CMAP decrement as a potential diagnostic marker for ALS

OBJECTIVE

We previously reported that decrement of compound muscle action potential (CMAP) by repetitive nerve stimulation (RNS) was greater in the median nerves than in the ulnar nerves of patients with amyotrophic lateral sclerosis (ALS). The aim of this study was to evaluate whether CMAP decrement by RNS is a feasible marker for the differentiation of ALS from other diseases.

MATERIALS & METHODS

We performed RNS in the median and ulnar nerves of 51 patients with ALS and 40 patients with other diseases.

RESULTS

The CMAP decrement was significantly greater in the median nerves of patients with ALS, compared to the disease control patients. In the median nerves of patients with ALS, CMAP decrement was significantly greater in the cervical region-onset group than in the other region-onset group.

CONCLUSIONS

The finding of CMAP decrement in the median nerves can be useful for differentiating ALS patients with cervical region onset from other controls with active neuropathic diseases.

Influence of IOP measurement through the wrong eyepiece of the slit lamp on Goldmann applanation tonometry

PURPOSE

This study examined whether intraocular pressure (IOP) measurements through the wrong eyepiece of the slit lamp may be a source of error.

METHODS

Seven skilled observers measured the IOP from seven healthy subjects. The observers used a Haag-Streit Goldmann applanation tonometer with two types of slit lamps (Haag-Streit and Rodenstock). In the Haag-Streit slit lamp the prism of the tonometer is aligned with the right part of the slit lamp optics. Conversely, in the Rodenstock slit lamp, the prism is aligned with the left. Each observer measured the IOP of each subject through the right eyepiece, through the left eyepiece, and under binocular vision.

RESULTS

The IOP measured with the left eyepiece of the Haag-Streit slit lamp was significantly higher than that measured with the right eyepiece and binocular vision. The IOP measured with the right eyepiece of the Rodenstock slit lamp was significantly higher than that measured with the left eyepiece and binocular vision.

CONCLUSIONS

IOP measurement through the wrong eyepiece of the slit lamp may be a source of error.

[Apparent size of stereoscopic images with disparity in relation to the function of accommodation]

PURPOSE

We investigated experimentally the relationship between the apparent size of stereoscopic images with disparity and the accommodative function.

METHODS

The judgement of the apparent stereoscopic image size used the subject reply. The size of the forward image, which was produced by crossed visual lines with binocular disparity and by a time-sharing type stereoscopic three-dimensional display using liquid crystal shutter glasses, was compared with the size of the plane image. The size of the backward image produced by uncrossed visual lines was also compared with the size of the plane image. Sixteen normal volunteers were requested to subjectively compare each image with the original plane image on the display screen in relation to its size. Accommodation was measured using an infrared optometer to record the step responses (from far to near, and near to far). The subjects were divided into two groups, a fast response group and slow response group.

RESULTS

It was found that the forward image was smaller than the plane image and the backward image was larger than the plane image, and this tendency was remarkable in the fast response group.

CONCLUSION

From these results, it appears that the state of accommodation affects the perceived size of stereoscopic images with disparity.

Influence of TT virus on the clinical course of alcoholic liver disease

The sera of 43 patients with alcoholic liver disease (ALD) who abstained from alcohol for 4 weeks, were tested for TT virus (TTV) DNA by polymerase chain reaction (PCR) using three different primer pairs (UTR PCR, N22 PCR and genotype-1 PCR). The clinical course of the TTV DNA-positive and -negative groups was compared. By UTR PCR which detects all TTV genotypes, TTV DNA was detected in 40 patients (93%). N22 PCR which detects primarily TTV genotypes 1-6, detected TTV DNA in 17 patients (40%). The alanine aminotransferase (ALT) level 4 weeks after the start of abstinence was significantly higher and the rate of change in ALT {[(ALT on admission-ALT 4 weeks after abstinence)/(ALT on admission)]x100} was lower in the patients who were positive by N22 PCR, than in those who were negative by N22 PCR. Twelve patients (28%) were positive for TTV genotype 1. In the TTV genotype 1-positive group, the ALT 4 weeks after the start of abstinence was significantly higher, and the improvement rates of ALT, gamma-glutamyl transpeptidase and alkaline phosphatase levels were lower than those in the TTV genotype 1-negative group. These results suggest that certain genotypes of TTV may interfere with the improvement of liver function following the start of abstinence in ALD patients.

TT virus mRNAs detected in the bone marrow cells from an infected individual

Although replicative forms of TT virus (TTV) DNA have been found in the liver and bone marrow cells, mRNAs of TTV have not yet been detected in these tissues. The entire nucleotide sequence of a TTV clone [TYM9 (3759 bases)] isolated from a patient with high TTV viremia (10(6) copies/ml) was determined, and the poly(A)(+) RNAs from bone marrow cells were subjected to reverse transcription-polymerase chain reaction with primers specific for the TYM9 sequence. Sequence analysis of the amplified products revealed the presence of three distinct species of spliced TTV mRNAs [2.9, 1.2, and 1.0 kilobases (kb)] with common 5' and 3' termini as well as splicing to bind nucleotide (nt) 181 to nt 283. The shorter mRNAs of 1.2 kb and 1.0 kb possessed another splicing to join nt 681 with nt 2341 or nt 2579. The transcription profile of TTV found in an infected human corroborates that observed in vitro.

Immunohistochemical localization of MYOC/TIGR protein in the trabecular tissue of normal and glaucomatous eyes

PURPOSE

To examine immunohistochemically the localization of myocilin/trabecular meshwork inducible glucocorticoid response (MYOC/TIGR) protein in the glaucomatous and normal trabecular meshworks.

METHODS

Trabecular tissues were used from one eye with late-onset goniodysgenetic glaucoma, three with primary open angle glaucoma (one of which had the MYOC/TIGR gene mutation), two with exfoliation glaucoma and one without glaucoma. For light microscopic immunohistochemistry, frozen sections were stained by the avidin-biotin complex method using anti-MYOC/TIGR polyclonal antibody. For electron microscopic immunohistochemistry, the pre-embedding method using the same antibody was performed. Double immunostaining using both anti-MYOC/TIGR and anti-type VI collagen antibodies was done by the immunofluorescence method.

