Glycosaminoglycan and collagen fibrillar interactions in the mouse corneal stroma.

When sections of mouse corneal stroma were treated with 20 mM adenosine 5'-triphosphate (ATP) in phosphate buffered saline, pH 4.0, at 37 degrees C and observed by electron microscopy, numerous periodic fibrils with about 100-nm periodicity appeared which were the aggregated form of type VI collagen (type VI collagen fibrils). They occurred in close association with D-periodic fibrillar collagens (striated collagen fibrils). However, when the tissue was digested with chondroitinase ABC or testicular hyaluronidase prior to the ATP treatment, type IV collagen fibrils were segregated from striated collagen fibrils, even though the type VI collagen fibrils themselves aggregated to form the 100 nm-periodic structures. Keratanase or Streptomyces hyaluronidase had no such effect. One possible suggestion is that the ATP-aggregated type VI collagen fibrils are connected with striated collagen fibrils through chondroitin/dermatan sulfate glycosaminoglycans.

Experimental formation of 100 nm periodic fibrils in the mouse corneal stroma and trabecular meshwork.

The so-called long-spacing collagen that exhibits approximately 100 nm periodicity has been observed in the interstitial connective tissue of various organs under normal and pathological conditions. Although we, as well as many other investigators, have reported an increasing amount of these structures with age in the human trabecular meshwork, the pathological significance and the mechanism of its formation are still unknown. We incubated mouse ocular tissues in culture medium containing 20 mM ATP and prepared them for electron microscopic observation according to the method of Bruns et al (J Cell Biol 103:393, 1986). After the incubation, abundant 100 nm periodic fibrils were observed in the corneal stroma and the region of the trabecular meshwork, both of which show no structure of 100 nm periodicity under normal conditions. For the experimental formation of 100 nm periodic fibrils, ATP, acidic condition and temperature around 37 degrees C are necessary. The 100 nm periodic fibrils observed in our experiment were very similar to long-spacing collagen, in that the dark transverse bands have 100 nm intervals and very fine filaments of 6-7 nm diameter axially connect the bands. Long-spacing collagen is not usually observed in the human cornea, even in aged persons. The results of our study suggest that the occurrence of long-spacing collagen is related to special conditions developing in the trabecular meshwork with age but not in the corneal stroma. Experimental studies of 100 nm periodic fibril formation in mice offer a useful model for the age-related increase of long-spacing collagen in the trabecular meshwork of the human eye.

Binocular depth-from-motion in infantile and late-onset esotropia patients with poor stereopsis.

PURPOSE: There are at least two possible ways to detect motion-in-depth binocular without monocular cues: the binocular disparities at different times and a mechanism that detects interocular velocity differences. The perception of interocular velocity differences (Binocular depth-from-motion [BDFM]) depends on the relative velocity of the images on the retina of the left and right eyes, and this information can be experienced by normal and some strabismic patients. The purpose of this study was to determine the characteristics of esotropic patients who have BDFM but have poor stereopsis. METHODS: Forty-one infantile and 28 late-onset esotropia patients with poor stereopsis were studied. Dynamic stereopsis and BDFM were tested with computer-generated random dot stereograms and kinematograms. The correlations between BDFM and other binocular functional tests were determined. RESULTS: A total of 31 (44.9%) patients, 15 (36.5%) of the infantile and 16 (57.1%) of the late-onset esotropia group, passed the BDFM test. None of these patients passed the random dot stereo test under static or dynamic conditions. Fusion of the Worth four dot test at near 0.3 m was correlated with the presence of BDFM. Three of the 15 infantile and 10 of the 16 late-onset esotropic patients with positive BDFM showed gross stereopsis as measured by the Titmus Fly. The angle of strabismus was significantly smaller in the patients with positive BDFM for the infantile and the late-onset esotropia groups. CONCLUSIONS: BDFM was present in about half of the esotropic patients who do not have fine stereopsis. Ocular alignment within 10 to 15 prism diopters is an important factor in obtaining BDFM. Strabismus surgery still provides some binocular benefit for infantile esotropia patients who were bypassed for early surgery. Separate mechanisms may underlie static stereopsis and BDFM.

Detection of platelet mitochondrial DNA deletions in Kearns-Sayre syndrome.

