Presence and development of diabetic retinopathy in 16 999 patients with type 1 diabetes in the Danish Registry of Diabetic Retinopathy

PURPOSE

To evaluate the five-year incidence of diabetic retinopathy (DR) and associated risk markers in patients with type 1 diabetes in the national Danish DR-screening programme.

METHODS

Based on national data, we included all 16 999 patients with type 1 diabetes in the Danish Registry of Diabetic Retinopathy, who attended the national screening programme in the period 2013-2018. According to the worse eye at first screening, DR was classified (levels 0-4) and linked with various national health registries to retrieve information on diabetes duration, systemic comorbidity, and medication.

RESULTS

At first screening, median age and duration of diabetes were 45.0 and 16.7 years, and 57.5% were males. The prevalence and five-year incidences for DR and progression to proliferative DR (PDR) were 44.2%, 8.9% and 2.0%, respectively. In multivariable Cox models, the incidence endpoints were associated with duration of diabetes (hazard ratio [HR] 1.76, 95% confidence interval [CI] 1.63-1.89, and HR 2.04, 95% CI 1.73-2.40 per 10 years), moderately low Charlson Comorbidity Index score (HR 1.27, 95% CI 1.10-1.47, and HR 2.80, 95% CI 2.23-3.51), and use of blood pressure lowering medication (HR 1.20, 95% CI 1.05-1.36, and HR 1.98, 95% CI 1.53-2.57).

CONCLUSION

In a study of all patients with type 1 diabetes from the Danish DR-screening programme, we identified duration of diabetes, systemic disease and use of anti-hypertensive treatment as consistent risk markers for incident and progressive DR.

Inter-grader reliability in the Danish screening programme for diabetic retinopathy

PURPOSE

The Danish Registry of Diabetic Retinopathy includes information from >200 000 patients who attends diabetic retinopathy (DR) screening in Denmark. Screening of patients with uncomplicated type 2 diabetes is often performed by practicing ophthalmologists, while patients with type 1 and complicated type 2 diabetes attends screening at hospitals. We performed a clinical reliability study of retinal images from Danish screening facilities to explore the inter-grader agreement between the primary screening ophthalmologist and a blinded, certified grader.

METHODS

Invitations to participate were sent to screening facilities across Denmark. The primary grader uploaded fundus photographs with information on estimated level of DR (International Clinical Diabetic Retinopathy scale as 0 [no DR], 1-3 [mild, moderate or severe nonproliferative DR {NPDR}], or 4 [proliferative DR {PDR}]), region of screening, image style, and screening facility. Images were then regraded by a blinded, certified, secondary grader. Weighted kappa analysis was performed to evaluate agreement.

RESULTS

Fundus photographs from 230 patients (458 eyes) were received from practicing ophthalmologists (52.6%) and hospital-based grading centres (47.4%) from all Danish regions. Reported levels of DR by the primary graders were 66.8%, 12.2%, 13.1%, 1.3% and 5.5% for DR levels 0-4. The overall agreement between primary and secondary graders was 93% (κ = 0.83). Based on screening facility agreement was 96% (κ = 0.89) and 90% (κ = 0.76) for practicing ophthalmologists and hospital-based graders.

CONCLUSION

In this nationwide study, we observed a high overall inter-grader agreement and based on this, it is reasonable to assume that reported DR gradings in the screening programme in Denmark, accurately reflect the truth.

Five-Year Incidence of Proliferative Diabetic Retinopathy and Associated Risk Factors in a Nationwide Cohort of 201 945 Danish Patients with Diabetes

Purpose

To evaluate the proliferative diabetic retinopathy (PDR) progression rates and identify the demographic and clinical characteristics of patients who later developed PDR compared with patients who did not progress to that state.

Design

A national 5-year register-based cohort study including 201 945 patients with diabetes.

Subjects

Patients with diabetes who had attended the Danish national screening program (2013-2018) for diabetic retinopathy (DR).