RESULTS

With light microscopy, immunoreactivity was seen in the whole trabecular meshwork of each of the specimens. No notable differences were detected in staining among the types of glaucoma, or between the eyes with and those without the gene mutation. Under electron microscopy, immunoreaction products were observed not only in the cytoplasm of the trabecular cells but also in the extracellular matrix, where staining was associated with the long-spacing collagen, fine granular materials and possibly microfibrils. With double immunohistochemistry, MYOC/TIGR was colocalized with type VI collagen in the trabecular meshwork.

CONCLUSIONS

In glaucomatous and normal trabecular meshworks, the MYOC/TIGR protein is distributed in the extracellular matrix colocalizing with type VI collagen.

Species-specific TT viruses in humans and nonhuman primates and their phylogenetic relatedness

By means of polymerase chain reaction with a primer pair (NG133-NG147) deduced from the untranslated region (UTR) of TT virus (TTV), TTVs with markedly distinct genomic lengths were recovered from sera of humans and nonhuman primates, and their entire nucleotide sequences were determined. A human TTV [TGP96 of 2908 nucleotides (nt)] was obtained that was about 900 nt shorter than heretofore reported TTVs (3787-3853 nt). Likewise, TTVs of chimpanzee occurred in two distinct genomic sizes [Pt-TTV6 (3690 nt) and Pt-TTV8-II (2785 nt)]. Two TTVs of Japanese macaque [Mf-TTV3 (3798 nt) and Mf-TTV9 (3763 nt)] were comparable in genomic length, but only 55% similar in sequence. These five human and nonhuman primate TTVs, along with TTVs of tamarin [So-TTV2 (3371 nt)] and douroucouli [At-TTV3 (3718 nt)], were compared over the entire nucleotide sequence. Although the seven TTVs were only < or = 55% similar, they share a common genomic organization with two open reading frames (ORFs), designated ORF1 (654-735 amino acids) and ORF2 (91-152 amino acids). The N-terminal sequences of ORF1 proteins were rich in arginine, and sequence motifs necessary for transcription and replication were conserved among them all. Like the human prototype TTV (TA278), all seven TTVs from various animals possessed in common two 15-nt sequences (CGAATGGCTGAGTTT and AGGGGCAATTCGGGC) in the UTR that were covered by NG133 and NG147, respectively. These primers would be instrumental in research on TTVs in previously unexamined species for defining their virological characteristics and evolutionary relationships.

Transmission of human TT virus of genotype 1a to chimpanzees with fecal supernatant or serum from patients with acute TTV infection

Fecal supernatant or serum containing TT virus (TTV) of genotype 1a (10(5) copies/ml) from patients with acute TTV infection was inoculated intravenously into two naive chimpanzees. Serum samples were obtained weekly and tested for TTV DNA by genotype 1-specific polymerase chain reaction. TTV DNA was detected in chimpanzee 228 at weeks 5-15 after inoculation with 0.5 ml of serum, and in chimpanzee 234 at weeks 7-19 after inoculation with 1 ml of fecal supernatant. The TTV DNA titer peaked at weeks 12 and 13 in chimpanzee 228 and at weeks 14-16 in chimpanzee 234. Mild biochemical and histological changes in biopsied liver samples were observed in both chimpanzees in association with the reduction in TTV titer. TTV DNA was transient in chimpanzee 228, but in chimpanzee 234 it reappeared at week 21 and persisted through week 30. These results indicate that TTV in feces is infectious and suggest that TTV has hepatitis-inducing capacity.

Sequestration of TT virus of restricted genotypes in peripheral blood mononuclear cells

Peripheral blood mononuclear cells (PBMC) harbored TT virus (TTV) of genotypes (3 and 4) different from those (1 and 2) of free virions in plasma of the same individuals. PBMC may act as a reservoir, and TTV of particular genotypes might have tropism for hematopoietic cells.

The entire nucleotide sequences of two distinct TT virus (TTV) isolates (TJN01 and TJN02) remotely related to the original TTV isolates

TT virus (TTV) has a wide range of sequence divergence by which it is classified into at least 16 genotypes. A TTV isolate of genotype 12 (TJNO1) and another of genotype 13 (TJN02) were sequenced in the entire genome, and compared with the reported TTV isolates. TJN01 and TJN02 had genomic lengths of 3787 and 3794 nucleotides (nt), respectively, which were shorter by 66 and 59 nt than the prototype TTV isolate of genotype 1 (TA278). TJN01 and TJN02 shared the nucleotide sequence with TA278 merely in 53.9% and 55.2%, respectively. They possessed two major open reading frames (ORFs) and the noncoding region with a GC-rich region forming stem-loop structures, which are characteristic of TTV. However, their amino acid sequences in ORF1 were similar to that of TA278 in only 35.4 and 34.0%, respectively; TJN01 was 45.4% similar to TJN02. Comparison with TTV isolates of the same genotype identified hypervariable regions in ORF1 of TJN01 and TJN02, as in the prototype TTV of genotype 1. However, quasispecies were barely observed in them. Furthermore, sequences of hypervariable regions scarcely changed during 2-5.5 years in both TJN01 and TJN02. These results indicate that TTV of genotypes 12 and 13 are much different from the prototype TTV of genotype 1.

Replicative forms of TT virus DNA in bone marrow cells

TT virus (TTV) is a human virus consisting of a single-stranded, circular DNA genome of 3.8 kilobases (kb). To examine whether TTV replicates in peripheral blood mononuclear cells (PBMCs) and bone marrow cells (BMCs), DNA was extracted from the PBMCs and/or BMCs of six TTV-infected individuals and separated by agarose gel electrophoresis. The TTV DNAs from the PBMCs migrated to the 2.0- to 2.5-kb region. The TTV DNAs from the BMCs migrated to the 2.0- to 2. 5-kb and 3.3- to 6.1-kb regions. The faster-migrating TTV DNAs were sensitive to S1 nuclease, while the slower-migrating TTV DNAs were resistant and their position on the agarose gel shifted to the position of the full genomic size upon digestion with restriction enzyme PstI. Full-length inverted polymerase chain reaction on the slower-migrating, double-stranded TTV DNAs from the BMCs amplified a 3.8-kb product. Replicative intermediate forms of TTV DNA are present in BMCs but not in PBMCs.

