Carotid artery intima-media thickness, HDL cholesterol levels, and gender associated with poor visual acuity in patients with branch retinal artery occlusion

PURPOSE

To investigate factors associated with poor visual acuity (VA) in branch retinal artery occlusion (BRAO).

METHODS

This was a retrospective cross-sectional study of 72 eyes with BRAO of 72 patients. For statistical comparison, we divided the patients into worse-VA (decimal VA < 0.5) and better-VA (decimal VA > = 0.5) groups. We examined the association of clinical findings, including blood biochemical test data and carotid artery ultrasound parameters, with poor VA.

RESULTS

Median age, hematocrit, hemoglobin and high-density lipoprotein (HDL) differed significantly between the groups (P = 0.018, P < 0.01, P < 0.01, and P = 0.025). There was a tendency towards higher median IMT-Bmax in the worse-VA group (worse-VA vs. better-VA: 2.70 mm vs. 1.60 mm, P = 0.152). Spearman's rank correlation test revealed that logMAR VA was significantly correlated to IMT-Bmax (rs = 0.31, P < 0.01) and IMT-Cmax (rs = 0.24, P = 0.035). Furthermore, logMAR VA was significantly correlated to HDL level (rs = -0.33, P < 0.01). Multivariate logistic regression analysis revealed that IMT-Bmax (odds ratio [OR] = 2.70, P = 0.049), HDL level (OR = 0.91, P = 0.032), and female gender (OR = 15.63, P = 0.032) were independently associated with worse VA in BRAO.

CONCLUSIONS

We found that increased IMT-Bmax, decreased HDL, and female sex were associated with poor VA in BRAO patients. Our findings might suggest novel risk factors for visual dysfunction in BRAO and may provide new insights into the pathomechanisms underlying BRAO.

Chemoprevention of Breast Cancer with Fenretinide (4-HPR): Study of Long-Term Visual and Ophthalmologic Tolerability

Background

Fenretinide (4-HPR) is a synthetic retinoid being clinically tested in the chemoprevention of different tumors and precancerous lesions. Though safer than many other retinoids in experimental models, in humans 4-HPR may induce adverse effects that mainly affect the eye and visual function. Such effects are thought to be caused by the reduction of plasma retinol levels, which occurs after administration of the retinoid.

Methods

A series of 826 women treated with 4-HPR was studied to quantify the incidence and temporal pattern of occurrence of visual (dark adaptation) and ophthalmologic complaints (ocular dryness, lacrimation, conjunctivitis or photophobia) and to investigate the possible association between their occurrence and plasma retinol levels.

Results

The cumulative incidence of visual complaints reached nearly 20% at 5 years. The occurrence of these symptoms was more frequent at the start of treatment. The probability of developing visual complaints was significantly higher in patients with lower plasma retinol concentrations following 4-HPR treatment. The cumulative incidence of ophthalmologic complaints was 8% at 5 years. The occurrence of these complaints was evenly distributed during treatment. Ophthalmologic complaints were not associated with a greater degree of reduction of plasma retinol concentrations, but rather with the patient's age, since symptomatic patients were generally older than asymptomatic patients.

Conclusions

Visual and ophthalmologic complaints are common during 4-HPR treatment: their estimated 5-year cumulative incidence is close to 20% and 8%, respectively. However, the pattern of occurrence over time and the underlying mechanisms of these two types of complaints seem different.

Risk factors of diabetic retinopathy and sight-threatening diabetic retinopathy: a cross-sectional study of 13 473 patients with type 2 diabetes mellitus in mainland China

OBJECTIVE

To explore the risk factors of diabetic retinopathy (DR) and sight-threatening diabetic retinopathy (STDR) among Chinese patients with diabetes.

DESIGN, SETTING AND PARTICIPANTS

A cross-sectional investigation was performed in eight screening clinics in six provinces across mainland China. Information about the risk factors was recorded in screening clinics. Some risk factors (sex, age, diagnosis age, diabetes duration, systolic blood pressure (SBP), diastolic blood pressure, fasting blood glucose (FBG) and glycosylated haemoglobin (HbA1c)) were recorded in all eight clinics, while others were collected only in a subset of the clinics. The relationships between the risk factors and DR and between the risk factors and STDR were explored for the eight factors mentioned above and for all factors studied.

MAIN OUTCOMES AND MEASURES

Risk factors of DR and STDR were assessed, and a nomogram of the results was produced.

RESULTS

Younger age, longer diabetes duration, higher SBP, higher FBG and higher HbA1c were found to be independent risk factors for both DR and STDR in the eight-factor analyses. In the all-factor analysis, younger age, longer diabetes duration, higher SBP, oral medicine use and insulin use were independent risk factors for both DR and STDR; higher postprandial blood glucose (PBG), HbA1c, triglyceride andlow-density lipoprotein were independent risk factors for DR only, and higher FBG was a risk factor for STDR only.

