Additional measures of macular function beyond visual acuity

PURPOSE

Visual function is a complex process in which external visual stimuli are interpreted. Patients with retinal diseases and prolonged follow-up times may experience changes in their visual function that are not detected by the standard visual acuity measure, as they are a result of other alterations in visual function. With the advancement of different methods to evaluate visual function, additional measurements have become available, and further standardization suggests that some methods may be promising for use in clinical trials or routine clinical practice. The objectives of this article are to review these additional measurements and to provide guidance on their application.

METHODS

The Vision Academy's membership of international retinal disease experts reviewed the literature and developed consensus recommendations for the application of additional measures of visual function in routine clinical practice or clinical trials.

RESULTS

Measures such as low-luminance visual acuity, contrast sensitivity, retinal fixation and microperimetry, and reading performance are measures which can complement visual acuity measurements to provide an assessment of overall visual function, including impact on patients' quality of life. Measures such as dark adaptation, color vision testing, binocular vision testing, visual recognition testing, and shape discrimination require further optimization and validation before they can be implemented in everyday clinical practice.

CONCLUSION

Additional measurements of visual function may help identify patients who could benefit from earlier diagnosis, detection of disease progression, and therapeutic intervention. New and additional functional clinical trial endpoints are required to fully understand the early stages of macular disease, its progression, and the response to treatment.

Rationale and Design of VOYAGER: Long-term Outcomes of Faricimab and Port Delivery System with Ranibizumab for Neovascular Age-Related Macular Degeneration and Diabetic Macular Edema in Clinical Practice

Purpose

To describe the rationale and design of the VOYAGER (NCT05476926) study, which aims to investigate the safety and effectiveness of faricimab and the Port Delivery System with ranibizumab (PDS) for neovascular age-related macular degeneration (nAMD) or diabetic macular edema (DME) in clinical practice. VOYAGER also aims to understand drivers of clinical practice treatment outcomes by gaining novel insight into the intersection of treatment regimens, decisions, anatomic outcomes, and vision.

Design

Primary data collection, noninterventional, prospective, multinational, multicenter clinical practice study.

Participants

At least 5000 patients initiating/continuing faricimab or PDS for nAMD/DME (500 sites, 31 countries).

Methods

Management will be per usual care, with no mandated scheduled visits/imaging protocol requirements. Using robust methodologies, relevant clinical and ophthalmic data, including visual acuity (VA), and data on treatment clinical setting/regimens/philosophies, presence of anatomic features, and safety events will be collected. Routinely collected fundus images will be uploaded to the proprietary Imaging Platform for analysis. An innovative investigator interface will graphically display the patient treatment journey with the aim of optimizing treatment decisions.

Main Outcome Measures

Primary end point: VA change from baseline at 12 months per study cohort (faricimab in nAMD and in DME, PDS in nAMD). Secondary end points: VA change over time and per treatment regimens (fixed, treat-and-extend, pro re nata, and other) and number. Exploratory end points: VA change in relation to presence/location of anatomic features that impact vision (fluid, central subfield thickness, fibrosis, atrophy, subretinal hyperreflective material, diabetic retinopathy severity, and disorganization of retinal inner layers) and per treatment regimen/philosophies. The impact of regional and practice differences on outcomes will be assessed as will safety.

Results

Recruitment commenced in November 2022 and will continue until late 2027, allowing for up to 5 years follow-up. Exploratory interim analyses are planned annually.

Conclusions

VOYAGER is an innovative study of retinal diseases that will assess the effectiveness and safety of faricimab and PDS in nAMD and DME and identify clinician- and disease-related factors driving treatment outcomes in clinical practices globally to help optimize vision outcomes.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

The impact of COVID-19 on aflibercept treatment of neovascular AMD in Sweden - data from the Swedish Macula Register

BACKGROUND

The purpose of the study was to compare the real-world aflibercept treatment and visual outcomes, and to examine the adherence to pandemic guidelines in two groups of patients with treatment-naïve neovascular age-related macular degeneration (nAMD) before and during the first year of the COVID-19 pandemic in Sweden up to the 1-year follow-up.

METHODS

This is a retrospective observational study including 2915 treatment naïve eyes with nAMD. Using data from the Swedish Macula Register (SMR), 1597 eyes initiating treatment between 1 July 2018 and 31 January 2019 (pre-pandemic group) were compared with 1318 eyes starting treatment between 1 February and 31 August 2020 (pandemic group). The eyes were then followed for 1 year ± 2 months, hence the first group was unaffected by the pandemic while the second group was affected. The focus was on baseline characteristics, visual acuity (VA) change from baseline, number of injections, treatment regimen, number of appointments and the frequency and length of appointment delays. The Wilcoxon Signed-Rank Test was used to compare baseline VA to follow-up VA within the respective groups. The Mann-Whitney U-test and Fisher's exact test were used to compare outcomes between the groups.

RESULTS

Baseline characteristics were similar between the two groups. The percentage of eyes with an available follow-up VA after 1 year was 58% in the pre-pandemic group vs. 44% in the pandemic group. VA in the pre-pandemic group had increased significantly after 1 year, from 62.2 ± 14.1 letters to 64.8 ± 16.1 letters (n = 921); p < 0.0001. In the pandemic group, VA increased from 61.1 ± 15.8 to 64.9 ± 16.9 (n = 575); p < 0.0001. There was no significant difference in mean VA change between the groups; p = 0.1734. The pre-pandemic group had significantly more delays than the pandemic group, 45% vs. 36%; p < 0.0001.

CONCLUSIONS

The pre-pandemic and pandemic groups had similar VA gains at 1-year follow-up, but with a reduced number of available VA in the pandemic group. Clinics were able to implement and prioritize injection visits excluding VA measurements, helping to reduce delays and maintain VA gains during the COVID-19 pandemic.

CURRENT CONCEPTS AND MODALITIES FOR MONITORING THE FELLOW EYE IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION: An Expert Panel Consensus

Neovascular age-related macular degeneration in one eye is a major risk factor for developing neovascular age-related macular degeneration in the fellow eye; effective monitoring is therefore critical. This review summarizes existing and developing methods to monitor the fellow eye of patients with unilateral neovascular age-related macular degeneration and provides guidance for patients and clinicians.

The presence of neovascular age-related macular degeneration (nAMD) in one eye is a major risk factor for the development of disease in the fellow eye. Several methods exist to help physicians monitor the fellow eye, with new technologies becoming increasingly available.

