Ocular echography in the prognosis of vitreous haemorrhage in type II diabetes mellitus

Purpose: In this study, we have attempted to demonstrate the presence of various echographic parameters which could be associated with a non-spontaneous resorption of vitreous haemorrhage in type II diabetes mellitus and correlate these parameters with clinical outcome. Subjects and methods:We studied 297 eyes of 257 patients with diabetic retinopathy and vitreous haemorrhage without tractional macular retinal detachment ophthalmoscopically and echographically. Of the total eyes studied, a 3-month follow-up visit (including ultrasound) was available in 208 eyes. We retrospectively reviewed the medical records of each patient. Results:The echographic parameters associated with non-resorption ofthe vitreous haemorrhage were: extramacular tractional retinal detachment, fibrovascular membranes and location of the haemorrhage within the subhyaloidal space (in contrast to within the intragel space). In addition, the duration of the vitreous haemorrhage and the presence of panretinal laser photocoagulation at the time of presentation with a vitreous haemorrhage influenced the resolution of the vitreous haemorrhage. We were also able to construct a logarith micfunction that could be used to predict the prognosis of avitreous haemorrhage in type II diabetes mellitus. Conclusions: When employed to evaluate vitreous haemorrhages in non-insulin-dependent diabetes mellitus, ocular ultrasound can provide useful prognostic information regarding the lack of resorption of vitreous haemorrhages in type II diabetics. This revised version was published online in July 2006 with corrections to the Cover Date.     

Diabetic papillopathy in type II diabetic patients

PURPOSE: To evaluate the patient characteristics and fundus findings of patients with type II diabetes presenting with diabetic papillopathy. METHODS: The authors retrospectively reviewed the medical records of 3,235 patients with diabetes followed in their institution since 1986 and identified the patients with unilateral or bilateral transient disk swelling and without significant deterioration of best-corrected visual acuity. The authors investigated patient demographics, symptoms, fundus findings, ancillary test results, and clinical course of those patients. RESULTS: Twenty-four eyes of 16 patients with type II diabetes mellitus met the criteria. Patients had a mean age of 57.1 (+/-8.8) years and had diabetes mellitus of long duration (mean 10.0 +/- 8.6 years). Approximately half of the patients had poor metabolic control. Disk swelling was bilateral in 8 (50%) patients and resolved in an average of 7.8 +/- 3.7 months. A total of 13 (54%) eyes had nonproliferative and 2 (8%) eyes had proliferative diabetic retinopathy at presentation. In 4 (17%) eyes retinopathy progression into the proliferative stage occurred and panretinal photocoagulation was performed. CONCLUSIONS: Diabetic papillopathy may be found in older patients with type II diabetes. Nonproliferative or proliferative diabetic retinopathy as well as macular edema may also be associated with this disorder.     

The role of color vision disturbances in diagnostics of early diabetic retinopathy

PURPOSE: The evaluations of color vision sensitivity in children with type I diabetes mellitus without retinopathy. MATERIAL AND METHOD: We examined 96 young patients. They was divided into three groups: I: 35 children from 7 to 16 years old with insulin-dependent diabetes mellitus duration of 1-8 years, II: 30 children with type I diabetes lasting more then 8 years, III--31 non-diabetic subjects as a control-matched for age and sex, without visual or systemic symptoms. The examinations of colour vision sensitivity were done with the IF-2AII-color Anomaloscope. In all cases were tested the dynamic blue-green equation of Moreland and two variables were determined: setting (matching) range (SR), calculated mid point (matching mid point) (CMP). RESULTS: In the blue-green equation setting range (SR) was significantly (p < 0.01) enlarged in the II group (diabetes mellitus duration > 8 years) and calculated mid point (CMP) was shifted but no significant. The results indicate a diminution of the colour discriminating sensitivity in the short wavelength half of the visible spectrum and diminution of the blue cone sensitivity in early diabetic retinopathy. CONCLUSIONS: Blue-green colour vision testing with the anomaloscope may serve as an additional test in the diagnosis of early diabetic retinopathy in children without vascular changes at the eye fundus.     

