Glycolytic oscillation and effect of metabolic inhibitor on rat lens.

Abnormalities in glucose metabolism are thought to be among the main causes of cataract formation. We have taken noninvasive biochemical measurements of the lens which provides us with information concerning glucose metabolism in the lens epithelium. The autofluorescence of reduced pyridine nucleotides (PN) and oxidized flavoproteins (Fp) in the rat lens epithelium was measured noninvasively as a function of time using redox fluorometry. The oscillations of the metabolic ratio, PN/Fp, were measured in vivo, in situ, and in the organ-cultured lens. The PN/Fp ratio in the organ-cultured lens ranged from 1.05 to 2.57 within a period of 60-90 minutes (mean +/- SD = 1.52 +/- 0.36). This PN/Fp ratio increased by 23% when a respiratory inhibitor (8 mM KCN) was applied to the lens. However, it decreased by 10% in the presence of a complete metabolic inhibitor (8 mM iodoacetamide). The presence of metabolic oscillations in the in vivo, in situ and cultured lens indicates that this oscillation is a local phenomenon. In cell-free extract systems, oscillations of several intermediates in the glycolytic pathway have been previously demonstrated and this PN/Fp oscillation is thought to be a reflection of glycolytic oscillation.     

Metabolic changes in the corneal epithelium resulting from hard contact lens wear.

The metabolic state of rabbit corneas was monitored in vivo using the noninvasive method of corneal redox fluorometry. The autofluorescence signals of reduced pyridine nucleotides (PN) and oxidized flavoproteins (Fp) were measured in the corneal epithelium with and without contact lens wear. The PN/Fp ratio, which is related to the metabolic status of the tissue, was then calculated for each of these conditions. After application of polymethylmethacrylate (PMMA) contact lenses having an oxygen transmissibility (Dk) of less than 0.1, the PN signal increased and the Fp signal decreased. The PN/Fp ratio, generally a more precise indicator of metabolic state than either of these two quantities alone, was 1.93 +/- 0.78 without contact lenses, and increased to 2.78 +/- 0.86 (p less than 0.0001) with contact lenses. When oxygen-permeable silicon contact lenses (Dk = 12.5) were placed on the corneas, the PN/Fp ratio was found to increase slightly, but not as much as with the PMMA lenses. Newly developed highly oxygen-permeable contact lenses (Dk = 58.8) did not increase this ratio. Our findings indicate that redox fluorometry can be valuable in determining the effects of contact lens wear on corneal metabolism.     

Noninvasive metabolic analysis of the diabetic cornea and lens: in vivo measurement]

In vivo measurement of metabolic changes in diabetic cornea and lens were performed using redox fluorometry in nonobese diabetic (NOD) mice. Autofluorescence from reduced pyridine nucleotides (PN) and oxidized flavoproteins (Fp) were measured, and the PN/Fp ratio was used as a tissue metabolism indicator. The PN/Fp ratios were significantly higher in the diabetic corneal endothelium. Morphometric analysis of the corneal endothelium using specular microscopy revealed no significant differences between the two groups. These results indicate that redox fluorometry is able to detect early metabolic changes in the corneal endothelium and lens epithelium, which are induced by diabetes mellitus. Activation of the polyol pathway may be responsible for the change. Corneal epithelia may be less susceptible to diabetic changes than the corneal endothelium and lens epithelium.     