Anti-VEGF intravitreal injections in the era of COVID-19: responding to different levels of epidemic pressure

Purpose

Following the first wave of the COVID-19 pandemic in early 2020, the easing of strict measures to reduce its spread has led to a resurgence of cases in many countries at both the national and local level. This article addresses how guidance for ophthalmologists on managing patients with retinal disease receiving intravitreal injections of anti-vascular endothelial growth factor (VEGF) during the pandemic should be adapted to the local epidemic pressure, with more or less stringent measures implemented according to the ebb and flow of the pandemic.

Methods

The Vision Academy’s membership of international retinal disease experts analyzed guidance for anti-VEGF intravitreal injections during the COVID-19 pandemic and graded the recommendations according to three levels of increasing epidemic pressure. The revised recommendations were discussed, refined, and voted on by the 14-member Vision Academy Steering Committee for consensus.

Results

Protocols to minimize the exposure of patients and healthcare staff to COVID-19, including use of personal protective equipment, physical distancing, and hygiene measures, should be routinely implemented and intensified according to local infection rates and pressure on the hospital/clinic or healthcare system. In areas with many COVID-19-positive clusters, additional measures including pre-screening of patients, postponement of non-urgent appointments, and simplification of complex intravitreal anti-VEGF regimens should be considered. Treatment prioritization for those at greatest risk of irreversible vision loss should be implemented in areas where COVID-19 cases are increasing exponentially and healthcare resources are strained.

Conclusion

Consistency in monitoring of local infection rates and adjustment of clinical practice accordingly will be required as we move forward through the COVID-19 era. Ophthalmologists must continue to carefully weigh the risk–benefits to minimize the exposure of patients and healthcare staff to COVID-19, ensure that patients receive sight-saving treatment, and avoid the potential long-term impact of prolonged treatment postponement.

Guidance for anti-VEGF intravitreal injections during the COVID-19 pandemic

Purpose

There is an urgent need to address how to best provide ophthalmic care for patients with retinal disease receiving intravitreal injections with anti-vascular endothelial growth factor agents during the ongoing global COVID-19 pandemic. This article provides guidance for ophthalmologists on how to deliver the best possible care for patients while minimizing the risk of infection.

Methods

The Vision Academy’s Steering Committee of international retinal disease experts convened to discuss key considerations for managing patients with retinal disease during the COVID-19 pandemic. After reviewing the existing literature on the issue, members put forward recommendations that were systematically refined and voted on to develop this guidance.

Results

The considerations focus on the implementation of steps to minimize the exposure of patients and healthcare staff to COVID-19. These include the use of personal protective equipment, adherence to scrupulous hygiene and disinfection protocols, pre-screening to identify symptomatic patients, and reducing the number of people in waiting rooms. Other important measures include triaging of patients to identify those at the greatest risk of irreversible vision loss and prioritization of treatment visits over monitoring visits where possible. In order to limit patient exposure, ophthalmologists should refrain from using treatment regimens that require frequent monitoring.

Conclusion

Management of patients with retinal disease receiving intravitreal injections during the COVID-19 pandemic will require adjustment to regular clinical practice to minimize the risk of exposure of patients and healthcare staff, and to prioritize those with the greatest medical need. The safety of patients and healthcare staff should be of paramount importance in all decision-making.

Treatment for neovascular age-related macular degeneration in Sweden: outcomes at seven years in the Swedish Macula Register

PURPOSE

To present Swedish Macula Register (SMR) data regarding treatment of neovascular age-related macular degeneration (AMD) in clinical practice since 2008.

METHODS

A retrospective register-based study was conducted. Evaluation of baseline demographics, visual outcome and number of injections during this period is presented.

RESULTS

Mean age at diagnosis was 79 ± (SD) 8 years; 65% were female. The proportion of patients with <2 months' duration of symptoms increased from 26% in 2008 to 41% in 2014 (p = 0.001). Mean visual acuity (VA) at baseline increased from 54.3 ± 15.0 early treatment diabetic retinopathy study (ETDRS) letters in 2008 to 57.8 ± 15.6 letters in 2014 (CI₉₅ 2.6; 4.3; p < 0.001). Mean VA after 1 year of treatment increased from 57.8 ± 17.7 ETDRS letters for patients who started the treatment in 2008 to 62.8 ± 16.4 ETDRS letters in patients starting treatment in 2014 (CI₉₅ 2.67; 4.64; p < 0.001). During all study years, the proportion of patients with an improvement in VA of between 5 and 15 letters was around 30%, while 14% had VA improvement of more than 15 letters. The mean number of injections during the first treatment year increased from 4.3 ± 1.9 in 2008 to 5.9 ± 2.9 in 2014 (CI₉₅ 1.40; 1.67; p < 0.001). Seven-year follow-up of 322 eyes showed a mean change of -1 letters from baseline, with a mean of 21 injections for the entire period.

CONCLUSION

The duration of symptoms before treatment decreased, while VA at baseline and after 1 year of treatment increased over the years and so did the number of injections. Long-term follow-up demonstrated stable VA.

No improvement in injection frequency or in visual outcome over time in two cohorts of patients from the same Swedish county treated for wet age-related macular degeneration

Background

Although ranibizumab has been used for the treatment of wet age-related macular degeneration (AMD) since 2007, real-world studies still report undertreatment resulting in a less favorable visual outcome. In this study, two different time cohorts of patients treated with ranibizumab for wet AMD in routine care were analyzed to observe whether there was a change over time regarding visual outcome, injection frequency, and quality of life (QoL).

Methods

We compared patients with treatment-naïve wet AMD in two observational follow-up cohorts 2007–2010 (n=50 patients) and 2009–2013 (n=26). After a loading dose of three intravitreal ranibizumab injections, the patients were treated under the pro re nata regimen. Visual acuity (VA) was examined by Early Treatment Diabetic Retinopathy Study (ETDRS) charts. The National Eye Institute Visual Functioning Questionnaire 25 was answered by patients at baseline and at 37±7 months (cohort 1) and at 45±4 months (cohort 2).

Results

At baseline, the cohorts were homogeneous considering mean age (76±7 vs 75±8 years), mean VA (53±14 vs 52±15 ETDRS letters), and mean self-reported symptom duration (14±11 vs 13±11 weeks). Mean VA decreased in both cohorts over time, from 53±14 to 45±24 letters (P=0.011) and from 52±15 to 46±22 letters (P=0.175), respectively. The patients received a mean of 8±5 and 9±7 injections, respectively. The mean composite score change from baseline to follow-up decreased in cohort 1 from 64±21 to 59±25 scores (P=0.04) but increased in cohort 2 from 64±28 to 67±23 scores (P=0.38).

Conclusion

We could not demonstrate any improvement in the number of injections in two different time cohorts of patients treated with ranibizumab for wet AMD in a Swedish county. Visual outcomes decreased after 3 years of follow-up, but QoL scores were divergent.