CONCLUSIONS

In this cross-sectional investigation, several risk factors were found for DR and STDR. Notably, FBG, PBG and HbA1c were all risk factors for DR or STDR, suggesting that stricter blood glucose control in clinical practice is required.

Oximetry in glaucoma: correlation of metabolic change with structural and functional damage

PURPOSE

To determine whether retinal vessel oxygen saturation in patients with glaucoma is associated with structural optic disc and retinal nerve fibre layer (RNFL) changes and visual field (VF) defects.

METHODS

Fifty-nine patients with confirmed glaucoma were recruited at University Hospitals Leuven. Retinal oxygen saturation in patients with glaucoma was measured with a noninvasive spectrophotometric retinal oximeter (Oxymap ehf, Reykjavik, Iceland). VF and Heidelberg retinal tomographies (HRTs) were performed on the same day. Statistical analysis was performed using Student's t-test and Pearson's or Spearman correlation coefficient.

RESULTS

The mean oxygen saturation in venules was higher in patients with severe VF defects compared to those patients with mild VF defects (69 ± 3% versus 65 ± 6% respectively; p = 0.0003; n = 59). Accordingly, the arteriovenous (AV) difference in oxygen saturation was lower in patients with worse VF compared to those with better VF (29 ± 3% versus 33 ± 6% respectively; p = 0.002). The oxygen saturation in venules correlated with the VF mean defects (r = -0.42; p = 0.001; n = 59) as well as with the structural HRT parameters rim area and RNFL thickness (r = -0.39; p = 0.008 and r = -0.26; p = 0.05 respectively; n = 53). The AV difference decreased significantly as the VF defect worsened (r = 0.38; p = 0.003), as the rim area diminished (r = 0.29; p = 0.03) and as the RNFL thickness decreased (r = 0.27; p = 0.05). No correlation was found between the oxygen saturation in retinal arterioles and either of these parameters.

CONCLUSION

Severe glaucomatous damage is associated with increased oxygen saturation in retinal venules and decreased AV difference in oxygen saturation. These data suggest that in eyes with severe glaucomatous damage, reduced retinal oxygen consumption is consistent with tissue loss.

Biological risk of older adults with visual impairments

OBJECTIVES

To investigate whether biological markers of health differ among older adults with visual impairment compared to those with normal vision.

DESIGN

We use data from the National Health and Nutrition Examination Survey (1999 - 2006) to investigate clinically defined at-risk levels for 10 biological markers.

SETTING

Survey participants were non-institutionalized.

PARTICIPANTS

Nationally representative (U.S.) sample of older adults age 65 and older, categorized as having blindness (20/200 or worse), low vision (20/40 to 20/100) or normal vision (better than 20/40).

INTERVENTION

Separate binary logistic regressions (one for each biomarker, with two at-risk cut points for BMI: obese and underweight) were computed to determine the odds of having at-risk levels of each biomarker.

MEASUREMENTS

Biomarkers included: systolic and diastolic blood pressure, high-density lipoprotein, low-density lipoprotein (LDL) cholesterol, total cholesterol, glycated hemoglobin, body mass index (BMI), fasting triglycerides, C-reactive protein, and plasma homocysteine.

RESULTS

Older adults who were blind were more likely to have high-risk levels of LDL cholesterol, homocysteine, and to be underweight (BMI>18.5). Similarly, older adults with LV were more likely to have high-risk levels of homocysteine compared to older adults with normal vision.

CONCLUSION

As several of the high-risk biomarkers associated with visual impairment were diet-related, our results suggest the importance of nutrition and diet programs aimed towards educating older people who are visually impaired.

Reversal of vision metamorphopsia caused by pons and cerebellum infarction

Metamorphopsia is a visual illusion related to the perception of an object's shape, size, colour or angle. Reversal of vision metamorphopsia is a rare, transient form of metamorphopsia described as an inversion of the field of vision, usually a 180-degree reversion within the frontal plane. We describe the case of a 64-year-old male patient who first experienced a 90-degree rotation of the field of vision and then had the impression of his body rotating in space. The symptoms were preceded by disequilibrium, astigmatism and vomiting. Magnetic resonance imaging of the head showed focuses of vasogenic lesions in the pons and left cerebellar hemisphere. Magnetic resonance angiography of cerebral vessels did not reveal the left vertebral artery. This is the first described case of reversal of vision metamorphopsia with 90-degree rotation of the field of vision with accompanying disorder of the spatial position of the body.

[Influence of chronic exposure to heavy metals on eyesight]

PURPOSE

The aim of the study was to investigate relationship between chronic occupational exposure to heavy metals and eyesight, with particular lead influence.

