Blue-on-yellow and achromatic perimetry in diabetic children without retinopathy

Discriminating early-stage diabetic retinopathy with subjective and objective perimetry

Introduction

To prevent progression of early-stage diabetic retinopathy, we need functional tests that can distinguish multiple levels of neural damage before classical vasculopathy. To that end, we compared multifocal pupillographic objective perimetry (mfPOP), and two types of subjective automated perimetry (SAP), in persons with type 2 diabetes (PwT2D) with either no retinopathy (noDR) or mild to-moderate non-proliferative retinopathy (mmDR).

Methods

Both eyes were assessed by two mfPOP test methods that present stimuli within either the central ±15° (OFA15) or ±30° (OFA30), each producing per-region sensitivities and response delays. The SAP tests were 24-2 Short Wavelength Automated Perimetry and 24-2 Matrix perimetry.

Results

Five of eight mfPOP global indices were significantly different between noDR and mmDR eyes, but none of the equivalent measures differed for SAP. Per-region mfPOP identified significant hypersensitivity and longer delays in the peripheral visual field, verifying earlier findings. Diagnostic power for discrimination of noDR vs. mmDR, and normal controls vs. PwT2D, was much higher for mfPOP than SAP. The mfPOP per-region delays provided the best discrimination. The presence of localized rather than global changes in delay ruled out iris neuropathy as a major factor.

Discussion

mfPOP response delays may provide new surrogate endpoints for studies of interventions for early-stage diabetic eye damage.

Objective perimetry identifies regional functional progression and recovery in mild Diabetic Macular Oedema

PURPOSE

Retinal function beyond foveal vision is not routinely examined in the clinical screening and management of diabetic retinopathy although growing evidence suggests it may precede structural changes. In this study we compare optical coherence tomography (OCT) based macular structure with function measured objectively with the ObjectiveFIELD Analyzer (OFA), and with Matrix perimetry. We did that longitudinally in Type 2 diabetes (T2D) patients with mild Diabetic Macular Oedema (DMO) with good vision and a similar number of T2D patients without DMO, to evaluate changes in retinal function more peripherally over the natural course of retinopathy.

METHODS

Both eyes of 16 T2D patients (65.0 ± 10.1, 10 females), 10 with baseline DMO, were followed for up longitudinally for 27 months providing 94 data sets. Vasculopathy was assessed by fundus photography. Retinopathy was graded using to Early Treatment of Diabetic Retinopathy Study (ETDRS) guidelines. Posterior-pole OCT quantified a 64-region/eye thickness grid. Retinal function was measured with 10-2 Matrix perimetry, and the FDA-cleared OFA. Two multifocal pupillographic objective perimetry (mfPOP) variants presented 44 stimuli/eye within either the central 30° or 60° of the visual field, providing sensitivities and delays for each test-region. OCT, Matrix and 30° OFA data were mapped to a common 44 region/eye grid allowing change over time to be compared at the same retinal regions.

RESULTS

In eyes that presented with DMO at baseline, mean retinal thickness reduced from 237 ± 25 μm to 234.2 ± 26.7 μm, while the initially non-DMO eyes significantly increased their mean thickness from 250.7 ± 24.4 μm to 255.7 ± 20.6 μm (both p<0.05). Eyes that reduced in retinal thickness over time recovered to more normal OFA sensitivities and delays (all p<0.021). Matrix perimetry quantified fewer regions that changed significantly over the 27 months, mostly presenting in the central 8 degrees.

CONCLUSIONS

Changes in retinal function measured by OFA possibly offer greater power to monitor DMO over time than Matrix perimetry data.

Visual Field Abnormalities in Early-Stage Diabetic Retinopathy Assessed by Chromatic Perimetry

Purpose

The purpose of this study was to define the nature and extent of sensitivity loss using chromatic perimetry in diabetics who have mild or no retinopathy.

