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PubMed1997

Relationship of protein-glutathione mixed disulfide and thioltransferase in H2O2-induced cataract in cultured pig lens.

It has been previously shown in H2O2-induced cataract model in the rat lens that protein-GSH (PSSG) formation precedes protein-protein disulfide (PSSP) conjugation and lens opacity. This elevated PSSG spontaneously reduces to a normal level when H2O2 is removed. To verify if thioltransferase (TTase), an enzyme that is known in other tissues to dethiolate PSSG, takes part in this recovery process, we examined the relationship of PSSG and TTase in this cataract model. To ensure enough tissue would be available for various biochemical studies, H2O2 induced cataract in pig lens was established and validated with the rat lens model. The study was divided into two parts. One part was to examine the effect of H2O2 concentration, ranging from 0.1 mM-10 mM, during 24 hr. Another part was to study the H2O2 (1.5 mM) induced cataract progression and recovery, parallel to the long-term study in rat lenses reported previously. These lenses were compared for transparency, wet weight, GSH, PSSG levels and the activity of two redox regulating enzymes, glutathione reductase (GR) and TTase. For the most part, pig lens responded to oxidation parallel to the rat lens except that a higher concentration of H2O2 was needed to achieve the same results. Damage induced by H2O3 was concentration dependent. In general TTase activity and GSH level were depleted with a concomitant increase in PSSG. The D50 (50% damage) for GSH in pig lens was 1.5 mM H2O2 (0.5 mM for rat lens) which was chosen for further studies in cataract progression and recovery. At 1.5 mM H2O2, pig lens showed superficial opacity within 24 hr and deeper cortical opacity in 48 hr. The pre-exposed lens became less cloudy when H2O3 was removed from the medium. Incubation of the lens in 1.5 mM H2O2 for one day also induced 50% GSH depletion and four fold PSSG elevations. This accumulated PSSG was dethiolated spontaneously in the absence of H2O2, similar to the findings in the rat lens and human lens models. In contrast protein-cysteine (PSSC) showed little change and did not respond to the recovery condition. TTase lost 50% activity in these lenses during 24-hr H2O3 exposure but regained most of it under recovery. The study on rat lens showed similar results as before, therefore only data on the relationship of TTase activity to PSSG level during cataract development and recovery is reported here. It was found that in the H2O2 (0.5 mM)-exposed rat lenses, the TTase activity was depleted but PSSG accumulation was accelerated within 8 hr. Both recovered quickly (within 8 hr) as soon as the oxidant was removed. Therefore, protein thiolation and dethiolation processes in the cultured rat or pig lenses display a mirror image with the activity pattern of TTase. Based on the close relationship between lens TTase and PSSG indicated above, it is speculated that TTase may regulate PSSG and maintain it at a low concentration in situ. This repair process may contribute to the improved transparency during recovery. Further studies are planned to substantiate this hypothesis.

Animals↗
PubMed1997

Steroid-induced cataract: new perspective from in vitro and lens culture studies.

The prevailing view regarding the mechanism of steroid cataract formation holds that glucocorticoids are covalently bound to lens proteins resulting in destabilization of the protein structure allowing further modification (i.e. oxidation) leading to cataract. Alternative hypotheses (e.g. that cataracts result from glucocorticoid receptor mediated effects) have been difficult to test since protein binding does in fact occur for many cataractogenic steroids. A glucocorticoid lacking the typical glucocorticoid hydroxy group at C21 (fluorometholone, FML), other steroids which can bind to proteins but lack glucocorticoid activity, and a glucocorticoid antagonist (RU486) have been utilized to discriminate between these two hypotheses. Purified bovine beta-crystallin incubated with three different 3H-steroids, dexamethasone (Dex), aldosterone or progesterone demonstrated that the C-21 hydroxyl group is not essential for steroid binding. Progesterone (with no C-21 OH) bound to the greatest extent. Pretreatment of the protein with aspirin to acetylate the free protein amino groups blocked this binding, demonstrating the probability of a Schiff base mechanism. Lens culture studies with the same three radiolabeled steroids demonstrated much the same result. Rat lenses cultured for 48 hr-11 days, demonstrated that loss of GSH is an early and significant effect of several glucocorticoids (Dex, prednisolone and FML) but is not seen with other non-glucocorticoid steroids. However, none of the steroids tested consistently produced lenticular opacification (i.e. cataracts) in this in vitro system, nor did they alter rubidium transport. We suggest that a mechanism other than covalent binding of steroids to lens proteins is responsible for glucocorticoid induced cataracts because: (1) non-glucocorticoids were demonstrated to bind lens proteins as well or better than the glucocorticoid Dex and (2) only glucocorticoids, and not other steroids, lowered lens reduced glutathione content which has been demonstrated to be associated with other forms of cataract.