MATERIAL AND METHODS

The experimental group was composed of 120 workers of Copper Steelwork Plant "Legnica", divided into 2 groups, based on the degree and period of exposure to heavy metals. 75 men hired in direct production with work residency of 7 to 34 years (mean 21.2) made the experimental Group A--the occupationally exposed group. Group B with 45 white-collar men with work residency of 4 to 39 years (mean 19.8) made the environmentally exposed group. All workers underwent complex ophthalmic examination with particular lens investigation following pupil dilation, lead and cadmium level in full blood determination and free erythrocyte protoporphyrin (FEP) test, as indicator of human body lead overload.

RESULTS

Mean lead levels in both groups were considerably higher than permissible concentration in biological material (PCB) for occupationally exposed workers, and was higher for those working directly in production. Free erythrocyte protoporphyrin (FEP) level was correct in both groups. Lenticular changes were noticed in 26 (21.7%) patients, of whom 18 (69.2%) were hired in direct production. Similarly, fundus changes were shown in 17 patients, 16 (22%) from Group A; changes in field of vision in 3 patients. Furthermore, 15 men working in direct production complained of burning sensation, tearing and periodic redness in the eyes.

CONCLUSIONS

Mean blood cadmium and lead levels, higher in occupationally exposed workers was statistically important only in case of lead. However, the correct FEP level indicates that an organism was not overload with lead. In these workers (group A) lenticular changes were observed more often and were more intense (cortex opacitates, posterior subcapsular cataract). Fundus changes noticed in both groups were of low degree and coexisting diseases may have promoted their progression. Field of vision changes noticed in 3 workers may have been caused by lead toxicity to optic nerve. Periodical conjuctival inflammatory states are caused by irritative dust and smoke therefore protective eye wear is indicated.

Induction of hyperglycaemia in zebrafish (Danio rerio) leads to morphological changes in the retina

Diabetes affects over 16 million Americans yearly, resulting in hyperglycaemia and microvascular complications, including retinopathy, neuropathy and nephropathy. Animal models have been developed to examine the immunological aspects of type 1 diabetes and the pathogenic mechanisms associated with diabetic retinopathy, but the methods of diabetes induction raise concerns regarding these models. Zebrafish (Danio rerio) have been used extensively to study developmental processes and mutant zebrafish strains have been used to examine vision disease present in humans. In this paper, we have induced hyperglycaemia in zebrafish by alternately immersing the fish in glucose solution or water. Eyes from untreated fish or fish exposed to alternating glucose/water solutions for 28 days were dissected, sectioned and stained to visualise cell bodies in the retina. In untreated fish retinas, the inner plexiform layer (IPL) and inner nuclear layer (INL) were approximately the same thickness, whereas in fish repeatedly exposed to glucose solutions the IPL was approximately 55% the thickness of the INL. Both the IPL and INL were significantly reduced in retinas of treated fish, compared to untreated fish, similar to that seen in other animal models of diabetes and in diabetic patients. These results suggest that zebrafish may be used as an animal model in which to study diabetic retinopathy.

Intravascular oxygen saturation in retinal vessels in normal subjects and open-angle glaucoma subjects

PURPOSE

To measure the oxygen saturation (SO(2)) in retinal arterioles and venules in patients with glaucomatous optic neuropathy.

METHODS

We examined SO(2) in retinal arterioles and venules simultaneously by imaging spectrometry. Oxygen saturation was evaluated according to the difference of the extinction spectra of haemoglobin and oxyhaemoglobin. The arterio-venous difference (avD) was calculated by (SO(2art) - SO(2ven)). The optic nerve head topography was estimated by Heidelberg retinal tomography and the visual field using the Octopus G1. We examined one eye in each of 58 healthy persons (mean age 58.6 +/- 10.7 years; mean rim area 1.52 +/- 0.33 mm(2); mean defect 0.65 +/- 1.31 dB; mean intraocular pressure [IOP] 18.5 +/- 2.7 mmHg), 49 patients with normal-tension primary open-angle glaucoma (NTG) (mean age 63.0 +/- 8.5 years; mean rim area 0.89 +/- 0.34 mm(2); mean defect 5.4 +/- 4.1 dB; mean IOP 19.2 +/- 2.9 mmHg), and 45 patients with high-tension primary open-angle glaucoma (POAG) (mean age 62.6 +/- 10.3 years; mean rim area 0.97 +/- 0.47 mm(2); mean defect 7.1 +/- 6.4 dB; mean IOP 31.6 +/- 10.8 mmHg).

RESULTS

The intraclass correlation coefficients of the SO(2) measurement were 0.82 (arteriole) and 0.59 (venule). In normal eyes, the SO(2art), SO(2ven) and avD were 92.3 +/- 3.4%, 55.7 +/- 6.8% and 36.6 +/- 7.0%, respectively. Equivalent data were 89.7 +/- 5.4%, 56.0 +/- 8.3% and 33.7 +/- 10.6%, respectively, in NTG eyes and 91.4 +/- 4.0%, 58.3 +/- 10.5% and 33.1 +/- 11.5%, respectively, in POAG eyes. Over all examined eyes, the arteriolar SO(2) and the retinal arterio-venous difference correlated significantly with the rim area.