Methods

Thirty-four individuals with type II diabetes mellitus who have mild nonproliferative diabetic retinopathy (MDR; N = 17) or no diabetic retinopathy (NDR; N = 17) and 15 visually normal, non-diabetic controls participated. Sensitivity was assessed along the horizontal visual field meridian using an Octopus 900 perimeter. Measurements were performed under light- and dark-adapted conditions using long-wavelength (red) and short-wavelength (blue) Goldmann III targets. Cumulative defect curves (CDCs) were constructed to determine whether field sensitivity loss was diffuse or localized.

Results

Sensitivity was reduced significantly under light-adapted conditions for both stimulus colors for the NDR (mean defect ± SEM = -2.1 dB ± 0.6) and MDR (mean defect ± SEM = -4.0 dB ± 0.7) groups. Sensitivity was also reduced under dark-adapted conditions for both stimulus colors for the NDR (mean defect ± SEM = -1.9 dB ± 0.7) and MDR (mean defect ± SEM = -4.5 ± 1.0 dB) groups. For both diabetic groups, field loss tended to be diffuse under light-adapted conditions (up to 6.9 dB loss) and localized under dark-adapted conditions (up to 15.4 dB loss).

Conclusions

Visual field sensitivity losses suggest neural abnormalities in early stage diabetic eye disease and the pattern of the sensitivity losses differed depending on the adaptation conditions. Chromatic perimetry may be useful for subtyping individuals who have mild or no diabetic retinopathy and for better understanding their neural dysfunction.

OCTA and Functional Signs of Preclinical Retinopathy in Type 1 Diabetes Mellitus

BACKGROUND AND OBJECTIVE

There is an emerging role for optical coherence tomography angiography (OCTA) in detecting microvasculature changes in diabetic retinopathy (DR). This study aimed to investigate visual functions and OCTA parameters of retinal and choriocapillaris (CC) flow in patients with type 1 diabetes mellitus (T1DM) without apparent DR.

PATIENTS AND METHODS

Patients and age-matched healthy volunteers were enrolled. All participants underwent low-luminance visual acuity assessment, OCT, and OCTA. Assessed OCTA parameters included foveal avascular zone area, acircularity index, vessel density (VD), skeletonized density, and CC flow deficits.

RESULTS

Low-luminance deficit (LLD) was significantly higher in patients with diabetes mellitus and correlated with skeletonized density and VD in the superficial vascular plexus (SVP). In the T1DM group, vessel density and skeletonized density were reduced in the SVP and deep capillary plexus. Flow deficits density and the mean size of the flow deficits were increased in patients with T1DM.

CONCLUSION

Functional and microvasculature changes were observed at the preclinical stage of DR. Correlation of LLD and OCTA parameters can be a sign of early neurovascular impairment. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:S30-S34.].

Comparison between blue-on-yellow and white-on-white perimetry in patients with branch retinal vein occlusion

This study aimed to compare blue-on-yellow (B/Y) perimetry with white-on-white (W/W) perimetry in eyes with branch retinal vein occlusion (BRVO). The following measurements were performed in 29 eyes of 29 patients with resolved BRVO: W/W and B/Y perimetries using 10-2 test grid, retinal volume (RV) using optical coherence tomography (OCT), and vessel densities (VD) of the superficial capillary layer (VDs) and deep capillary layer (VDd) using OCT angiography (OCTA). First, the difference in the retinal sensitivity (RS) between BRVO-affected and unaffected areas was compared between RS_B/Y and RS_W/W in the parafoveal and extrafoveal areas. Moreover, the structure–function relationship between vessel density and RS was compared between B/Y and W/W perimetries (RS_B/Y and RS_W/W, respectively). The difference in RS between BRVO-affected and unaffected areas was significantly larger with RS_B/Y than with RS_W/W in both the parafoveal and extrafoveal areas. In the parafoveal area, VDs, VDd, and RV were significantly correlated with both RS_W/W and RS_B/Y. In contrast, in the extrafoveal area, only VDd was included in the optimal models. Our findings suggest that RS_B/Y more strongly reflects the anatomical structure and BRVO-affected area.