Methods

We used the first screening episode as the index date and included both eyes of patients with and without subsequent progression of PDR. Data were linked with various national health registries to investigate relevant clinical and demographic parameters. The International Clinical Retinopathy Disease Scale was used to classify DR, with no DR as level 0, mild DR as level 1, moderate DR as level 2, severe DR as level 3, and PDR as level 4.

Main Outcome Measures

Hazard ratios (HRs) for incident PDR for all relevant demographic and clinical parameters and 1-, 3-, and 5-year incidence rates of PDR according to baseline DR level.

Results

Progression to PDR within 5 years was identified in 2384 eyes of 1780 patients. Proliferative diabetic retinopathy progression rates from baseline DR level 3 at 1, 3 and 5 years were 3.6%, 10.9%, and 14.7%, respectively. The median number of visits was 3 (interquartile range, 1-4). Progression to PDR was predicted in a multivariable model by duration of diabetes (HR, 4.66 per 10 years; 95% confidence interval [CI], 4.05-5.37), type 1 diabetes (HR, 9.61; 95% CI, 8.01-11.53), a Charlson Comorbidity Index score of > 0 (score 1: HR, 4.62; 95% CI, 4.14-5.15; score 2: HR, 2.28; 95% CI, 1.90-2.74; score ≥ 3: HR, 4.28; 95% CI, 3.54-5.17), use of insulin (HR, 5.33; 95% CI, 4.49-6.33), and use of antihypertensive medications (HR, 2.23; 95% CI, 1.90-2.61).

Conclusions

In a 5-year longitudinal study of an entire screening nation, we found increased risk of PDR with increasing baseline DR levels, longer duration of diabetes, type 1 diabetes, systemic comorbidity, use of insulin, and blood pressure-lowering medications. Most interestingly, we found lower risk of progression from DR level 3 to PDR compared with that in previous studies.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

Predictive value of retinal oximetry, optical coherence tomography angiography and microperimetry in patients with treatment-naïve branch retinal vein occlusion

Vascular endothelial growth factor inhibitors have substantially improved the visual outcomes in patients with macular edema (ME) caused by branch retinal vein occlusion (BRVO), but treatment outcomes are highly variable and early prediction of expected clinical outcome would be important for individualized treatment.As non-invasive metabolic, structural and functional retinal markers might act as early predictors of clinical outcomes, we performed a 12-month, prospective study aimed to evaluate if baseline retinal oximetry, optical coherence tomography angiography (OCT-A) or microperimetry were able to predict need of treatment, structural or functional outcome in patients with ME caused by treatment-näive BRVO.We evaluated 41 eyes of 41 patients with a mean age of 69.6 years and 56% females. We found a strong tendency towards a higher retinal arteriolar oxygen saturation in patients without a need of additional aflibercept treatment after the loading phase (99.8% vs. 92.3%, adjusted odds ratio 0.80 (95% confidence interval 0.64-1.00), adjusted p = 0.058), but otherwise, retinal oximetry, OCT-A or microperimetry were not able to predict need of treatment, structural nor functional outcomes. (Trial registration: clinicaltrials.gov, S-20,170,084. Registered 24 August 2014, https://clinicaltrials.gov/ct2/show/NCT03651011 ).

Presence and development of diabetic retinopathy in 153 238 patients with type 2 diabetes in the Danish Registry of Diabetic Retinopathy

PURPOSE

The purpose of the study was to evaluate the prevalence and incidence of diabetic retinopathy (DR) along with associated markers in patients with type 2 diabetes in the Danish DR-screening programme.

METHODS

We included all persons with type 2 diabetes in the Danish Registry of Diabetic Retinopathy, who had attended at least one episode of DR screening in 2013-2018. DR was classified as levels 0-4 indicating increasing severity. Data were linked with various national health registries to retrieve information on diabetes duration, marital status, comorbidity and systemic medication.