CONCLUSION

Eyes with NTG showed significantly decreased arteriolar SO(2). These changes were not seen in POAG patients.

Adrenocortical insufficiency after pituitary surgery: an audit of the reliability of the conventional short synacthen test

BACKGROUND

Assessment of the hypothalamic-pituitary-adrenal (HPA) axis after pituitary surgery is important for appropriate decision making regarding replacement therapy. The synacthen test is often used but is questioned, as time has to elapse for adrenal atrophy to develop.

OBJECTIVE

To audit the use of the 250 microg synacthen test after transsphenoidal adenomectomy.

METHODS

A retrospective study of 110 patients submitted to first-time transsphenoidal adenomectomy. Anterior pituitary testing was performed preoperatively, 1 week and 1, 3, 6 and 12 months postoperatively. The adrenocortical function was tested by a synacthen test (250 microg synacthen i.v.).

RESULTS

Thirty-two out of 71 patients with normal HPA function before surgery developed insufficiency postoperatively, seven patients presenting an insufficient test response after 1 week, 16 after 1 month and nine after 3 months, whereas none became insufficient during the remaining follow-up. Three patients presented symptomatic adrenal insufficiency during the first postoperative week despite a normal test. All of these developed an insufficient test 1 month postoperatively. A 1-week basal plasma cortisol > 400 nmol/l indicated HPA sufficiency, whereas a basal cortisol < or = 100 nmol/l indicated insufficiency when related to the diagnosis based on the 3-month synacthen test.

CONCLUSION

This study confirms that the synacthen test is of limited use in the early postoperative phase, because out of 62 patients with normal 1-week postoperative synacthen responses, 23 patients developed a test that was indicative of adrenal insufficiency over 1-3 months. Our results indicate that a large proportion of patients should be considered for hydrocortisone replacement therapy up to 3 months postoperatively followed by reassessment of the HPA axis.

[Baclofen-intoxication in a child resulting in coma, bradycardia and transitory defect of visual power]

A twelve and a half year old girl of foreign nationality was been found in her domestic environment in unwakeable condition. The emergency was alarmed, and she was transferred to the children's hospital. Her condition at this time: she was unconscious and suffering from cold sweat but her circulation was stable and her respiration sufficient. Because of language barriers it was difficult to find out the antecedence of her state, but an empty box of pills (Amitryptilin) lying next to the patient may serve as a first hint to a intoxication. The father denied that his daughter might have consumed drugs or alcohol and meant that any abuse of medicine was out of the question. First urinary measurements to check if any drugs might be involved remain inconspicuous; in a control measurement of the blood 12 hours later only an elevation of the CPK is noticed as an unusual detail. The CPK-MB remains being according to normal. The native CT of the skull remains inconspicuous as well as the control with contrastation after 12 hours and a MRT-examination after 36 hours. The liquor punction does not give hints to any pathological facts. The EEG shows a high degree of continuous irregular slowe waves over both hemispheres in the delta and theta activity range. This gives reason to assume an encephalitis. The result of an electrocardiogram reveals a sinus bradycardia. The therapy was symptomatically, virustatically with aciclovir, antibiotically with cefotaxim and prophylactically against edema of brain with dexamethason. After 24 hours the patient abruptly awakes from coma and after 36 hours the reason for the coma can be stated: The toxicological examinations of the blood lead to the result: Intoxication with Baclofen. Explantation for the origin of the tablets: The family lives together with an aunt, who, after a cerebrovascular accident, was treated with Baclofen, Amitryptilin and ASA.

Use of an arginine-restricted diet to slow progression of visual loss in patients with gyrate atrophy

OBJECTIVE

To quantify the effect of long-term reduction of plasma ornithine levels through adherence to an arginine-restricted diet on visual function in patients of all ages with gyrate atrophy of the retina and choroid.

METHODS

A long-term observational study was conducted on 27 patients with gyrate atrophy, 17 of whom elected to comply with the arginine-restricted diet and 10 who were unable to comply. The mean rates of change in the electroretinogram combined response, electroretinogram flicker response, and kinetic and static perimetry were determined.

RESULTS

After mean follow-up of 13.9 years for the patients on the diet and 14.1 years for those not on the diet, the mean rates of change for the diet group compared with those of the no-diet group were statistically significantly slower for all outcome measures (age-adjusted P<.05) except for static perimetry (P =.06).

CONCLUSIONS

Adhering to an arginine-restricted diet so as to lower the plasma ornithine level below an average of 5.29 to 6.61 mg/dL (400-500 micromol/L) will slow the loss of function as measured by sequential electroretinography and visual field examinations.