[Intraocular pressure during hemodialysis]

Hemodialysis, a useful treatment for patients with severely compromised renal function, has also unfavorable side effects. In the ophthalmologic area, a rise in intraocular pressure (IOP) during dialysis accompanied by ocular pain has been reported. In our study when measuring IOP, as well as serum osmolality and plasma CO2 pressure every 30 minutes during routine hemodialysis in renal failure patients with a normal aqueous outflow facility, the mean percent changes of IOP to the initial value showed no significant difference at any time, although the changes in serum osmolality decreased significantly. The mean percent changes of plasma CO2 pressure also did not show any significant difference during dialysis. In patients with a poor aqueous outflow facility, the mean percent changes of IOP increased significantly after 90 minutes, with the exception of the change at 180 minutes. The mean percent changes of serum osmolality decreased significantly after starting dialysis. A negative correlation in the mean percent change of IOP with that of serum osmolality was detected. The administration of an intravenous hyperosmotic agent prevented significant changes not only in serum osmolality but also in IOP. Therefore, it is considered that hemodialysis causes a decrease in serum osmolality, resulting in an osmotic gradient between the plasma and the intraocular fluids due to the presence of the blood-ocular barrier. Although the osmotic gradient draws water from the plasma into the eye, if there is no abnormal obstruction in the aqueous outflow pathway, an amount of aqueous humor matching the increase in intraocular fluid goes through the pathway out of the eye to maintain the normal level of IOP. In eyes with an obstructed aqueous outflow pathway, however, this compensatory mechanism of aqueous humor drainage does not work well, and results in an IOP elevation.

Species-specific TT viruses and cross-species infection in nonhuman primates

Viruses resembling human TT virus (TTV) were searched for in sera from nonhuman primates by PCR with primers deduced from well-conserved areas in the untranslated region. TTV DNA was detected in 102 (98%) of 104 chimpanzees, 9 (90%) of 10 Japanese macaques, 4 (100%) of 4 red-bellied tamarins, 5 (83%) of 6 cotton-top tamarins, and 5 (100%) of 5 douroucoulis tested. Analysis of the amplification products of 90 to 106 nucleotides revealed TTV DNA sequences specific for each species, with a decreasing similarity to human TTV in the order of chimpanzee, Japanese macaque, and tamarin/douroucouli TTVs. Full-length viral sequences were amplified by PCR with inverted nested primers deduced from the untranslated region of TTV DNA from each species. All animal TTVs were found to be circular with a genomic length at 3.5 to 3.8 kb, which was comparable to or slightly shorter than human TTV. Sequences closely similar to human TTV were determined by PCR with primers deduced from a coding region (N22 region) and were detected in 49 (47%) of the 104 chimpanzees; they were not found in any animals of the other species. Sequence analysis of the N22 region (222 to 225 nucleotides) of chimpanzee TTV DNAs disclosed four genetic groups that differed by 36.1 to 50.2% from one another; they were 35.0 to 52.8% divergent from any of the 16 genotypes of human TTV. Of the 104 chimpanzees, only 1 was viremic with human TTV of genotype 1a. It was among the 53 chimpanzees which had been used in transmission experiments with human hepatitis viruses. Antibody to TTV of genotype 1a was detected significantly more frequently in the chimpanzees that had been used in transmission experiments than in those that had not (8 of 28 [29%] and 3 of 35 [9%], respectively; P = 0.038). These results indicate that species-specific TTVs are prevalent in nonhuman primates and that human TTV can cross-infect chimpanzees.

Postmortem findings two weeks after oral treatment for metastatic Candida endophthalmitis with fluconazole

The purpose of this histological study was to present postmortem findings in both eyes of a 53-year-old male with liver dysfunction 2 weeks after short-time oral treatment with 200 mg/day fluconazole for metastatic Candida endophthalmitis due to intravenous hyperalimentation for 18 days. Candida had been demonstrated in the venous blood and on the tip of the intravenous catheter. The bilateral fungal endophthalmitis with hypopyon responded well to fungistatic therapy, but the patient suddenly died from heart failure. Both eyes were obtained at autopsy. Candida was demonstrated only in vitreous puff balls but not in the retina or uvea. Fluconazole administered for a short period had little effect in eliminating fungus from vitreous puff balls, which have no blood supply. Prolonged administration of the antifungal drug or vitrectomy should be considered when treating an eye with vitreous puff balls in the presence of fungal endophthalmitis.

Histopathological changes in iridocorneal angle of inherited glaucoma in rabbits

BACKGROUND

We examined morphologically the angular region of eyes affected by inherited glaucoma in rabbits genetically developed by crossbreeding in order to investigate the etiologic changes in the iridocorneal angle and to establish whether this strain of rabbit is a suitable animal model of goniodysgenetic glaucoma in humans.

METHODS

The angular regions of both normal and glaucomatous eyes from four rabbits having unilateral inherited glaucoma were observed with light and electron microscopy.

RESULTS

In the glaucomatous eyes angular region, the aqueous plexus corresponding to Schlemm's canal in humans was open and located far peripherally to the peripheral margin of the anterior chamber angle, although the plexus of one glaucomatous eye was poorly developed with a small lumen. In the angular meshwork, which corresponds to the trabecular meshwork in humans, a thick abnormal tissue with round cells embedded in the extracellular matrix was located just beneath the plexus. A large amount of extracellular matrix of basal lamina-like material was observed in the thick tissue. In the normal eyes, the angular region consisted of well-developed trabecular sheets with neither a thick tissue nor accumulations of extracellular matrix in the angular meshwork.

CONCLUSION

The findings observed in the glaucomatous eyes are much the same as those observed in goniodysgenetic glaucoma in humans, suggesting that this strain of inherited glaucoma rabbits is a suitable animal model of goniodysgenetic glaucoma in humans. The present study also supports the hypothesis that the presence of a thick subcanalicular tissue due to maldevelopment of the iridocorneal angle is one of the main causes of this type of glaucoma.

[Iris vessel involvement in iris-nevus syndrome]

PURPOSE

To report a case of iris-nevus syndrome accompanied by disruption of the blood-aqueous barrier in the iris which was confirmed angiographically and histopathologically.

CASE

The patient was a 39-year-old woman. She noticed blurred vision in the left eye which was diagnosed as left glaucoma. Specular microscopy revealed low endothelial cell density in the left cornea. The left iris showed atrophy with clusters of nodular iris nevus and distorted pupil. The left iridocorneal angle was closed with peripheral anterior synechia.

FINDINGS

Indocyanine green iris angiography revealed more vessels on the surface of the left iris than on the right. In fluorescein iris angiography, the dye leaked from the iris vessels in areas where the iris showed advanced atrophy. The trabecular tissue obtained by trabeculectomy from the patient's left eye showed histopathologically a lining of corneal endothelial cells on the surface of the iris. The density of the vessels was high in the iris stroma. Some cells covering the vessel wall showed degeneration with opening of the zonula occludens. Schlemm's canal had narrowed lumina, and the intertrabecular spaces were closed.

