Kuruto Fujisawa

Changes in light scattering intensity of the transparent lenses of subjects selected from population-based surveys depending on age; Analysis through Scheimpflug images

The physiological ageing changes of decreasing lens transparency were objectively evaluated in a total of 1,040 eyes selected from 1,685 individuals who were the subjects of population-based cataract epidemiological surveys performed in three climatically different survey fields in Japan. The lens transparency changes were evaluated from the light scattering intensity on thirteen different lens layers seen in slit images taken by the latest type of Scheimpflug camera. The mean percentage prevalence of cataracts in all the epidemiological survey subjects including grading from I to III, which was also judged objectively through documented images, was 64.6% in the Noto subjects, 46.6% in the Hokkaido subjects and 38.0% in the Okinawa subjects. The lens transparency at all of the measuring points decreased with ageing. The above changes, seen in the lenses of subjects in their 40s to 60s, were obviously more prominent compared with those seen in subjects in their 40s. Although there were some differences in transparency decrease with ageing among the subjects of the three areas, the authors tentatively propose to show the data obtained from the Noto subjects as representative of Japanese individuals. Lens transparency changes on each lens layer showed characteristic ageing changes and those of the representative four layers showed an exponential decrease in transparency. The decreasing ratio might accelerate from age as early as the mid-40s.

Quantitative Evaluation of Nuclear Cataract Using Image Analysis

To quantitatively evaluate nuclear lens opacification, we applied image analysis techniques. Utilizing a newly developed anterior eye segment analysis system, Scheimpflug slit images were taken in 65 eyes with transparent lenses and 31 eyes with nuclear cataract. In transparent lenses, scattering light intensity of the anterior fetal nucleus (AFN) was equal to or less than that of the posterior fetal nucleus (PFN). In eyes with nuclear cataract, scattering light intensity of the AFN was higher than that of the PFN. Utilizing this phenomenon, nuclear opacification was evaluated by the difference of scattering light intensity between the AFN and PFN (delta i value). The methodology applied in this investigation provides precise grading of nuclear cataract and progression thereof.

[Influence of cyclosporin on steroid-induced cataract].

PURPOSE To study the effect of cyclosporin on steroid-induced cataract in patients after renal transplantation. SUBJECTS AND METHODS 140 patients who received renal transplantation and ophthalmological examinations before and over 12 months after surgery at Kanazawa Medical University were investigated retrospectively. The subjects were divided into the following two groups: the conventional therapy group(Group C) who were administered azathioprin and methylprednisolone and the triple therapy group(Group T) who were administered azathioprin, methylprednisolone and cyclosporin. There were 73 subjects in group C and 67 in group T. Judgement of steroid cataract followed Crews classification and steroid cataract was diagnosed when vacuoles or opacity were seen in the posterior subcapsular region. Subjects that had any lens opacity before renal transplantation were excluded. RESULTS The total dose of systemic steroid during the first year and in the final observation period in group T was significantly higher than in group C. The prevalence of steroid cataract was 55% and 63% for the 1st year, 72% and 89% for the 2nd year, 74% and 92% for the 3rd year and 83% and 96% for the 5th year in groups C and T, respectively. By the third year, the rate of subjects whose corrected visual acuity was less than 0.8 or who received cataract surgery was significantly higher in group T than in group C. There was no significant difference in the total dose between the subjects with cataract over grade I and those of grade 0 and I in both groups C and T. In group C, the total dose of steroid pulse therapy was significantly higher in the subjects with steroid cataract over grade I than in those with grade 0 and I. CONCLUSIONS Using cyclosporin, although the total dose of systemic steroid was decreased, the rate of steroid cataract increased. Cyclosporin may accelerate the development of steroid cataract. Steroid pulse therapy is considered to be a risk factor for developing steroid cataract.

Visual acuity disturbance in subjects over 50 years of age in a population-based cataract survey

Visual acuity is still an essential examination item in cataract epidemiological studies, even though this parameter lacks objective reliability. A population-based epidemiological study was conducted in a rural area of Japan to find out the relationship between visual acuity levels and cataracts, the types of gradings of which were evaluated by an objectively reliable method through lens images, and to serve as a sample for researchers who perform epidemiological studies on cataract but lack the latest methodology. 863 participants above 50 years of age were examined and those previously diagnosed with ocular diseases which affect visual acuity were excluded from the analysis as much as possible. The mean visual acuity (LogMAR) in subjects in their 50s, 60s, 70s and over 80 years of age was 1.1, 1.0, 0.7 and 0.4, respectively. Both the mean and the distribution of visual acuity showed a statistically significant relationship to ageing (p < 0.01, p < 0.01). Both age and cataract grading showed a statistically significant relationship to visual acuity (p < 0.01), but there was no significant interaction effect between these two variables upon visual acuity. Visual acuity worsened remarkably with ageing in the eyes with grade III, whereas that of eyes with grades I and II remained fairly stable at a level of 0.7-1.0, except for those above 80 years of age. A fairly good visual acuity of 1.0, 0.8 and 0.7 remained in the eyes with pure cortical cataract of grades I, II and III, respectively, whereas those with mixed type cataract were 0.9, 0.6 and 0.3, respectively.