Risk factors for Type II diabetes and diabetic retinopathy in a mexican-american population: Proyecto VER

PURPOSE: Risk factors for type II diabetes and diabetic retinopathy were determined in a population-based study of Mexican-Americans. DESIGN: Proyecto VER (Vision, Evaluation, and Research) is a cross-sectional study in a random sample of the self-described Hispanic populations in Tucson and Nogales, Arizona, age 40 and older. METHODS: Of 6,659 eligible subjects, 4,774 (72%) participated in the home questionnaire and clinic visit. Diabetes was defined as self-report of a physician diagnosis or hemoglobin A(1c) value of > or = 7.0%. Only type II diabetes was included. Diabetic retinopathy was assessed on stereo fundus photographs of all persons with diabetes. Questions were asked about demographic, personal, socioeconomic, and diabetes related variables. RESULTS: 1023 (21.4%) of the sample had type II diabetes, and 68% were in the low-income group (annual income less than $20,000). Diabetes was associated with Native-American ancestry, higher acculturation, low income, less education, and increasing body mass index after age and gender adjustment. Persons with previously undiscovered diabetes were more likely to have no regular source of care, no insurance, and currently smoke compared with persons with known diabetes. Only low income was related to proliferative retinopathy, once adjusted for other factors (odds ratio [OR] = 3.93, 95%, confidence limitations [CL] = 1.31-11.80). CONCLUSIONS: Several socioeconomic and other factors were associated with diabetes, but few were related to diabetic retinopathy. Persons in the low-income group appeared to be at greater risk of diabetes and the ocular complications of diabetes compared with those with more income. Further longitudinal studies in this population are needed to confirm the associations.     

Pars-plana vitrectomy in diabetic traction retinal detachments with holes

PURPOSE: To evaluate results and prognostic factors of pars-plana vitrectomy (ppv) using membrane peeling and C2F6-gas for diabetic traction retinal detachments with a hole. METHODS: We retrospectively reviewed the healing course of 84 eyes, which were treated in this way consecutively (follow-up 6-32 month). C2F6 was always used in case of a retinal hole at the posterior pole or in the upper part of the eye. The influence of HBA1c, type of diabetes, preoperative visual acuity, preoperative laser-coagulation and macular status over treatment results and rate of complications were studied using multivariate logistic regression analysis. RESULTS: Preoperatively 56% of the eyes showed premacular vitreous hemorrhage and 69% macular detachment. Using on an average 1.3 treatments in 73% retina was completely reattached and in 85% visual acuity remained unchanged or improved. The most important prognostic factors were HBA1c < 9.3, type II diabetes and bad vision preoperatively. Postoperative complications such as rubeosis, secondary glaucoma and repeated vitreous hemorrhages were more frequent in case of type I diabetes, HBA1c > or = 9.3 and insufficient laser treatment. CONCLUSION: Best corrected blood sugar levels preoperatively and sufficient laser treatment seem to be very important to decrease the risk for rubeosis and repeated vitreous hemorrhages especially for patients with type I diabetes.     

Vogt-Koyanagi-Harada associated with diabetes mellitus and celiac disease in a 3-year-old girl

PURPOSE: To present a case of Vogt-Koyanagi-Harada (VKH) associated with type I diabetes mellitus and celiac disease in a 3 year old female. METHODS: We studied a three-year old female who presented with clinical manifestation of VKH and type I Diabetes mellitus and celiac disease. RESULTS: Patient was found to have hyperglycemia with type I diabetes mellitus. Duodenal mucosal biopsy specimen confirmed the diagnosis of celiac disease. Patient's ocular inflammation was treated by topical and systemic corticosteroid and immune-suppressive therapy. Her diabetes mellitus was controlled by insulin and her celiac disease was controlled by gluten-free diet. CONCLUSIONS: The association of VKH with two autoimmune diseases (celiac disease and type I diabetes mellitus) is rare. This case is, to our knowledge, the youngest patient reported with VKH.     

Pupil cycle time and contrast sensitivity in type II diabetes mellitus patients: a pilot study

Context:

Pupil cycle time (PCT) has been widely used for examination of ocular diabetic autonomic neuropathy (DAN).

