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The visual outcome of cataract surgery in diabetics with retinopathy is poorer than in non-diabetics, and appears to be particularly poor in eyes with maculopathyl. Postoperative macular oedema may represent clinically significant macular oedema unrecognized or untreated because of lens opacity, diabetic macular oedema stimulated or exacerbated by cataract surgery2–5, or a form of the Irvine Gass syndrome6,7. The reduction in incidence of postoperative astigmatism and inflammation associated with the adoption of small incision techniques for cataract surgery permits an attempt to redefine these syndromes, which we undertook using intraoperative and serial postoperative fundus fluorescein angiography.

Cystic fibrosis (CF) is a fairly common lethal genetic disease in whites, inherited via an autosomal recessive pattern. Several clinically evident anomalies of the eye such as xerophthalmia, papilledema, retinal alterations and optic neuropathy have been described. In the present study we investigated lens changes in 40 patients affected by CF, to relate the results to the stage of digestive insufficency. Each patient underwent an accurate ocular examination including visual acuity, slit-lamp examination, and measurement of lens transparency with the Opacity Lens Meter 701. The results were compared with those of an age- and sex-matched control group. The comparison between the lens opacity values obtained in the CF patients and those measured in the control group showed a statistically significant difference; moreover, lens transparency was more decreased in patients with severe digestive insufficiency.

The present study describes the influence of cataract on high-pass resolution perimetry results. Twenty-five otherwise healthy patients were examined before and after cataract surgery. Their preoperative visual acuities ranged from 0.1 to 0.8 and their mean resolution thresholds from 3.9 to 12.3 dB. Both elevated mean thresholds and local visual fields defects were observed. In patients with low-grade cataract, i.e. preoperative visual acuity 0.3 to 0.65, the mean improvement in perimetric results after operation was approximately 1 dB. In patients with higher degrees of lens opacity, visual acuity 0.1 to 0.25, the difference between pre- and postoperative perimetry results showed a wide range, 1.4-6.2 dB. In conclusion, cataract induced different types of visual field defects. The general threshold increase due to low-grade cataract (VA > or = 0.3) could be compensated for by subtracting 1 dB from the measured value.

The increasingly widespread use of cellular phones, and the general proliferation of radiofrequency (RF) or microwave equipment in modern telecommunications, have generated an increasing interest in possible adverse health consequences of the ensuing exposure to RF fields. Epidemiological studies offer — in principle — powerful tools for evaluating the impact on humans of occupational or environmental exposures. In a recent ‘opinion piece’, Goldsmith (1995) summarized that he ‘presents evidence that sufficient microwave exposures are associated with all four of these outcomes . . . ’, one outcome being cancer. A WHO report (1993), on the other hand, concluded that ‘epidemiological . . . studies do not provide clear evidence of detrimental health effects in humans from exposure to RF fields’. It thus appears prudent to review epidemiological studies of RF exposures, with particular emphasis on studies relevant to mobile telecommunication situations.

The purpose of the present study was to evaluate the change in visual acuity and refraction taking place in eyes with progressing early lens opacities. Four hundred and ten hypercholesterolemic men in Eastern Finland who participated in the Kuopio Atherosclerosis Prevention Study were followed up for 3 years. Lens opacities were graded using the lens opacity classification system II (LOCS II). The change of visual acuity and refractive error from baseline to a 36-month examination was compared for different types of lens opacities. During the 3-year period, progression in the LOCS II was observed in 9.2% of the eyes for nuclear, in 4.8% for cortical and in 0.5% of the eyes for posterior subcapsular opacities. Increasing nuclear sclerosis reduced visual acuity statistically significantly both with and without correction. Hypermetropization was seen to continue in eyes with no lens opacity progression. Myopization was more common in eyes with lens opacity progression, although this was not statistically significant.