Lens redox fluorometry: pyridine nucleotide fluorescence and analysis of diabetic lens

We performed both ex vivo and in vivo fluorometric analyses of pyridine nucleotides (PN) in rabbit and rat lenses. Rabbit lens PN fluorescence (99% NADH) was found to have an excitation maximum at 366 nm and an emission maximum at 462 nm (366:462). The only other fluorescent chromophore in that region of the spectrum has excitation and emission peaks at 328 and 460 nm, respectively. Anaerobic glycolysis in the lens was stimulated by KCN, a known inhibitor of mitochondrial respiration, after which a time-study of fluorescence intensities was performed. Over the course of a 3.5 hr period following treatment with KCN, the PN signal showed a statistically significant increase relative to that in the control lenses (those treated with KCl). while the 328:460 signal (which may be due to some protein involved in energy transfer with the PN) had a significantly greater decrease. We also found that fluorescence intensity of NADH in solution is linearly proportional to physiologic-range concentration. Moreover, there was a close correlation between fluorescence intensity of rat lens PN as measured on a specular microscope-coupled redox fluorometer capable of in vivo use, and the lens PN levels as determined by the analytical cycling assay technique. This fluorometer was then employed to assess the redox state in rats with streptozotocin-induced diabetes. The normalized ratio of PN to flavoproteins (Fp) in the lens epithelium increased from 0.96 +/- 0.12 in the normal state to 1.48 +/- 0.30 2 weeks after diabetes induction. In contrast, the ratio in the diabetic lens treated with an aldose reductase inhibitor, sorbinil, did not increase. The increase in the PN:Fp ratio therefore reflects activation of the polyol pathway and its associated metabolic activities, which results in an increase in the NADH:NAD ratio in the diabetic rat lenses. Our results indicate that the non-invasive, real-time method of redox fluorometry may be useful in the early detection and evaluation of cataracts and other disorders in lens metabolism, long before opacities occur. It can be used to monitor the disease process and evaluate the efficacy of such drugs as aldose reductase inhibitors on a biochemical level.     

Metabolic analysis of the diseased human corneal endothelium]

Redox states of the corneal endothelium in 42 recipient corneas obtained at the penetrating keratoplasty were measured non-invasively using ocular redox fluorometry. Autofluorescence from reduced pyridine nucleotides (PN) and oxidized flavoproteins (Fp) were measured, and the PN/Fp ratio was used as an indicator of the redox state. Endothelial damage was graded as normal, mildly damaged, moderately damaged, and severely damaged, based on the histopathological findings. Mildly damaged endothelium showed a significantly higher PN/Fp ratio than the that in normal endothelium whereas the ratio was significantly lower in the severely damaged endothelium. These changes in the redox state may represent compensation and decompensation processes of the endothelial metabolism. Ocular redox fluorometry was shown to be useful for the evaluation of the metabolic state in the human corneal endothelium.     

Investigation of corneal autofluorescence in diabetic patients

PURPOSE: The investigation of corneal autofluorescence in diabetic patients. OBJECTS AND METHODS: Corneal autofluorescence was investigated with a newly-developed fluorophotometer (wave length: excitation, 290-390 nm; emission, 430-630 nm) having, fluorescence characteristics involving those of reduced pyridine nucleotides (PN) and advanced glycation endoproduct (AGE) except pentosidine and pyrraline. Twenty-eight patients with non-insulin-dependent diabetes mellitus and sixty-seven healthy volunteers were studied. RESULTS: The corneal autofluorescence was 1.65 times higher than that of controls (p < 0.0001). In non-insulin-dependent diabetes mellitus, the corneal autofluorescence was not correlated significantly with various diabetic parameters in blood (r < 0.4). In controls, the corneal autofluorescence was correlated significantly with age (r = 0.438). CONCLUSION: The corneal autofluorescence has some relation with PN and AGE accumulation in the cornea.     

Investigation of Corneal Autofluorescence in Diabetic Patients

Purpose: The investigation of corneal autofluorescence in diabetic patients.Objects and Methods: Corneal autofluorescence was investigated with a newly-developed fluorophotometer (wave length: excitation, 290-390 nm; emission, 430-630 nm) having, fluorescence characteristics involving those of reduced pyridine nucleotides (PN) and advanced glycation endoproduct (AGE) except pentosidine and pyrraline. Twenty-eight patients with non-insulin-dependent diabetes mellitus and sixty-seven healthy volunteers were studied.Results: The corneal autofluorescence was 1.65 times higher than that of controls (P <.0001). In non-insulin-dependent diabetes mellitus, the corneal autofluorescenece was not correlated significantly with various diabetic parameters in blood (r < 0.4). In controls, the corneal autofluorescence was correlated significantly with age (r = 0.438).Conclusion: The corneal autofluorescence has some relation with PN and AGE accumulation in the cornea.     