A critical review: Psychophysical assessments of diabetic retinopathy

Diabetic retinal disease remains a leading cause of vision loss despite currently available screening methods, ocular treatments, and efforts to control metabolic dysfunction. It is now understood that diabetes damages the entire retina and the cellular components of the neurovascular unit. Multiple studies have demonstrated impairment of various aspects of retinal function across the spectrum of retinopathy severity. Here we review these tests, the principles underlying their use, clinical data from multiple publications, the strengths and limitations of the studies, and prospects for their application to understand the pathophysiology of diabetic retinal disease and monitor its response to therapy. We focus on visual acuity, contrast sensitivity, color vision, visual field, and dark adaptation and their use to understand the pathophysiology of diabetic retinopathy and as potential endpoints for clinical trials.

HbA1c and retinal sensitivity in diabetics using microperimetry

PURPOSE

The purpose of this study was to determine the relationship between HbA1c values and retinal sensitivity at central 10° using the MP-1 microperimeter.

METHODS

A prospective study was carried out on 32 healthy subjects (control group) and 60 diabetic patients. The diabetic patients were divided into 2 groups. Group 1 comprised of 30 patients without diabetic retinopathy (DR) and group 2 had 30 patients with mild non-proliferative DR. A full-threshold microperimetry of the central 10° of retina (the macula) was performed on all subjects, utilizing 32 points with the MP-1. The relationship between light sensitivity and HbA1c value was calculated using linear regression analysis.

RESULTS

Total mean sensitivity at 10° for group 1 without DR, group 2 with mild NPDR and control group were 18.67±0.83, 17.98±1.42 and 19.45±0.34 (dB), respectively. There was a significant difference in total mean retinal sensitivity at 10° between the 3 groups (F(2,89)=18.14, p=0.001). A simple linear regression was calculated to predict HbA1c based on retinal sensitivity. A significant regression equation was found (F(1,90)=107.61, p=0.0001, with an R² of 0.545). The linear regression analysis revealed that there was a 0.64dB decline in mean retinal sensitivity within the central 10° diameter with an increase of 1mmHg of HbA1c.

CONCLUSION

Retinal sensitivity at the central 10° of the macula is affected by changes in HbA1c values.

Short wavelength automated perimetry can detect visual field changes in diabetic patients without retinopathy

Purpose:

The purpose of the following study is to compare short wave automated perimetry (SWAP) versus standard automated perimetry (SAP) for early detection of diabetic retinopathy (DR).

Materials and Methods:

A total of 40 diabetic patients, divided into group I without DR (20 patients = 40 eyes) and group II with mild non-proliferative DR (20 patients = 40 eyes) were included. They were tested with central 24-2 threshold test with both shortwave and SAP to compare sensitivity values and local visual field indices in both of them. A total of 20 healthy age and gender matched subjects were assessed as a control group.

Results:

Control group showed no differences between SWAP and SAP regarding mean deviation (MD), corrected pattern standard deviation (CPSD) or short fluctuations (SF). In group I, MD showed significant more deflection in SWAP (−4.44 ± 2.02 dB) compared to SAP (−0.96 ± 1.81 dB) (P =0.000002). However, CPSD and SF were not different between SWAP and SAP. In group II, MD and SF showed significantly different values in SWAP (−5.75 ± 3.11 dB and 2.0 ± 0.95) compared to SAP (−3.91 ± 2.87 dB and 2.86 ± 1.23) (P =0.01 and 0.006 respectively). There are no differences regarding CPSD between SWAP and SAP. The SWAP technique was significantly more sensitive than SAP in patients without retinopathy (p), but no difference exists between the two techniques in patients with non-proliferative DR.

Conclusion:

The SWAP technique has a higher yield and efficacy to pick up abnormal findings in diabetic patients without overt retinopathy rather than patients with clinical retinopathy.