To assess the crystalline lens opacity level by measuring ocular light scattering with a double-pass system.Prospective, single-center, cross-sectional study.Two hundred fifty-three eyes of 135 patients referred for cataract evaluation were enrolled. Patients with corneal or retinal anomalies potentially impairing ocular transparency were excluded. Lens opacification was assessed by the Lens opacities classification system III. Optical Quality Analysis System (Visiometrics SL) measurements provided ocular Modulation Transfer Function cutoff frequency and Objective Scatter Index. Best-corrected visual acuity and Quality of Vision questionnaire scores (Rasch-scaled) were recorded. We analyzed correlations between visual acuity, type and severity of cataract, Optical Quality Analysis System measurements, and discomfort level in each group.In patients with best-corrected visual acuity better than 20/32, we found correlations between Objective Scatter Index, Modulation Transfer Function, and visual acuity (r = 0.4, P.0001). The Objective Scatter Index, Modulation Transfer Function, and visual acuity were correlated with each type of cataract. In patients with good visual acuity and moderate functional symptoms, the Objective Scatter Index values also were correlated to the severity of posterior subcapsular cataract (r = 0.4, P = .0006).Patients with incipient cataract may report visual discomfort, despite minor lens opacity on slit-lamp examination, minor loss of best-corrected visual acuity, or both. The measurement of ocular scattering with the Optical Quality Analysis System device may be a useful tool in the preoperative evaluation of patients with early cataract.

Age-related lens opacity is the major cause of loss of vision affecting more than half of the world's blind. The development of cataract is associated with changes in the structure of the lens. The lens consists largely of closely packed fibre cells forming a transparent syncytium. The main intrinsic polypeptide (MIP) of the lens fibre cells forms 40% of the fibre membrane, and forms a system of membrane channels. The precise structure and function of these channels remains obscure, although their role as large water-filled channels has been suggested in maintenance of structural integrity as well as their role in transport of nutrients. MIP is a member of a large family of channels of common ancestry. Some of the most recent studies of structure and function of this family have been carried out on CHIP (a water channel found in red blood cells) which is a member of this family closely related to MIP. Both CHIP and MIP m-RNA's have been expressed in oocyte membranes, and water permeabilities per channel have been measured. Surprisingly, CHIP and MIP channels have high and low water permeabilities, respectively. This is discussed in terms of recent high resolution structure determinations, the lens fibre MIP function, and future studies.

Purpose To propose a general conversion approximation algorithm and illustrate its application to two cataract classification systems, the Lens Opacity Classification System III (LOCS III) and Wisconsin Cataract Grading System (Wisconsin system). Methods Lens opacity of 3265 participants (78.7% response rate) aged 40 to 80 years from the Singapore Malay Eye study were assessed both clinically during slit-lamp examination using LOCS III, and via slit-lamp and retro-illumination photographic grading using the Wisconsin system. Collapsed contingency tables were used to convert between the LOCS III and Wisconsin System. Results The conversion between the two cataract classification systems is affected by the direction of transformation. The conversion algorithm was validated and explained with an application example. Conclusions An approximate conversion algorithm for any two cataract grading systems was proposed and applied to the LOCS III and Wisconsin system. These findings provide general ways to pool and compare cataract prevalence using different grading systems in epidemiological studies.

We compared pre- and postoperative visual acuities in 45 cataract patients without ocular pathology except lens opacity (group 1) and 20 patients with ocular pathologies and lens opacity (group 2) using Variable Contrast Visual Acuity Charts. Charts 1 and 4 have 90% contrast; chart 4 has white optotypes on a black background (reverse polarity), charts 2 and 3 have 15% and 2.5% contrast, respectively. The mean preoperative visual acuities of groups 1 and 2 measured with the high-contrast Landolt optotypes ranged from 0.02-0.80 and 0.22-0.40, respectively. Visual acuity improvements between the pre- and postoperative periods ranged from 1.37-1.61 and 0.52-1.24 octaves in groups 1 and 2, respectively, with the different charts. Visual acuity improvement was poorest with chart 3. The group 1 mean preoperative visual acuity measured with chart 2 was 1.11 octaves lower than with chart 1. In group 2, the visual acuity reduction was 1.81 octaves. The relation between the visual acuities measured with the high-contrast intermediate-contrast optotypes are important for predicting postoperative visual acuity improvement. An abnormal contrast acuity profile may indicate the presence of additional ocular pathologies.