Reduced occurrence of severe visual impairment after introduction of anti-Vascular Endothelial Growth Factor in wet age-related macular degeneration - a population- and register-based study from northern Sweden

PURPOSE

To study the occurrence of severe visual impairment (SVI) and treatment outcome at 12 months in patients treated for wet age-related macular degeneration (AMD) by use of data from the Swedish Macula Register (SMR) and referrals to the regional low vision clinics in five northern counties.

METHODS

Referrals to low vision clinics during 2005, 2009 and 2013 and treatment outcome at 12 months from the SMR database from 2008 until 2013 in patients >65 years of age in five northern counties were included in the survey.

RESULTS

The rate of referral due to AMD was significantly reduced during the time period (-48%; p < 0.001). At 12 months, a significant slight mean improvement in logMAR visual acuity (VA) was observed (-0.01, SD 0.37; p < 0.001) after a mean of 5.0 ± 2.3 anti-vascular endothelial growth factor (VEGF)-injections were administered. Age and low baseline VA was associated with less favourable visual outcome (p < 0.001).

CONCLUSION

Referral rate to low vision clinic is a valuable tool for estimating occurrence of SVI and fell between the years 2005 until 2013. Data from the SMR showed improvement in visual acuity on the whole, but also identified patients at high risk for developing SVI during anti-VEGF-treatment.

Macular dysfunction in drusen maculopathy assessed with multifocal electroretinogram and optical coherence tomography

Purpose

To study the relationship between macular function assessed by multifocal electroretinogram (mfERG) and morphological changes evaluated with optical coherence tomography (OCT) and fundus photography in patients with drusen maculopathy.

Methods

Ten patients (age 71 ± 5 years) with drusen maculopathy were compared to fifteen healthy control patients (age 67 ± 7 years). One eye per patient was examined with OCT, color fundus pictures, and mfERG (103 hexagons) recorded in nine areas corresponding to the nine areas of the OCT retinal map. Drusen density for every separated area was registered.

Results

All nine areas in the maculopathy group demonstrated prolonged implicit time compared to healthy controls; the mean value for the maculopathy group was 31.3 milliseconds (95% confidence intervals [CI]: 30.9–31.6) vs 27.9 milliseconds (95% CI: 27.5–28.2; P = 0.006) for the control group. The amplitude in the foveal area was lower in the maculopathy group; the mean value for the maculopathy group was 25.1 nV/deg² (95% CI: 18.4–31.7) vs 33.9 nV/deg² (95% CI: 27–40.9; P = 0.03) for the control group. mfERG in the maculopathy group demonstrated no differences in areas with or without drusen. There was no correlation between the retinal thickness assessed with OCT and the mfERG response.

Conclusion

Eyes with drusen maculopathy demonstrated functional changes compared to healthy controls evaluated with mfERG. Drusen seems to be associated with general macular dysfunction.

Three-year follow-up of visual outcome and quality of life in patients with age-related macular degeneration

Background

The purpose of this study was to evaluate the visual outcome and self-reported vision-targeted health status in patients treated with intravitreal ranibizumab for wet age-related macular degeneration (AMD).

Methods

A total of 51 eyes from 50 patients aged 76 ± 7 years, with wet AMD not previously treated, were included in this prospective study. Best corrected visual acuity was examined using Early Treatment Diabetic Research Study charts and near vision reading. All patients underwent an ophthalmological examination, including fluorescein and indocyanine green angiography (occult cases) and optical coherence tomography. The Visual Function Questionnaire test was completed before and 37 ± 7 months after the start of intravitreal injections.

Results

The patients received a mean number of 7.8 ± 5.0 (range 2–22) injections. One month after the third intravitreal injection, significant improvement was seen in both visual acuity (53 ± 14 to 61 ± 14 letter, P = 0.001) and near vision (17 ± 9 to 11 ± 8 points, P = 0.001). During follow-up, mean visual acuity decreased from 53 ± 14 to 44 ± 24 letters (P = 0.011), and near vision decreased from 17 ± 9 to 20 ± 11 points (P = 0.048). Despite visual impairment, the quality of life test revealed no significant decrease in mental health (P = 0.529) or ability to read a newspaper (P = 0.21), but a decrease in distance activities (reading street signs, steps, going to the theater) from 57 ± 27 to 46 ± 31 points (P = 0.007) was documented.

Conclusion

Decreased visual acuity was related to a decrease in self-reported visual function for distance activities, while mental health items, such as worrying, were not influenced.

Multifocal Visual Evoked Potentials (mfVEP) in Diabetic Patients with and without Polyneuropathy

Previously not shown this study support that mfVEP is an indicator of optic nerve neuropathy in diabetic patients and there could be a correlation between the optic nerve dysfunction and diabetic poly neuropathy. The early optic nerve involvement might explain some of the visual complain in this group of diabetic patients.

PURPOSE

To investigate the function of the visual pathway measured by mfVEP (multifocal Visual Evoked Potentials) in patients with diabetic retinopathy and neurophysiologically verified polyneuropathy

SUBJECTS AND METHODS

Thirty-two diabetic patients with the same degree of diabetic retinopathy were classified with neurography regarding polyneuropathy and further examined with mfVEP. The mfVEPs of eighteen patients with polyneuropathy were compared to those of fourteen diabetic patients without polyneuropathy and to those of ten nondiabetic subjects.

RESULTS

Diabetic duration, and the number of patients who had undergone panretinal photocoagulation for proliferative diabetic retinopathy were similar in the two patient groups, 29±13 vs 25±7 years, p=0.3. Both groups of patients with diabetic retinopathy had significantly lower amplitudes in the mfVEP than the healthy subjects. In addition the mfVEP amplitudes, which reflect selected areas of the visual function, were significantly reduced in the lower nasal quadrant in patients with neuropathy compared to patients without neuropathy.

CONCLUSION

The results indicate that mfVEP could be an indicator of optic nerve neuropathy in patients with diabetic retinopathy. The early optic nerve involvement might explain some of the visual complaints in this group of diabetic patients.

Multifocal electroretinography amplitudes increase after photocoagulation in areas with increased retinal thickness and hard exudates

PURPOSE

This study aimed to evaluate local response on multifocal electroretinography (mfERG) and to assess retinal thickness with optical coherence tomography (OCT) after focal laser treatment in areas with retinal oedema and exudates in patients with diabetic retinopathy.