Non-invasive assessment of the donor corneal endothelium using ocular redox fluorometry.

AIMS: To investigate the usefulness of ocular redox fluorometry for evaluating donor corneal endothelial viability. METHODS: Corneas from 42 recipients of penetrating keratoplasty and four donor corneas were examined by ocular redox fluorometry. Autofluorescence from reduced pyridine nucleotides (PN) and oxidised flavoproteins (Fp) of the human corneal endothelium were measured non-invasively, and the PN/Fp ratio was used as a tissue metabolic indicator. Specular microscopy and electron microscopy were also performed. RESULTS: Both the quality of specular microscopic image and the PN/Fp ratio were significantly correlated with the degree of corneal endothelial damage determined by histological examination. Corneas with poor specular microscopic image showed significantly decreased PN/Fp ratio compared with corneas with good or fair specular images (p = 0.041 and 0.027, respectively). The PN/Fp ratio increased in corneas with mildly damaged endothelium but decreased in corneas with severely damaged endothelium determined by histological examination. Evaluation of corneal endothelium by combination of specular microscopy and ocular redox fluorometry showed excellent association with that of histopathological examination (p < 0.0001). CONCLUSION: Ocular redox fluorometry is useful for assessing donor corneal endothelial viability. Combination of ocular redox fluorometry and specular microscopy may increase the ability of donor cornea selection.     

Changes in the energy metabolism of cultured lens epithelial cells in comparison with the fresh lens

Energy metabolism of bovine cultured lens epithelial cells (CLEC) was compared to that of fresh bovine lens. CLEC contained high levels of ATP (44 nmol mg protein-1) and creatine phosphate (13 nmol mg protein-1). An ATP/ADP ratio of ten and a creatine phosphate/creatine ratio of two indicated the cells were in a well-energized state. ATP concentration in fresh epithelium was comparable to that of CLEC; however in the anterior cortex it was tenfold lower. In contrast to fresh lenses, CLEC were able to oxidize glucose, lactate and palmitic acid. Lactate was oxidized at the highest rate. In CLEC, 42% of the ATP generated by catabolizing glucose resulted from oxidative phosphorylation. Glucose (5 mM) was degraded to lactate and CO2 at a 2:1 ratio. The hexose monophosphate pathway accounted for two thirds of the CO2 produced. In the fresh whole bovine lens palmitate was not oxidized and lactate was oxidized to a lesser degree than in CLEC. Only one-tenth of the ATP generated by glucose catabolism in the fresh whole lens was derived from oxidative phosphorylation. This was also the case for a preparation of fresh epithelium, maintained in air and 100% oxygen, demonstrating that the preferential glycolytic catabolism of glucose in lens is not caused by limited oxygen diffusion. In the fresh bovine lens the epithelium accounted for one third of the glucose catabolism of the whole lens, even though it had only about 0.1% of its protein mass. In fresh human lenses, conversion of glucose into lactate was even more pronounced--the lactate/CO2 ratio was 73:1.(ABSTRACT TRUNCATED AT 250 WORDS)     

Spectral profiling of autofluorescence associated with lipofuscin,Bruch's Membrane,and sub-RPE deposits in normal and AMD eyes