To establish a noninvasive genetic diagnosing method for Kearns-Sayre syndrome, the authors used the polymerase chain reaction (PCR) technique for detecting mitochondrial DNA (mtDNA) deletions in the platelets and directly sequenced the crossover regions of the deleted mtDNA using the fluorescence-based automated sequencing system. The mtDNA deletions were identified in the platelets of three of four patients. The sizes and locations of deletions were determined by the nesting primer PCR method, in which the primary PCR products derived from deleted mtDNAs undergo reamplification using a series of nesting primers. With the fluorescence-based sequencing of templates amplified by the asymmetric PCR method, deleted mtDNA was sequenced directly without cloning. In patient 1, guanine (G) was found at the boundaries of a deleted segment spanning 8400 base pairs (bp) between the CO1 and ND6 genes. In patient 2, a 9-bp directly repeated sequence of 5'-ACCTCCCTC-3' (where A = adenine, C = cytosine, and T = thymine) was found at the boundaries of a deleted segment spanning 7221 bp between the CO1 and ND5 genes. In patient 3, an 8-bp sequence of 5'-TCGCTGTC-3' was found at the boundaries of a deleted segment spanning 4664 bp between the ATPase6 and ND5 genes. Deletions were not detected in the mtDNA of patient 4 or in that of the mothers of the patients. Previously, the genetic diagnosis of this syndrome required muscle biopsy specimens and the use of Southern blot analysis. However, this method requires neither muscle biopsy nor isotopes and is more rapid than the Southern blot method.(ABSTRACT TRUNCATED AT 250 WORDS)

Stimulus deprivation amblyopia. Simultaneous recording of local macular electroretinogram and visual evoked response.

Local macular electroretinogram (ERG) and visual evoked response (VER) were recorded simultaneously in ten adult patients with stimulus deprivation amblyopia. The fundus was monitored by an infrared television fundus camera. The location of the stimulus spot and eccentric fixating point were also monitored during recording. Responses in amblyopic eyes were compared with those in the normal fellow eyes in terms of the size of the stimulus spot, location of the eccentric fixating point in response to the stimulus spot, and visual acuity. The amplitude of VER in the amblyopic eye showed enhancement when the stimulus spot centering around the fovea involved the eccentric fixating point. The amplitude and peak time of the ERG in the amblyopic eye was essentially normal regardless of the degree of eccentricity of the fixating point and visual acuity.

Fluorescein angiography of peripheral retina and pars plana during vitrectomy for proliferative diabetic retinopathy.

PURPOSE: To evaluate the extreme peripheral retina and pars plana during vitrectomy in patients with proliferative diabetic retinopathy. METHODS: In a prospective study using a modified ophthalmic endoscopic system and an intraocular light source, we performed fluorescein angiography during pars plana vitrectomy in 12 eyes of 10 patients with proliferative diabetic retinopathy. Vitrectomy had been performed previously in two patients, and the subsequent surgery was necessary because of recurrent vitreous hemorrhage in one patient and silicone oil removal in the other. RESULTS: All 12 eyes of 10 patients demonstrated a wide avascular area in the peripheral retina anterior to the previous photocoagulation scar. At the ora serrata in two eyes, a fibrovascular ridge of peripheral retinal vessels with fluorescein leakage that resembled the demarcation line in retinopathy of prematurity was noted; one eye had developed neovascular glaucoma 4 weeks after vitrectomy with maximum augmentation of endolaser photocoagulation, and the other eye had neovascular glaucoma that had been treated with photocoagulation 1 year before vitrectomy. In the two eyes that had undergone previous pars plana vitrectomy, fluorescein leakage was apparent at the fibrous scar of the sclerotomy site. CONCLUSION: Intraoperative fluorescein angiography using an endoscope disclosed unusual findings in the extreme peripheral retina and pars plana of patients with proliferative diabetic retinopathy. Intraoperative fluorescein angiography may aid intraoperative evaluation and treatment of proliferative diabetic retinopathy.

Treatment of fungal corneal ulcers with amphotericin B ointment.

PURPOSE: To report two patients with severe fungal corneal ulcers who were treated successfully with topical amphotericin B ointment. METHODS: Two eyes of two patients developed corneal ulcers and hypopyon after corneal foreign body removal. Aspergillus fumigatus and Fusarium solani were isolated in Patients 1 and 2, respectively. By antifungal susceptibility testing, amphotericin B was shown to have the lowest minimal inhibitory concentration. RESULT: Topical administration of amphotericin B ointment resulted in dramatic improvement in fungal corneal ulcers. CONCLUSIONS: Antifungal susceptibility tests may aid with selection of antifungal agents. Amphotericin B ointment is one of the promising therapies for keratomycosis caused by antimycotic-resistant fungi.

Identification of anterior uveal tumor border by transscleral transillumination and an ophthalmic endoscope.