RESULTS

Among 153 238 persons with type 2 diabetes, median age and duration of diabetes were 66.9 and 5.3 years and 56.4% were males. Prevalence and 5-year incidences of DR, 2-step-or-more progression of DR and progression to proliferative DR (PDR) were 8.8%, 3.8%, 0.7% and 0.2%, respectively. In multivariable models, leading markers of incident DR and progression to PDR were duration of diabetes (HR 1.98, 95% CI 1.87-2.09; HR 2.89, 95% CI 2.34-3.58 per 10 years of duration) and use of insulin (HR 1.88, 95% CI 1.76-2.01; HR 2.40, 95% CI 1.84-3.13), while the use of cholesterol-lowering medicine was a protecting marker (HR 0.87, 95% CI 0.81-0.93; HR 0.70, 95% CI 0.52-0.93). From 2013 to 2015, 3-year incidence rates of PDR decreased from 1.22 to 0.45 events per 1000 person-years.

CONCLUSION

Nationally, among Danish individuals with type 2 diabetes attending DR screening, we identified duration of diabetes and use of insulin as the most important predictor for the development of DR, while cholesterol-lowering medicine was a protective factor.

Bidirectional 5-year risks of diabetic retinopathy, glaucoma and/or ocular hypertension: Results from a national screening programme

PURPOSE

We aimed to investigate if diabetic retinopathy (DR), glaucoma and/or ocular hypertension (OHT) are prospectively linked, as previous studies have proposed cross-sectional associations, but longitudinal data from larger cohorts are lacking.

METHODS

We performed a bidirectional 5 years prospective, registry-based cohort study. We extracted data from national registers, including the Danish Registry of Diabetic Retinopathy, the Danish Civil Registration System, the Danish National Patient Register and the Danish National Prescription Registry. DR level was defined by the highest level of the two eyes. Glaucoma and/or OHT was defined by diagnostic codes (H40*) or at least three redeemed prescriptions of glaucoma medication (S01E*) within 1 year. We included 205 970 persons with diabetes and 1 003 170 age- and gender-matched non-diabetes controls. Exposures were level-specific DR (i) and glaucoma and/or OHT (ii), and outcomes were hazard ratios (HRs) for 5 years incident glaucoma and/or OHT (i) and DR (ii).

RESULTS

Persons with diabetes were more likely to develop glaucoma and/or OHT (multivariable adjusted HR 1.11, 95% CI 1.06-1.15), but this did not depend on the level of DR. In persons with diabetes, those with glaucoma and/or OHT were more likely to develop DR (multivariable adjusted HR 1.12, 95% CI 1.03-1.23) within 5 years.

CONCLUSION

In a national cohort, diabetes associated with a little higher risk of upcoming glaucoma and/or OHT, and, inversely, the presence of the latter predicted a higher risk of incident DR. Nevertheless, our data do not seem to justify including glaucoma evaluation in the national Danish DR-screening programme.

Retinal telangiectasia-like lesions in a 15-year-old female with Hereditary hemorrhagic telangiectasia – a case report

Background

Hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber syndrome is a bleeding disorder that can affect all parts of the body including the eyes. Different ocular abnormalities have been described in relation to HHT, but the pathogenesis of retinal involvement is still unknown. A few cases have described chorioretinal abnormalities primarily occurring in elderly patients. In this study, we present a unique case of a young female with known HHT and a series of retinal fundus images including optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) with macular telangiectasia-like lesions.

Case presentation

A young female genetically diagnosed with hereditary hemorrhagic telangiectasia (HHT), is regularly attending retinal screening since she is diagnosed with Type 1 diabetes. At one visit, abnormal retinal telangiectasia-like lesions in the macula, are observed. These abnormalities are monitored over an extended period of time with fundus imaging, and further investigated with OCT and OCTA. The patient has no visual complaints at any time and best-corrected visual acuity is 20/20 Snellen equivalent in both eyes.

Conclusions

To the best of our knowledge, this is the first case to describe the occurrence of telangiectasia-like lesions in macula with secondary choriocapillaris atrophy in a patient diagnosed with HHT in such a young age.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02658-7.

Attendance in a national screening program for diabetic retinopathy: a population-based study of 205,970 patients

AIMS

A nationwide diabetic retinopathy (DR) screening program has been established in Denmark since 2013. We aimed to perform an evaluation of adherence to DR screenings and to examine whether non-adherence was correlated to DR progression.

