Biometry of 3 types of intraocular lenses using Scheimpflug photography.

PURPOSE: To compare differences in intraocular lens (IOL) decentration and tilt and anterior chamber depth (ACD) using Scheimpflug photography as well as best corrected visual acuity (BCVA) in eyes having phacoemulsification with implantation of 1 of 3 types of IOLs. SETTING: Chung-Ang University Hospital, Seoul, Korea. METHODS: This study comprised 137 cataractous eyes of 108 patients having phacoemulsification and IOL implantation. Eyes were randomized into 3 groups based on IOL type: poly(methyl methacrylate) (PMMA) (n = 65); silicone (n = 47); soft acrylic (n = 25). Biometric analysis was performed with an EAS-1000 Scheimpflug camera 1, 3, and 6 months after surgery. Best corrected visual acuity was also measured at these visits. RESULTS: The anterior chamber was deeper 1 month after surgery, with no statistical difference among groups. There were no significant differences among groups in IOL decentration and tilt or final BCVA during the follow-up. CONCLUSIONS: In this study in which a properly constructed continuous curvilinear capsulorhexis was created and IOLs were accurately placed in normal capsular bags, changes in ACD, IOL decentration and tilt, and BCVA were similar in eyes with a PMMA, silicone, or soft acrylic IOL.

Clinical evaluation of corneal diseases associated with floppy eyelid syndrome.

We examined 18 cases of floppy eyelid syndrome, first reported in the Orient, in patients ranging in age from 11 to 55 years (mean 24 years); 16 were men and two were women. In contrast to previous reports in which almost all patients were obese men, only three of our patients were mildly obese. The most common abnormal corneal finding was punctate epithelial keratopathy (five patients-28%). Keratoconus was detectable in three patients (17%) overall; it was bilateral in one case and unilateral in two. Other miscellaneous corneal findings were corneal astigmatism and corneal opacity. In two cases, we found a familial tendency to skin hyperextensibility and joint hypermobility, and in one case, floppy eyelid syndrome developed after pars plana vitrectomy. The pathogenesis of the syndrome is still unknown, but our findings suggest that the more important pathogenetic risk factors are not obesity and sleeping pattern, but genetic collagen and/or elastin abnormality.

Temporary amaurosis with persistent visual field defect following acute blood loss.

Visual loss and field defects commonly occur after acute blood loss. We present a case of bilateral permanent visual field defect in a 30-year-old man after a massive hemorrhage caused by large vessel injury during a right nephrectomy. His postoperative visual acuity decreased significantly, and his visual field showed peripheral constriction and inferior altitudinal field defect in both eyes. A year and a half after the operation, visual acuity recovered to the preoperative level, but the field did not show improvement. We advance that this is a possible result of extensive injury to the occipital area, excluding the corresponding area of the macula.

Histopathologic and ultrastructural findings of photocoagulation lesions produced by transpupillary diode laser in the rabbit retina.

Transpupillary retinal photocoagulations were performed on ten eyes of five pigmented rabbits using a diode laser (Nidek Co., LTD, Aichi, Japan) emitting infrared radiation at 800 nm wavelength. A histological and an ultrastructural study on the treated eyes were done at 1, 3, 5, and 7 days after retinal photocoagulations. The purpose of this study was to observe the sequential changes in the retina and the choroid following transpupillary diode laser retinal photocoagulations at the parameters of laser power which produced a grayish white retinal discoloration with distinct white center. It seemed that the lesion was grade 3 retinal photocoagulation by Tso et al's classification. It appeared that the parameters necessary to produce grade 3 photocoagulation lesions were 160 mW power, and 0.2 second duration at 200 microns size. In general, with an agreement to other reports, histologic study of the diode laser lesions showed that the outer retina was damaged more severely than the inner retina. However, on day 1 after laser treatment, the alterations were more profound in the inner retina than in the outer retina and an occasional swelling of the axons in the nerve fiber layer was observed on the ultrastructural study. The results observed have not been found in other previous studies and suggest that the inner retina might be injured directly by 800 nm wavelength diode laser radiations. Thus we could conclude that 800 nm wavelength diode radiation might be absorbed by melanin pigment and also by other chromophores contained in inner retinal tissues. Further studies must follow to verify the laser-tissue interactions in diode laser retinal photocoagulations.

A photodocumented study on lens thickness and densitometric value according to the type of cataract.

Photodocumented measurements of the lens thickness using an EAS-1000 Scheimpflug camera were performed in 261 cataract eyes (162 pure type) compared with 52 control eyes. The lens thickness in normal eyes usually increased with age by 0.015 mm annually. The cataractous lens, especially in the anterior subcapsular type combined with the superficial cortical and posterior subcapsular types of opacity, showed statistically significant lens thinning. The photodocumented values of lens thickness were higher in 7.9%, and those of the anterior chamber depth were lower in 5% compared with A scan ultrasonographic measurements.