Aldosterone↗
PubMed1998

An impediment to glutathione diffusion in older normal human lenses: a possible precondition for nuclear cataract.

Human age-related nuclear cataract is associated with progressive and widespread oxidation of proteins, particularly in the centre of the lens. The reasons for the onset of cataract and why this disease should take place only in the lenses of older individuals remain unclear. However, a common feature of nuclear cataract is the low concentration of reduced glutathione (GSH) in the centre of the lens. GSH is the principal lenticular antioxidant of the lens and it is synthesized and regenerated in the lens cortex. In this study we investigated the diffusion of glutathione within the human lens as a function of age. Normal human lenses were incubated in artificial aqueous humor containing [35S]cysteine and the label was metabolically incorporated into GSH. After 48-h incubation, lenses were sectioned and phosphorimaging was used to determine the distribution of 35S label. In young lenses, label appeared to diffuse uniformly throughout the whole lens. By contrast, in lenses over the age of 30, very little 35S had penetrated to the centre of the lens. A distinct zonal pattern of label distribution was noted in the older lenses after 48 h incubation, which had dimensions of approximately 7.2 mm (diameter) by 2.8 mm (axial). In some older lenses this pattern was noticeable even after 96-h incubation. Thus a barrier to the diffusion of GSH was observed in older normal lenses which was not present in younger lenses. Furthermore, the internal zone thus delineated has dimensions that coincide with those of the coloured and sclerotic zone present in nuclear cataract lenses. Since nuclear cataract is a disease of the elderly, and maintenance of GSH is known to be vital for lens clarity, we propose that the development of a barrier to the movement of GSH from its site of synthesis and regeneration in the cortex, into the nucleus in older normal lenses, may over time allow oxidative modification of protein to take place in the nucleus, resulting ultimately in nuclear cataract.

Adolescent↗
PubMed1999

Localization of MIP 26 in nuclear fiber cells from aged normal and age-related nuclear cataractous human lenses.

The purpose of the current study was to localize the lens membrane protein, MIP 26, in nuclear fiber cells from different regions of aged normal and age-related cataractous human lenses. Adult, juvenile, fetal and embryonic nuclear regions in aged normal and age-related nuclear cataractous lenses were morphologically and biochemically characterized using the technologies of immuno-gold (5 nm) labeling, semi-thin sections (200-500 nm), serial sections, DiI staining following by photobleaching, transmission electron microscopy and spot-blot analysis. Numbers of gold particles per micron length of plasma membrane and numbers of gold particles per square micron of cytosol in the embryonic-fetal and juvenile-adult nuclear regions were quantified. Results showed that the labeling pattern of MIP 26 localized to the cytosol was unique to senescent fiber cells from age-related cataractous lenses. Numbers of gold particles per square micron of cytosol in the embryonic-fetal nucleus of age-related cataractous lenses were significantly elevated (P<0.001) above numbers from fiber cells located within the adult or juvenile nuclei of the same lens or senescent fiber cells from aged normal lenses. Some of the cytosolic labeling in cataracts was localized to lipid vesicles, while the remaining labeling was negative for the lipid specific stain DiI. Spot blot analysis demonstrated that binding of the ant-MIP 26 serum was exclusive to large molecular weight components greater than 10 kDa, and not to small molecular weight fragments of the protein. The results of the current study supply further evidence that damage to membranes occurs in senescent fiber cells during age-related nuclear cataracts, resulting in the internalization of structures containing the membrane protein MIP 26.

Aged↗
PubMed2000

Formation of hydroxyl radicals in the human lens is related to the severity of nuclear cataract.