METHODS

Twelve diabetes patients (aged 60 +/- 14 years, diabetes duration 16 +/- 8 years) treated with focal or grid photocoagulation in areas with retinal oedema and/or exudates underwent mfERG and OCT before and 3 months after treatment. The average thickness (in microm) in any of the nine sectors (defined according to the ETDRS) treated with photocoagulation was measured. Amplitudes and implicit times were analysed in corresponding areas on the mfERG.

RESULTS

Mean mfERG amplitudes increased after photocoagulation (21.5 +/- 8.0 nV/deg(2) versus 16.8 +/- 6.1 nV/deg(2); p = 0.012), whereas no difference was seen in implicit times. Mean OCT values in the treated regions were lower at follow-up (272 +/- 23 microm versus 327 +/- 79 microm; p = 0.013). No correlation was seen between changes in mfERG response and changes in OCT values. The decrease in retinal thickness was correlated with the number of laser spots applied (p = 0.002).

CONCLUSIONS

Focal argon laser treatment is effective in reducing retinal thickness. In addition, treated areas tend to show improved retinal function as demonstrated by increased amplitudes on mfERG.

Electrophysiological evaluation and visual outcome in patients with central retinal vein occlusion, primary open-angle glaucoma and neovascular glaucoma

PURPOSE

To evaluate patients with central retinal vein occlusion (CRVO) and neovascular glaucoma (NVG) using electrophysiology in order to gain better understanding of visual outcome and risk factors, such as previously diagnosed primary open-angle glaucoma (POAG).

METHODS

Eighty-three patients (83 eyes) initially presenting with CRVO and examined with full-field electroretinography (ERG) within 3 months of the thrombotic event were analysed retrospectively regarding treatment, risk factors and visual outcome. In addition, 30 patients initially presenting with NVG caused by CRVO were also investigated regarding risk factors using electrophysiology in order to determine the cause of their visual impairment.

RESULTS

Nineteen (23%) of the 83 patients initially presenting with CRVO had been diagnosed previously with POAG. Ninety-five per cent (18/19) of all the patients with previously diagnosed glaucoma developed ischaemic CRVO. Thirty-four per cent of the patients initially presenting with CRVO (28/83) developed NVG. Sixty-eight per cent (13/19) of the patients with previous glaucoma developed NVG, compared to 23% (15/64) of the patients without previous POAG. In the patients who initially presented with NVG, full-field ERG demonstrated a remaining retinal function of both cones and rods, indicating that the main cause of visual impairment is ischaemia of the ganglion cell layer.

CONCLUSION

Glaucoma is a significant risk factor for developing ischaemic CRVO and subsequent NVG. The presence of POAG in CRVO worsens visual outcome. NVG is associated with preserved photoreceptor function, thus indicating ischaemia of the ganglion cell layer as the primary cause of visual impairment. This emphasizes the importance of prompt treatment of ischaemia and elevated intraocular pressure in these patients.

Improved retinal function after trabeculectomy in glaucoma patients

PURPOSE

To investigate retinal function after reduction of intraocular pressure (IOP) by filtration surgery in patients with medically uncontrolled glaucoma.

METHODS

Eleven patients (11 eyes) with medically uncontrolled glaucoma underwent trabeculectomy. Clinical investigation, visual field (testing with standard automated perimetry (SAP-Humphrey), optical coherence tomography (OCT), full-field electroretinography (full-field ERG) and multifocal electroretinography (mfERG) were performed preoperatively as well as 2 and 6 months after surgery.

DESIGN

Interventional prospective, consecutive case series.

RESULTS

No significant reduction was seen in mean log MAR visual acuity 2 or 6 months after filtration surgery. The mean preoperative intraocular pressure of 27.1 (+/-6.2) mmHg decreased to 19.0(+/-6.1) mmHg 2 months after surgery and to 17.1 (+/- 3.4) mmHg 6 months after surgery (both p = 0.001). The reduction in IOP significantly decreased the number of anti-glaucoma agents used, from 3.7 +/- 1.6 at baseline to 0.8 +/- 0.9 2 months after surgery and to 1.3 +/- 1.2 6 months after surgery (p = 0.004 and p = 0.008 respectively). The results of SAP, OCT and full-field ERG did not show any significant difference between pre- and postoperative values at any point in time. No significant improvement was found with regard to the first positive peak (P(1)) amplitudes in the macular retina (area 1) or in the perimacular retina/periphery (area 2) when measured with mfERG 2 months after surgery. The mfERG examinations revealed significantly improved P(1) amplitudes 6 months after surgery in both area 1 and area 2, compared with the preoperative values (p = 0.042 and p = 0.014 respectively). The implicit time of P(1) decreased significantly 6 months after surgery in area 2 compared with the preoperative values (p = 0.023).

CONCLUSION

A significant lowering of IOP seems to improve the function of the central retina, as demonstrated by increased amplitudes and reduced implicit times assessed with mfERG.

Retinopathy in subjects with impaired fasting glucose: the NANSY-Eye baseline report

AIMS

Network for Pharmacoepidemiology (NEPI) Antidiabetes Study-Eye is a randomized placebo-controlled Swedish trial investigating if treatment with sulphonylurea, in addition to dietary regulation and increased exercise, delays the development of retinopathy in subjects with impaired fasting glucose (IFG).

METHODS

Subjects were surveyed in primary care with repeated fasting blood glucose measurements. Those with a mean of two consecutive values >or=5.6 and <6.1 mmol/l were invited to participate. Baseline physical examination included blood pressure and body mass index (BMI). Fundus photos were taken in two fields using 35-mm diafilm. The alternative classification of the Wisconsin Epidemiologic Study of Diabetic Retinopathy was used to classify the retinopathy level.

RESULTS

At baseline, 90 men and 64 women with IFG were photographed. Of these, 16 subjects (10%) had mild or very mild retinopathy. There was no difference in occurrence of retinopathy between subjects with known diagnosis of hypertension or not. However, subjects with retinopathy had significantly higher systolic (154 vs. 141 mmHg, p = 0.013) and diastolic (86 vs. 81 mmHg, p = 0.008) blood pressure levels independent of differences in age, sex and known hypertension. There was a corresponding difference in BMI, being greater in subjects with than in those without retinopathy (32.4 vs. 29.2 kg/m(2), p = 0.013). There were no associations between levels of fasting blood glucose or haemoglobin A1c, on the one hand, and retinopathy, on the other.

CONCLUSION

Retinopathy may be present even before type 2 diabetes is manifest. It is associated with higher blood pressure levels and higher BMI values, that is, with predominant features of the metabolic syndrome.

Sight-threatening retinopathy is associated with lower mortality in type 2 diabetic subjects: a 10-year observation study

AIMS

To study associations between diabetic retinopathy and development of stroke, myocardial infarction and death in type 2 diabetic patients.