Progression of early retinal dysfunction in diabetes over time: results of a long-term prospective clinical study

We explored signs of retinal dysfunction over time in diabetic subjects before or early in the course of retinopathy. Patients with no, mild, or moderate retinopathy were consecutively recruited and underwent standard automated perimetry, visual acuity measurement, and fundus photography. These examinations and measurements of HbA1c and blood pressure were repeated for up to 5 years from baseline. Visual field improvement/deterioration in diabetic subjects was evaluated using significance limits for change. Progression or regression of retinopathy was defined as a two-step change on the Early Treatment Diabetic Retinopathy Study final severity scale. Seventy-four subjects completed at least 3 years of follow-up, and 22% showed visual field worsening, defined as repeated significant deterioration at ≥10% of the test points, whereas only 1% showed field improvement. Worsening occurred in subjects both with and without vascular lesions. The degree of retinopathy was stable throughout the observation period in 68 of 74 eyes, improved in 4, and worsened in 2. Visual field deterioration was not correlated with a change in retinopathy. By using perimetry with an analysis tailored for monitoring diabetic subjects, we were able to demonstrate progression of retinal dysfunction over time, which may represent early signs of retinal neurodegeneration.

Current trends in the monitoring and treatment of diabetic retinopathy in young adults

The diagnosis and treatment of diabetic retinopathy (DR) in young adults have significantly improved in recent years. Research methods have widened significantly, for example, by introducing spectral optical tomography of the eye. Invasive diagnostics, for example, fluorescein angiography, are done less frequently. The early introduction of an insulin pump to improve the administration of insulin is likely to delay the development of diabetic retinopathy, which is particularly important for young patients with type 1 diabetes mellitus (T1DM). The first years of diabetes occurring during childhood and youth are the most appropriate to introduce proper therapeutic intervention before any irreversible changes in the eyes appear. The treatment of DR includes increased metabolic control, laserotherapy, pharmacological treatment (antiangiogenic and anti-inflammatory treatment, enzymatic vitreolysis, and intravitreal injections), and surgery. This paper summarizes the up-to-date developments in the diagnostics and treatment of DR. In the literature search, authors used online databases, PubMed, and clinitrials.gov and browsed through individual ophthalmology journals, books, and leading pharmaceutical company websites.

Functional and structural change in diabetic eyes. Interim results from an ongoing longitudinal prospective study

PURPOSE

To presents results after 18 months of follow-up of a longitudinal study aiming at exploring the correlation between diabetic retinal vascular lesions and functional change.

METHODS

Patients were consecutively recruited from attendees to the screening program for diabetic retinopathy. Subjects are followed every sixth month for the first 3 years and thereafter annually up to 5 years. Progression of diabetic retinopathy is evaluated using the Early Treatment Diabetic Retinopathy Study (ETDRS) scale and improvement/deterioration in visual fields by predefined significance limits for change.

RESULTS

  Of 81 subjects, with no/mild/moderate diabetic retinopathy included, 76 have passed the 18-month visit. At that time, retinal progression by two steps according to the ETDRS scale had occurred in two subjects. Visual acuity was -0.14 logMAR and had decreased with two letters (0.04 logMAR) (p < 0.001) from baseline. The global visual field index mean deviation was almost unchanged with a negligible improvement of 0.03 dB (p = 0.79). In 21 subjects, repeated significant deterioration was seen in ≥10% of all points tested in the field, while almost no improved points were noted. The two subjects with retinal progression were not among those 21 with indication of perimetric progression.

CONCLUSIONS

This is, to our knowledge, the first longitudinal study evaluating change of visual fields in a representative diabetic cohort with no or mild/moderate retinopathy. In this interim report, we demonstrate deteriorated perimetric sensitivity in subjects already at 18 months of follow-up. The results will have implications for evaluating change in visual function in future clinical trials.

Short-wavelength automated perimetry in type I diabetic patients without retinal involvement: a test modification to decrease test duration

PURPOSE

To compare short-wavelength automated perimetry (SWAP) between type I diabetic patients without clinical posterior segment involvement and nondiabetic control subjects.

METHODS

Forty eyes of diabetic patients without obvious posterior segment involvement and 34 eyes of the nondiabetic control group were included in the study. A complete set of ophthalmic examination was followed by SWAP perimetry in all subjects. Short-wavelength automated perimetry results were compared between the 2 groups. In addition, as a modification to SWAP, the data of the central 16 points were omitted and the resulting data of the remaining 60 points (corrected data) were compared between the 2 groups.