METHODS

The population consisted of a register-based cohort, who participated in the screening program from 2013 to 2018. We analyzed age, gender, marital status, DR level (International Clinical DR severity scale, none, mild-, moderate-, severe non-proliferative DR (NPDR) and proliferative DR (PDR)), comorbidities and socioeconomic factors. The attendance pattern of patients was grouped as either timely (no delays > 33%), delayed (delays > 33%) or one-time attendance (unexplained).

RESULTS

We included 205,970 patients with 591,136 screenings. Rates of timely, delayed and one-time attendance were 53.0%, 35.5% and 11.5%, respectively. DR level at baseline was associated with delays (mild-, moderate-, severe NPDR and PDR) and one-time attendance (moderate-, severe NPDR and PDR) with relative risk ratios (RRR) of 1.68, 2.27, 3.14, 2.44 and 1.18, 2.07, 1.26, respectively (P < 0.05). Delays at previous screenings were associated with progression to severe NPDR or PDR (hazard ratio (HR) 2.27, 6.25 and 12.84 for 1, 2 and 3+ delays, respectively). Any given delay doubled the risk of progression (HR 2.28).

CONCLUSIONS

In a national cohort of 205,970 patients, almost half of the patients attended DR screening later than scheduled or dropped out after first screening episode. This was, in particular, true for patients with any levels of DR at baseline. DR progression in patients with delayed attendance, increased with the number of missed appointments.

Navigated laser and aflibercept versus aflibercept monotherapy in treatment-naïve branch retinal vein occlusion: A 12-month randomized trial

PURPOSE

Angiostatic agents have proven effective in the treatment of macular oedema in patients with branch retinal vein occlusion (BRVO). However, treatment is inconvenient and expensive, and novel treatment regimens are warranted. We aimed to evaluate if combination treatment of navigated central retinal laser and aflibercept lowered the treatment burden in these patients.

METHODS

Treatment-naïve patients with BRVO and macular oedema were included at two centres and randomized 1:1 to three monthly injections of 2.0 mg aflibercept with (Group A) or without (Group B) navigated central laser, followed by aflibercept as needed from month 4 through 12. Re-treatment need was evaluated, and secondary endpoints included functional and anatomical outcomes and safety evaluated by retinal microperimetry.

RESULTS

We evaluated 41 eyes of 41 patients with a mean age of 69.6 years. Baseline median best-corrected visual acuity (BCVA) was 70.0 letters, and median central retinal thickness (CRT) was 502 μm with no difference between Groups A (n = 21) and B (n = 20). Percentage of patients needing re-treatment after month three was 71% and 80% (p = 0.72). At month 12, groups did not differ in number of injections after loading (1 versus 2, p = 0.43), change in BCVA (+12.8 versus +15.1 letters, p = 0.48), CRT (-195 versus -181 μm, p = 0.82), or retinal sensitivity (+3.3 versus +4.1 dB, p = 0.67).

CONCLUSION

In treatment-naïve BRVO patients, addition of navigated central laser to aflibercept did not lower treatment burden or affect functional or anatomical outcomes. A low number of intravitreal injections were needed for successful outcome in both treatment arms.

Diabetic Retinopathy Predicts Risk of Alzheimer’s Disease: A Danish Registry-Based Nationwide Cohort Study

Background:

Retinal neurodegeneration is evident in early diabetic retinopathy (DR) which may be associated with other neurodegenerative diseases like Alzheimer's disease (AD).

Objective:

To investigate diabetes and DR as a risk marker of present and incident AD.

Methods:

A register-based cohort study was performed. We included 134,327 persons with diabetes above 60 years of age, who had attended DR screening, and 651,936 age- and gender-matched persons without diabetes.