CONCLUSION

Disruption of the blood-aqueous barrier may occur in iris-nevus syndrome.

Early changes in iris blood vessels in exfoliation syndrome

PURPOSE

To look for possible changes in iris blood vessels that might precede the formation of true exfoliation material, and to correlate these changes, if present, to aging of the iris.

METHODS

Iris blood vessels of 10 clinically normal irises from 10 eyes (ages: 1 day-80 years), 4 irises with exfoliation (ages: 64-80 years) and 3 irises from primary open-angle glaucoma (POAG) (ages: 27-65 years) were examined with an electron microscope.

RESULTS

Pronounced multilayering of the basal lamina around the vessels, abnormal excessive formation of microfibrils, presence of atrophic invaginations in the outer cell membranes of endothelial cells containing interlacing basal lamina, and an apparent decrease in the perivascular collagen fibers were evident in exfoliative iris vessels devoid of true exfoliation material. Similar, but much milder, changes were evident in normal aged and POAG irises.

CONCLUSIONS

Abnormal elastic tissue and/or basal lamina production plays a role early in the formation of exfoliation material around iris blood vessels.

Ultrastructural examination of corneal epithelium of spontaneously obese, hyperglycemic rats

PURPOSE

Otsuka Long-Evans Tokushima fatty (OLETF) rats spontaneously become obese and hyperglycemic with age. We investigated whether the development of hyperglycemia would alter the ultrastructure of the corneal epithelium.

METHODS

Scanning and transmission electron microscopy (SEM and TEM) were used to examine the morphology of corneal epithelial cells. Fourteen OLETF rats were evaluated, and 9 Long-Evans Tokushima Otsuka (LETO) rats were used as control. Non-hyperglycemic OLETF rats served as controls.

RESULTS

SEM showed exfoliative changes in the surface of the central corneal epithelium of the hyperglycemic OLETF rats. These superficial epithelial cells were irregular in shape as compared to polygonal shapes of those of LETO and non-hyperglycemic OLETF rats. The mean anterior surface area of individual superficial epithelial cells was significantly smaller in the hyperglycemic OLETF than that of the LETO or the non-hyperglycemic OLETF rats. Central protrusion(s) could be found in some of the superficial cells of all rats examined, although this phenomenon was more common in the hyperglycemic rats than in the non-hyperglycemic rats. TEM revealed that there were numerous cytoplasmic vacuoles and wide intercellular spaces in the central corneal epithelium of the hyperglycemic OLETF rats, but not in the non-hyperglycemic rats.

CONCLUSIONS

The development of spontaneous hyperglycemia in OLETF rats alters the ultrastructure of the corneal epithelium. The alterations included abnormalities of the corneal epithelial surface observed by SEM and the presence of intracellular vacuoles and enlarged intercellular spaces detected by TEM.

[Effects of brovincamine fumarate on choroidal blood volume in rabbits]

We examined the effects of brovincamine fumarate, a Ca(2+)-channel blocker, on choroidal blood flow. We measured the choroidal blood volume continuously for 1 hour using laser Doppler flowmetry, as well as systemic blood pressure, heart rate, and intraocular pressure in six urethane-anesthetized rabbits after intravenous administration of 0.1 mg/kg or 0.5 mg/kg brovincamine. As a control, ten rabbits receiving no medication were used. All the data were recorded and analyzed using MacLab on a computer. In both the 0.1 mg/kg and 0.5 mg/kg brovincamine-injected groups, the choroidal blood volume decreased significantly after administration, but showed no significant difference from controls. Vascular resistance in the choroid showed a significant increase over the value before administration and over the control group. The heart rate decreased significantly compared to the value before injection and to the control group. The mean blood pressure in both dose groups and the intraocular pressure in the 0.5 mg/kg injected group were significantly higher than the controls. These results indicate that intravenous administration of 0.1 mg/kg or 0.5 mg/kg brovincamine does not cause an increase in the choroidal blood volume in urethane-anesthetized rabbits.

Mechanism of intraocular pressure elevation during hemodialysis

PURPOSE

To detect the mechanism of intraocular pressure elevation during hemodialysis.

METHODS

We measured intraocular pressure, as well as serum osmolality and plasma CO2 pressure, every 30 min during hemodialysis, in 5 eyes with severely compromised aqueous outflow facility (Group A) from 4 renal failure patients. The same measurements were repeated on the same eyes using intravenous hyperosmotic Glyceol to prevent a rapid change in serum osmolality. We also measured the same parameters on 8 eyes with normal aqueous outflow facility (Group B) from 5 patients. The mean +/- SE of percent changes in each parameter was used for the statistical analysis.

RESULTS

In Group A, the mean percent change of intraocular pressure increased significantly after 90 min, with the exception of the change at 180 min. The mean percent change of serum osmolality decreased significantly after starting dialysis. A negative correlation in the mean percent change of intraocular pressure with serum osmolality was detected (r = -0.759, r < 0.0001). The administration of intravenous hyperosmotic agent prevented significant changes in not only serum osmolality but also intraocular pressure. In Group B, the mean percent change in intraocular pressure showed no significant difference at any time, although the change in serum osmolality decreased significantly.

CONCLUSION

A remarkable rise in intraocular pressure occurs during hemodialysis in eyes with an impaired aqueous outflow, when serum osmolality decreases rapidly.

Double staining of proteoglycans and the HNK-1 carbohydrate epitope in pseudoexfoliation material

PURPOSE

We combined the techniques of both immunogold and cupromeronic-blue staining with electron microscopy to investigate the possible relationship between proteoglycans and the HNK-1 carbohydrate epitope in pseudoexfoliation material.

METHODS

The anterior segment was obtained from an enucleated eye with pseudoexfoliation syndrome. After cupromeronic-blue staining, following the method of Scott, specimens were embedded in L. R. White resin. Ultrathin sections were incubated successively in primary monoclonal antibodies, and 10 nm gold-conjugated secondary antibody.

RESULTS

The present study showed simultaneous presence of the HNK-1 epitope and proteoglycans associated with zonular fibrils and pseudoexfoliation material on the posterior surface of the iris. The HNK-1 epitope was immunolocalized to the periphery of the pseudoexfoliation fibers, while cupromeronic blue-positive filaments bridged adjacent pseudoexfoliation fibers.