RESULTS

Mean deviation in the diabetic patients (group I) was -6.51 dB and in the control group (group II) -3.0 dB; the difference was statistically significant. Mean corrected sensitivity in group I was 19.79 dB and in group II 22.37 dB. Mean corrected total deviation in group I was -6.67 and in group II -3.22. Both differences were highly statistically significant. The mean corrected pattern deviation in group I was -3.29 and in group II -3.04, which was not a statistically significant difference.

CONCLUSIONS

Short-wave automated perimetry abnormalities precede diabetic retinopathy in type I diabetic patients and omission of central 16 points does not compromise test results in this situation.

Predicting the risk of diabetic retinopathy in type 2 diabetic patients

AIMS

Diabetic retinopathy (DR) is often asymptomatic even in its more advanced stages. Timely and repeated screening for DR avoids a late diagnosis of DR, but the high number of diabetic patients precludes a frequent screening; thus, the need for a method to identify patients at higher risk for DR becomes crucial.

METHODS

A prospective analysis of 5034 type 2 diabetic patients followed from 1996 to 2007 and not affected by retinopathy at the time of the recruitment was performed. Patients were randomly divided (ratio 2:1) into two groups: the train data set and the test set (3327 and 1707 patients, respectively). Factors associated with the occurrence of DR were assessed by the Cox's proportional hazard model.

RESULTS

Duration of diabetes, glycosylated hemoglobin, systolic blood Pressure, male gender, albuminuria and diabetes therapy other than diet were all significantly associated with the occurrence of DR.

CONCLUSIONS

The nomogram could help in ranking the type 2 diabetic patients at higher risk to develop DR and thus with a need for more frequent ophthalmologic checks, without enhancing neither the time nor the costs.

[Functional glaucoma diagnosis]

Achromatic perimetry is the gold standard in glaucoma diagnosis for detecting functional defects from glaucomatous optic neuropathy. Because achromatic perimetry is only able to detect scotomas after loss of up to 30-40% of retinal ganglion cells, early diagnosis using this method is rarely possible. Therefore, a lot of new perimetric procedures have been developed in recent years to detect new scotomas at a very early stage. This review summarizes the theoretical background of retinal ganglion cells in order to better understand the theoretical approaches of new perimetric methods. In addition, the most important commercial perimetric devices currently available are presented.

Test-retest variability for standard automated perimetry and short-wavelength automated perimetry in diabetic patients

PURPOSE

To assess limits for significant improvement or deterioration of visual fields in diabetic patients based on short-term test-retest variability in subjects with different degrees of retinopathy.

METHODS

Fifty patients with diabetic retinopathy ranging from level 10 to 75 [according to the Early Treatment Diabetic Retinopathy Study (ETDRS) severity scale] were tested repeatedly with both standard automated perimetry (SAP) and short-wavelength automated perimetry (SWAP) with short intervals. The association between visual field loss and degree of retinopathy outside fovea was analysed. Test-retest variability of global and local visual field indices and prediction limits for significant change were calculated.

RESULTS

The amount of visual field loss was significantly associated to the degree of retinopathy, with a correlation coefficient of -0.51 for SAP (P = 0.0003) and -0.45 for SWAP (P = 0.002). Global test-retest variability was smaller with SAP than with SWAP (P < 0.0001). For both SAP and SWAP, local test-retest variability was considerably smaller at test points with normal sensitivity than at test points with reduced sensitivity (P < 0.0001). Paracentral test points within 10 degrees of eccentricity had less variability than peripheral points (P < 0.0001), implying that smaller change is required to reach statistically significant improvement or deterioration at initially normal and paracentral points than at depressed points and peripherally located test points.

CONCLUSION

Our results propose that SAP, as well as SWAP, can be useful for monitoring visual function outside fovea in diabetic patients with various degrees of retinopathy. We report a preference for SAP because of less variability generally. Limits for significant improvement or deterioration have been assessed but need future validation in a longitudinal study.

Influence of clinical factors on blue-on-yellow perimetry for diabetic patients without retinopathy: comparison with white-on-white perimetry

PURPOSE

To investigate the influence of clinical factors (duration of diabetes mellitus, fasting blood sugar level, fructosamine concentration, and hemoglobin A1c) on blue-on-yellow (B-on-Y) perimetry compared with white-on-white (W-on-W) perimetry for diabetics without retinopathy.