PURPOSE: To report a method for identifying the borders of anterior uveal tumors in deeply pigmented eyes. METHOD: The borders of the anterior uveal tumors were marked by transscleral transillumination with a fiberoptic light and observed from the vitreous cavity using an ophthalmic endoscope. RESULTS: The ophthalmic endoscope disclosed a bright orange spot by transscleral transillumination of a normal uvea in deeply pigmented eyes. Two anterior uveal melanomas and one adenocarcinoma of the nonpigmented ciliary epithelium did not transmit light through the tumors. CONCLUSION: With an ophthalmic endoscope and transscleral transillumination, the borders of ciliary body tumors can be identified and clearly demarcated, even in deeply pigmented eyes.

In vitro retinal and erythrocyte polyol pathway regulation by hormones and an aldose reductase inhibitor.

The effects of a high-glucose medium, insulin, and an aldose reductase inhibitor (ONO-2235) on sorbitol accumulation were compared in the human erythrocyte and the rabbit retina, while the effects of epinephrine on in vitro sorbitol accumulation were investigated in the human and rabbit retina. In both erythrocytes and the retina, linear increments of sorbitol accumulation were observed in a dose-dependent manner with 5 to 50 mM glucose. These increments were markedly inhibited by 100 microM ONO-2235 but not by insulin (400 microU/ml). In the presence of 5 mM glucose, a dose-dependent increase of the sorbitol content of the rabbit retina was seen following epinephrine stimulation (0.4-4.0 microM and this was markedly reduced by 100 microM ONO-2235. Moreover, both 50 mM glucose and 4.0 microM epinephrine increased the sorbitol content of the retina from a diabetic patient, and the glucose-induced increment in sorbitol was significantly reduced by 100 microM ONO-2235. Our data suggested that aldose reductase inhibitors might be useful for the treatment of diabetic retinopathy, since the polyol pathway appears to be an important factor in its pathogenesis, and that catecholamines might have some role in the activation of the retinal polyol pathway.

Histological examination of chick embryos with ocular hypoplasia.

From so-called "dead-in-pipped-eggs" provided by the Poultry Breeding Center of Gifu Prefecture, we obtained two chick embryos with hypoplastic eyes on external examination, and studied the visual system and cranial nerve nuclei innervating the extraocular muscles. The upper bills of both embryos deviated toward one side when observed with the naked eye. In histological sections from the most severely affected eyeball of each case primordial retinal tissue in the poorly developed orbit seemed to be at the stage of optic vesicle formation; it had not differentiated into individual layers. The optic nerve was absent from these eyeballs and the neural retina had multiple folds. The ciliary ganglion was smaller on the more severely affected side than on the contralateral side which had only mild hypoplasia. The optic nerve, which was present on the contralateral side, bifurcated at the level of the chiasma close to the diencephalic base; one branch ran toward the ipsilateral optic tectum and the other toward the contralateral brain region. The oculomotor and trochlear nerve nuclei could be identified bilaterally in one of the embryonic brains but not in the other. These findings suggest that hypoplasia of the neural retina and optic nerve in an orbit leads to bifurcation of the contralateral optic nerve which, under normal conditions, should completely cross at the chiasma. This may also suggest that retinal afferents from the brain are also affected in the hypoplastic eyeball.

Studies on development of visual acuity in infants measured by the Teller Acuity Cards.

In order to confirm the reproducibility of visual acuity measurements in infants and to elucidate the cause of the plateau and decrease in the developmental curve between the ages of 9 and 15 months, we have retrospectively studied visual acuity measured by the Teller Acuity Cards (TAC) in infants aged 2 to 28 months. The visual acuity measured by TAC was higher than that obtained by the conventional preferential looking (PL) method in infants until the age of 14 months. No statistically significant difference was observed between the first eye and the second (fellow) eye measurements. Although monocular visual acuity decreased in infants aged from 9 to 12 months, binocular visual acuity showed an increase in the same age group. The first binocular measurement was better than the last binocular measurement on the same day. Although the first binocular measurement showed an increase in infants aged from 9 to 15 months, the second binocular measurement decreased in the same age group. Our results suggest that all these phenomena mentioned above are likely to be due to the psychological or behavioral rejection to the examinations.

Long-term observation of infants with macular hemorrhage in the neonatal period.