Aims:

The primary aim of this study was to evaluate the difference of contrast sensitivity according to PCT results, and the secondary aim was to determine the factors associated with PCT difference for type II diabetes patients.

Settings and Design:

A clinical pilot study that included a total of 60 eyes of 60 type II diabetes patients.

Materials and Methods:

We divided all patients into three groups according to PCT results. Group A and Group C were composed of patients who had upper one third PCT and lower one third PCT, respectively. We analyzed difference of age, diabetes duration, hypertension duration, mean best corrected visual acuity (BCVA), mean spherical equivalent (SE), HbA1C, glomerular filtration rate (GFR), stage of diabetic retinopathy, and Cardiac Autonomic Function Score (CAFS). Contrast sensitivity and decrease of visual acuity by glare were also estimated and analyzed for 28 eyes of 28 non-proliferative diabetic retinopathy (NPDR) patients. Group [NPDR] A and Group [NPDR] C were defined as those who had lower one third PCT and upper one third PCT, respectively.

Statistical Analysis:

Statistical analysis was done using SPSS 17.0 software.

Results and Conclusions:

Each group contained 20 eyes. Significant differences between Group A and Group C were observed in duration of diabetes and CAFS (P ≤ 0.001 and P <0.001, respectively). Contrast sensitivity in Group [NPDR] A was significantly more than in Group [NPDR] C at all cpds (all P ≤ 0.001). We found that PCT can influence contrast sensitivity or glare in diabetes patients and also confirmed a significant correlation of PCT with CAFS and duration of diabetes.     

Cataract types in diabetics and non-diabetics: a densitometric study with the Topcon-Scheimpflug camera

BACKGROUND: The purpose of this study was to compare types of cataract which appear in patients with the cataractogenous risk factor diabetes mellitus type II and in non-diabetics. MATERIALS AND METHODS: The opaque lenses of 46 diabetics (group I) and 83 non-diabetics (group II) in the age range of 55-93 years, who had to undergo a cataract operation, were documented using the Topcon-Scheimpflug camera SL-45 followed by densitometric analysis. RESULTS: Although there was no significant difference relating to the metabolic disorder, we found a higher percentage of opacity of the deeper anterior (I = 8.7 % II = 3.6 %) as well as in the anterior and posterior cortex (I = 13.0 % II = 8.4 %) comparing diabetics and non-diabetics. CONCLUSION: Diabetics revealed a higher percentage of opacity of the area of the cortex than non-diabetics without detecting any significance. Thereby, we could show positive associations between the existence of diabetes mellitus type II and a higher risk of opacities of the cortex.     

Corneal endothelial morphology and central thickness in patients with type II diabetes mellitus

Purpose: To investigate corneal endothelial cell density and morphology in type II diabetic and non‐diabetic patients and to relate potential differences to the glycaemic status. Methods: A prospective clinical study including 107 patients with type II diabetes and 128 non‐diabetic patients. Sample size was based on a power calculation (power = 0.90; p = 0.05). The diabetic patients had on average more than four HbA1c tests performed (mean 4.1; range 2–14) with intervals of at least 3 months as a reflection of the long‐term glycaemic status. The controls had no diabetes confirmed by two causal blood tests. The endothelial cell density, the variation in endothelial cell size (CV), the percentage of hexagonal cells, and the central corneal thickness (CCT) were recorded. Results: Type II diabetic subjects did not differ from the non‐diabetic control subjects with regards to endothelial cell density, hexagonality or variation in CV, but showed a significant increase in CCT (538 versus 546 μm, p < 0.05). In the diabetic group, lower cell counts were associated with higher HbA1_c values (p < 0.05). The HbA1c did not, however, have any impact on the CCT. Conclusion: Type II diabetes has no impact on corneal cell density or morphology in subjects with good glycaemic status. However, higher HbA1c was associated with lower endothelial cell density. CCT was significantly increased in the diabetic group_.     

Corneal endothelium evaluation in type I and type II diabetes mellitus.