METHODS

During a 10-year observation period, 363 type 2 diabetic patients (diagnosis > or =30 years of age) attending an outpatient clinic were studied regarding the prevalence and incidence of retinopathy and associated risk factors, i.e., (HbA(1c), blood pressure, albuminuria, plasma creatinine, age, sex and diabetes duration) in relation to the development of myocardial infarction, stroke and death. The degree of retinopathy was classified as no retinopathy, background or sight-threatening retinopathy, i.e., clinically significant macular edema, severe non-proliferative or proliferative retinopathy.

RESULTS

During the study period, 62 patients had had myocardial infarction, 54 stroke and 99 patients died. Patients with sight-threatening retinopathy at baseline (n=41) had a 2.2-fold increased (p<0.01) risk for death compared to patients with no or background retinopathy, even when controlled for medical risk factors. When adjusted for medical risk factors, patients with no retinopathy at baseline (n=226) who remained without retinopathy or developed background retinopathy (n=187) during the study period, had a 3.6-fold increased risk for death (95% CI, 1.1, 11.8), (p=0.03), compared to patients who developed sight-threatening retinopathy (n=39), while the incidence of myocardial infarction did not differ. More patients who developed sight-threatening retinopathy were treated with ACE inhibitors than patients who did not (41% versus 24%; p=0.03).

CONCLUSION

Despite more medical risk factors, patients who developed sight-threatening retinopathy had lower mortality compared to patients with no or background retinopathy at follow-up. More patients who developed sight-threatening retinopathy were treated with ACE inhibitors but this seemed not to have influenced the lower mortality rate in this group, whereas the use of ACE inhibitors in patients who did not develop sight-threatening retinopathy was connected with lower mortality rate.

In diabetic retinopathy, foveal thickness of 300 mum seems to correlate with functionally significant loss of vision

PURPOSE

To study the relationship between foveal thickness assessed by optical coherence tomography (OCT) and foveal function measured with multi focal electroretinography (mfERG) in patients with non-proliferative diabetic retinopathy, and with no previous laser treatment.

METHODS

Twenty-six eyes from 18 diabetic patients (13 men), aged 59 years, (range 28-79 years), diabetes duration 15 years, (range 2-27 years), with a macular thickness between 200 and 600 microm were evaluated by mfERG, visual acuity (ETDRS score) and OCT. Mean amplitudes and implicit times of the mfERG responses were analyzed within the four innermost (14 degrees) of the six concentric rings. For comparison with the results from the OCT (diameter of measured area = 6 mm) we analyzed the summed response from the first and second ring (central zone), corresponding to the central area of the OCT. The third(zone 2) and fourth (zone 3)of the four innermost of the six concentric rings measured by the mfERG corresponding to the second and third area of OCT.

RESULTS

An increased macular thickness in the central area of the OCT correlated to reduced amplitudes (r = -0.541; P = 0.004) and prolonged implicit times (r = 0.548; P = 0.004) in the central zone of the mfERG, and inversely correlated with visual acuity, -0.49; P = 0.045. Retinal thickness in the second area was correlated to prolonged implicit times in the second mfERG zone (r = -0.416; P = 0.034). No correlations were found for the third area of the OCT. When macular thickness exceeded 300 mum the decrease of amplitudes and prolonged implicit times, measured by mfERG, seemed to be more pronounced.

CONCLUSION

In conclusion increased macular thickness is correlated with reduced amplitudes and prolonged implicit times on the mf ERG and worse visual acuity.

Multifocal electroretinography (mfERG) in insulin dependent diabetics with and without clinically apparent retinopathy

PURPOSE

To study the retinal function, using multifocal electroretinography (mfERG), in diabetic patients with mild and moderate retinopathy, and in diabetics without clinically apparent retinopathy.

METHODS

Thirty-one patients with insulin dependent diabetes mellitus, eleven without any clinically apparent retinopathy, twelve with mild retinopathy and eight with moderate retinopathy, were studied. Ophthalmologic examination included testing of visual acuity, fundus inspection, fundus photography and mfERG. Sixteen subjects without eye disease and with normal visual acuity were used as controls for comparison of mfERG results.

RESULTS

The patients had a mean diabetes duration of 23+/-9 years. All patients and controls had a visual acuity of 1.0. In the first order component of the mfERG there were significantly higher ring amplitudes in the diabetics compared to the controls (p=0.001). In the second-order component of the mfERG, there was a significantly prolonged implicit time in the diabetics who had retinopathy compared to those without any retinopathy (p=0.026). The third positive waveform in the ring amplitudes of the second-order component, were absent in 15/31 of patients with diabetes, but were easily distinguished in all the controls; p<0.001. This waveform was absent in 6/11 patients without retinopathy.

CONCLUSION

Patients with insulin dependent diabetes have specific abnormalities in both the first and the second-order component of the mfERG. These abnormalities reflect both vascular changes in the retina and, probably simultaneously, pathology in inner retinal function, also in the diabetics without clinically apparent retinopathy.

Vitrectomy Seems to be Beneficial for Advanced Diffuse Diabetic Macular Oedema not Responding to Laser Treatment

BACKGROUND

To evaluate the surgical efficacy of vitrectomy, with optical coherence tomography, in patients with non-ischemic and ischemic diffuse diabetic macular oedema not responding to laser treatment.

METHODS

Ten eyes from nine patients (aged 46.0 +/- 20 years, diabetes duration 12.4 +/- 4 years) operated with vitrectomy for diabetic macular oedema not responding to laser treatment were evaluated before and 6 months postoperatively. Retinal thickness was assessed with optical coherence tomography, OCT, measuring the mean values of the centre of fovea and the second and third concentric rings from foveola. Four patients with type 1 diabetes had ischemic and five patients (6 eyes) with type 2 diabetes had non-ischemic diffuse macular oedema diagnosed on fluorescein angiography (FA). All eyes had an attached vitreous diagnosed on OCT.

RESULTS

Mean foveal thickness for the three concentric rings from centre and out was significantly less 6 months postoperatively 437 +/- 125 vs. 286 +/- 67 microm; p = 0.027, 426 +/- 105 vs. 308 +/- 35 microm; p = 0.019 and 404 +/- 69 microm vs. 318 +/- 29 microm; p = 0.011 respectively. The decrease in foveal thickness was similar for eyes with and without signs of ischemic maculopathy. There was a trend toward improved visual acuity (VA) 6 months after surgery 0.4; range 0.2-0.6 compared to 0.3; range 0.1-0.5 before vitrectomy; p = 0.107).

CONCLUSION

Vitrectomy seems to be a beneficial treatment for both ischemic and non-ischemic advanced diffuse diabetic macular oedema not responding to laser treatment.