The prevalence of retinopathy in an unselected population of type 2 diabetes patients from Arhus County, Denmark

PURPOSE

To determine the prevalence of diabetic retinopathy and the causes of visual impairment in an unselected population of type 2 diabetes patients, and to describe the risk factors for developing diabetic retinopathy in this population.

METHODS

A total of 10 851 type 2 diabetes patients were identified in the county of Arhus. A representative sample of 378 patients underwent a routine ocular examination, including fundus photography. Blood pressure and serum haemoglobin A1c, total cholesterol, high density lipoprotein cholesterol, triglyceride and apolipoprotein a were measured.

RESULTS

The prevalence of diabetic retinopathy in the type 2 diabetes population was 31.5%. In all, 2.9% had proliferative diabetic retinopathy and 5.3% had clinically significant macular oedema. Of the latter, 8/20 (40%) were newly identified and had not yet been laser-treated. There was a positive correlation between severity of retinopathy and duration of diabetes, HbA(1c), systolic blood pressure and treatment with insulin. None of the patients had social blindness (visual acuity < 0.1), but 15/378 (4.0%) had developed visual impairment (VA < 0.3).

CONCLUSION

The prevalence of diabetic retinopathy and visual impairment in this unselected type 2 diabetes population was lower than anticipated from the existing literature, and causes other than diabetic retinopathy contributed significantly to the occurrence of visual loss. A substantial number of the patients with vision-threatening diabetic maculopathy had not been referred for timely photocoagulation treatment.

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.

[The endothelin-1 level in blood serum of patients with primary open angle glaucoma abd its influence on the static perimetry abd Gdx changes]

PURPOSE

The aim of the work was to define the relationships between the endothelin-1 level in blood serum of glaucoma patients concerning the visual field defects and the number of nerve fibers.

MATERIAL AND METHODS

24 women and 14 men, aged 38-74 year (mean 53.4 year) with primary open angle glaucoma, without any systemic diseases. The control group consisted of 20 healthy women and men, aged 34-70 year (mean 52.6 year). The endothelin-1 level was tested with the enzymo-immunologic method from the blood serum. The visual field defects were examined with the Humphrey static perimetry. The nerve fibers were analyzed with the Gdx apparatus.

RESULTS

Mean value of ET-1 in blood serum were similar in both examined groups, it was 0.51 in group of glaucoma patients and 0.54(fmol/l) in the control group. There were no significant correlations between ET-1 level, static perimetry, GDx parameters and age in the group of patients with POAG. The statistics significances were stated for ET-1 level and MD-parameter in static perimetry (p < 0.03) and ET-1 level with The Number--the GDx parameter (p < 0.03).

CONCLUSION

There was no significant level of ET-1 in blood serum in group of patients with POAG. There have not been stated any relationships between the static perimetry and GDx changes in patients with POAG to endothelin-1 level in blood serum. It is the preliminary communication.

Optic neuropathy from folic acid deficiency without alcohol abuse

A 47-year-old woman with a 2-month history of bilateral progressive visual loss was found to have a bilateral retrobulbar optic neuropathy. Her serum vitamin B(12) concentration and hemoglobin level were normal, but her serum folic acid concentration was decreased. The patient had a minimal alcohol intake and moderate tobacco use that had been unchanged for over 20 years; however, she had markedly altered her diet 4 years earlier in the setting of clinical depression. After treatment with oral folic acid and diet modification without change in her tobacco or alcohol use, the patient's visual function returned to normal. This case supports the role of folic acid deficiency as an important cause of some cases of nutritional optic neuropathy.

Nutritional factors and visual function in premature infants

Approximately 5-7% of all infants are born prematurely, and birth before 37 weeks is the most common cause of neonatal mortality, morbidity and long-term disability. Premature infants are poorly equipped for life outside the womb, and oxidant stress has been implicated in the aetiology of visual impairment in these infants, who are often exposed to increased O2 concentrations and high light intensity in neonatal units. The carotenoids lutein and zeaxanthin, which give the macular area of the eye its yellow colour, are located in the retinal pigment epithelium of the eye, and are believed to play a role in protecting it against oxidative and light damage. The macular pigments are of dietary origin, and green leafy vegetables are the primary source of lutein and zeaxanthin. Lutein is one of the five most common carotenoids found in the diet. There is current interest in the macular pigment in relation to age-related macular degeneration, but these pigments may also have a protective role in the retinal pigment epithelium of the newborn infant. Little information is available on blood lutein and zeaxanthin levels in neonates. Levels of lutein in human milk are two to three times higher than those of beta-carotene, whereas their concentrations in the mothers' blood are approximately the same. Human milk is the main dietary source of lutein and zeaxanthin for infants until weaning occurs. The biochemical mechanisms which mediate the transport of the macular carotenoids into the eye are not known, but tubulin has been identified as the major carotenoid-binding protein, and may play a role in the physiology of the macula.