Results:

At baseline, the prevalence of AD was 0.7% and 1.3% among patients with and without diabetes, respectively. In a multivariable regression model, patients with diabetes were less likely to have AD at baseline (adjusted OR 0.63, 95% CI 0.59–0.68). During follow-up, incident AD was registered for 1473 (0.35%) and 6,899 (0.34%) persons with and without diabetes, respectively. Compared to persons without diabetes, persons with diabetes and no DR had a lower risk to develop AD (adjusted HR 0.87, 95% CI 0.81–0.93), while persons with diabetes and DR had higher risk of AD (adjusted HR 1.24, 95% CI 1.08–1.43). When persons with diabetes and no DR were used as references, a higher risk of incident AD was observed in persons with DR (adjusted HR 1.34, 95% CI 1.18–1.53).

Conclusion:

Individuals with diabetes without DR were less likely to develop AD compared to persons without diabetes. However, individuals with DR had a 34% higher risk of incident AD, which raise the question whether screening for cognitive impairment should be done among individuals with DR.

Evidence-based Danish guidelines for screening of diabetic retinopathy

PURPOSE

Diabetic retinopathy (DR) is among the leading causes of visual loss in the working-age population. It is generally accepted that screening of DR is cost-effective and can detect DR before it becomes sight-threatening to allow timely treatment.

METHODS

A group of retinal specialists was formed by the Danish Ophthalmological Society with the aim to formulate contemporary evidence-based guidelines for screening of DR in order to implement these in the Danish screening system.

RESULTS

We hereby present evidence for DR-screening regarding (1) classification of DR, (2) examination techniques, (3) screening intervals and (4) automated screening. It is our recommendation that the International Clinical Retinopathy Disease Severity Scale should be used to classify DR. As a minimum, mydriatic two-field disc- and macular-centred images are required. In the case of suspected clinically significant diabetic macular oedema, supplementary optical coherence tomography can increase the diagnostic accuracy. There is solid evidence to support a flexible, individualized screening regimen. In particular, it is possible to prolong screening intervals to 24-48 months for patients with no or mild nonproliferative diabetic retinopathy (NPDR), but it is also possible to use extended intervals of 12-24 months for patients with moderate NPDR given that these are well-regulated regarding glycaemic control (HbA1c ≤ 53 mmol/mol) and blood pressure (≤130/80 mmHg). Automated screening of DR is encouraging but is not ready for implementation at present.

CONCLUSION

Danish evidenced-based guidelines for screening of DR support high-quality imaging and allow flexible, individualized screening intervals with a potential for extension to patients with low risk of DR progression.

Monitoring of Diabetic Retinopathy in relation to Bariatric Surgery: a Prospective Observational Study

BACKGROUND

To investigate the need for closer perioperative monitoring of diabetic retinopathy in patients with type 2 diabetes undergoing bariatric surgery.

METHODS

Prospective observational clinical study of 56 patients with type 2 diabetes undergoing bariatric surgery. The patients were examined with 7-field fundus images and optical coherence tomography scans 2 weeks before and 1, 3, 6 and 12 months after bariatric surgery. Worsening was defined as a two-step change in the Wisconsin Epidemiologic Study of Diabetic Retinopathy scale or appearance or worsening of macular edema. Postoperative changes were analyzed in a mixed model.

RESULTS

Six patients (11 %) had any worsening at any visit, and three (5 %) persisted at 1 year. Of the 24 patients with preoperative retinopathy, 4-13 % worsened and 9-22 % improved, with significant overall improvement at 6 months (p = 0.01). Only one (3%) of the 32 patients without preoperative diabetic retinopathy had a transient worsening at 6 months. No patients developed macular edema, but the whole cohort had a minor increase in center point foveal thickness that peaked 6 months postoperatively. The patients were required to have good glucose control preoperatively where HbA1c was 6.4 ± 1.9 %.

CONCLUSIONS

Diabetic retinopathy was clinically stable after bariatric surgery, and none of the observed changes would have resulted in a changed screening interval at our center. This supports adherence to regular diabetic retinopathy screening guidelines following bariatric surgery in well-controlled patients. A clinically negligible but statistically significant foveal thickening 6 months postoperatively warrants further study.