Recent studies have identified specific hydroxylated amino acid oxidation products which strongly suggest the presence of hydroxyl radical (HO.)-damaged proteins in human cataractous lenses. In the present study, the ability of early stage (type II) and advanced (type IV) nuclear cataractous lens homogenates to catalyse HO. production in the presence of H(2)O(2)was investigated using electron paramagnetic resonance (EPR) spectroscopy with the free radical trap, 5,5-dimethyl-1-pyrroline- N -oxide (DMPO). Cataractous lens homogenates incubated with 1 m m H(2)O(2)generated a distinct HO. signal, which was significantly more intense in the nuclear region of the type IV compared to the type II lenses. The ability of individual lens nuclei and cortices to stimulate HO. production was positively correlated. The DMPO-HO. signal was competitively inhibited by ethanol, confirming that the DMPO-HO. signal was due to HO. formation and not DMPO-OOH degradation. The metal ion chelator, diethylenetriaminepentaacetic acid, also inhibited HO. formation, indicating that lenticular metal ions play a key role in HO. formation. Cataractous lens homogenates also stimulated ascorbyl radical production, further suggesting the presence of redox-active metal ions in the tissue. Analysis of lenses for total Fe and Cu (using atomic absorption spectrometry) showed that the more advanced type IV lenses tended to have higher Fe, but similar Cu, levels compared to the type II lenses. The levels of both metals were lower in non-cataractous lenses. These data support the hypothesis that transition metal-mediated HO. production may play a role in the aetiology of age-related nuclear cataract.

Ascorbic Acid↗
PubMed2001

Suppressive effects of thyroxine on glucocorticoid (gc)-induced metabolic changes and cataract formation on developing chick embryos.

To prevent cataracts induced by glucocorticoids (GC) as a systemic disease, the suppression of oxidative stress caused by GC in the hepatic metabolism is of significant interest. In this study, to elucidate the formative mechanism of GC-induced cataracts, we examined the preventive effect and then analysed the mechanisms of thyroxine on GC-induced cataract formation. Fifteen day old chick embryos were administered with 0.25 micromol hydrocortisone succinate sodium (HC), and then 12-30 nmol of thyroxine 4 hr after HC administration. At the indicated time after HC treatment, we examined the incidence of cataract formation, the levels of serum glucose and lipids, lenticular and hepatic glutathione (GSH), and lipid peroxide (LPO) in the lens, blood and liver. Almost all lenses (96%) removed 48 hr after HC administration were opaque. Thyroxine prevented HC-induced cataract formation effectively, and suppressed the elevations of serum glucose and LPO in the lens, blood and liver. The treatment prevented the decreased lenticular GSH level at 48 hr, but the hepatic GSH level at 24 hr remained lowered in contrast to the results of previous studies using insulin. Moreover, thyroxine did not decrease the elevated serum lipid level (triglyceride and non-esterified fatty acid) caused by HC. Under thyroxine treatment, in constant to insulin, acceleration of GSH-GSSG cycle rather than GSH de novo synthesis keeps a certain level of hepatic GSH necessary for diminishing the elevation of LPO as a risk factor of GC-induced cataract formation. The regulation of metabolic changes ensured the maintenance of hepatic GSH level, which is necessary to reduce oxidative stress produced by GC and to protect the lens from oxidative stress leading to opacification.

Animals↗
PubMed2001

The effect of high and very low fluorescent light exposure levels on age-related cataract in a pigmented mouse strain.

This study examined the effect of fluorescent light on the timing and severity of age-related cataracts in a fully pigmented mouse strain, the (C57BL/6 x C3H)F1, that normally develops slowly progressing age-related cataracts only beyond middle age. Two groups of 56 animals each were exposed, respectively, either to a daily range of 66-222 foot candles (FC) or to 1 FC of standard fluorescent lighting for a period beginning at 5 weeks of age and ending at 33.5 months (by which time approximately 65% of the colony had died). Contrary to previous reports involving albino rats or mice and a strain of pigmented but cataract-prone transgenic mice, the two groups of animals in this experiment did not differ for cataract development in time of first occurrence, rate of advancement, or degree of severity. It was concluded that genetic predisposition, based on levels of oxidative free radical production vs antioxidant enzyme and repair enzyme protection in the lens, was probably the major factor governing the rate and degree of age-related cataract development in these animals. The effect of relatively intense life-long fluorescent light exposure was so minimal as not to be manifested in this strain of mice under the conditions of this experiment. Remarkably, maintaining the one group of mice in semi-darkness from 5 weeks of age to beyond their mean lifespans did nothing to delay or reduce the incidence or severity of their age-related cataracts.