Goldmann perimetry in acromegaly: a survey of 307 cases from 1951 through 1996

OBJECTIVE

Because visual pathway lesions are a common complication of pituitary tumors, visual field examinations in patients with acromegaly were studied. Proportion and outcome of visual field defects in patients with acromegaly were evaluated.

DESIGN

Large, retrospective case series.

PARTICIPANTS

We reviewed 307 cases of acromegaly seen from 1951 through 1996 at a single referral center.

METHODS

Kinetic visual field testing had been performed with the Goldmann perimeter, and the frequency of visual field defects and their correlation with other clinical manifestations and characteristics of the adenoma were examined.

MAIN OUTCOME MEASURES

Repeat visual field examinations.

RESULTS

Of the 307 patients included in the analysis, a visual field defect that could be attributed to the pituitary adenoma was observed in 62 (20.2%) during follow-up. Visual field defects were bilateral in 38 (61.3%) of these cases. Patients with visual field abnormalities were significantly younger (P = 0.04), had larger tumors (P < 0.001), had more suprasellar extensions (P < 0.001), and had higher levels of growth hormone in their serum (P = 0.04) than patients free of visual field defects. At the end of the follow-up period, visual field examination remained abnormal in 32 (10.4%). Return to a normal visual field examination after treatment was more frequently observed in patients who were less than 40 years of age at the time of diagnosis (P = 0.004). Secondary empty sella syndrome was the main cause of visual field defects after treatment. Abnormal visual field, either at the time of diagnosis or during follow-up, decreased from 27% of patients between 1951 and 1975 to 15.4% of patients between 1976 and 1996, when modern neuroimaging techniques became available.

CONCLUSIONS

Endocrinologic and neuroimaging follow-up of patients with acromegaly should be accompanied by ophthalmic assessment. Factors predictive of visual field defects have been identified.

Blood lead levels and vision

Childhood exposure to lead remains a considerable public health concern. Exposure to lead can cause deficits in the visual system and visual perceptual skills. Optometrists should perform a simple personal-risk screening questionnaire when children manifest visual perceptual symptoms or difficulty in school. In addition, optometrists should be able to act as an information resource for parents with children at risk for elevated BLLs.

Hypovitaminosis A in metropolitan Adelaide

Hypovitaminosis A is a well-recognized condition in many developing countries. However, in the developed world the diagnosis is frequently missed or delayed because of its rarity. A 67-year-old man from metropolitan Adelaide presented to us with gradual but severe bilateral visual loss. He had marked punctate epithelial keratopathy in both eyes. Hypovitaminosis was suspected because of his bizarre dietary habit, and this was confirmed by a combination of impression cytology of the ocular surface and biochemical testing of his venous blood. His vision responded dramatically to vitamin A supplementation. Hypovitaminosis A should be suspected in severe cases of 'dry-eye', especially in those patients with unusual dietary habit or malabsorption.

Hyperhomocysteinemia: a new risk factor for central retinal vein occlusion

PURPOSE

Previous studies have documented that an elevated plasma homocysteine level is a risk factor for vascular disease. The purpose of this study is to determine whether hyperhomocysteinemia is a risk factor for central retinal vein occlusion.

METHODS

This case-controlled study involved reassessment of 74 patients with documented central retinal vein occlusion. Control subjects consisted of individuals referred to the same clinic for assessment of a nonretinal vascular disease. Hyperhomocysteinemia was defined as a total plasma homocysteine level above the 95th percentile in the control group.

RESULTS

The mean total plasma homocysteine level was 11.58 mumol/L for cases and 9.49 mumol/L for controls. Of the 74 patients with a central retinal vein occlusion, 21.6% had total plasma homocysteine levels above the 95th percentile in the control group (odds ratio, 6.53; 95% confidence interval, 1.81 to 23.50, P = .003). Hyperhomocysteinemia was present in 55% of cases with bilateral disease, 30% of ischemic cases, and 31% of cases with severe visual loss.

CONCLUSION

Hyperhomocysteinemia is a risk factor for central retinal vein occlusion.

Cyclosporine therapy for severe sight-threatening uveitis in children and adolescents

OBJECTIVE

To review the safety and efficacy of cyclosporine in the treatment of children with severe bilateral sight-threatening intermediate uveitis or panuveitis.

DESIGN/PARTICIPANTS

A retrospective chart review was performed on all children younger than 18 years of age with chronic bilateral sight-threatening uveitis who were treated with cyclosporine.

MAIN OUTCOME MEASURES

Assessment of the therapeutic efficacy and development of adverse effects of cyclosporine after 6 months, 2 years, and 4 years of therapy was performed.