CONCLUSIONS

Proteoglycans and the HNK-1 epitope might play a substantial role in the formation of pseudoexfoliation material via their adhesive function. Proteoglycans probably do not directly bear the HNK-1 epitope in pseudoexfoliation material.

Ciliary body band width as an indicator of goniodysgenesis

PURPOSE

To evaluate the gonioscopic signs indicative of underdevelopment of the iridocorneal angle and thereby obtain a correct diagnosis of goniodysgenetic glaucoma.

METHODS

We examined morphologically the iridocorneal angle of 28 enucleated human eyes, including those from premature infants as well as from older subjects. The ratio of the ciliary body band width to the width of the posterior limbus (the distance between the termination of Descemet's membrane and the iris root), termed the theoretic C/L ratio, was calculated by drawing on light micrographs. Data were compared for three age groups: premature infants, children, and subjects older than 9 years. We also examined clinically the appearance of the ciliary body band on gonioscopy in 135 eyes of 69 younger patients having primary glaucoma with open iridocorneal angles and in 94 eyes of 47 age-matched control subjects.

RESULTS

The theoretic C/L ratio +/-SD was 1.4% +/- 2.7% in premature infants, 24.0% +/- 5.4% in children, and 36.7% +/- 8.0% in the older subjects. There was a statistically significant difference between each of the three groups (between premature infants and children, P < .001; between children and older subjects, P < .005; between premature infants and older subjects, P < .001). On gonioscopy, 105 of 135 glaucomatous eyes (77.8%) and 13 of 94 control eyes (13.8%) showed either an invisible or very narrow ciliary body band (P < .0001).

CONCLUSION

The ciliary body band seen on gonioscopy provides an indicator of the development of the iridocorneal angle. An invisible or very narrow ciliary body band represents an underdevelopment of the angle.

Distribution and characterization of proteoglycans associated with exfoliation material

PURPOSE

To examine the distribution of proteoglycans in the exfoliation materials in order to investigate the nature of the materials.

METHODS

The anterior parts of two eyes with exfoliation syndrome were examined by electron microscopy after staining with cupromeronic blue (cmb). Some specimens were treated with enzymes and/or nitrous acid prior to staining. The effects of the enzymes were evaluated statistically by counting the density of the cmb-positive filaments in the exfoliation materials, using a computer. One eye with exfoliation syndrome stained with alcian blue was observed with light microscopy.

RESULTS

Exfoliation materials were observed along the epithelial cells of the iris and ciliary body, and in the trabecular meshwork and zonules. In tissue specimens treated with cmb, electron-dense filaments were seen associated with the exfoliation materials. Microfibrils in the trabecular meshwork and iris, and zonular fibrils themselves were free of any filament staining, while the exfoliation materials located closely to the fibrils contained the electron-dense filaments. In the tissue specimens treated with chondroitinase AC, chondroitinase B, chondroitinase ABC or nitrous acid before cmb staining, the amount of the filament associated with exfoliation materials decreased in comparison to the controls. Digestion with keratinase did not demonstrate any significant changes in staining. A combination treatment with chondroitinase ABC and nitrous acid eliminated almost all filaments associated with the exfoliation materials. In the eye stained with alcian blue, the zonules that did not stain for the dye demonstrated an accumulation of exfoliation materials that stained strongly for alcian blue.

CONCLUSIONS

Exfoliation materials contain chondroitin sulfate, dermatan sulfate, heparan sulfate proteoglycans. Depositions of proteoglycans on the microfibrils may be closely associated with the formation of exfoliation materials.

Distribution of proteoglycans in the trabecular tissue of eyes with neovascular glaucoma

We investigated histo-chemically the composition and distribution of proteoglycans in the trabecular tissue of eyes with neovascular glaucoma. Cupromeronic blue in combination with a series of enzyme digestions and nitrous acid treatment were used. The spaces between the trabecular beams were lined by a single layer of vascular endothelium and were filled with red blood cells. A basal lamina and microfibrils were detected just beneath the newly formed vascular endothelial cells. Chondroitin-sulfate- and dermatan-sulfate-type proteoglycans were present in association with collagen fibrils in the extracellular matrix. Heparan-sulfate-type proteoglycans were present in association with the basal lamina of both the vascular endothelial cells and the trabecular cells. It is unlikely that these abnormalities in the type or distribution of proteoglycans in the trabecular meshwork have a major role in the pathogenesis of glaucoma.

Neovascular tissue in the intertrabecular spaces in eyes with neovascular glaucoma

AIMS/BACKGROUND

To investigate histological changes in the trabecular meshwork in eyes with neovascular glaucoma.

METHODS

Light and electron microscopic studies were carried out on the trabecular meshwork of three enucleated eyes with neovascular glaucoma. The presence and distribution of factor VIII in the trabecular meshwork was assessed using the ABC method.

RESULTS

Peripheral anterior synechiae covering the trabecular meshwork were detected in two eyes, which would explain the rise in intraocular pressure. In the third the angle was not completely closed by peripheral anterior synechiae. The spaces between the trabecular beams were lined by a single layer of vascular endothelium, and were filled with red blood cells in this patient. Factor VIII was positively stained in the endothelial cells, lining both these spaces and Schlemm's canal. A basal lamina and microfibrils were detected just beneath the newly formed vascular endothelial cells.

CONCLUSION

The neovascular tissue found in the trabecular spaces might be one of the factors responsible for intraocular pressure elevation in eyes with neovascular glaucoma.

Ultrasound biomicroscopic analysis of transient shallow anterior chamber in Vogt-Koyanagi-Harada syndrome

PURPOSE

To evaluate the mechanism of formation of the transient shallow anterior chamber in Vogt-Koyanagi-Harada syndrome.

METHODS

Two patients with Vogt-Koyanagi-Harada syndrome with shallow anterior chambers were examined with an ultrasound biomicroscope.

RESULTS

A ciliochoroidal detachment, which was not obvious on ophthalmoscopic examination, was clearly demonstrated in both patients by ultra-sound biomicroscopy. The detachment disappeared after systemic corticosteroid therapy.

CONCLUSION

The shallowing of the anterior chamber in two patients with Vogt-Koyanagi-Harada syndrome was caused by suprachoroidal effusion secondary to inflammation of the uvea.

Ultrastructural age-related changes on the posterior iris surface. A possible relationship to the pathogenesis of exfoliation

OBJECTIVES

To verify the presence of age-related changes in the human iris and to determine whether such changes could be related to the pathogenesis of the exfoliation syndrome.