BACKGROUND: The purpose of this study is to evaluate the corneal endothelium in type I and type II diabetic patients. METHODS: Seventy-five diabetics divided into type I and type II groups and 62 healthy volunteers took part in the study. The mean endothelial cell density and morphology, and the central corneal thickness were evaluated and statistical analysis was done. RESULTS: All evaluated parameters were found to be significantly different in both diabetic groups with reduction of the mean cell density of 5% in type II and of 11% in type I diabetes with respect to the normal age-matched control group. Important alterations of endothelial morphology were observed. The central corneal pachymetry was significantly higher in diabetics, with p < 0.01 in the type I group and p < 0.05 in the type II group. CONCLUSION: It is concluded that corneal endothelium in diabetics should still be considered as a tissue under continuous metabolic stress with consequent high vulnerability, especially in case of any external insult such as a surgical procedure.     

Elevated vitreous nitric oxide levels in patients with proliferative diabetic retinopathy

PURPOSE: The aim of this study was to determine nitric oxide levels in the vitreous of patients with proliferative diabetic retinopathy. METHODS: Using the spectrophotometric method based on Griess reaction, we measured levels of nitrite, the stable product of nitric oxide, in the vitreous of 21 eyes of 21 patients who underwent vitrectomy for the treatment of proliferative diabetic retinopathy with tractional retinal detachment, prospectively. Three samples were excluded from the study because of blood contamination. The control group was made up of vitreous samples from 15 eyes of 15 normal cadavers and five eyes of five patients who were undergoing vitrectomy for macular hole surgery.RESULTS: Nitrite levels were 0. 524 +/- 0.27 microM and 0.383 +/- 0.17 microM in the vitreous of patients with proliferative diabetic retinopathy of diabetes type I and type II, respectively. In 15 cadaver eyes and five vitreous samples from patients who underwent macular hole surgery, nitrite levels were below the detection limit (less than 0.08 microM). There was no significant difference between nitrite levels in patients with type I and type II diabetes (P =.56), whereas there was a significant difference between diabetes groups and controls (P <. 00001).CONCLUSION: Vitreous nitric oxide levels are elevated in patients with proliferative diabetic retinopathy with tractional retinal detachment. Nitric oxide may play a role in the pathogenesis of proliferative diabetic retinopathy.     

Aqueous flare intensity in relation to different stages of diabetic retinopathy.

PURPOSE: To compare laser flare intensity in patients with diabetes mellitus (DM) type I and type II to different stages of diabetic retinopathy (DR) and controls. METHODS: This study comprised 88 consecutive patients with DM type I and 40 controls in the same age range, divided into two age groups: 20-34 years and 35-50 years; 108 consecutive patients with DM type II and 32 controls were also divided into two age groups: 45-59 years and 60-75 years. Patients with glaucoma, exfoliation syndrome, media opacities, uveitis, within 96 hours after laser photocoagulation, treatment with topical and systemic drugs which can affect aqueous protein concentration, were excluded. One eye was randomly selected from each diabetic patient and control. Flare intensity was measured with a laser flare meter without mydriatic drops, and was then correlated with the stages of DR within each age group. RESULTS: Eyes with advanced DR, such as moderate-severe, severe non-proliferative DR and proliferative DR (PDR), had significantly higher flare intensity than controls and eyes without retinopathy in all age groups (p<0.05). Flare intensity values were similar for controls and eyes with mild-moderate DR in all age groups except the older patients with DM type II, particularly those with clinically significant macular edema (CSME) (p<0.05). Eyes with regressed proliferative DR and no indication for laser photocoagulation had significantly lower flare values than eyes with an indication for therapy (p<0.05). Eyes with iris rubeosis (IR) had significantly higher flare than those without IR (p<0.05). Flare values were significantly correlated with the duration of diabetes in DM types I and II (p<0.05). CONCLUSIONS: Flare intensity was increased in eyes with mild-moderate DR with CSME, and in eyes with advanced and severe stages of DR. Aqueous flare was related to the duration of diabetes.     