RESULTS

Between 1983 and 1992, 15 children and adolescents were treated with cyclosporine. After 6 months, visual acuity improved or stabilized in 82.1% of eyes, while median vitreous inflammation decreased from 2.0 to 0.5. After 2 and 4 years, visual acuity improved or stabilized in 64% and 75% of eyes, respectively. Median vitreous inflammation remained 0.5 after 2 and 4 years of therapy. Mean creatinine clearance and hemoglobin values decreased and serum creatinine increased after 6 months. After 2 years, only mean hemoglobin values remained decreased. After 4 years, no significant differences were noted in any of the laboratory studies. The most frequently noted side effects included transient increases in serum creatinine in 53%, gingival hyperplasia in 40%, and hirsutism in 20% of patients.

CONCLUSIONS

The authors' results suggest that cyclosporine is a safe and effective therapy for the treatment of children with severe bilateral sight-threatening intermediate uveitis or panuveitis.

Digoxin visual toxicity with therapeutic blood levels of digoxin

PURPOSE

To report two cases of digoxin-related visual disturbances associated with therapeutic blood levels of digoxin.

METHODS

Case reports. One patient reported shimmering lights in the field of vision of both eyes; the second patient had a corrected visual acuity of BE, 20/40 and generalized visual field depression in both eyes. Both patients experienced these symptoms while receiving digoxin.

RESULTS

Both patients had digoxin blood levels in the therapeutic range (1.7 and 1.0 ng/ml, respectively). Therapeutic levels are 0.5 to 2.0 ng/ml. After discontinuing digoxin, the first patient noted that the shimmering light symptoms resolved, and the second patient had improved visual acuity and visual fields.

CONCLUSIONS

Digoxin-related visual toxicity may be associated with therapeutic blood levels of digoxin. Recognition of this entity may avoid unnecessary testing and frustration.

Risk factors for high-risk proliferative diabetic retinopathy and severe visual loss: Early Treatment Diabetic Retinopathy Study Report #18

PURPOSE

To identify risk factors for the development of high-risk proliferative diabetic retinopathy (PDR) and for the development of severe visual loss or vitrectomy (SVLV) in eyes assigned to deferral of photocoagulation in the Early Treatment Diabetic Retinopathy Study (ETDRS).

METHODS

Multivariable Cox models were constructed to evaluate the strength and statistical significance of baseline risk factors for development of high-risk PDR and of SVLV.

RESULTS

The baseline characteristics identified as risk factors for high-risk PDR were increased severity of retinopathy, decreased visual acuity (or increased extent of macular edema), higher glycosylated hemoglobin, history of diabetic neuropathy, lower hematocrit, elevated triglycerides, lower serum albumin, and persons with mild to moderate nonproliferative retinopathy, younger age (or type 1 diabetes). The predominant risk factor for development of SVLV was the prior development of high-risk PDR. The only other clearly significant factor was decreased visual acuity at baseline. In the eyes that developed SVLV before high-risk proliferative retinopathy was observed, baseline risk factors were decreased visual acuity (or increased extent of macular edema), older age (or type 2 diabetes), and female gender.

CONCLUSIONS

These analyses supported the view that the retinopathy-inhibiting effect of better glycemic control extends across all ages, both diabetes types, and all stages of retinopathy up to and including the severe nonproliferative and early proliferative stages and the possibility that reducing elevated blood lipids and treating anemia slow the progression of retinopathy.

Retinopathy and vision loss in insulin-dependent diabetes in Europe. The EURODIAB IDDM Complications Study

PURPOSE

To assess the frequency of retinopathy and vision loss in patients with insulin-dependent diabetes mellitus and their relations to potentially modifiable risk factors.

METHODS

The authors conducted a multicenter cross-sectional study of diabetic complications and their risk factors using standardized methods of assessment. The sample was comprised of 3250 insulin-dependent diabetic patients (1668 men, 1582 women) aged 15 to 60 years with mean (standard deviation) duration of diabetes of 14.7 (9.3) years from 31 European diabetes centers; 2991 of the patients were eligible for retinal photography. Visual acuity was measured using the Snellen chart. Retinopathy was evaluated by retinal photographs (two fields per eye) graded at a central facility. Glycated hemoglobin (HbA1c), cholesterol, triglyceride, fibrinogen, von Willebrand factor, and urinary albumin excretion rate were assessed at a single location.

RESULTS

Corrected visual acuity was greater than or equal to 1.0 in both eyes in 69.7% of patients and less than or equal to 0.1 in the best eye in 2.3%. Factors significantly related to vision loss were age, duration of diabetes, glycated hemoglobin (HbA1c), and level of retinopathy. Mild nonproliferative retinopathy was found in 25.8% of the patients, moderate-severe nonproliferative retinopathy in 9.8% of the patients, and proliferative retinopathy in 10.6% of the patients. After adjustment for age, duration of diabetes, HbA1c, and albumin excretion rate, significant risk factors for moderate-severe nonproliferative retinopathy were blood pressure and triglyceride, and risk factors for proliferative retinopathy were triglyceride and fibrinogen.