PURPOSE: To compare the autofluorescence spectra of retinal pigment epithelium (RPE)-associated lipofuscin, Bruch's membrane, and sub-RPE deposits (drusen and basal laminar-linear deposits) in eyes of donors with age-related macular degeneration (AMD) against eyes of age-matched control donors. METHODS: Cryosections were cut from the maculae of unfixed human donor eyes with AMD or from age-matched control eyes. Tissues were excited at wavelengths of 364, 488, 568, and 633 nm. Emission spectra were collected with a confocal microscope equipped with a spectrophotometric detector at 10-nm wavelength intervals between 400 and 800 nm. RESULTS: RPE lipofuscin had strong autofluorescent emissions that were excited at all wavelengths. Bruch's membrane exhibited strong autofluorescence with an emission peak of 485 +/- 5 nm when excited with 364-nm light. At 488-, 568-, and 633-nm excitations, Bruch's membrane and sub-RPE deposits in normal eyes exhibited minimal autofluorescence. In AMD eyes, however, both the 364- and 488-nm excitation wavelengths stimulated substantial blue-green emissions from sub-RPE deposits and Bruch's membrane, with average pixel intensities substantially exceeding that elicited in the yellow-orange range by RPE lipofuscin. CONCLUSIONS: These data suggest that an increase in blue-green autofluorescence of Bruch's membrane relative to the yellow-orange autofluorescence of RPE-associated lipofuscin is associated with AMD. Knowledge of these spectra will be useful in evaluating animal models of macular degenerative disease and in diagnosis of AMD, and will provide a novel signature for further analysis of the molecular entities emitting these fluorescent signatures.     

Lens autofluorescence in healthy individuals

We measured blue-green autofluorescence (AF, 495 nm/520 nm) of the lens in 43 random eyes of 43 healthy volunteers aged 6-86 years, five in each decade, using an instrument designed by one of us (HN). The instrument generates an autofluorescence profile, which consists of anterior and posterior juxtacortical peaks and a central plateau. The height of the anterior peak was taken as a maximum autofluorescence value and the square root of the ratio between the posterior and the anterior peak was used as a lens transmission index. The coefficient of variation for the measurement technique was 3.9% for maximum autofluorescence and 2.9% for lens transmission index. Both the maximum autofluorescence and the transmission index were highly correlated with age. Statistically over 90% of the variation in maximum autofluorescence values and almost 70% of the variation in transmission could be attributed to age.     

The effect of white light exposure on the rabbit eye lens as measured by fluorophotometry and spectrophotometry

Fluorophotometry and spectrophotometry of the rabbit lens were performed after white light exposure to detect possible changes in the lens before damage could be seen by biomicroscopic slit lamp examination. In nine rabbits the lens of one eye was exposed to white light and that of the fellow eye was used as a control. The incident light power was 240 mW for 90 min on a lenticular area of 3 mm2. Slit lamp examination of lens and cornea prior to, 1 hr after and 2 days after light exposure did not reveal any sign of damage. The mean in vivo autofluorescence ratio between exposed lens and non-exposed fellow lens was found to increase significantly from 1.0 +/- 0.08 S.D. (n = 9) before exposure to 3.3 +/- 0.8 S.D. (n = 9; P less than 0.004) 1 hr after exposure and hereafter to decay exponentially with a half time of 0.8 days to the ratio before exposure (correlation coefficient: -0.97, P = 0.0013). Three additional rabbits were exposed as described above with subsequent in vitro spectrophotometry of the lenses between 400 and 800 nm revealing an absorbance peak at 468 nm with a half width of 10 nm. The ratio between the absorbance peak of exposed lens and non-exposed fellow lens was found to increase from 1.1 before exposure to 2.8 1 hr after exposure and then to decrease to 1.4 at 1 day after exposure. The corresponding autofluorescence ratios measured in vivo before spectrophotometry were 0.93, 2.6 and 1.5, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Relationship between autofluorescence and advanced glycation end products in diabetic lenses