Polymorphisms in the promoter region of the basic fibroblast growth factor gene and proliferative diabetic retinopathy in Caucasians with type 2 diabetes

Background: Basic fibroblast growth factor (bFGF) expression is implicated in proliferative diabetic retinopathy (PDR). The aim of this study was to investigate the association of genetic polymorphisms (?553T/A, ?834T/A and ?921C/G) in the promoter region of the bFGF gene with PDR in patients with type 2 diabetes. The second aim was to determine whether serum levels of bFGF are affected by genetic factors. Methods: In this cross‐sectional case–control study 313 unrelated Caucasians (Slovene population) with type 2 diabetes mellitus were enrolled: 206 patients with PDR and the control group of 107 subjects with type 2 diabetes of duration of more than 10 years who had no clinical signs of diabetic retinopathy. We analysed serum bFGF levels in 78 subjects with type 2 diabetes and 25 subjects without diabetes. Results: The AT genotype of the ?553T/A polymorphism was present in 31 (15.0%) PDR patients and in seven (6.5%) controls (P = 0.03, odds ratio = 2.0, 95% confidence interval = 1.0–3.9). The AT genotype of the ?834T/A polymorphism was present in 12 (5.8%) PDR patients and in 15 (14.0%) controls (P = 0.01, odds ratio = 0.4, 95% confidence interval = 0.2–0.8). Significantly higher bFGF serum levels were demonstrated in diabetics with the AT genotype of the ?553 polymorphism compared with diabetics with the TT genotype, whereas the ?834 and ?921 polymorphisms failed to affect serum bFGF levels. Conclusions: We may conclude that the AT genotype of the 553 T/A polymorphism was associated with PDR in Caucasians with type 2 diabetes, therefore it might be used as a genetic marker of PDR in Caucasians, whereas carriage of the AT genotype of the ?834 T/A polymorphism might decrease PDR risk.     

K469E polymorphism of the intracellular adhesion molecule 1 gene is associated with proliferative diabetic retinopathy in Caucasians with type 2 diabetes

Background:  In proliferative diabetic retinopathy (PDR) increased levels of cytokines, inflammatory cells and angiogenic factors are present. These factors increase the expression of cellular adhesion molecules (CAMs) The objective of this study was to investigate the association between the polymorphisms of the ICAM-1 gene (K469E, G241A) and the development of PDR among patients with type 2 diabetes in the Slovenian population (Caucasians).
Methods:  For the purpose, 195 subjects with type 2 diabetes with PDR were compared with 143 subjects with type 2 diabetes of duration of more than 10 years who had no clinical signs of diabetic retinopathy. We analysed serum ICAM levels in 54 subjects with type 2 diabetes and 25 subjects without diabetes.
Results:  A significantly higher frequency of the EE genotype of the K469E polymorphism of the ICAM-1 was found in the patients with PDR compared with those without diabetic retinopathy (OR = 2.0, 95% confidence interval [CI] = 1.1–3.5; P  = 0.013), whereas the G241A polymorphism of the ICAM-1 gene failed to yield an association with PDR. Moreover, significantly higher sICAM-1 serum levels were demonstrated in diabetics with the EE genotype compared with those with the other (EK + KK) genotypes (918 ± 104 vs. 664 ± 209 µg/L; P  = 0.001). The G241A polymorphism of the ICAM-1 gene, on the other hand, failed to affect sICAM-1 serum levels in diabetics.
Conclusions:  We may conclude that the EE genotype of the K469E polymorphism of the ICAM-1 might be a risk factor for PDR in the Slovenian population (Caucasians) with type 2 diabetes.     