Age of Onset↗
PubMed2001

Biochemical and morphological changes during development of sugar cataract in Otsuka Long-Evans Tokushima fatty (OLETF) rat.

The relationship between the polyol pathway and sugar cataracts has been studied extensively using streptozotocin-induced diabetic rats and galactose fed rats as animal models for insulin-dependent diabetes mellitus (IDDM). In these models, sugar cataracts progress quickly, leading to rapid lenticular polyol accumulation in the early stages of cataract formation. In 1992, a new animal model of non-insulin-dependent diabetes mellitus (NIDDM), the Otsuka Long-Evans Tokushima Fatty (OLETF) rat, was established. In the present study, we examined both biochemical and morphological changes in the lenses of the OLETF rats to determine whether these changes reflect those associated with diabetic cataract formation and to clarify their relationship with the polyol pathway. For the biochemical analysis, we measured the enzyme activity of aldose reductase (AR) and sorbitol dehydrogenase (SDH) and the sorbitol levels using 20, 40 and 60 week old OLETF or control Long-Evans Tokushima Otsuka (LETO) rats. Enzyme activities of AR and SDH, which were lower in 20 week old OLETF rats than in LETO rats, were increased in 60 week old OLETF rats. The lenticular sorbitol level of the OLETF rats was similar to the control level at 20 weeks of age, but it was markedly increased at 40 weeks of age, and slightly decreased at 60 weeks of age compared with rats at 40 weeks but not compared with controls. Slight lens fiber swelling was observed in the anterior and/or posterior subcapsular regions of 40 week old OLETF rats, accompanying elevated sorbitol level and slightly increased SDH activity in the lens. Swelling and liquefaction of lens fibers were observed in the subcapsular and supranuclear region of 60 week old OLETF rats, as well as decreased lenticular sorbitol, and markedly increased SDH activity compared with rats at 40 weeks. AR activity was also increased causing the elevation of sorbitol in lenses of OLETF rats during the early stages of cataract formation. Despite differences in the etiology of diabetes mellitus, the strain of rat and the rate of disease progression in the OLETF rat model compared with other diabetic models, the present results support the theory that the polyol pathway via AR is a factor in the development of sugar cataracts.

Aldehyde Reductase↗
PubMed1986

Vision through nuclear and posterior subcapsular cataract.

We have developed a new set of tests for evaluation of visual function through media opacities, based on vernier acuity measurements (hyperacuity). In this paper, results of one of these tests, the 'gap test', are compared in patients with posterior subcapsular (PSC) cataract versus nuclear cataract (NC). Patients with PSC cataract often report multiple images or significant 'star burst' effects. We hypothesized the presence of 'multi-prismatic' and/or high frequency spurious resolution phenomena due to PSC cataract characteristic substructure. We were able to minimize these effects by using a pinhole held close to the eye, a large (adapting) background field of white light superimposed on the vernier test targets, a low-pass spatial filter applied to the targets. When the particular problems associated with PSC cataract are not present or are adequately addressed and when patients are matched for visual acuity, the hyperacuity 'gap test' shows less functional effect due to the opacity for PSC cataract than NC in all the cases we have tested. These findings, moreover, indicate that visual acuity provides an insufficient description of the effects of intraocular scattering on image formation. The results emphasize the importance and the necessity of developing models that better clarify the specific effects of different types of ocular media opacities.

Aged↗
PubMed1990

Clinical and physical measurements of the cataractous lens.

In connection with the clinical trial of an anti-cataract drug (Bendazac lysine) a number of examination methods were used to assess the progress of the cataract: slitlamp examination, visual acuity determination, and the measurement of the contrast sensitivity, light scatter in the eye and the autofluorescence and transmission of the lens. In this article the measurements of 43 patients (43 eyes) are presented, taken at the time that medication was started. In this way we can get an impression of the value of these measurements for the study of cataractous lenses. The contrast sensitivity of the cataractous eye is lowered for all spatial frequencies as compared with the normal population. Light scatter is greatly increased. The autofluorescent profile of the lens with nuclear cataract differs markedly from that of the lens with cortical cataract.

Aged↗
PubMed1993

Morphological study of the cataractous lens of the senescence accelerated mouse.