METHODS

Both B-on-Y perimetry and W-on-W perimetry were performed for 33 diabetics without retinopathy. Thirty-three subjects with healthy eyes served as age-matched controls.

RESULTS

For both diabetic patients and controls, mean deviation (MD) and corrected pattern SD of perimetry showed no difference irrespective of B-on-Y or W-on-W perimetry. For diabetics, MD of B-on-Y perimetry decreased in proportion to the morbid period with diabetes mellitus, with the same being true with deterioration of the clinical factors. Multiple regression analysis disclosed no differences in MD of clinical factors for W-on-W perimetry, despite the duration of diabetes mellitus exerting a significant influence on MD of B-on-Y perimetry.

CONCLUSION

Even at the premorbid stage of diabetic retinopathy, longer duration of diabetes mellitus and longer persistence of poorly controlled diabetes mellitus are associated with an insidious progress of dysfunction in the retinal blue cone system.

Visual fields correlate better than visual acuity to severity of diabetic retinopathy

AIMS/HYPOTHESIS

We compared the outcomes of perimetric and visual acuity tests in patients with diabetic retinopathy.

METHODS

We examined 59 diabetic patients with different degrees of retinopathy using stereo fundus photography in accordance with the Early Treatment of Diabetic Retinopathy Study (ETDRS) and fluorescein angiography. Conventional white-on-white perimetry (WWP) and short wavelength automated perimetry (SWAP) were performed and analysed with reference to normal values. Visual acuity was measured with ETDRS charts.

RESULTS

Regression analysis revealed that visual acuity was significantly associated with increasing severity of retinopathy according to the ETDRS scale when visual acuity was estimated by counting logarithm of minimum angle of resolution (LogMar) scores, but not when visual acuity was measured by the conventional reading of the smallest line that could be seen. Visual acuity decreased by 0.02 LogMar per ETDRS step (p=0.03). The degree of visual field loss was significantly associated with increasing severity of retinopathy according to the ETDRS scale, perimetric sensitivity decreasing by 0.44 dB per ETDRS step (p=0.0001) using WWP, and by 0.40 dB per ETDRS step (p=0.04) with SWAP. The size of the area of the foveal avascular zone and adjacent perifoveal intercapillary areas (PIAs) also affected the central visual field as obtained both by WWP (-2.6 dB/mm2, p=0.03), and by SWAP (-7.9 dB/mm2, p=0.002), but did not affect visual acuity. The regression model fit for peripheral retinopathy according to the ETDRS scale was better using WWP than SWAP or visual acuity, while SWAP testing was superior to both WWP and visual acuity when measuring effects caused by enlarged foveal avascular zones and PIAs.

CONCLUSIONS/INTERPRETATION

Perimetry can provide more useful information than visual acuity on functional loss in diabetic retinopathy, particularly when the perifoveal capillary network is damaged.

Comparison of achromatic and blue-on-yellow perimetry in patients with resolved central serous chorioretinopathy

Central serous chorioretinopathy (CSCR) is a disorder characterized by the serous detachment of the sensory retina in the posterior pole. Although CSCR usually resolves spontaneously, the patients may notice residual visual deficits, despite recovering normal visual acuity. The aim of this study is to compare the blue-on-yellow perimetric parameters with conventional automated perimetric parameters in the detection of visual deficits in patients with resolved CSCR. Eighteen patients who had spontaneous recovered from CSCR were enrolled this study. All subjects were examined twice with each type of perimetry. Wilcoxon test was used for statistical analysis. The achromatic perimetric mean deviation values were significantly higher in patients with CSCR than in the control group, while statistically a significant difference was determined for all of blue-on-yellow perimetric values. In conclusion the loss of central retinal sensitivity remains after resolution of the CSCR even if the visual acuity has recovered to normal. Blue-on-yellow perimetry is more sensitive than achromatic perimetry to reveal this central sensitivity loss.