Autofluorescence and advanced glycation end product (AGE) levels were measured in the lenses of 9 diabetic Chinese hamsters and 6 age-matched controls. Lens autofluorescence also was measured in 37 diabetic patients and 14 age-matched controls. Lens autofluorescence values were measured noninvasively with a lens measurement system using color filters with peak transmission at 365- and 434-nm wavelengths (excitation and emission, respectively) that are characteristic of AGE fluorescence. The peak lens autofluorescence level was used as the lens autofluorescence value, and the mean lens autofluorescence values from both eyes of each subject were used for statistical analysis. The AGE levels in one lens from each hamster were measured by noncompetitive enzyme-linked immunosorbent assay with a polyclonal anti-AGE antibody. We found a 2.2 times increase of the mean lens autofluorescence value of diabetic hamsters in comparison with that of controls (P<0.01). We also found a 1.5 times increase of the mean AGE level from the lenses of diabetic hamsters in comparison with that of controls (P<0.01). Moreover, a statistically significant positive correlation between the AGE level and autofluorescence value in the same lenses was observed in all hamsters (rho=0.58, P<0.05). In human subjects, we found a 1.4 times increase of the mean lens autofluorescence value of diabetic patients in comparison with that of age-matched controls (P<0.01). Our results suggest that non invasive measurement of lens autofluorescence may be a guide to AGE levels in lenses.     

Different states of energy metabolism in the vertebrate retina can be identified by stimulus-related changesin near UV transmission

Background Our aim was to identify different states of energy metabolism in the perfused isolated vertebrate retina by simultaneous recordings of light-evoked changes of transretinal potential (TRP) and spectroscopic changes related to oxidation of pyridine nucleotides. Methods Isolated retinas were obtained from R.esc. and superfused. For each setting, three experiments were performed. Eighteen retinas were used. TRP as a response to light stimulation was recorded simultaneously with stimulus-induced transmission shift at 350 nm. These responses were recorded under normal conditions, under withdrawal of oxygen and glucose, and after addition of electron transport inhibitors and uncouplers of oxidative phosphorylation. Results Under normal conditions, TRP was strongly correlated with transmission shift after light stimulation. Without oxygen, amplitudes of stimulus-related TRP decreased and response related increase of transmission at 350 nm was reduced. The retina showed a much higher general absorption of the analyzing light. During glucose lack, an overall increase in transmission at 350 nm could be observed. The addition of Amytal yielded a specific reduction of the OFF components. Cyanide attenuated the ON and OFF components. Dinitrophenol yielded a considerable loss of the electrical ON response. Transmission change was affected less than electrical signal. Chlorophenylhydrazine induced a reproducible reduction of electrical responses, with a relative increase of transmission shift at 350 nm. Conclusion In the isolated perfused retina, different states of energy metabolism and their specific impact on neuroretinal responses can be examined by simultaneous recordings of stimulus-related neuronal activity and spectroscopic changes.     

Lens transmission of blue-green light in diabetic patients as measured by autofluorophotometry

Lens transmission for blue-green light (lambda = 490 nm and 530 nm) was assessed by means of fluorophotometry in 67 diabetic patients without cataracts and compared with that of 52 healthy controls. Lens transmission was determined from peak autofluorescence values in the anterior and posterior parts of the lens, assuming an about equal fluorescence peak quantum efficiency in both parts. The variation in lens transmission between individuals of about the same age was found to be larger in the diabetic patients than in the healthy controls. Decrease in lens transmission as a function of age occurred about 15 years earlier in patients with diabetes of more than 10 years' duration than in the healthy controls. The calculated average extra decrease of lens transmission in the diabetic group amounted to 0.5% for each year of diabetes.     

Unscheduled DNA synthesis in lens epithelium after in vivo exposure to UV radiation in the 300 nm wavelength region

A quantitative autoradiographic method was developed to study the pattern of DNA synthesis in the rat lens epithelium after in vivo exposure to UV radiation in the 300 nm wavelength region. It was found that UV radiation (peak transmission = 298 nm, half-width = +/- 10 nm) induces unscheduled DNA synthesis and that the proportion of nuclei in S-phase concurrently is reduced indicating an inhibition of the scheduled DNA synthesis. The registered unscheduled DNA synthesis is believed to be excision repair of DNA damage induced by the UV radiation. Excision repair in lens epithelial cells could be one mechanism involved in the correlation between exposure to sunlight and cataracts.     