The IGF-Axis and Diabetic Retinopathy Before and After Gastric Bypass Surgery

BACKGROUND

Laparoscopic gastric bypass (LGB) abruptly causes remission of type 2 diabetes (T2D). Such dramatic metabolic changes have previously been found to cause worsening of diabetic retinopathy (DR) and circulating insulin-like growth factor I (IGF-I) has been suggested as a causal mediator. We aimed to evaluate baseline imbalances in the circulating IGF-system and changes after LGB in patients with T2D.

METHODS

Prospective ocular examinations and measurement of the IGF-axis before and 3 and 12 months after LGB. IGF-bioactivity was measured by cell-based IGF-I receptor (IGF-IR) kinase activation assay (bioactive IGF). Total IGF-I, IGF-II and IGF binding protein (IGFBP) 1 and 3 were determined by immunoassays.

RESULTS

At baseline, 18 of 36 patients presented with DR. These patients had higher levels of bioactive IGF (p = 0.03) than patients without DR and this association was strengthened in multivariate analysis (p = 0.006). Three patients had worsening of DR, unrelated to other markers. In univariate analysis, bioactive IGF increased at 3 months (p = 0.05) but this change became insignificant in multivariate analysis (p = 0.11). IGFBP-1 increased whereas IGFBP-3 and total IGF-II decreased at the two postoperative visits (p ≤ 0.001). Total IGF-I showed no significant changes. HbA1c, glucose, HOMA-IR and lipids improved after surgery. Two patients did not complete the 12-month visit.

CONCLUSIONS

In obese T2D patients, bioactive IGF is a potential biomarker for DR and levels tended to increase 3 months after bariatric surgery. IGFBP-1 increased while IGFBP-3 and total IGF-II decreased postoperatively, but these changes were unassociated with the development of DR. Markers of the metabolic syndrome improved.

Intravitreal ranibizumab for diabetic macular oedema in previously vitrectomized eyes

PURPOSE

There is little information about the efficacy of intravitreal vascular endothelial growth factor (VEGF) inhibition in vitrectomized eyes. This study aimed to evaluate the efficacy of anti-VEGF (ranibizumab) on diabetic macular oedema in previously vitrectomized eyes.

METHODS

A nationwide retrospective review of medical records from 2010 to 2013.

RESULTS

We identified 33 previously vitrectomized eyes in 28 patients treated with ranibizumab injections for diabetic macular oedema. Median follow-up was 323 days (interquartile range 72-1404 days). Baseline mean visual acuity was 0.57 logMAR (95% CI 0.13-1.01) before injections. After an average of 4.7 injections (range 1-15), mean visual acuity remained stable at 0.54 logMAR (95% CI 0.13-0.95) with a mean improvement of 0.03 (p = 0. 45, 95% CI -0.12 to 0.06). In 12 eyes (36%), visual acuity improved 0.1 logMAR or more, in 12 eyes (36%), vision was unchanged (gain or loss of 0-0.05 logMAR), and in nine eyes (27%), vision decreased 0.1 logMAR or more. Mean central foveal thickness (CFT) on optical coherence tomography (OCT) scan was 412 μm (95% CI 390-434 μm) before injections. After injections, the mean CFT decreased to 352 μm (95% CI 334-370 μm). The mean reduction in CFT was 14% (95% CI 4-24%, p = 0.01). Sixteen eyes (48.5%) became devoid of oedema on the last OCT scan. Despite the significant reduction in CFT, the visual acuity remained unchanged.

CONCLUSION

Intravitreal ranibizumab can be effective in previously vitrectomized eyes with diabetic macular oedema. However, the response is variable and should be carefully monitored.

The Danish Registry of Diabetic Retinopathy

AIM OF DATABASE

To monitor the development of diabetic eye disease in Denmark and to evaluate the accessibility and effectiveness of diabetic eye screening programs with focus on interregional variations.

TARGET POPULATION

The target population includes all patients diagnosed with diabetes. Denmark (5.5 million inhabitants) has ~320,000 diabetes patients with an annual increase of 27,000 newly diagnosed patients. The Danish Registry of Diabetic Retinopathy (DiaBase) collects data on all diabetes patients aged ≥18 years who attend screening for diabetic eye disease in hospital eye departments and in private ophthalmological practice. In 2014-2015, DiaBase included data collected from 77,968 diabetes patients.