The knowledge of the multifactorial genesis of the so-called senile cataract has initiated an intensified search for cataract-related risk factors. The mechanisms of syn- and cocataractogenesis could already be shown in the Department of Experimental Ophthalmology, Bonn, in the seventies. Subsequently, cataract epidemiology became a field of interest in 1980 when all available epidemiological data related to cataract research were first collected and reviewed. It has become obvious that the various types of cataract morphology do not represent one unique disease ‘senile cataract’ but reflect different biochemical characteristics. A preliminary study assigned data of case history as well as blood and lens biochemistry to four types of lens opacity. Scheimpflug photography and multilinear microdensitometry were the basis for classifying cataract lenses. After increasing the number of involved patients, the data were analyzed by means of multivariate statistics. The originally used cataract classification system was enlarged to eight types of frequently seen cataract morphologies. A control group was built up to enable case-control studies as well as to obtain characteristics of normal lens density related to age.

The sensitivity of the visual field declines with age. The density of the crystalline lens increases with age and may be partly responsible for the decline in sensitivity. To determine whether lens opacity influences the mean threshold of the visual field, 82 normal subjects were enrolled. All had their lens opacity measured with the Interzeag Lens Opacity Meter 701 and the visual field assessed with the Ring Resolution Perimeter. Lens opacity was highly correlated with age, while mean visual field threshold was also correlated with age but showed much greater variation. Multiple regression failed to show any influence of lens opacity measurements on the mean field threshold after age had been accounted for.

The effect of ascorbic acid 2-O-alpha-glucoside (AA-2G) on hydrocortisone (HC)-induced lens opacity in developing chick embryo was examined and compared with those of ascorbic acid (AsA) and ascorbic acid 2-phosphate (AA-2P). The opacity was dose-dependently inhibited by a single administration of 10 or 20 mumol/egg of AA-2G and by three repeated administrations of 1, 3 or 10 mumol/egg of AA-2G. AA-2G was the most effective among the three compounds. Glucose did not enhance the preventive effect of AsA against HC-induced opacity, and neither dehydro ascorbic acid nor glucose also prevented HC-induced cataract. In the histological study, we observed many small vacuoles in the nuclear region of the opaque lens treated with HC. AA-2G inhibited the formation of such vacuoles, an effect closely correlated with the prevention of cataract formation.

X-ray irradiation and a galactose diet are two of the main approaches to experimental cataractogenesis that provide a useful model for examining the changes in the lens compared to human cataract. We measured the lens thickness in six sibling New Zealand rabbits with an RF signal, before and after irradiation and a galactose diet. In this paper we discuss our results and the importance of ultrasonic evaluation with an RF signal, to discover the early stages of cataract, before the appearance of lens opacities.

Purpose: To investigate the changes of visual field index (VFI) compared with mean deviation (MD) and pattern standard deviation (PSD) before and after cataract surgery. Methods: The present study included 77 eyes of 77 patients who were diagnosed with both glaucoma and cataracts and underwent cataract surgery. Preoperative and postoperative VFI, MD, and PSD were examined. Lens opacity type was classified as cortical, nucleosclerosis, or posterior subcapsular opacity (PSCO), and the MD, PSD, and VFI were compared before and after cataract surgery. Results: Preoperative and postoperative MD were -13.648.97, -11.949.67(p=0.113), PSD were 6.183.30, 5.913.31(p=0.344), and VFI were 67.0033.43, 70.5533.19(p=0.440), respectively. MD showed statistically significant difference in cortical and PSCO type before and after cataract surgery. PSD (p=0.025) and VFI (p=0.020) showed a statistically significant difference in cortical type. Conclusions: VFI is an effective parameter to monitor the progression of glaucoma in cataract patients with nucleosclerosis and PSCO, but has limitations in cataract patients with cortical opacity.

Age-corrected normal values for the Opacity Lens Meter (OLM) 701 were established by measuring 1598 eyes of 799 healthy volunteers. This study revealed a remarkable age-relation for the normal values. The average readings of the OLM of the 30-year-old subjects were around 10 units whereas the average for the 65-year-olds was close to 20 units. The best fit of the opacity vs. age was a quadratic function. The interindividual variation was small in the young and quite large in the older population. The correlation between contralateral eyes was high (R = 0.93).