Lens autofluorescence and light scatter in relation to the lens opacities classification system, LOCS III.

PURPOSE: To compare values of the human lens autofluorescence and back light scatter measurements with the improved Lens Opacities Classification System, LOCS III. METHODS: We measured autofluorescence and back light scatter of the lens from 122 smoking males aged 57 to 76 years who participated in a cancer prevention study. The retroillumination and slit-lamp photographs of the lenses were graded according to LOCS III by the Center for Ophthalmic Research in Boston. Lens fluorometry was carried out with a previously described technique using blue-green (495 nm/520 nm) autofluorescence range. Interzeag Lens Opacity Meter 701 was used for light scatter measurements. RESULTS: LOCS III nuclear opalescence and color grades were statistically significantly correlated with lens autofluorescence as well as with light scatter values. The lens transmission index of autofluorescence measurements showed the highest correlation with the nuclear color (r = -0.71; p < 0.0001) and the light scatter value with nuclear opalescence (r = 0.64; p < 0.0001). There was no correlation between autofluorescence measurements and LOCS III grades of cortical or posterior subcapsular cataract. A weak relation could be found between the grades of cortical cataract and light scatter values. CONCLUSIONS: The lens fluorometry provides a practical clinical technique to evaluate the yellow coloration and opalescence of the human lens nucleus. It may be a useful additional tool together with a subjective grading system in the follow-up of optical changes occurring in the nuclear region of the lens.     

Metabolic and morphologic changes in the corneal endothelium. The effects of potassium cyanide, iodoacetamide, and ouabain.

The metabolic pathways of glycolysis and mitochondrial respiration in the corneal endothelial cell are the primary sources of the adenosine triphosphate (ATP) necessary to maintain endothelial structure and pump fluid to maintain the corneal stroma in its normally dehydrated and transparent state. The correlation between endothelial metabolism and morphology in rabbits was studied for 7 days after the application of three different agents: (1) iodoacetamide, used to inhibit ATP synthesis from both glycolysis and respiration; (2) potassium cyanide (KCN), used to inhibit ATP synthesis from respiration only; and (3) ouabain, used to inhibit fluid pumping but not ATP synthesis. After application of each of these three drugs to the corneal endothelium, changes in endothelial morphology were measured. The greatest change resulted from the use of iodoacetamide. Specular microscopic examination of the endothelium after the application of iodoacetamide showed progressive degradation of the integrity of the cellular structure; after 6 hr, there were no discernible cell borders. In those corneas treated with either KCN or ouabain, only minor changes in the endothelium were seen during the full 7 days of the investigation. Computer-assisted morphometric analysis showed an increase in the coefficient of variation of both cell area and perimeter in all cases. This increase was greater in the corneas treated with ouabain than those treated with either iodoacetamide or KCN. Redox fluorometry showed that the metabolic ratio (autofluorescence of reduced pyridine nucleotides divided by that of oxidized flavoproteins) decreased significantly in the iodoacetamide-treated corneas, increased significantly in the KCN group, and showed no significant change in the corneas in the ouabain group, all compared with a control group. The results showed that (1) when ATP produced by both glycolysis and respiration was inhibited by 0.1 mmol/l iodoacetamide, the endothelial cells could not survive, but (2) when ATP synthesis produced by respiration alone was inhibited by 1.0 mmol/l KCN, the cells could survive for at least 1 wk on the ATP produced by anaerobic glycolysis. Furthermore, the polymegathism seen after application of ouabain, a drug that is not believed to affect ATP synthesis but inhibits the endothelial pump function, is greater than that seen as a result of reduced pump function caused by inhibited respiration produced by 1.0 mmol/l KCN. Combining specular microscopy, computer-assisted morphometric analysis, redox fluorometry, and corneal pachymetry allowed correlations between corneal endothelial metabolism, pump function, and morphology to be studied.     