Ten infants with macular hemorrhage in the neonatal period were tested to assess visual acuity, stereopsis, and ocular position. Contrast sensitivity was examined in three of them. The duration of hemorrhages was 1 month in four patients, 1.5 months in one patient, 2 months in two patients, 3 months in one patient, 4 months in one patient (corrected gestational 3 months), and 5 months in one patient (corrected gestational 2.5 months). None of the patients developed deprivation amblyopia or visual loss due to abnormality of macula. The results suggest that there is essentially no risk of visual deprivation for 3 months after birth. If there is any poor visual acuity, abnormal ocular position, abnormal eye movement, or poor stereopsis in the infant with neonatal macular hemorrhage, we have to elucidate the cause of the symptoms.

Studies on the function of the checkerboard pattern stimulator: analysis of ocular positions during stimulation.

PURPOSE: To analyze the effectiveness of the checkerboard pattern stimulator (CPS) in facilitating stereopsis in patients with acquired esotropia. METHODS: Fourteen patients were treated with checkerboard pattern stimulation following surgical correction of the ocular alignment. In order to determine the cause of the difference in the effectiveness of CPS on exotropes and esotropes, a separate study was carried out on 15 subjects: 5 orthophores, 5 exophores, and 5 esophores. RESULTS: Eight of the 14 patients achieved stereopsis; the remaining 6 cases did not show marked improvement in stereoacuity. The CPS was more effective on exotropes, as reported previously, than on esotropes (P = 0.047, chi2 test). By recording the ocular positions of the 15 subjects in the separate study, we found a tendency toward exodeviation in the orthophoric and exophoric subjects but not in esophoric subjects. CONCLUSIONS: Our results suggest that CPS develops sensory fusion by providing an identical pattern simultaneously to the foveas of both eyes and has no effect on convergence training and motor fusion.

Motion perception tested with reversing grating in Duane's syndrome.

Many papers have reported that motion perception asymmetry (MPA) is replaced by motion perception symmetry (MPS) by the 4th to 5th month after birth, when stereopsis starts to occur in normal infants. Duane's syndrome is a congenital motor abnormality, it does, however, reportedly show good stereopsis. We confirmed the stereopsis in Duane's syndrome and checked the motion perception (MP) by using the Reversing Grating Test to investigate if the congenital motor abnormality affects the MP in patients whose binocular sensory system is well developed. Thirty-eight Duane's syndrome patients aged 3 to 45 years were included in the present study. They were divided into 24 cases of Duane I, 9 cases of Duane II, 5 cases of Duane III. The Titmus Stereo Tests, Lang Stereotest, and TV-Random Dot Stereo Test were used to examine the stereopsis. Thirty-four patients had good stereopsis, and 4 had poor stereopsis. None of them showed MPA in any spatial frequencies (1/ 4, 1/2, 1 cycles/degree) examined. The Reversing Grating Test is useful for examining MPA in strabismus patients with eye movement limitations.

Changes in nystagmus after simultaneous surgery for bilateral congenital cataracts.

The presence of nystagmus has been considered as an indicator of poor prognosis in infants with bilateral congenital cataracts. However, of the 10 infants with preoperative nystagmus reported in this study, after simultaneous surgery for bilateral congenital cataracts, 5 cases showed a resolution of nystagmus or reduction to latent nystagmus postoperatively. This study was carried out to clarify what factors resolved or reduced the preoperative nystagmus. Those 5 cases in whom nystagmus was ameliorated postoperatively were operated on within one month after the onset. Age of nystagmus onset, age at surgery or type of cataract did not affect this amelioration of nystagmus. In contrast, the 5 cases who had no postoperative change in nystagmus were operated on later than this period. Our results demonstrate that it is possible to resolve or reduce preoperative nystagmus in bilateral congenital cataracts by a simultaneous bilateral lens removal within one month after the onset of nystagmus.

Two cases of acquired syphilis with acute central chorioretinitis as initial manifestation.

Acquired syphilis has become an overlooked cause of posterior uveitis including chorioretinitis. Two male cases of bilateral acute acquired syphilitic chorioretinitis were observed, one of whom demonstrated an early delay of choroidal circulation during fluorescein angiography, possibly indicating the choroidal or subretinal neovascular proliferation which occurred later. Although both patients had been treated with oral prednisone for approximately one month before their initial visit to our clinic, good visual recovery had not been achieved. Diagnosis was first confirmed by the positive results of serologic Treponema pallidum hemagglutination and Venereal Disease Research Laboratory tests. The patients were successfully treated with orally administered bacampicillin, which resulted in the complete recovery of visual acuity and normal fundus appearance except for slight pigmentary changes of the retina in the macular area.

Extrafoveal photostress recovery testing with a scanning laser ophthalmoscope.

