cases of different course of diabetic retinopathy in pregnancy: absence of manifestation, stable course and progression to macular edema and aggressive proliferation.

Results. The reasons for progression of diabetic retinopathy during pregnancy were analyzed. The most important were the compensation of diabetes mellitus in preconception period and throughout pregnancy, the severity of retinopathy, and the presence of concomitant pathology. It is emphasized that timely detection of progression signs of retinopathy and laser coagulation during pregnancy makes it possible to stabilize the course of disease and improve visual prognosis. Thus, the monitoring of pregnant women with diabetes mellitus requires an individual approach and careful dynamic observation during pregnancy and in postpartum period. Timely laser coagulation in progression of retinopathy can contribute to preservation of visual functions.

Conclusions. Clinical course of diabetic retinopathy in pregnancy is variable: no manifestation, stabilization, progression. Progression of diabetic retinopathy during pregnancy is determined by many factors, in particular, the compensation of diabetes mellitus in preconception period and throughout pregnancy, the severity and stabilization of retinopathy as results of treatment in preconception period, the presence of concomitant pathology. Timely detection of signs of diabetic retinopathy progression and its treatment, particularly laser coagulation of the retina, during pregnancy allows stabilizing the course of disease. There may be an aggressive course of diabetic retinopathy with progression in postpartum period, in connection with which, active monitoring of patients with retinopathy after childbirth is required. 

Prevalence, progression, and outcomes of diabetic retinopathy during pregnancy in Indian scenario

Purpose

The objective of this study is to evaluate pattern of diabetic retinopathy (DR) during pregnancy in females with pregestational diabetes mellitus (DM).

Methods

This is an ambispective observational cohort study conducted at an Indian tertiary care centre. A total of 50 pregnant females with pregestational DM were included while those with gestational DM were excluded from the study. Ocular examination (inclusive of fundus photography) was conducted and systemic parameters (inclusive of Glycated hemoglobin) were assessed during each of the 3 trimesters and 3 months postpartum. The prevalence and progression of DR during pregnancy in the study cohort were the main outcome measures.

Results

Three of the 50 patients had type 1 DM while 47 had type II DM. All the patients with type I DM were insulin dependent while 19 patients with type II DM were insulin dependent. Overall prevalence of DR was 8% (4/50); 2 cases had nonproliferative DR (NPDR), and 2 had proliferative DR (PDR). During the study period, worsening was seen in both the patients with PDR and one required vitrectomy. Mean visual acuity in patients with PDR decreased from 0.77 logMAR units at presentation to 1.23 logMAR at final follow-up. There was no change in the mean visual acuity of patients with NPDR. None of the patients with NPDR converted to PDR. There was no new onset DR in the patients without DR at presentation. Assessment of risk factors for DR revealed significantly higher duration of DM (14 ± 6.32 years vs. 3.43 ± 1.43 years, P = 0.0008). The median age was also higher in the DR patients (31 years vs. 29 years, P = 0.32).

Conclusion

No new onset cases were seen during the course of pregnancy and no conversion from NPDR to PDR was seen; however, a worsening of the two PDR cases was observed. No cases of DR were seen in noninsulin-dependent DM. None of the four participants with DR showed a spontaneous resolution of DR postpartum. Patients with PDR and long-standing DM require careful observation during pregnancy. A registry of diabetic mothers should be set up for development of guidelines for managing such cases.

A survey of ophthalmologists and gynecologists regarding termination of pregnancy and choice of delivery mode in the presence of eye diseases

PURPOSE

To evaluate and compare the attitudes of ophthalmologists and gynecologists in suggesting appropriate approach to pregnancy in different ocular conditions.

METHODS

Specialty-specific questionnaires on delivery mode and abortion indications for ophthalmic patients (refractive, vascular, oncologic, retinal, glaucoma, postoperation, posttrauma, and infectious) were designed and distributed among physician staff of Farabi Eye Hospital and Yas Women Hospital in Tehran. Attitudes and preferences of the ophthalmologists and gynecologists were quantified and compared.

RESULTS

Participants were 29 ophthalmologists and 19 gynecologists. Their mean age was 49.73 ± 7.57 and 46.79 ± 1.36 years, respectively. More than 50-70% ophthalmologists were in favor of normal vaginal delivery (NVD) in all ocular diseases. All gynecologists (100%) expressed their need for an ophthalmologist's opinion for decision-making. Ophthalmologists' top choices for conditions potentially requiring a caesarean section were corneal transplants (34.5%), high myopia (23%), retinal detachment (29%), and orbital tumors (34.5%), while two gynecologists recommended abortion in the presence of intraocular and orbital tumors and retinal detachment. In the case of a history of refractive surgery, orbital tumor and intraocular tumor, ophthalmologists recommend NVD over caesarean section twice as much as their gynecologist peers. For history of retinal detachment, glaucoma, retinal vascular accident and intraocular hemorrhage, no single gynecologist recommend NVD. The corresponding figure for ophthalmologist-recommended NVD were 67, 84, 72, and 81%.