The possibility of a relation between high myopia and lens opacity was studied. For this research, the Lens Opacity Meter 701 was used. The lens opacity values measured in 91 high-myopic eyes were compared with those measured in a control group of 106 emmetropic eyes. This comparison showed that myopic had always higher lens opacity values than emmetropic ones, and this result was statistically significant after the age of 20.

Color vision was studied in normal subjects above 50 years of age with the two equation method consisting of the red-green Rayleigh equation and the blue-green Moreland equation. In both matches, increasing age induced a slight progressive drift of the Match MidPoints (MMP) towards the short-wavelength primary. The drift was more pronounced for the Moreland match than for the Rayleigh match. Age had no effect on the Matching Ranges (MR), which remained within the limits of normality established for young subjects. Analysis of the results suggests that aging of the crystalline lens is responsible for the observed modifications of color vision. In clinical practice, this age effect can be neglected for the Rayleigh match, but it has to be taken into consideration for the Moreland match.

Since the suggestion to use sodium hyaluronate as a replacement for vitreous and aqueous humor by Balasz in 1972 [1], visco-surgery has gained far-reaching importance. The most widely used substance is 1% sodium hyaluronate (Healon, Pharmacia) which is biologically inactive, highly purified and has a molecular weight of approximately 4000000. It is viscous and highly elastic and not metabolized in the eye. A number of other viscous substances are available such as a combination of sodium hyaluronate and chondroitin sulphate, hydroxypropyl methylcellulose as such and in combination with chondroitin sulphate. The development of high viscosity substances is in progress and nonresorbable cross-linked hyaluronic acid has been used in experimental investigations on the rabbit eye [2,3].

The Lens Opacity Meter 701 (Interzeag, Switzerland) is a recently developed instrument for assessing cataract. It measures the degree of scatter of a red light beam by the lens. Fifty patients prior to cataract surgery had measurements made before and after dilatation of the pupil. Inconsistent results were found at pupil diameters of less than 4 mm. It is postulated that this was due to absorption of scattered light by the iris.

This report presents the results of a study designed to verify the influence of lens opacities on the visual field indices. Four age-matched groups of subjects were considered: healthy volunteers, glaucomatous patients without lens opacities, cataractous patients without glaucoma and glaucomatous patients with lens opacities. The quantification of lens opacities was performed with the Lens Opacity Meter 701 instrument. The visual field indices were obtained automatically from the G1 program of the Octopus system. The statistical analysis of the results (coefficient of correlation) has shown that only the visual field indices that correspond to uniform and diffuse loss of light sensitivity were influenced by the presence of cataract. On the contrary, the visual field indices that indicate local irregularities of the threshold were not significantly influenced by the presence of lens opacities.

Thirty five patients with proliferative diabetic retinopathy were examined with ultrasound. The authors show the correlation found between echography and vitreous surgery findings.

This chapter discusses diseases of the lens. Cataract means that the lens becomes opaque, but in the early stages this does not mean that the eye is blind. In fact, most old people have slight opacities in the lens which cause little or no loss of vision at first. Such cataracts are called early or immature cataracts. However, as the opacity progresses, the vision becomes increasingly blurred. When eventually the lens becomes totally opaque, the eye goes blind, and this is called a mature cataract. The progression of lens opacities varies very much. Sometimes a patient develops a mature cataract only a few months after the first signs of opacity in the lens. On the other hand, early opacities can be present in the lens for many years with no obvious progression at all. However, if opacity has formed, then it does not normally disappear spontaneously. The main symptom of lens opacity is a gradual and progressive loss of visual acuity. Eventually, when the cataract is mature, there is only perception of light.

The lens opacity meter, a recently developed clinical device for the examination of cataractous lenses, was used to evaluate nuclear opacification. In 215 noncataractous lenses of subjects aged 6–86 years, the opacity value (OV) ranged from 5.2 to 24.8 and increased with ageing. The OV measured in cortical cataracts with intrapupillary opacification was relatively higher than that without opacities. The scattered light intensity of the nuclear zone, measured from a Scheimpflug image, correlated well with the OV. In some cases with noncataractous eyes, the correlation between small-sized protein particles and the OV was examined. The lens opacity meter is useful to objectively evaluate changes in nuclear opacity.