DESIGN

Ultrastructural examination of the posterior surface of the normal iris in 9 enucleated eyes.

PATIENTS OR OTHER PARTICIPANTS

Eyes of persons aged 1 day, 3 months, and 3, 9, 27, 52, 59, 59, and 65 years.

MAIN OUTCOME MEASURE

The presence of aging changes in the iris.

RESULTS

Aging changes included duplication of the basal lamina of posterior iris pigment epithelial cells, formation of atrophic invaginations in the posterior cell membranes containing interlacing basal lamina, formation (or deposition) of microfibrils 11 to 13 nm in diameter, with a banding periodicity of 12 to 16 nm, deposition of electron-dense material in relation to the basal lamina and/or microfibrils, and the presence of some fine granular material overlying the basal lamina.

CONCLUSION

These changes have been consistently described before in association with exfoliation material, which suggests the possibility that exfoliation is an eventual aging process.

[Histopathological studies on the rds mouse retina--relationship between photoreceptor and pigment epithelial cells]

We used light and electron microscopy to examine detailed ultrastructural changes in the course of the development and degeneration of the rds mouse (rds/rds) retina with particular reference to the relationship between the photoreceptor and retinal pigment epithelial cells. During the first 6 postpartum days, the mutant retina showed the same developmental pattern as in normal mice. After that, however, rds mouse retinas failed to develop the photoreceptor outer segments. After 14 days, the photoreceptor inner segments and the cilia were all arranged parallel in the same direction in which the pigment epithelial cells extend their long microvilli. The inner segments and the cilia were very long and surrounded by the microvilli of the retinal pigment epithelial cells in the mutant retinas 21 days postpartum or latter. Some inner segments and cilia showed cytoplasmic degeneration in the part surrounded by the microvilli, while the other part appeared normal. There were pigment epithelial cells that contained fragments of the inner segments. The photoreceptor nucleus and inner segment were reduced in number after 21 days. These findings indicate that the pigment epithelial cells play a role in photoreceptor degeneration in rds mice.

Detection of proteoglycans in human posterior capsule opacification

Using cuprolinic blue staining, we histochemically examined the ultrastructural localization of proteoglycans in the fibrous-type human posterior capsule opacification. This capsule opacification contained proteoglycans that showed positive staining with cuprolinic blue. Many cuprolinic-blue-positive filaments were present within the bundles of collagen fibrils, basal lamina-like material and basal lamina of proliferated lens epithelial cells. Pretreatment with enzymes and nitrous acid revealed that the collagen fibrils contained chondroitin sulfate and dermatan sulfate, whereas the basal lamina-like material and basal lamina of epithelial cells contained heparan sulfate. These results suggest that proteoglycans are one of the components in posterior capsule opacification.

Anterior chamber angle vascularization in Sturge-Weber syndrome. Report of a case

The case of a 20-year-old woman with a left-sided facial hemangioma and a homolateral glaucoma is reported, complete with the histology of a trabeculectomy specimen. Her left eye had an episcleral hemangioma and goniodysgenetic features in the anterior chamber angle, while the intraocular pressure was measured to be 45 mmHg. The left optic disc showed a large cupping and the left visual field was constricted. The right eye had no glaucomatous changes. Histological examination of the trabeculectomy specimen by both light and electron microscopy showed multiple congenital anomalies. There was a cluster of blood vessels in the trabecular meshwork. Abnormal accumulations of fine granular extracellular matrixes were observed in both the juxtacanalicular connective tissue and around the vascular structures. The lumen of Schlemm's canal was subdivided into three or four parts with few giant vacuole structures. The endothelial cells lining the inner wall of Schlemm's canal contained a well-formed basal lamina with many villi projecting into the lumen. These findings suggest that the multiple anomalies observed in the trabecular tissue may contribute to the manifestation of glaucoma in Sturge-Weber syndrome.

Distribution and characterization of sulfated proteoglycans in the trabecular tissue of goniodysgenetic glaucoma

We evaluated histochemically the distribution of proteoglycans in the trabecular tissue of goniodysgenetic (developmental) glaucoma. Nine trabecular tissue specimens obtained at trabeculectomy from seven patients with goniodysgenetic glaucoma were stained with either cuprolinic blue or cupromeronic blue in combination with a series of enzyme and nitrous acid treatments. Within the extracellular matrix of the trabecular meshwork, many cupromeronic blue- or cuprolinic blue-positive filaments were observed in association with collagen fibrils, basal lamina, and basal lamina-like material. The extracellular matrices of elastin-like fibers, fine fibrillar materials, and fine granular materials were free from any reaction products. The enzyme and nitrous acid treatments disclosed that the reaction products associated with collagen fibrils represented both chondroitin sulfate and dermatan sulfate types, while those with basal lamina and basal lamina-like material represented heparan sulfate-type proteoglycans. Extensive accumulations of basal lamina-like material contained a great deal of heparan sulfate-type proteoglycans in the thick subcanalicular tissue of goniodysgenetic glaucoma. These results indicate that the class and distribution of proteoglycans in the goniodsygenetic trabecular tissues are virtually the same as that in the normal tissues. However, the large accumulation of basal lamina-like material with heparan sulfate-type proteoglycans can be one of the causes of the intraocular pressure increase in goniodysgenetic glaucoma.

Anterior capsule opacification in monkey eyes with posterior chamber intraocular lenses

OBJECTIVE

To examine the morphologic features of anterior capsule opacifications in pseudophakic monkey eyes.

METHODS

Extracapsular lens extraction with implantation of posterior chamber intraocular lenses in six monkey eyes. Eyes were enucleated 2, 4, and 12 months after implantation and then studied with light and electron microscopy. Distribution of proteoglycans was also examined with cuprolinic blue staining.

RESULTS

Anterior capsule opacifications were composed of proliferated cellular and extracellular matrix components situated between the anterior capsule and the optics of the intraocular lens. The morphologic features of the proliferated cells were consistent with epithelial cells, and these cells probably represented lens epithelial cells. The extracellular matrix, which consisted of collagen fibrils, basal lamina-like material, and microfibrils, was most prominent in the specimens obtained 12 months after lens implantation. The extracellular matrix contained proteoglycans that showed positive staining with cuprolinic blue.

CONCLUSIONS

Anterior capsule opacifications consisted of proliferated lens epithelial cells and aberrant extracellular matrix.