Calculation of intraocular lens power and to determine the relationship between ocular biometry and severity of diabetic retinopathy in patients with type II diabetes mellitus

Purpose:To calculate the intraocular lens power and to determine the relationship between ocular biometry and severity of diabetic retinopathy (DR) in patients with type II diabetes mellitus.Methods:The study group included 150 type II diabetic subjects with DR. The control group consisted of 150 type II diabetic subjects having no DR. Axial length (AL), corneal power, and anterior chamber depth were measured using LenStar. DR and diabetic macular edema were classified according to International DR Classification. Crystalline lens power was calculated using Barrett Universal II formula. AL to corneal radius ratio was calculated. Chi-square test was used for categorical variables.Results:In multivariate logistic models adjusting for age, sex, glycosylated hemoglobin, duration of diabetes, Mean age of patients in the study group was 62.45 ± 4.85 years, whereas in the control group, it was 63.37 ± 7.29 years. Of the eyes with DR, 117, 76, 69, and 38 had mild NPDR, moderate NPDR, severe NPDR, and PDR, respectively. The difference in the mean duration of diabetes mellitus and glycosylated hemoglobin in both study and control groups was found to be statistically significant. A progressive decrease in the mean AL and the anterior chamber depth was observed with increasing severity of DR, and difference was statistically significant. There was a progressive increase in intraocular lens power with increasing severity of DR, and difference was found to be statistically significant.Conclusion:In persons with diabetes mellitus, globe elongation plays quite an important role in protective effects against DR, with contribution from intraocular lens power and other refractive components.     

Blinking and superficial punctate keratopathy in patients with diabetes mellitus

AIM: To evaluate blinking patterns in patients with diabetes mellitus and whether blinking contributes to the formation of superficial punctate keratopathy in diabetic patients. METHODS: We examined 163 patients with type II diabetes mellitus and 76 without diabetes. Blinks were recorded, analysed using six parameters, and compared between patients with and without diabetes. Multivariate regression analysis was performed to assess the influence of other ocular factors, such as status of tear lipid layer, tear breakup time, corneal sensitivity, the result of cotton thread test, or blinking rate related to superficial punctate keratopathy. RESULTS: In patients with diabetes, the average mean and maximum interblinking times were longer, the average coefficient of variation of interblinking time was higher, and the average blinking rates were lower than those in patients without diabetes. Multivariate regression analysis revealed that the status of tear lipid layer and tear breakup time were significantly relevant to superficial punctate keratopathy (P < 0.01). CONCLUSION: Interblinking time was longer in diabetic patients, resulting in a decreased blinking rate. The prevalence of superficial punctate keratopathy cannot be predicted from blinking patterns in patients with diabetes.     

The post‐illumination pupil response of melanopsin‐expressing intrinsically photosensitive retinal ganglion cells in diabetes

Purpose: This study investigates the clinical utility of the melanopsin‐expressing intrinsically photosensitive retinal ganglion cell (ipRGC) controlled post‐illumination pupil response (PIPR) as a novel technique for documenting inner retinal function in patients with Type II diabetes without diabetic retinopathy. Methods: The PIPR was measured in seven patients with Type II diabetes, normal retinal nerve fibre thickness and no diabetic retinopathy compared to healthy age‐similar controls. A 488‐ and 610‐nm, 7.15‐diameter stimulus was presented in Maxwellian view to the right eye and the left consensual pupil light reflex was recorded. Results: The group data for the blue PIPR (488 nm) identified a trend of reduced ipRGC function in patients with diabetes with no retinopathy. The transient pupil constriction was lower on average in the diabetic group. The relationship between duration of diabetes and the blue PIPR amplitude was linear, suggesting that ipRGC function decreases with increasing diabetes duration. Conclusion: This is the first report to show that the ipRGC‐controlled PIPR may have clinical applications as a non‐invasive technique for determining the progression of inner neuroretinal changes in patients with diabetes before they are ophthalmoscopically or anatomically evident. The lower transient pupil constriction amplitude indicates that outer retinal photoreceptor inputs to the pupil light reflex may also be affected in diabetes.     