Evaluation of S-cone sensitivity in reattached macula following macula-off retinal detachment surgery

PURPOSE

To investigate the recovery of short-wavelength sensitivity in patients who had undergone successful reattachment of a rhegmatogenous retinal detachment with macular involvement.

METHODS

Postoperative assessment of the visual acuity and the visual fields by standard achromatic automated perimetry (SAP), and short-wavelength automated perimetry (SWAP, Humphrey visual field analyzer; macula test pattern) was performed on 12 patients after the macula was reattached. The follow-up period was up to 12 months.

RESULTS

The visual acuity and SAP sensitivity recovered rapidly after reattachment, with further moderate improvements up to 6 months after reattachment. The improvements stabilized by 9 to 12 months. The SWAP sensitivities improved more slowly than the visual acuity or SAP sensitivities, but they continued to improve even when visual acuity or SAP sensitivities had stabilized.

CONCLUSION

We conclude that measurement of the sensitivities of the short-wavelength-sensitive cones (S-cones) with SWAP may be a sensitive method to evaluate the visual recovery of the reattached macula following macula-off retinal detachment.

Color vision in epileptic adolescents treated with valproate and carbamazepine

OBJECTIVE

The aims of our study were to evaluate whether deficits in color vision exist in epileptic adolescents, to study if monotherapy with valproic acid (VPA) and carbamazepine (CBZ) can affect color vision, and to determine the possible relationship between abnormal color vision tests and AEDs dosage and their serum concentrations.

PATIENTS

We examined 45 epileptic patients before the beginning of therapy and after 1 year of VPA or CBZ monotherapy and 40 sex- and age-matched healthy controls.

METHODS

Color vision was evaluated with Farnsworth Munsell 100 (FM100) hue test and achromatic and short-wavelength automated perimetry (SWAP).

STATISTICAL ANALYSIS

To evaluate intergroup differences we used ANOVA with Scheffe's post hoc test, when appropriate. Repeated measures ANOVA was used to evaluate the intragroup modifications of total error score (TES) and perimetric threshold during the follow-up. Pearson's correlation test was performed to correlate chromatic sense and perimetric data and AEDs dosage and serum concentrations.

RESULTS

Before the beginning of therapy, there were no differences in central color vision and SWAP between controls and epileptic patients. After 1 year, patients treated with VPA or CBZ showed a deficit in FM100 hue test and SWAP parameters while no significant deficit was found in achromatic perimetry. In particular, with the FM100 hue test a higher number of errors was found in both groups of patients (CBZ patients: 166.00 +/- 27.72 TES; VPA patients: 151.19 +/- 44.09, P < 0.001) in comparison with controls (controls: 109.29 +/- 24.73) and baseline values (CBZ patients: 110.65 +/- 22.9; VPA patients 107.43 +/- 21.70). With SWAP patients of both groups showed significant variation of foveal threshold (controls: 21.07 +/- 2.01 dB; CBZ patients: 19.35 +/- 1.32, P < 0.001; VPA patients: 18.88 +/- 1.89, P < 0.001), full-field mean threshold perimetric sensitivity (controls: 18.50 +/- 1.24 dB; CBZ patients: 16.60 +/- 1.47, P < 0.001; VPA patients: 16.23 +/- 1.55, P < 0.001) and mean threshold perimetric sensitivity of the three evaluated subareas of the visual field (area 1 controls: 21.01 +/- 1.15; CBZ patients: 19.45 +/- 1.74, P = 0.001; VPA patients: 18.25 +/- 1.61, P < 0.001; area 2 controls: 18.40 +/- 1.43; CBZ patients: 16.07 +/- 1.58, P +/- 0.001; VPA patients: 16.13 +/- 1.46, P = 0.001; area 3 controls: 17.20 +/- 1.49; CBZ patients: 14.28 +/- 1.51, P < 0.001; VPA patients: 14.31 +/- 2.90, P = 0.001).

CONCLUSIONS

Our study demonstrates that treatment with VPA or CBZ can affect significantly both central and paracentral color vision after a short treatment period.