A murine model of accelerated aging, the senescence accelerated mouse (SAM), has been developed. There are three accelerated senescence-resistant (SAM-R) strains and eight senescence-prone (SAM-P) strains. The SAM-P strains have an earlier onset and more rapid advancement of senescence resulting from a significantly shorter lifespan compared with the SAM-R strains. Spontaneous cataracts have been found in some individuals of the SAM-P/9 strain. The SAM-P/1 strain, which was used in the present study, has such systemic senescent characteristics as senile amyloidosis and alopecia, but it was previously thought that cataract does not occur in this strain. However, we found cataractous changes in the lens of these animals at early stages of their life. The earliest change was the appearance of a ripple-mark body at about 3 months of age. The number of rippled rings increased with age. These changes later induced refractive distortion of retinal vessels. Whole-mount flat preparations of the epithelium showed that the number of cells was markedly decreased at the advanced stages of cataract. At the late stages of life the lens cortex became liquefied and developed into a mature cataract. Cataract formation in this strain may be related to reduced viability of the lens epithelium.

Aging↗
PubMed1990

The mechanisms of cataract formation.

This review summarizes current knowledge concerning cataract formation. Metabolically induced forms of cataract are discussed, but mainly aspects of cataract formation in older patients are described, especially with respect to lens protein modifications and epidemiological results. In most cases, cataract in older people is a multifactorial process and therefore cataracts appear in a multitude of different morphological types. Only accurate documentation of lens disturbances and the use of reproducible methods can provide more detailed information about the complexity of the disease cataract.

Aged↗
PubMed1990

Plasma polyol levels in patients with cataract.

Galactitol and sorbitol concentrations in plasma were determined in patients (with or without cataract) in whom homo- or heterozygosity for galactokinase, galactose-1-phosphate uridyltransferase, systemic or peripheral UDP-galactose epimerase and sorbitol dehydrogenase deficiency was confirmed. For the above disorders it can be concluded that elevation of plasma polyols is not always related to the presence or absence of cataract. In all cases with cataract, however, the plasma galactitol or sorbitol levels were elevated. In another group of patients with unexplained congenital or infantile cataracts, but without apparent enzyme defects, mild to moderately elevated concentrations of plasma galactitol or sorbitol were found in about 45%. In 8% of this group the cataract and the elevated plasma galactitol concentration could possibly have been related to partial maternal enzyme deficiency. In all the other cases the elevated plasma polyol concentration remains unexplained but could indicate a further cause of cataract formation due to a hitherto unknown galactose or glucose metabolic aberration.

Carbohydrate Epimerases↗
PubMed1995

Lens sorbitol dehydrogenase deficiency in a patient with congenital cataract.

UNLABELLED: Lens sorbitol dehydrogenase activity was assayed in patients with congenital cataracts, senile cataracts, without cataracts and in one fetal lens. In patients with congenital cataracts we did not observe any abnormality of galactose and sorbitol metabolising enzymes in erythrocytes. In one of these patients with inexplicable congenital cataracts lens sorbitol dehydrogenase deficiency was found. CONCLUSION: Determination of galactose metabolising enzymes, sorbitol dehydrogenase and polyols in lenses may help in understanding the mechanism of formation of inexplicable congenital cataracts.

Cataract↗
PubMed1986

The lenticular capsule and cellular migration in anterior capsular cataract.

A light and electron-microscopical study was performed on six lenses harboring anterior capsular cataract. The cataracts are typically divided by numerous sheets of basement membranes that merge with the lenticular capsule at the edge of the cataract. Basally, the cataract may or may not be bounded by a basement membrane. Myofibroblastlike cells may be observed, apparently traversing the basal border of the capsular cataract. Within the substance of the lens, isolated aggregations of collagenous material are present. Degenerating cells or collagenous aggregations are situated within the lenticular capsule. It is suggested that this configuration arises through the merging of basement membrane systems, surrounding the cells within the cataract, with the lenticular capsule.

Adult↗
PubMed2001

Two interactive genes responsible for a new inherited cataract (RCT) in the mouse.