Proteoglycans in the mouse interphotoreceptor matrix. V. Distribution at the apical surface of the pigment epithelium before and after retinal separation

The distribution of chondroitin sulfate proteoglycans in the mouse interphotoreceptor matrix (IPM) proximal to the retinal pigment epithelium (RPE) was evaluated with EM histochemical techniques using Cupromeronic Blue (CmB) before and after retinal separation. Densely packed, sheet-like processes surrounding vesicle-like compartments containing CmB staining were normal constituents of the IPM at the apical surface of the RPE. Most of the vesicle-like compartments, which appeared to be isolated from the IPM in single section profiles, were found to be continuous with the IPM when three-dimensional reconstructions of serial thin sections were evaluated. Analyses of stereo image pairs of semithin sections visualized by electron spectroscopic imaging (ESI) also demonstrated that the CmB stained proteoglycans in the lumen of these pseudovesicles were in continuity with the CmB stained components present in the IPM. Moreover, ESI demonstrated that the CmB stained profiles formed an elaborate interconnecting network extending from the apical border of the RPE to the level of the outer limiting membrane of the retina. After removal of the retina, rinsing of the RPE with Ringer's solution prior to fixation eliminated proteoglycan staining near the base of the apical processes, whereas staining near the tips of these processes remained. The CmB stained filaments remaining after rinsing were thicker and shorter, and made fewer interconnections than those in the non-separated preparations. These results suggest that two types of chondroitin sulfate proteoglycans are present in the IPM which differ in distribution and in the degree of aqueous solubility. Additionally, a closely associated retina appears to be required for maintenance of the normal structure of proteoglycans associated with the RPE surface. The elaborate topography at the RPE apical surface may play a role in the delivery and/or recovery of components of the IPM.

Goniodysgenesis of the eye with arthrogryposis multiplex congenita

We report an autopsy case of 4-day-old male infant with arthrogryposis multiplex congenita studied by histological methods in respect to the ocular tissues. The eye examined was normal in size, and the retina, optic nerve, choroid, sclera and extracocular muscle showed no remarkable histological changes. However, the cornea was thickened, and the iris, trabecular tissue and ciliary body showed maldevelopmental changes, which were all compatible with goniodysgenesis. The clinical data of this case did not demonstrate any signs of congenital glaucoma, but the present study indicates that an infant with arthrogryposis multiplex congenita has a potential for infantile glaucoma with goniodysgenesis.

Proteoglycans in the mouse interphotoreceptor matrix. IV. Retinal synthesis of chondroitin sulfate proteoglycan

To determine whether the mouse retina contributes chondroitin sulfate proteoglycan (CS-PG) to the interphotoreceptor matrix (IPM), 35SO4(2-) was used as a tracer for newly synthesized proteoglycan by retinas maintained in vitro in the absence of pigment epithelium. Following incubation with the tracer for 3 hr, the 35S-labeled proteoglycans present in the incubation medium and associated with isolated photoreceptor outer segments were analyzed separately. Proteoglycan was extracted with 4 M guanidine, and then separated on a G-25 column followed by DEAE ion exchange chromatography in the presence of 8 M urea. The proteoglycan fraction was eluted with a linear NaCl gradient of 0.15-1.0 M. Eluted 35S-labeled macromolecules were susceptible to chondroitinase AC and ABC degradation, indicating that virtually all the 35S-labeled proteoglycan synthesized by the mouse retina and secreted into the incubation media is of the chondroitin sulfate type. In parallel autoradiographic analysis of retinas following 35SO4(2-) incubation, silver grains were present over all retinal compartments, with 41-48% associated with the photoreceptor layer. Quantitative autoradiography of retinas following chondroitinase AC digestion of fixed retinas revealed significant (P less than 0.025) reduction in silver grains associated with the photoreceptor outer segment layer as compared to controls. These combined biochemical and autoradiographic studies indicate that the retina, possibly the photoreceptors, synthesize at least a portion of the CS-PG present in the IPM of the mouse.

Proteoglycans in the mouse interphotoreceptor matrix. III. Changes during photoreceptor development and degeneration in the rds mutant

The distribution of sulfated proteoglycans in the interphotoreceptor matrix (IPM) was examined during development and degeneration of photoreceptors in the rds mouse with electron microscopy after staining with the cationic dye Cupromeronic Blue (CmB). Three distinct CmB-positive filaments types were observed: type A (45-55 nm long and around 5 nm in diameter), type B (up to 0.5 micron long and 5-10 nm in diameter), and type C filaments (up to 1 micron long and 15-25 nm in diameter. During early postnatal development, before degenerative changes occur in photoreceptors, CmB-positive filaments were virtually identical in morphology and pattern of development as those recently reported for the normal mouse IPM (Tawara, Varner and Hollyfield, 1989, Exp. Eye Res. 48, 815-39). From 10 days to 1 year of age, during the period of progressive degeneration and loss of photoreceptor cells, numerous type B and type C filaments were present in the IPM. Type B filaments were distributed throughout the IPM, whereas type C were predominantly located around the apical termination of photoreceptor inner segments and between the pigment epithelial microvilli. Type A filaments were located principally in the apical cytoplasm of the pigment epithelial cells and in the proximal IPM. In the 20-month-old rds mouse, a time when virtually no photoreceptor cells remain, only minimal CmB staining was evident at the interface between the pigment epithelium and retina. Pretreatment with chondroitinase AC eliminated most CmB-positive filaments from the 18-day-old and 20-month-old mouse IPM. These findings suggest that there are no major differences in structural type or early postnatal development of chondroitin sulfate-type proteoglycans in the IPM between rds and normal mice. Any differences in distribution of chondroitin sulfate-type proteoglycans between rds and normal mice can be accounted for by the absence of photoreceptor outer segments and progressive loss of photoreceptor cells in this mutant. The disappearance of these IPM proteoglycans following photoreceptor degeneration suggests that photoreceptors may be critically involved in the maintenance of these matrix components.

[A case of Rubinstein-Taybi syndrome suspected with goniodysgenetic glaucoma]

We reported a case of Rubinstein-Taybi syndrome suspected in association with goniodysgenetic glaucoma, and studied using light and electron microscopy the anterior chamber angle tissues obtained surgically by trabeculectomy. The patient was 31-year old male, who had a systemic appearance of Rubinstein-Taybi syndrome with dwarfism, mental retardation, antimongoloid slant, flat-broad based thumbs, low set ears, high arched plate except for whorl of dermatographism. In addition to these malformations, goniodysgenetic glaucoma was also present which is characterized by underdevelopment of the angle recess and invisible ciliary body band in gonioscopic examination. The histopathological studies of the specimens revealed the presence of a compact tissue filled with a large amount of collagen fibers with few cells in the juxta-canalicular tissue of Schlemm's canal. There were 3 to 4 layers of trabecular sheets of corneoscleral meshwork at the anterior chamber side of the compact tissue. We conclude that the presence of the compact tissue under Schlemm's canal represents goniodysgenesis, underdevelopment of the trabecular meshwork, which is the primary cause of the glaucoma in this case.