The presence of an operculum verified by optical coherence tomography and other prognostic factors in macular hole surgery

PURPOSE

To evaluate the prognostic influence of the presence of an operculum in macular hole and to correlate the prognosis for postoperative visual acuity (VA) with the size of the macular hole, its duration and preoperative VA.

METHODS

We carried out a prospective study of 61 eyes of 59 patients with full thickness macular hole. All patients were examined with optical coherence tomography (OCT) in order to ascertain the presence of an operculum. The VA was measured with the ETDRS chart. A standard pars plana vitrectomy with inner limiting membrane peeling was performed in all cases and 20% C2F6 was used as tamponade.

RESULTS

Anatomical closure was obtained after one surgical procedure in 59/61 (97%) patients. Linear regression analysis showed only baseline VA to be predictive of visual outcome (p < 0.001). The presence of an operculum preoperatively did not correlate with VA either pre- or postoperatively, nor with the anatomical closure rate.

CONCLUSION

The finding that postoperative VA in macular hole correlates with preoperative VA seems to allow for good prediction of postoperative VA in macular hole surgery. However, the presence of an operculum is of no prognostic significance.

Nephropathy, but not retinopathy, is associated with the development of heart disease in Type 1 diabetes: a 12-year observation study of 462 patients

AIMS

To study the occurrence of heart disease and death in Type 1 diabetic patients and evaluate whether presence of microangiopathy, i.e. nephropathy and retinopathy, was associated with the outcome.

METHODS

A 12-year observation study of 462 Type 1 diabetic patients without a previous history of heart disease at baseline who were treated under routine care in a hospital out-patient clinic.

RESULTS

A total of 85 patients developed signs of heart disease, i.e. myocardial infarction (n = 41), angina (n = 23), and heart failure (n = 17) and 56 patients died. The mortality for patients without signs of heart disease during the observation period was 7.6% compared with 51% in patients with myocardial infarction (P < 0.001), 26% in patients with angina (P < 0.01) and 65% in patients with heart failure (P < 0.001). The relative risk for death was 9.0 (P < 0.001) and 2.5 (P < 0.05) times higher in patients with macroalbuminuria and microalbuminuria, respectively. The risk for cardiovascular death was 18.3 times (P < 0.001) higher in patients with macroalbuminuria compared with patients with normoalbuminuria. In patients with sight-threatening retinopathy, the relative risk for death was 7.0 times higher (P < 0.01) and the risk for coronary heart disease events 4.4 times higher (P < 0.05) compared with patients with no retinopathy. However, when retinopathy was adjusted for presence of macroalbuminuria, this association disappeared.

CONCLUSION

This study shows a high incidence of heart disease in patients with Type 1 diabetes. The worse prognosis was seen in patients with sight-threatening retinopathy and macroalbuminuria and microalbuminuria at baseline. Macroalbuminuria and microalbuminuria were independently associated with a high risk for heart disease and death while the association with sight-threatening retinopathy only occurred in the presence of nephropathy.

Macular function assessed with mfERG before and after panretinal photocoagulation in patients with proliferative diabetic retinopathy

PURPOSE

To examine macular function and its correlation to macular thickness before and after panretinal photocoagulation for proliferative retinopathy in diabetic patients.

METHODS

Ten diabetic patients (aged 57 +/- 10 years, diabetes duration 21 +/- 10 years) treated with panretinal photocoagulation outside the great vascular arcade underwent multifocal electroretinography (mfERG) and optical coherence tomography (OCT) before and 6 months after treatment. When focal treatment in the macular region was performed prior to panretinal photocoagulation the investigations took place 3 weeks after this treatment but before the panretinal photocoagulation. One eye per patient was examined. Amplitudes and implicit times of the mfERG response were analyzed within the four innermost (27 degrees) of the six concentric rings registered by the mfERG, which corresponds to the area measured by the OCT (psi 3.5 mm).

RESULTS

Visual acuity was similar before and after photocoagulation, 1.0; 0.7-1.0 (md, range) versus 1.0; 0.6-1.0 (md, range). The mean values of the ring average amplitudes were reduced in the first and second, third and fourth concentric rings from foveola after photocoagulation, p = 0.001, p = 0.011 and p = 0.004, respectively. No change was seen in implicit time after treatment. OCT values were similar before and after photocoagulation. There was no correlation between retinal thickness assessed with OCT and amplitudes measured by the mfERG.

CONCLUSION

In spite of unchanged values of retinal thickness and visual acuity, panretinal photocoagulation seems to cause a functional impairment in the adjacent untreated macula, shown by reduced amplitudes measured by the mfERG.

Type 1 diabetes patients with severe non-proliferative retinopathy may benefit from panretinal photocoagulation

PURPOSE

To examine whether panretinal photocoagulation for severe non-proliferative retinopathy in type 1 diabetes patients could halt the progression of retinopathy with subsequent vitreous haemorrhages and visual impairment.

METHODS

During a 10-year follow-up study period of 344 type 1 diabetes patients, 81 subjects went through panretinal photocoagulation. Forty patients were treated for severe non-proliferative retinopathy (age at onset of diabetes 14 +/- 8 years, diabetes duration 18 + 10 years) and 41 for proliferative retinopathy (age at onset 15 +/- 10 years, diabetes duration 22 + 13 years). One randomly selected eye per patient forms the basis for the study. Metabolic control, systolic and diastolic blood pressure, serum creatinine and urinary albumin levels were measured and analysed yearly during the follow-up period.

RESULTS

A total of 35% (14/40) of eyes treated for severe non-proliferative retinopathy developed neovascularizations during a mean time of 2.9 +/- 1.5 years. Vitreous haemorrhages were more frequent in eyes with proliferative retinopathy at treatment than in eyes with severe non-proliferative retinopathy (12/41 versus 2/40; p = 0.007). The number of vitrectomies due to vitreous haemorrhages in eyes treated for severe non-proliferative retinopathy tended to be lower (1/40 versus 6/41; p = 0.052). Before photocoagulation, visual acuity (VA) was similar in eyes with severe non-proliferative retinopathy and in those with proliferative retinopathy (1.0, 0.4-1.0 versus 1.0, 0.1-1.0; median and range). Visual impairment and blindness tended to develop more often in eyes treated for proliferative retinopathy compared to those treated for severe non-proliferative retinopathy (10/40 versus 4/40; p = 0.056). Eyes with neovascularizations at follow-up were more often visually impaired (VA < 0.5) than eyes without neovascularizations (15/55 versus 1/26; p = 0.016).