MAIN VARIABLES

The main variables provide data for calculation of performance indicators to monitor the quality of diabetic eye screening and development of diabetic retinopathy. Data with respect to age, sex, best corrected visual acuity, screening frequency, grading of diabetic retinopathy and maculopathy at each visit, progression/regression of diabetic eye disease, and prevalence of blindness were obtained. Data analysis from DiaBase's latest annual report (2014-2015) indicates that the prevalence of no diabetic retinopathy, nonproliferative diabetic retinopathy, and proliferative diabetic retinopathy is 78%, 18%, and 4%, respectively. The percentage of patients without diabetic maculopathy is 97%. The proportion of patients with regression of diabetic retinopathy (20%) is greater than the proportion of patients with progression of diabetic retinopathy (10%).

CONCLUSION

The collection of data from diabetic eye screening is still expanding in Denmark. Analysis of the data collected during the period 2014-2015 reveals an overall decrease of diabetic retinopathy compared to the previous year, although the number of patients newly diagnosed with diabetes has been increasing in Denmark. DiaBase is a useful tool to observe the quality of screening, prevalence, and progression/regression of diabetic eye disease.

Longstanding refractory pseudophakic cystoid macular edema resolved using intravitreal 0.7 mg dexamethasone implants

Background

Refractory pseudophakic cystoid macular edema (PCME) following cataract surgery has long posed a challenge to clinicians, but intravitreal injections with a sustained delivery 0.7 mg dexamethasone implant has emerged as a promising therapy for this condition.

Objective

To present a case of longstanding and refractory PCME with complete remission through 189 days of follow-up after two successive injections with intravitreal dexamethasone implants.

Case report

A 59-year-old male had experienced metamorphopsia for approximately 4 years and had been diagnosed with PCME 15 months earlier. Since the time of the diagnosis, the condition had been refractory to both subtenon triamcinolone acetonide and a total of five injections with intravitreal ranibizumab. After the last injection with ranibizumab, central subfield mean thickness was 640 μm, and the best corrected visual acuity was 78 Early Treatment Diabetic Retinopathy Study letters. Following an intravitreal injection with a dexamethasone implant, the macular edema resolved at the next follow-up. The macular edema returned 187 days after the first injection and was treated with another intravitreal dexamethasone implant. Again, the macular edema subsided completely, and best corrected visual acuity improved to 84 Early Treatment Diabetic Retinopathy Study letters, a condition which was maintained through an additional 189 days of follow-up.

Conclusion

Chronic PCME is traditionally a difficult condition to treat, but we are encouraged by the optimal response experienced with intravitreal sustained release dexamethasone implants in our patient whose longstanding PCME had been refractory to previous treatments with both subtenon triamcinolone and intravitreal ranibizumab. In this case, the condition appeared to be fully reversible once inflammation was controlled, but the need for monitoring and repeated injections remains an issue of concern.

Progression of diabetic retinopathy during pregnancy in women with type 2 diabetes

AIMS/HYPOTHESIS

We studied the progression of diabetic retinopathy during pregnancy in women with type 2 diabetes.

METHODS

Fundus photography was performed at median 10 (range 6-21) and 28 (27-37) gestational weeks in 80 of 110 (73%) consecutively referred pregnant women with type 2 diabetes. Diabetic retinopathy was classified in five stages. Progression was defined as at least one stage of deterioration of diabetic retinopathy and/or development of macular oedema on at least one eye between the two examinations. Macular oedema was defined as retinal thickening and/or hard exudates within a diameter of 1,500 microm in the macula area.