CONCLUSIONS

There is extreme inconsistency among ophthalmologists and gynecologists in managing ophthalmic-obstetric scenarios, especially for caesarean section indications. Clinical guideline development and consultation for decision-making in challenging cases are recommended.

Trends and racial and ethnic disparities in the prevalence of pregestational type 1 and type 2 diabetes in Northern California: 1996-2014

BACKGROUND

Despite concern for adverse perinatal outcomes in women with diabetes mellitus before pregnancy, recent data on the prevalence of pregestational type 1 and type 2 diabetes mellitus in the United States are lacking.

OBJECTIVE

The purpose of this study was to estimate changes in the prevalence of overall pregestational diabetes mellitus (all types) and pregestational type 1 and type 2 diabetes mellitus and to estimate whether changes varied by race-ethnicity from 1996-2014.

STUDY DESIGN

We conducted a cohort study among 655,428 pregnancies at a Northern California integrated health delivery system from 1996-2014. Logistic regression analyses provided estimates of prevalence and trends.

RESULTS

The age-adjusted prevalence (per 100 deliveries) of overall pregestational diabetes mellitus increased from 1996-1999 to 2012-2014 (from 0.58 [95% confidence interval, 0.54-0.63] to 1.06 [95% confidence interval, 1.00-1.12]; P_trend <.0001). Significant increases occurred in all racial-ethnic groups; the largest relative increase was among Hispanic women (121.8% [95% confidence interval, 84.4-166.7]); the smallest relative increase was among non-Hispanic white women (49.6% [95% confidence interval, 27.5-75.4]). The age-adjusted prevalence of pregestational type 1 and type 2 diabetes mellitus increased from 0.14 (95% confidence interval, 0.12-0.16) to 0.23 (95% confidence interval, 0.21-0.27; P_trend <.0001) and from 0.42 (95% confidence interval, 0.38-0.46) to 0.78 (95% confidence interval, 0.73-0.83; P_trend <.0001), respectively. The greatest relative increase in the prevalence of type 1 diabetes mellitus was in non-Hispanic white women (118.4% [95% confidence interval, 70.0-180.5]), who had the lowest increases in the prevalence of type 2 diabetes mellitus (13.6% [95% confidence interval, -8.0 to 40.1]). The greatest relative increase in the prevalence of type 2 diabetes mellitus was in Hispanic women (125.2% [95% confidence interval, 84.8-174.4]), followed by African American women (102.0% [95% confidence interval, 38.3-194.3]) and Asian women (93.3% [95% confidence interval, 48.9-150.9]).

CONCLUSIONS

The prevalence of overall pregestational diabetes mellitus and pregestational type 1 and type 2 diabetes mellitus increased from 1996-1999 to 2012-2014 and racial-ethnic disparities were observed, possibly because of differing prevalence of maternal obesity. Targeted prevention efforts, preconception care, and disease management strategies are needed to reduce the burden of diabetes mellitus and its sequelae.

Diabetic macular oedema

Diabetic macular oedema, characterised by exudative fluid accumulation in the macula, is the most common form of sight-threatening retinopathy in people with diabetes. It affects one in 15 people with diabetes resulting in more than 20 million cases worldwide. Few epidemiological studies have been done to specifically investigate risk factors for diabetic macular oedema, although poor glycaemic and blood pressure control are associated with the presence and development of the disorder. The pathophysiological processes begin with chronic hyperglycaemia, and interplay between vascular endothelial growth factor (VEGF) and inflammatory mediators. Non-invasive imaging using optical coherence tomography has allowed clinicians to detect mild levels of diabetic macular oedema in order to monitor progress and guide treatment. Although focal or grid laser photocoagulation was the traditional mode of treatment, intraocular pharmacotherapy with anti-VEGF agents is now the standard of care. However, these therapies are expensive and resource intensive. Emerging therapeutic strategies include improving efficacy and duration of VEGF suppression, targeting alternative pathways such as inflammation, the kallikrein-kinin system, the angiopoietin-Tie2 system, and neurodegeneration, and using subthreshold and targeted laser therapy. Ongoing research should lead to improvements in screening, diagnosis, and management of diabetic macular oedema.

Does tight control of systemic factors help in the management of diabetic retinopathy?

Diabetic retinopathy (DR), one of the leading causes of preventable blindness, is associated with many systemic factors that contribute to the development and progression of this microvascular complication of diabetes. While the duration of diabetes is the major risk factor for the development of DR, the main modifiable systemic risk factors for development and progression of DR are hyperglycemia, hypertension, and dyslipidemia. This review article looks at the evidence that control of these systemic factors has significant benefits in delaying the onset and progression of DR.