We used a modified photostress recovery test (PSRT) with microperimetry in a scanning laser ophthalmoscope (SLO) to evaluate the extrafoveal region. After the red-target threshold was determined, the retina was bleached with argon green laser illumination. Test spots were presented every 3 seconds at the testing point and subjects indicated when they saw the spot. We determined the recovery time in 17 normal subjects under the following conditions: bleaching times of 10, 20, and 30 seconds; spot intensities of 0, 2, and 4 dB greater than threshold; Goldmann I, II, and III spots; and spot locations 7.5 degrees temporal to, nasal to, above and below the fovea, and at the fovea. We also measured recovery times inside and outside the detachment in 11 patients with central serous chorioretinopathy. Recovery time was correlated with bleaching time and spot intensity, but not with the location of spot size in normal subjects. In patients with chorioretinopathy, the recovery time was longer inside than outside the detachment. This technique is useful for measurement of photostress recovery time at extrafoveal points, and for comparison of times at various testing points. Results in patients with chorioretinopathy suggest that this technique may be useful for studying the pathophysiology in ocular diseases.

Comparison of muscle volume between congenital and acquired superior oblique palsies by magnetic resonance imaging.

Magnetic resonance imaging (MRI) studies of superior oblique (SO) muscles have revealed a high incidence of SO muscle atrophy/hypoplasia in congenital SO palsy patients. It has also been reported that long-standing acquired SO palsy patients show atrophic SO muscles in the affected eye. The purpose of this study was to compare the incidence of SO muscle atrophy/hypoplasia in congenital and acquired SO palsy by utilizing MRI. Coronal MRI image planes were taken from 29 cases of unilateral congenital SO palsy and 9 cases of acquired unilateral SO palsy patients. The SO muscle bellies were traced and their sizes were measured from each image plane. The total volume of the affected superior oblique muscle was compared with that of the normal fellow eye. The mean volume of the affected superior oblique muscle to that of the normal muscle was 45.3% (SD = 30.1) in the congenital group and 65.8% (SD = 22.7) in the acquired group. The volume reduction of the SO muscle in congenital SO palsy patients appears to be mainly a congenital abnormality rather than a secondary change, as seen in acquired SO palsy patients.

Implication of polymodal receptor activities in intraocular pressure elevation by neurogenic inflammation.

We studied, using anesthetized albino rabbits, whether polymodal receptors are responsible for rise in the intraocular pressure (IOP) caused by algesic substances, and also whether substance P (SP) is involved in this phenomenon. Intracameral administration of bradykinin (BK), SP, hypertonic saline, and hypertonic glucose caused an IOP rise. The IOP responses to BK and hypertonic saline were reduced by benoxinate, but aspirin reduced only the response to BK. Repeated applications of BK caused a decrease in subsequent responses (tachyphylaxis). These results are consistent with the characteristics of responses of polymodal receptors, and suggest that these IOP responses are produced by neurogenic inflammation. The IOP response to SP also showed tachyphylaxis, but after the tachyphylaxis to SP had been established, subsequent intracameral administration of BK still produced a marked rise in IOP. Moreover, the administration of SP into the posterior chamber, which is known to be the site of the blood-aqueous barrier, caused a much smaller rise in the IOP. These observations indicate that the IOP response to algesic substances might be caused by activation of the polymodal receptors, and that SP might not be a mediator in these responses.

S-antigen localization in developing rds mouse retina.

The morphology of the photoreceptor cell and localization of the cytoplasmic soluble protein, S-antigen, in the retina of the developing retinal degeneration slow (rds) mutant mouse (2-505 postnatal days) were studied by improved immunocytochemical and freeze-substitution methods. Anti-S-antigen antibody labeling was observed first in the postnatal 10-day retina under light microscope. Labeling signals increased progressively to a maximum level in 20 days, and then decreased gradually to an undetectable level by 505 postnatal days. By electron microscopic immunocytochemical methods, S-antigen was detected first in the photoreceptor cells at 3 postnatal days, and increased with development. It was located in the entire cytoplasm of the photoreceptor cell including the rudimentary outer segment, but degenerated and disappeared by 505 postnatal days. S-antigen was also present in the membranous vesicles budding off from the photoreceptor membrane to the subretinal space. The rds photoreceptor cell seems to lose other soluble proteins together with these vesicles. From these results and other published data, we speculate that the degeneration of the photoreceptor cells may be the secondary effects of the loss of a large amount of soluble and membrane proteins following the malfunction of membrane. Recent reports show the rds mouse must have a gene defect in the membrane component such as peripherin or the 39 kDa protein.