RESULTS

Diabetic retinopathy, mainly mild, was present in 11 (14%) women in early pregnancy. Median duration of diabetes was 3 years (range 0-16 years). At baseline, HbA(1c) was 6.4% (1.0) (mean [SD]), systolic BP 121 (13) and diastolic BP 72 (9) mmHg. Prior to pregnancy, 22 (28%) women had been on insulin treatment. During pregnancy 74 women (93%) were treated with insulin and 11 (14%) with antihypertensive medication. Progression of diabetic retinopathy was observed in 11 (14%) women. Progression was mainly mild, but one woman with poor glycaemic control and uncontrolled hypertension progressed from mild retinopathy to sight-threatening retinopathy with proliferations, clinically significant macular oedema and impaired vision in both eyes. Progression of diabetic retinopathy was associated with a longer duration of diabetes (p = 0.03) and insulin treatment before pregnancy (p = 0.004).

CONCLUSIONS/INTERPRETATION

Despite a low risk of progression of retinopathy in pregnant women with type 2 diabetes, sight-threatening deterioration did occur.

Pregnancy-induced sight-threatening diabetic retinopathy in women with Type 1 diabetes

AIMS

To determine the progression of diabetic retinopathy in pregnant women with diabetes offered tight glycaemic and blood pressure control.

METHODS

A prospective study of 102 (87%) out of 117 consecutive pregnant women with Type 1 diabetes for median 16 years (range 1-36) and HbA(1c) 6.7% (4.9-10.8) in early pregnancy. Fundus photography was performed at 8 and 27 weeks. Retinopathy was classified in five stages. Diabetic macular oedema was classified as present in a mild form or as clinically significant macular oedema (CSMO). Progression was defined as at least one stage of deterioration of retinopathy and/or development of macular oedema in at least one eye. Sight-threatening progression was defined as loss of visual acuity>or=0.2 on Snellen's chart or laser treatment performed during pregnancy due to proliferative retinopathy or CSMO.

RESULTS

Diabetic retinopathy was present at inclusion in at least one eye in 64 (63%) women and proliferative retinopathy and macular oedema were present in nine and 16 women, respectively. Progression of retinopathy occurred in 28 (27%) women. Sight-threatening progression occurred in six women; in three, visual acuity deteriorated and four required laser treatment. Sight-threatening progression was associated with presence of macular oedema (P=0.007), impaired visual acuity (P=0.03) and higher blood pressure (P=0.016) in early pregnancy, but not with HbA1c, decline in HbA1c, or prevalence of severe hypoglycaemia.

CONCLUSIONS

Loss of visual acuity and the need for laser treatment during diabetic pregnancy remain clinical problems associated with presence of macular oedema, visual impairment and higher blood pressure in early pregnancy.

Pharmacokinetics of intravitreal 5-fluorouracil prodrugs in silicone oil: experimental studies in pigs

PURPOSE

To examine the in vivo pharmacokinetics of intravitreal 5-Fluorouracil (5-FU) following tamponade with 5-FU prodrug silicone oil formulations.

METHOD

Two different alkoxycarbonyl 5-FU prodrugs denoted C12 and C18 were synthesized and formulated as silicone oil suspensions. A total of 26 pigs underwent conventional three-port lens-sparing pars plana vitrectomy. Approximately 1.6 ml of the prodrug-silicone oil formulation was placed in the vitreous cavity. Operated eyes were enucleated between 20 min and 168 hours postoperatively, and analysed for their content of free 5-FU by high performance liquid chromatography.

RESULTS

With the C12 prodrug silicone oil formulation, the concentration of free 5-FU in the vitreous water phase 1 hour after surgery was 3.30 +/- 1.62 microg/ml. After 4 hours this concentration had declined to 1 microg/ml. With the C18 prodrug, the concentration of free vitreal 5-FU never reached 1 microg/ml during the 7 days these experiments lasted. A mathematical model is presented that can explain the measured data if the clearance of 5-FU from the vitreous water phase follows first order kinetics with a half-life of 20 min.

CONCLUSION

These experiments, and the model analysis, suggest that the elimination half-life of 5-FU in the vitreous cavity of a vitrectomized, silicone oil-filled eye is very fast. The model analysis indicates that an alkoxycarbonyl 5-FU prodrug with a specific release rate constant of 10.7 microg/square root h cm(2) can maintain an intravitreal 5-FU concentration above 1 microg/ml for 5 days in the porcine eye.