Menstrual cycle dependent changes in blue-on-yellow visual field analysis of young diabetic women with severe non-proliferative diabetic retinopathy

PURPOSE

To evaluate menstrual cycle dependent changes on blue-on-yellow visual fields of diabetic women, and to compare the results with those of healthy women.

METHODS

Left eyes of 93 normally menstruating women were included in the study, comprising 45 with type-1 diabetes mellitus and severe non-proliferative diabetic retinopathy and 48 healthy controls. All subjects underwent baseline complete ocular examination and achromatic visual field analysis. Blue-on-yellow visual field tests (short-wavelength automated perimetry) were performed in both follicular (days 7-10 of the cycle) and luteal phases (days 3-6 before the bleeding) of two consecutive menstrual cycles. Visual field analyses were performed using Humphrey Field Analyser II with full threshold, central 30-2 program. Visual fields were divided into four regions: superior temporal, inferior temporal, superior nasal and inferior nasal. Visual field mean sensitivity (MS) was calculated for all regions separately.

RESULTS

The mean ages of diabetic and control subjects were not significantly different (P > 0.05). Mean MS values of the diabetic group were significantly lower than that of the control group (P < 0.05). Control subjects did not demonstrate any menstrual cycle dependent changes in MS values (P > 0.05). However, diabetic women demonstrated a significant decrease in MS values in the luteal phase (P < 0.05). The decrease in MS was most marked in the nasal visual field (P < 0.05).

CONCLUSION

Young diabetic women demonstrated a significant depression in visual field threshold sensitivity in the luteal phase of the menstrual cycle. Nasal visual fields are more prone to have menstrual cycle dependent threshold sensitivity depression. This should be taken into consideration in the clinical assessment of women with advanced diabetes who are at risk of glaucomatous optic neuropathy.

Blue-on-yellow perimetry versus achromatic perimetry in type 1 diabetes patients without retinopathy

In this study, we compared the blue-on-yellow perimetric parameters with conventional automated static threshold perimetric parameters in the detection of psychophysical abnormality in patients with type 1 diabetes mellitus (DM) without diabetic retinopathy. Forty-three patients with type 1 DM without diabetic retinopathy were included this study. Thirty subjects served as age-matched control group. Blue-on yellow perimetry was performed and the results compared to white-on-white perimetry. The values of mean deviation by blue-on-yellow perimetry in the diabetic group were significantly higher than in the control group (P=0.0001). The indices of short fluctuation, pattern standard deviation, corrected pattern standard deviation and foveal sensitivity which all relate to localized depression in sensitivity were similar in both groups. The achromatic perimetric parameters were not different between the groups. We conclude that the short-wavelength-sensitive cones are vulnerable to damage from hyperglycemia and this influence can be detected early by blue-on-yellow perimetry in diabetic patients without retinopathy.

Retinopathy in juvenile diabetes: a 10-year (1990-2000) review

Diabetic retinopathy (DR) is the most frequent complication of diabetes and a leading cause of impaired vision in the Western world. There is general agreement that early diagnosis and treatment of DR can slow its progression and help to prevent blindness. However, as a result of its asymptomatic nature and its etiopathogenesis, which is still unclear due to its multifactorial complexity, DR-related blindness has a growing social impact in industrialized countries. Therefore, in order to gain a better understanding of this serious disease, the author performed an updated 10-year review of risk factors and management of DR in type 1 diabetes.

Short-wavelength automated perimetry: it's role in the clinic and for understanding ganglion cell function

Short-wavelength automated perimetry (SWAP) is a more sensitive test than standard achromatic perimetry for early loss of vision due to glaucoma and other ocular and neurological diseases. SWAP is also more successful for detecting changes in vision as glaucoma progresses. Results from various visual function-specific tests, including SWAP, suggest that there are individual differences in ocular hypertensive and glaucoma eyes in the subtype of ganglion cell first affected. However, the disease targets the same retinal area for all function-specific tests that show a deficit in a given individual. Psychophysical tests of vision are critical to understand glaucoma's effect on retinal ganglion cells, to verify the success or failure of treatment including new neuroprotective agents, and to determine the relationship of genetic markers for glaucoma to the presence and progress of the disease.