Pupillary autonomic denervation with increasing duration of diabetes mellitus

BACKGROUND/AIMS: The autonomic pupillary changes in type I and II diabetic patients without clinical evidence of diabetic autonomic neuropathy (DAN) were compared with age matched controls. The relation between pupillary and cardiovascular autonomic function was assessed in the diabetic patients. METHODS: A case-control study was performed with diabetics grouped according to type and duration of diabetes. Static infrared pupillography was used to compare mean dark adapted pupil size and mean percentage changes in pupil size with pilocarpine 0.1% and cocaine 4% in the diabetic and control groups. All diabetic patients underwent cardiovascular autonomic function assessment using the Valsalva ratio, the 30:15 ratio, and testing for orthostatic hypotension. RESULTS: In total, 72 type I and 69 type II diabetic patients were compared with 120 controls. Mean dark adapted pupil size was significantly smaller in diabetic groups than controls. Except for type I diabetics with disease for less than 5 years, all patient groups had significantly greater mean percentage constriction in pupil size in response to dilute pilocarpine than controls. There was no significant difference between the mean percentage dilatation in response to cocaine 4% in diabetics and controls. A high proportion of patients had normal cardiovascular autonomic function particularly when this was assessed with the Valsalva ratio. CONCLUSIONS: Denervation hypersensitivity to dilute pilocarpine is a result of damage to the pupillary parasympathetic supply of diabetic patients. This occurs before the pupillary sympathetic pathway is affected, it can be detected early in the disease, and it may be a possible explanation for the small pupil size seen in diabetic patients. Pupillary autonomic dysfunction occurs before cardiovascular autonomic changes and detection of pupil denervation hypersensitivity to dilute pilocarpine is an inexpensive way to detect early DAN.     

Manifest diabetes and keratoconus: A retrospective case-control study

Purpose: To assess the influence of diabetes on the development of keratoconus to show whether biomechanical effects are also reflected in epidemiology. The two diseases have opposite impact on the biomechanics of the corneal stroma: manifest diabetes stiffens the cornea, whereas keratectasia weakens the tensile strength of the stroma. Methods: The retrospective case-control study included files of 1142 patients, with 571 patients in the case group (keratoconus patients) and 571 in the control group (clinical population). The groups were well matched with respect to sex and age. We established the number of diabetics in both groups and compared it statistically by means of the odds ratio to determine whether diabetes can be interpreted as having a „protective effect” whether it is a „risk factor” for the development of keratoconus. Results: Two patients of the keratoconus group had manifest diabetes that developed many years after the diagnosis of keratoconus, while nine cases of diabetes were found in the control group. Statistical analysis revealed a strong protective effect of manifest diabetes regarding keratoconus (odds ratio=0.2195, P=0.034). This effect was evident only in type II diabetes patients. Conclusions: The protective effect of manifest diabetes may be explained by the induction of cross-links in the stroma, preventing biomechanical weakening of the cornea. This study shows that different biomechanical changes can be superimposed and assume epidemiological relevance. Received: 20 September 1999 Accepted: 4 November 1999     

Hypertension and diabetes synergistically strengthen the association with cataracts among Chinese

AIM: To examine the relationship between age-related cataracts (ARC) and comorbid hypertension and diabetes. METHODS: We analyzed the administrative records of 6,467 patients aged 50 years and older admitted to the ophthalmological department of a tertiary hospital from January 1st, 2011 to May 20th, 2017. With either eye considered, an ARC (n=3,343) was defined as the presence of lens opacity or previous cataract surgery without evidence of trauma, congenital anomalies or using certain medications. Patients admitted to the same department during the same period due to ocular traumas without clinical evidence of cataracts (n=379) were recruited as the cataract-free controls. Unconditional logistic regressions were obtained the odds ratio (OR) of hypertension and diabetes among ARC patients adjusted for age, sex and health care accessibility. RESULTS: Hypertension was diagnosed in 29.54% of men with any type of cataracts, in 30.12% of men with an ARC, and 10.82% of men of cataract-free controls. Diabetes was diagnosed in 16.64% of men with any type of cataracts, in 16.48% of men with ARC and 4.22% of men of cataract-free controls. Similar patterns were observed among women. After adjusting for age, sex, and health care accessibility, hypertension was weakly [OR=1.83 (95%CI: 1.23, 2.74)] and diabetes was strongly [3.38 (1.86, 6.15)] associated with ARCs. The adjusted OR of comorbid hypertension and diabetes among adults with ARC was 18.20 (4.38, 75.59). CONCLUSION: Hypertension and diabetes were independently associated with ARC. Hypertension and diabetes, if co-existing, multiplicatively strengthened the association with ARC.