CONCLUSION

In type 1 diabetes, panretinal photocoagulation may be beneficial even at the severe non-proliferative retinopathy stage in terms of preventing vitreous haemorrhage, subsequent vitrectomy and visual impairment.

Diabetic retinopathy, visual acuity, and medical risk indicators: a continuous 10-year follow-up study in Type 1 diabetic patients under routine care

The objective of this study was to describe incidence and progression of diabetic retinopathy in relation to medical risk indicators as well as visual acuity outcome after a continuous follow-up period of 10 years in a Type 1 diabetic population treated under routine care. The incidence and progression of retinopathy and their association to HbA(1c), blood pressure, urinary albumin, serum creatinine levels, and insulin dosage were studied prospectively in 452 Type 1 diabetic patients. The degree of retinopathy was classified as no retinopathy, background, or sight-threatening retinopathy, i.e. clinically significant macular edema, severe nonproliferative, or proliferative retinopathy. Impaired visual acuity was defined as a visual acuity <0.5 and blindness as a visual acuity < or =0.1 in the best eye. In patients still alive at follow-up (n=344), 61% (69/114) developed any retinopathy, 45% (51/114) background retinopathy, and 16% (18/114) sight-threatening retinopathy. Progression from background to sight-threatening retinopathy occurred in 56% (73/131). In 2% (6/335), visual acuity dropped to <0.5 and in less than 1% (3/340) to < or =0.1. Patients who developed any retinopathy and patients who progressed to sight-threatening retinopathy had higher mean HbA(1c) levels over time compared to those who remained stable (P<.001 in both cases). Patients who developed any retinopathy had higher levels of mean diastolic blood pressure (P=.036), whereas no differences were seen in systolic blood pressure levels between the groups. Cox regression analysis, including all patients, showed mean HbA(1c) to be an independent risk indicator for both development and progression of retinopathy, whereas mean diastolic blood pressure was only a risk indicator for the incidence of retinopathy. Metabolic control is an important risk indicator for both development and progression of retinopathy, whereas diastolic blood pressure is important for the development of retinopathy in Type 1 diabetes. The number of patients who became blind during 10 years of follow-up was low.

Photocoagulation of diabetic macular oedema--complications and visual outcome

PURPOSE

To describe complications and visual outcome of photocoagulation for clinically significant macular oedema.

SUBJECTS AND METHODS

Evaluation of macular oedema and complications of photocoagulation in 194 eyes, defined as subretinal fibrosis, atrophic creep of the pigment epithelium and subretinal neovascularization was based on stereo fundus photo grading. The study included 25 patients with type 1 and 93 patients with type 2 diabetes (age 32 +/- 10 and 65 +/- 9 years, respectively). The statistical evaluations were based on one eye per patient.

RESULTS

Follow-up time was 5.5 +/- 2.4 years (mean +/- SD). Complications within 1/3 ODD from the centre of the macula were seen in 4% (1/23) of eyes of patients with type 1 diabetes, compared to 26% (20/76) of eyes among patients with type 2 diabetes (p=0.02). Hard exsudates before treatment were more common in type 2 than in type 1 diabetic eyes, 70/82 vs. 11/23 (p<0.001). In all eyes, hard exsudates were more often associated with subretinal fibrosis or atrophic creep (35/133 eyes) than diffuse oedema (5/44 eyes) (p=0.04).

CONCLUSION

Photocoagulation for clinically significant macular oedema with hard exudates, particularly when subfoveally located, was more often associated with subretinal fibrosis or atrophic creep of the pigment epithelium than photocoagulation of oedema without hard exudates. Hard exudates as well as complications after photocoagulation were more common in type 2 than in type 1 diabetes, resulting in poorer visual outcome in this group of patients.

Contrast sensitivity and visual recovery time in diabetic patients treated with panretinal photocoagulation

PURPOSE

To study patients treated with panretinal photocoagulation regarding contrast sensitivity and visual recovery time after exposure to glare.

METHODS

To compare contrast sensitivity and visual recovery-time after exposure to glare in eyes (n=20) from 20 type 1 diabetic patients treated with panretinal photocoagulation for proliferative retinopathy with eyes (n= 19) from 19 un-treated type 1 diabetic patients. Contrast sensitivity was tested with a low contrast acuity chart, before and during exposure to either a uniform background illumination or a spotlight. Visual recovery time was defined as the time required to regain baseline visual acuity during light exposure.

RESULTS

Contrast thresholds values were higher in eyes treated with panretinal photocoagulation compared to un-treated eyes before illumination 4.2 +/- 1.2% vs. 3.1 +/- 1.7% (p=0.006), during background illumination 5.8 +/- 5.1% vs. 3.9 +/- 4.8% (p=0.001), and during spotlight exposure 5.6 +/- 2.2% vs. 3.2 +/- 1.8% (p<0.001). Furthermore, recovery time was longer both during background illumination, 20; 5-50 sec vs. 2; 2-80 sec. (md;range), (p<0.001) and during spotlight illumination 27; 5-70 sec vs. 2;1-60 sec. (md;range) (p<0.001).

CONCLUSION

Eyes treated with panretinal photocoagulation had higher contrast threshold levels at baseline and during glare, as well as a prolonged visual recovery time compared to un-treated eyes with mild background retinopathy.

The temporal development of retinopathy and nephropathy in type 1 diabetes mellitus during 15 years diabetes duration

In this prospective study, the 10- and 15-year incidence and course of retinopathy were examined in relation to medical risk indicators from 3.1 +/- 1.9 (mean -/+ SD) years diabetes duration and onwards in 29 adult type 1 diabetic patients treated under routine care. A total of 28 patients were followed for 10 years and 20 patients for 15 years diabetes duration. After 10 years diabetes duration, 11 patients had developed any retinopathy (ten patients background retinopathy and one patient clinically-significant macular oedema). After 15 years diabetes duration, 16 patients had developed any retinopathy (12 patients developed background retinopathy and four patients developed potentially sight-threatening retinopathy, i.e. clinically significant macular oedema (n = 2) or severe non-proliferative retinopathy (n = 2)). None of the patients developed proliferative retinopathy. No differences were seen in mean HbA1c values between patients without any retinopathy and patients with background retinopathy, whereas patients who developed potentially sight-threatening retinopathy had higher mean HbA1c levels than patients without any retinopathy. Patients who developed potentially sight-threatening retinopathy had higher levels of mean HbA1c both after 10 (9.7 +/- 1.6 vs 6.9 +/- 1.5%; P < 0.05) and 15 years diabetes duration (9.3 +/- 1.2 vs 7.1 +/- 1.3%; P < 0.05), compared to patients without any retinopathy. They also had higher levels of mean HbA1c than patients with background retinopathy after 15 years diabetes duration (9.3 +/- 1.2 vs 7.7 +/- 1.1%; P < 0.05). There were no differences in blood pressure levels between patients who developed retinopathy and those who did not. Only two patients developed clinical signs of nephropathy (urinary albumin 320-1590 mg/l) after 12 and 13 years diabetes duration, respectively. At those time points, both patients had already developed background retinopathy since 2 years. In conclusion, the present study shows that the incidence of retinopathy is associated with the duration of diabetes and that there is a strong association between the degree of metabolic control and development of potentially sight-threatening retinopathy. The study also indicates that the development of retinopathy does not seem to be associated with hypertension or clinical signs of nephropathy.