CONCLUSION

Vision loss is a common complication of patients with insulin-dependent diabetes, with diabetic retinopathy an important cause. Apart from poor glycemic control, several other potentially modifiable risk factors for retinopathy may be important, including elevated blood pressure, plasma triglyceride, and fibrinogen. In view of the possible barriers to the full implementation of strict glycemic control in this type of diabetes, additional strategies for the prevention and slowing of progression of retinopathy should be investigated, such as blood pressure and lipid lowering therapies.

Transurethral resection of the prostate, serum glycine levels, and ocular evoked potentials

Complications of transurethral resection of the prostate (TURP syndrome) when glycine is used as the irrigating fluid include cardiovascular and central nervous system abnormalities that occasionally include transient blindness. Serum sodium, glycine, potassium, chloride, ammonia, osmolality, carbonate, and blood urea nitrogen of 17 patients having TURP and 10 having cystoscopic examination were measured. Electroretinograms and visually evoked potentials (VEPs) were recorded in the preanesthetic preparatory area and in the recovery room immediately after surgery. Four patients reported visual aberrations coincident with increases in serum levels of glycine from a mean before surgery of 137.7 +/- 45.1 to 7,812.2 +/- 2,486.6 microM/l, mean +/- SD, after TURP. These patients also showed a reduction of serum sodium from 138 +/- 4.5 to 122 +/- 8.6 mEq/l that correlated significantly with serum levels of glycine (rho = -0.81). There were no statistically significant changes of serum ammonia and osmolality. Electroretinograms consistently demonstrated complete loss of oscillatory potentials. Thirty hertz flicker-following was also abolished. VEPs were more variably affected with prolongation of component "P100" latency found in both groups and probably resulting from sedative effects of diazepam. Patients experiencing the TURP syndrome showed abolishment of 30 Hz flicker-following in their VEPs. The elevated serum levels of glycine may contribute directly to visual aberrations resulting from glycine's role as an inhibitory transmitter in the retina.

Visual symptoms associated with the presence of a lupus anticoagulant

The lupus anticoagulant is an acquired serum immunoglobulin that prolongs several coagulation parameters, most notably the partial thromboplastin time (PTT). Most commonly, this condition is found in association with systemic lupus erythematosus (SLE) but may be seen with other collagen-vascular diseases and in otherwise healthy individuals. Despite the laboratory tests suggesting impaired coagulation, clinically the lupus anticoagulant has been associated with thrombosis. The authors present five patients with the lupus anticoagulant who came to medical attention because of branch retinal artery occlusion, ischemic optic neuropathy, transient visual loss, transient diplopia, or vertebrobasilar insufficiency. Eleven previously reported patients with the lupus anticoagulant and disturbed vision are also reviewed with additional findings of retinal venous occlusive disease and homonymous visual field loss. The relationship of these findings to retinopathy in SLE is discussed. Patients with the lupus anticoagulant (with or without SLE) may develop disturbances in vision due to thrombosis from a hypercoagulable state. We recommended obtaining a PTT, VDRL, and the more sensitive anticardiolipin antibody in patients with unexplained visual symptoms.

[Visual and neurological disturbances accompanying with pregnancies of hyperprolactinemic patients]

Twenty-three hyperprolactinemic infertile cases become pregnant after surgical treatment and/or bromocriptine administration, and 18 of them accomplished normal full-term deliveries. Serial ophthalmological examination which had been performed monthly throughout pregnancy revealed that four cases bearing pituitary adenomas developed visual disturbances which manifested themselves in the latter part of gestational period. The objective signs detected in these cases were bitemporal hemianopsia, temporal and nasal visual defects and the disappearance of central isopter. Another patient with microadenoma complained of headache at 16 weeks of gestation and it became more severe as gestation progressed. Bromocriptine (1.25 mg/day) was effective in diminishing this symptom. Although all these cases recovered from visual disturbances and headache after delivery, two of them were operated on transsphenoidally when radiological evidence of pituitary enlargement was found in the postpartum period. It is generally accepted that nearly 20% of hyperprolactinemic patients have pituitary adenomas. In view of the limited accuracy of techniques used in diagnosing pituitary tumor, it is legitimate to postulate that most hyperprolactinemic infertile patients have microadenoma to some extent. For this reason, a detailed follow up of visual field and neurological signs throughout pregnancy of hyperprolactinemic patients is important in early detection of changes in pituitary size.

Ocular manifestations of mercury poisoning

One hundred patients suffering from organomercury poisoning who were hospitalized in the Medical City, University of Baghdad, were examined ophthalmologically in the period between March and December 1972, and were reviewed again about 10 months later.The examination included clinical signs and symptoms, slit lamp examination of the anterior segment of the eyes, examination for visual field changes and, in the autopsied cases, analysis of the optic nerve and the occipital cortex. In addition, aqueous humour was aspirated in 10 patients and in 10 controls for the estimation of the mercury level.