We measured the lens thickness in a group of patients with normal lenses compared to a group of patients with different age and with various types of lens opacities.

Lens opacity was quantified in 85 cataractous patients, using a new instrument: the lens opacity meter 701 (LOM; Interzeag, Schlieren, Switzerland). Cataracts were classified as nuclear, cortical, subcapsular and mixed forms. Sensitivity, specificity and reproducibility of the results were evaluated by statistical analysis. Visual acuity was correlated with LOM values in patients with nuclear and mixed cataracts. Moreover, the instrument gave a good degree of reproducibility only in patients who presented these forms of lens opacities. Our findings demonstrate that the LOM 701 is able to detect and to measure only lens opacities which affect the central area of the lens.

The fascinating article by Klein et al 1 reporting that estrogens were associated with a protective effect against lens opacity reminded me of a strange (and unpublished) result from a case-control study by myself and colleagues that was carried out in Oxford, England. 2 In that study, we compared 423 patients aged 50 to 79 years with cataracts who were admitted to the Oxford Eye Hospital with 608 controls in the same age range recruited from other hospitals and from the age-sex registers of local general practitioners. This analysis included only data on the 639 women in the study. We asked a general question on drugs that were taken regularly for at least 4 months with a follow-up question that asked specifically about the contraceptive pill. During analysis we looked at total steroids as a risk factor but also identified all subjects who reported the use of contraceptive pills or

The visual results achieved after surgery in 38 patients with monocular congenital cataract and 34 with binocular congenital cataracts are reported. Thirty-two of the monocular aphakics were corrected postoperatively by contact lenses and six by intraocular lenses. Only one of the 32 eyes corrected with contact lenses achieved a visual acuity of 6/60 and 31 demonstrated a visual acuity lower than 6/60 (20/200). On the other hand, out of the six patients corrected by intraocular lenses, three whose visual acuity could be reliably recorded all achieved a visual acuity better than 6/60 and two of them reached a visual acuity of 6/12(20/40). From our group of patients with binocular congenital cataract it appears that delayed surgery beyond one year of age when the lens opacity allows undisturbed activity resulted in better visual acuity than in eyes whose opacity disturbed the child's activity and necessitated earlier surgery.

The authors report a simplified method for the clinical application and interpretation of the pupil cycle time test (PCT-test time) in the diagnosis of uniocular optic neuropathies. It is shown that normal interocular differences of ten pupil cycles are less than 0.2 sec at a 99% confidence level, such interocular differences being a gaussian age-independent parameter. Deep uniocular amblyopia as well as unilateral retinal disease which affect the whole extension of the posterior pole of the eye or more, significantly influence the interocular differences of the PCT-test time. Unilateral cataracts do not influence this if a regular pupil cycling response can be elicited in the eye with the lens opacity. If retinal disease or previous amblyopia have been ruled out both in the suspected and in the normal eye, the finding of an interocular difference in the PCT-test time more than 0.2 sec for ten pupil cycles or an insufficient pupil cycling to edge-light pupil stimulation will strongly support the clinical ...

Lens aging has been measured in vivo using a new instrument: the lens opacity meter 701 (Interzeag, Schlieren, Switzerland). Statistical analyses have been performed to verify the occurrence of the phenomenon, the sex differences and the reproducibility of the obtained results. The findings demonstrate an increase in the light scattering in the normal lens with aging, which is similar in both sexes. The instrument detects this process and the measurements have a high degree of reproducibility.

Since oxidative stress is a well substantiated hypothesis of cataract pathogenesis, screening was performed in acellular systems in order to select scavengers of reactive oxygen species; the selected compounds are at present being tested in lens culture and in animal models.

Favor, in the Appendix to a paper by Ehling and his collaborators (Ehling et al., 1982), develops a method that tests for the presence of a partially penetrant dominant cataract mutation in a suspected parent (showing lens opacity) outcrossed to a homozygous strain-101 mouse when no individual with lens opacity is observed in the progeny. This method, based on the Chi-square distribution, is examined as to the validity of the Normal approximation. An alternative procedure is discussed.