Pre-eclampsia is a potent risk factor for deterioration of retinopathy during pregnancy in Type 1 diabetic patients

The aim of the present study was to examine the influence of pregnancy on deterioration of retinopathy in patients with Type 1 diabetes mellitus. Sixty-five pregnant Type 1 diabetic women attending the University Hospital in Lund were studied retrospectively. The degree of retinopathy, and levels of HbA1c and blood pressure 12 months before, during, and 6 months after pregnancy were compared of those of 56 non-pregnant Type 1 diabetic women matched for age and duration of diabetes. For all patients, sight-threatening deterioration of retinopathy did not differ between the pregnancy group (9/65) and the control group (6/56). Over time, pregnant patients had lower HbA1c levels than controls (p < 0.001). Pregnant patients with sight-threatening deterioration of retinopathy had higher HbA1c levels than those without (p = 0.028 and the decrement in HbA1c between the 6-14th and the 20th week of gestation was more pronounced (p = 0.006). In those patients who developed pre-eclampsia during pregnancy, deterioration of retinopathy ocurred more frequently compared to those without pre-eclampsia (4/8 vs 5/65; p = 0.005). In conclusion, sight-threatening deterioration of retinopathy was not more common during pregnancy in IDDM patients than among age- and duration-matched control patients. In pregnant patients, deterioration of retinopathy was associated with the pregestational degree of metabolic control as well as with a rapidly improved glycaemic control acheived during pregnancy. Among those in whom deterioration occurred during pregnancy, pre-eclampsia was a potent risk factor.

The incidence of nephropathy in type 1 diabetic patients with proliferative retinopathy: a 10-year follow-up study

Patients with type 1 diabetes mellitus and with proliferative retinopathy often have a concomitant diabetic nephropathy. However, in cross-sectional studies it has been shown that 35% of patients with proliferative retinopathy do not show signs of diabetic nephropathy. The aim of the present study was to examine the incidence of diabetic nephropathy in type 1 diabetic patients with proliferative retinopathy but without signs of nephropathy. To that end, out of 102 consecutive patients with proliferative retinopathy attending the University Hospital, Lund, in 1986, 24 patients did not show any clinical signs of nephropathy, and were followed for 10 years regarding the development of nephropathy. Their age was 36.7 +/- 9.8 years, age at onset 11.8 +/- 7.5 years, diabetes duration 25.7 +/- 6.9 years and duration of proliferative retinopathy 4.6 +/- 3.8 years (mean +/- S.D.). At entry, no patient had albuminuria (< 30 mg/l), and albumin creatinine clearance ratio was < 0.01 x 10(-3). During the 10-year follow-up period, two of the patients showed isolated higher peaks of elevated urinary albumin, but none of the 24 patients developed persistent microalbuminuria (> or = 30 mg/l). Two patients died before follow-up, but none of these had developed microalbuminuria at the time for death. Based on mean annual measurements, there were no increases in HbA1c, systolic and diastolic blood pressure, and serum creatinine levels. At entry, seven of the patients were treated with antihypertensive drugs and another three patients received such treatment during the study period. In conclusion, in a subgroup of patients with proliferative retinopathy, i.e. without clinical signs of diabetic nephropathy, no patient developed persistent microalbuminuria during a 10-year follow-up period. These results indicate further evidence for at least partly different pathogenic mechanisms behind diabetic retinopathy and nephropathy.

Pre-eclampsia is a potent risk factor for deterioration of retinopathy during pregnancy in Type 1 diabetic patients

The aim of the present study was to examine the influence of pregnancy on deterioration of retinopathy in patients with Type 1 diabetes mellitus. Sixty-five pregnant Type 1 diabetic women attending the University Hospital in Lund were studied retrospectively. The degree of retinopathy, and levels of HbA1c and blood pressure 12 months before, during, and 6 months after pregnancy were compared of those of 56 non-pregnant Type 1 diabetic women matched for age and duration of diabetes. For all patients, sight-threatening deterioration of retinopathy did not differ between the pregnancy group (9/65) and the control group (6/56). Over time, pregnant patients had lower HbA1c levels than controls (p < 0.001). Pregnant patients with sight-threatening deterioration of retinopathy had higher HbA1c levels than those without (p = 0.028 and the decrement in HbA1c between the 6-14th and the 20th week of gestation was more pronounced (p = 0.006). In those patients who developed pre-eclampsia during pregnancy, deterioration of retinopathy ocurred more frequently compared to those without pre-eclampsia (4/8 vs 5/65; p = 0.005). In conclusion, sight-threatening deterioration of retinopathy was not more common during pregnancy in IDDM patients than among age- and duration-matched control patients. In pregnant patients, deterioration of retinopathy was associated with the pregestational degree of metabolic control as well as with a rapidly improved glycaemic control acheived during pregnancy. Among those in whom deterioration occurred during pregnancy, pre-eclampsia was a potent risk factor.

Poor metabolic control, early age at onset, and marginal folate deficiency are associated with increasing levels of plasma homocysteine in insulin-dependent diabetes mellitus. A five-year follow-up study

In a previous study, we showed that diabetic patients exhibited significantly increased concentrations of total plasma homocysteine (tHcy), but not until the onset of nephropathy. It was suggested that the hyperhomocysteinaemia might contribute to the accelerated atherosclerotic process in diabetic patients. In the present study, we have analysed the main determinants of plasma homocysteine (i.e. serum cobalamin, blood folate and serum creatinine), and also some other parameters related to diabetes mellitus, such as medical history, metabolic and renal quantities, on two occasions with a 5-year interval in 50 patients with insulin-dependent diabetes mellitus, in order to further elucidate the relation between plasma tHcy and diabetes mellitus. The result of the present study shows that diabetic patients with the lowest age at onset and with the poorest metabolic control are those most prone to a rapid increase in plasma tHcy concentration. The increment in plasma tHcy concentration in this group of patients may at least partly be explained by a marginal deficiency of blood folate concentrations.