We discovered a mutant mouse, RCT (Rinshoken cataract), with a new congenital cataract in strain SJL/J. The opacity of the lens associated with microphthalmia could be observed visually at 3 to 3.5 months of age. Marked degeneration of the lens, including loss of the fine structure of the lens fibers and swelling of epithelial cells with vacuoles of various sizes in the cortex, but no other defects except photoreceptor degeneration in the retina, was detected. Histological change in the lens was first observed at 2 days after birth. No sex-related differences were detected, and normal phenotypes in the F1 progeny of RCT and normal mice indicated that the cataract was recessive. The chromosomal location of the causative gene was determined by interval mapping by using intersubspecific backcross progeny of RCT and MSM/Ms, an inbred strain from the Japanese wild mouse Mus musculus molossinus. Backcross progeny were divided into three groups according to phenotype: mice (1) with an early-onset cataract, which can be detected visually as in RCT mice, (2) with a late-onset cataract, which can be detected histologically but not visually, and (3) with a normal lens. Three phenotypes were found to be expressed by allele combinations of two recessive genes, rct and mrct (a modifier of rct). The rct locus essential for the onset of the cataract was tightly linked to D4Mit278 on Chromosome (Chr) 4 with no recombination. The mrct locus was closely linked to D5Mit239 (chi2 = 66.3, P << 0.00001) on Chr 5.

Animals↗
PubMed2005

Combined cataract and glaucoma surgery: endoscope-controlled erbium:YAG-laser goniotomy versus trabeculectomy.

BACKGROUND: To compare endoscopic infrared laser trabecular ablation and trabeculectomy (both combined with cataract surgery) regarding intraocular pressure (IOP), visual acuity, anti-glaucomatous drugs and complications. METHODS: Seventeen eyes of 14 patients [age 74.7+/-11.7 years (arithmetic mean +/- standard deviation)]-13 with primary open-angle glaucoma (POAG) and four with pseudoexfoliation glaucoma (PEXG)-underwent standard cataract surgery. After lens implantation, a probe (1.1 mm external diameter) with optic and laser fibres and an irrigation tube was introduced through the cataract incision. To perforate Schlemm's canal, 15-17 single pulses (16 mJ, 160 micros) were applied using a photo-ablative infrared laser (Er:YAG, lambda=2.94 microm). All eyes except one received antiglaucoma treatment. The control group treated with cataract surgery and trabeculectomy consisted of 17 eyes (13 POAG, four PEXG) of 15 patients (age 75.0+/-5.6 years), each eye received antiglaucoma treatment. RESULTS: Mean follow-up was 3 years. The eyes treated with the endoscopic laser showed a mean preoperative IOP of 23.3+/-4.3 mmHg, which was reduced to 15.0+/-2.1 mmHg (mean IOP lowering 33.7%) after 3 years. Five eyes needed no medication for IOP-control after the procedure. Two eyes needed further surgery for IOP-control. In the control group, mean IOP was 24.5+/-2.6 mmHg in the beginning and 17.3+/-6.2 mmHg after 3 years, corresponding to a 33.3% lowering of IOP. Six eyes needed no medication, four eyes needed further surgery to lower IOP. CONCLUSIONS: After 3 years follow-up of a small pilot group, combined endoscopic infrared laser surgery with cataract surgery seems to be a safe and effective way to lower IOP. It shows the same ability to lower IOP as combined cataract surgery with trabeculectomy. In addition, there are markedly less complications with the endoscope-controlled photo-ablative laser procedure.

Aged↗
PubMedDate not supplied

Evaluation of optical function using a new point spread function analysis system in cataractous and pseudophakic eyes: preliminary results.

PURPOSE: To evaluate optical function in cataractous and pseudophakic eyes using the new point spread function (PSF) analysis system in a clinical setting. METHODS: We applied this new analysis system in the study of two cataractous eyes and one pseudophakic eye of two patients. Using a PSF analyzer, double-pass PSF was measured directly for each subject, and the single-pass modulation transfer function (MTF) and single-pass PSF were calculated. The simulated retinal images of various sizes of Landolt's rings and their contrast characteristics were also calculated by the PSF analyzer. RESULTS: The MTF and the contrast of the simulated retinal images degraded in cataractous eyes were compared with data for normal eyes; the degradation pattern depended on the opacification pattern. The MTF and the contrast of the simulated retinal images in the pseudophakic eye improved significantly compared with the cataractous eyes, although both values were lower in the pseudophakic eye than in young normal eyes. CONCLUSIONS: Our data showed degradation of optical function in cataractous and pseudophakic eyes in comparison with optical function in young normal eyes. If further accumulations of PSF data are made, it may be possible to establish an objective standard by which to measure the progression of cataract, as well as an objective indication for treatment in the future.

Aged↗