晶状体内糖基化终末产物含量与糖尿病视网膜病变程度的关联分析

背景 糖基化终末产物(AGEs)在晶状体中沉积是糖尿病并发症发生的危险因素,研究发现AGEs与晶状体自发荧光有关,且晶状体蛋白为长寿蛋白,其中AGEs的蓄积与糖尿病视网膜病变(DR)程度的关系值得研究. 目的 探讨并分析晶状体中AGEs自发荧光强度变化是否对糖尿病严重程度有预测作用. 方法 采用横断面研究设计,对2015年9-12月在沈阳何氏眼科医院就诊的白内障患者100例100眼进行分析,按照患者有无糖尿病分为非糖尿病组40例40眼和糖尿病组60例60眼,糖尿病组患者再根据眼部并发症情况分为非DR组(NDR组)、非增生期DR组(NPDR组)和增生期DR组(PDR组),每个亚组均为20例20眼.所有患者均评估接受血浆糖化血红蛋白(HbA1c)和餐前血糖(FBG)测定,并采用晶状体荧光显微镜(Clearpath DS120)测定受检眼晶状体自发荧光强度,分析糖尿病患者晶状体自发荧光强度值与HbA1c水平和糖尿病程度的关系.结果 非糖尿病组、NDR组、NPDR组和PDR组间年龄和糖尿病病程总体比较差异均无统计学意义(F=2.587、2.899,均P＞0.05);NDR组、NPDR组和PDR组患者FBG和HbA1c水平均明显高于非糖尿病组,差异均有统计学意义(均P＜0.01).非糖尿病组、NDR组、NPDR组和PDR组受检眼晶状体自发荧光强度值分别为(0.159±0.032)、(0.256±0.024)、(0.319±0.013)和(0.394±0.035) cd,总体比较差异有统计学意义(F=90.265,P=0.000),其中NDR组、NPDR组和PDR组晶状体自发荧光强度值均明显高于非糖尿病组,且NDR组、NPDR组和PDR组随着病情的加重晶状体自发荧光强度值逐渐增加,差异均有统计学意义(均P＜0.01).糖尿病患者晶状体自发荧光强度值与血HbA1c水平呈中等线性正相关(r=0.654,P＜0.05).结论 糖尿病患者晶状体自发荧光强度值与DR严重程度和血HbA1c水平均有一定关联,在一定条件下可作为DR早期评估的指标之一.     

Torpedo maculopathy: a morphofunctional evaluation

To describe the optical coherence tomography (OCT), the standard short-wavelength fundus autofluorescence (SW-FAF) and near-infrared fundus autofluorescence (NIR-FAF), and the microperimetric findings in a child with a unique unilateral lesion of the temporal macula previously called torpedo maculopathy. A 4-year-old female with torpedo maculopathy was evaluated with spectral-domain OCT (SD-OCT), standard SW-FAF (excitation 488 nm, emission >500 nm) and NIR-FAF (excitation 787 nm, emission >800 nm). Microperimetry was performed to assess retinal sensitivity changes correlated to the macular lesion. SD-OCT showed an abnormally thin retinal pigment epithelium signal and an increased signal transmission in the choroid corresponding to the torpedo lesion with no neuroretinal changes. SW-FAF resulted in normal fluorescence of the lesion except for a small hyperfluorescent area at the tail level. NIR-FAF showed hypofluorescence corresponding to the lesion. Macular microperimetry showed reduced retinal sensitivity along the pigmented margins of the lesion with normal values over the lesion. The patient was re-evaluated 12 months later and no change was documented with all diagnostic techniques. This case supports a congenital defect of retinal pigment epithelium. The absence of both functional changes at lesion level and neuroretinal changes at OCT may depend on the very early detection of this lesion.