Freshly isolated rabbit lenses were cultured in isosmolar TC-199 medium or hyperosmolar medium containing 180 mM sorbitol or mannitol. These experiments were performed to investigate the probable effects of hyperosmolar media on lens clarity and the ability of lens fiber cells to synthesize membrane intrinsic protein, MP-26. The data from these experiments show that incubation in hyperosmolar medium causes depressed MP-26 synthesis, whereas the presence of sugar alcohols in the culture medium induced anterior and posterior subcapsular opacities. The cation levels of lenses incubated in iso- and hyperosmolar medium were also measured. Data from these experiments revealed that although the experimental lenses display prominent opacities, their cation levels are generally similar to those of control lenses. It is proposed that the observed lens opacities are due to the presence of sugar alcohols in the culture medium and not to hyperosmolar shock.

6 months after a double perforation of the eye, a dense scar of the vitreous body was observed with the slitlamp. The inferior part of the posterior lens surface was compressed, but no lens opacity could be seen. Such lens deformations are generally produced by tumors and are known since 1930. But it seems that such compressing scars of the vitreous body have never been described.

The effect of the antibiotics gentamycin and chloramphenicol on lens opacity was studied in an organ culture system. Opacity was monitored by split laser beam. Both antibiotics enhanced the onset of opacity in the cultured lenses under a variety of conditions. For instance, treatment with 5.0 mg/ml gentamycin for 60 min caused initial opacity after 4.8 +/- 1.3 days as opposed to untreated lenses at which initial opacity appeared after 18.1 +/- 2.99 days. Exposure to 20 mg/ml chloramphenicol for 60 min caused initial opacity after 4.6 +/- 1.51 days. Continuous exposure to penicillin and streptomycin (0.1 mg/ml each) did not enhance the onset of opacity.

We studied the influence of cataracts on visual fields in 36 eyes of 36 patients before and after cataract extraction with intraocular lens implantation. Lens opacity was quantified with a slit-lamp system. The influence of cataracts on the visual fields was slightly but statistically significantly larger in the central than in the midperipheral region. Lens opacity had a high correlation with the visual field changes and moderate but still significant correlation with changes in visual acuity. Measurement of stray light back scattered from the cataractous lens allowed prediction of the influence of cataract on the visual field.

The visual functions, before and after surgery, of 19 children with bilateral congenital cataract are evaluated. Some of the children, in spite of the poor vision before surgery and the late age at surgery, developed good vision with binocular functions. These children probably had an incomplete lens opacity in their early childhood which became completely opaque at an age at which irreversible stimulus deprivation amblyopia is unlikely to develop. Therefore, children over the age of 6 years with poor vision due to congenital cataract, on whom no information is available concerning the density of their lens opacities in early childhood, should not be regarded as having a poor visual prognosis.

A pin-point lens opacity can be detected at a frequency of 90% in weanling mice from inbred strain NAW-wa-2+ − +/Sp. Defective lenses show abnormal thickening of the anterior epithelium localized over a region of persistent contact between the primary lens fiber mass and the epithelium. A morphological study of lens development indicates that the mutant strain clearly differs from normal as early as the twelfth day of embryonic life. In a lens sector associated with the naso-ventral quadrant of the optic cup, cells undergoing the elongation characteristic of primary lens fibers are separated from the normal boundary of the anterior epithelium by a peculiar group of cells. These cells can still be detected on the following day; they do not differentiate into primary fibers. They contribute to the anterior epithelium instead, and the zone of elongation is asymmetrically displaced from the equator. Secondary fibers formed in this sector before birth do not completely displace the primary fibers from contact with the anterior epithelium. If secondary fibers formed during the neonatal period do not accomplish separation, abnormal thickening of the anterior epithelium begins around the end of the second week of postnatal life. The epithelial thickening and capsule-like material deposited within it apparently provide the structural basis for the opacity detected upon gross examination.

Lens opacitities developing during hypothermia and cardiac arrest in the Syrian Golden hamster are lesser in degree if the eyelids are kept shut during hypothermia, and much denser if the eyelids are kept open, even though the closed eye is colder than the open eye. The lenses become clear upon reanimation of the animal.