Diabetic retinopathy in pregnancy: a review

The prevalence of diabetes in pregnancy is increasing. Pre-existing diabetes is present in 1 in 167 pregnancies in Australia, divided equally between type 1 and type 2 diabetes. Diabetic retinopathy is a leading cause of blindness in women during their childbearing years, and pregnancy increases the short-term risk of diabetic retinopathy progression. We examine the risk factors for progression of diabetic retinopathy during pregnancy including duration of diabetes, baseline level of retinopathy, level of glycaemic control and hypertension. We also examine current screening and management guidelines and their levels of evidence, current treatment options for diabetic retinopathy and avenues for further research.

Diabetic retinopathy: intravitreal vascular endothelial growth factor inhibitors for diabetic macular oedema

INTRODUCTION

Diabetic retinopathy is the most common microvascular complication of diabetes. It is also the most common cause of blindness in working-age adults in industrialised nations. Older people and those with worse diabetes control, hypertension, and hyperlipidaemia are most at risk. Diabetic macular oedema, which can occur at any stage of diabetic retinopathy, is related to increased vascular permeability and breakdown of the blood retinal barrier, in part related to increased vascular endothelial growth factor (VEGF) levels. About 1% to 3% of people with diabetes suffer vision loss because of diabetic macular oedema.

METHODS AND OUTCOMES

We conducted a systematic overview, aiming to answer the following clinical questions: What are the effects of intravitreal VEGF inhibitors versus each other for diabetic macular oedema? What are the effects of intravitreal VEGF inhibitors plus laser therapy versus intravitreal VEGF inhibitors alone for diabetic macular oedema? We searched: Medline, Embase, The Cochrane Library, and other important databases up to September 2014 (Clinical Evidence overviews are updated periodically; please check our website for the most up-to-date version of this overview).

RESULTS

At this update, searching of electronic databases retrieved 240 studies. After deduplication and removal of conference abstracts, 149 records were screened for inclusion in the overview. Appraisal of titles and abstracts led to the exclusion of 90 studies and the further review of 59 full publications. Of the 59 full articles evaluated, eight systematic reviews and four RCTs were added at this update. We performed a GRADE evaluation for four PICO combinations.

CONCLUSIONS

In this systematic overview, we categorised the efficacy for six comparisons based on information about the effectiveness and safety of intravitreal VEGF inhibitors aflibercept, bevacizumab, and ranibizumab, and each of these intravitreal VEGF inhibitors plus laser therapy.

Epidemiology of diabetic retinopathy, diabetic macular edema and related vision loss

Diabetic retinopathy (DR) is a leading cause of vision-loss globally. Of an estimated 285 million people with diabetes mellitus worldwide, approximately one third have signs of DR and of these, a further one third of DR is vision-threatening DR, including diabetic macular edema (DME). The identification of established modifiable risk factors for DR such as hyperglycemia and hypertension has provided the basis for risk factor control in preventing onset and progression of DR. Additional research investigating novel risk factors has improved our understanding of multiple biological pathways involved in the pathogenesis of DR and DME, especially those involved in inflammation and oxidative stress. Variations in DR prevalence between populations have also sparked interest in genetic studies to identify loci associated with disease susceptibility. In this review, major trends in the prevalence, incidence, progression and regression of DR and DME are explored, and gaps in literature identified. Established and novel risk factors are also extensively reviewed with a focus on landmark studies and updates from the recent literature.

Epidemiology of diabetic retinopathy, diabetic macular edema and related vision loss

Diabetic retinopathy (DR) is a leading cause of vision-loss globally. Of an estimated 285 million people with diabetes mellitus worldwide, approximately one third have signs of DR and of these, a further one third of DR is vision-threatening DR, including diabetic macular edema (DME). The identification of established modifiable risk factors for DR such as hyperglycemia and hypertension has provided the basis for risk factor control in preventing onset and progression of DR. Additional research investigating novel risk factors has improved our understanding of multiple biological pathways involved in the pathogenesis of DR and DME, especially those involved in inflammation and oxidative stress. Variations in DR prevalence between populations have also sparked interest in genetic studies to identify loci associated with disease susceptibility. In this review, major trends in the prevalence, incidence, progression and regression of DR and DME are explored, and gaps in literature identified. Established and novel risk factors are also extensively reviewed with a focus on landmark studies and updates from the recent literature.

Epidemiology of diabetic retinopathy, diabetic macular edema and related vision loss

Diabetic retinopathy (DR) is a leading cause of vision-loss globally. Of an estimated 285 million people with diabetes mellitus worldwide, approximately one third have signs of DR and of these, a further one third of DR is vision-threatening DR, including diabetic macular edema (DME). The identification of established modifiable risk factors for DR such as hyperglycemia and hypertension has provided the basis for risk factor control in preventing onset and progression of DR. Additional research investigating novel risk factors has improved our understanding of multiple biological pathways involved in the pathogenesis of DR and DME, especially those involved in inflammation and oxidative stress. Variations in DR prevalence between populations have also sparked interest in genetic studies to identify loci associated with disease susceptibility. In this review, major trends in the prevalence, incidence, progression and regression of DR and DME are explored, and gaps in literature identified. Established and novel risk factors are also extensively reviewed with a focus on landmark studies and updates from the recent literature.