Distribution and characterization of sulfated proteoglycans in the human trabecular tissue

The distribution of proteoglycans in the trabecular tissue of human eyes was evaluated histochemically, using Cupromeronic Blue in combination with a series of enzyme digestions and nitrous acid treatment. Within the extracellular matrix of the trabecular meshwork, many Cupromeronic Blue-positive filaments were observed in association with collagen fibrils, basal lamina, a basal lamina-like material and a fine fibrillar-like material. Pretreatment with chondroitinase AC reduced the staining associated with the collagen fibrils, whereas filament staining in this location was completely eliminated by pretreatment with chondroitinase ABC. Nitrous acid treatment eliminated almost all the filament staining associated with the basal lamina and basal lamina-like material. When the tissue was treated with chondroitinase AC, chondroitinase ABC or nitrous acid, filament staining associated with the fine fibrillar-like material was reduced. After a combined treatment with nitrous acid followed by incubation with chondroitinase ABC, all filament staining in the trabecular meshwork was eliminated. These results are consistent with an interpretation that human trabecular tissue contains three distinct types of sulfated proteoglycans, namely chondroitin sulfate, dermatan sulfate and heparan sulfate-type proteoglycans. Proteoglycans containing chondroitin sulfate and dermatan sulfate are present in association with collagen fibrils. Proteoglycans of heparan sulfate-type are associated with the basal lamina and the basal lamina-like material. Chondroitin sulfate, dermatan sulfate and heparan sulfate-type proteoglycans are present in association with the fine fibrillar-like component. The basal lamina, basal lamina-like material and fine fibrillar-like components associated with these negatively charged proteoglycans may be important contributors to aqueous outflow resistance in the juxtacanalicular connective tissue.

Proteoglycans in the mouse interphotoreceptor matrix. II. Origin and development of proteoglycans

The development and cellular origin of chondroitin sulfate-type proteoglycans in the interphotoreceptor matrix (IPM) of the mouse retina were examined with electron microscopy after staining with the cationic dye, Cupromeronic Blue. In the IPM of the developing retina, three structural types of Cupromeronic Blue-positive filaments were observed. Type A filaments measured 45-55 nm in length and around 5 nm in diameter. At birth, a few type A filaments were present in the IPM and they increased in number during subsequent days postpartum. Type A filaments were present in high density in the cytoplasm of the pigment epithelial cells at all stages examined where they were associated with the Golgi apparatus and cytoplasmic vesicles. Type B filaments, measuring 60-80 nm in length and 5-10 nm in diameter, were occasionally observed in the IPM of the newborn mouse. Type B filaments increased in number during subsequent development and by 14 days postpartum, their location was restricted predominantly to the IPM around photoreceptor inner segments and the connecting cilia. Type C filaments, measuring 15-25 nm diameter with extremely long profiles (up to several microns), were first consistently observed in the IPM at 6 days postpartum, the time when photoreceptor outer segments begin to develop. During subsequent days postpartum, type C filaments increased in number. By 18 days postpartum, when photoreceptors have achieved their adult length, type C filaments were interconnected in a net-like meshwork investing the photoreceptor outer segments. All three Cupromeronic Blue-positive filament types were sensitive to chondroitinase AC, but not to Streptomyces hyaluronidase. Cupromeronic Blue-stained filaments were rarely observed in the cytoplasm of the photoreceptor or Müller cells at any of the stages examined. These findings suggest that proteoglycans of the chondroitin sulfate-type present between the retina and pigment epithelium of the adult mouse are secreted principally by the retinal pigment epithelial cells, and that these components begin to be elaborated into the IPM a few days prior to the stage when photoreceptor outer segment development is initiated. Organization of the proteoglycans to form an extracellular meshwork surrounding the photoreceptors takes place during the period when photoreceptor outer segments are elongating to achieve their adult length.

Proteoglycans in the mouse interphotoreceptor matrix. I. Histochemical studies using cuprolinic blue

Cuprolinic Blue, when applied at a critical electrolyte concentration, can be utilized for assessing the localization and structural characteristics of proteoglycans with electron microscopy. We have used this cytochemical procedure to evaluate the distribution of proteoglycan in the interphotoreceptor matrix of the mouse retina. Cuprolinic Blue-positive filaments of two distinct morphological types were present surrounding both rod and cone photoreceptors. Large filaments, 115-135 nm long and 15-25 nm in diameter, were distributed in the interphotoreceptor matrix around the outer segment and outer portion of the inner segment. These filaments appeared linked to each other to form a complex meshwork. Smaller filaments, 60-70 nm long and 5-10 nm in diameter, were principally observed around the photoreceptor inner segments. Incubation of retinas with chondroitinase AC and chondroitinase ABC eliminated Cuprolinic Blue staining of both large and small filaments, whereas hyaluronidase treatment reduced the size of the filaments but did not eliminate their staining. When retinas were washed extensively prior to fixation and staining, Cuprolinic Blue-positive filaments remained associated with the photoreceptor cell surface. These results suggest that the interphotoreceptor matrix of the mouse retina contains at least two structural types of proteoglycan, of the chondroitin sulfate-type, which are differentially distributed in this compartment. One of the proteoglycans forms a complex meshwork which surrounds the photoreceptors. Both are insoluble and appear to be firmly attached to the photoreceptor plasma membrane.

Histological study on transient ocular hypertension after laser iridotomy in rabbits

We performed argon-laser iridotomy on pigmented rabbits and examined histologically the tissue of the anterior chamber angle, the iris, and the ciliary body. After laser iridotomy, 9/10 eyes showed an elevation in transient intraocular pressure. Deposits of blood plasma with fibrin were observed in the tissue of the circumferential anterior chamber angle from eyes enucleated at a period of high intraocular pressure. In the eyes in which ocular pressures returned to the baseline, the quantity of blood plasma was small. In the laser-irradiated iris and iris processes, cells constructing the vessel wall were degenerated, and blood plasma and fibrin exuded. In and around the ciliary body, fibrin was not demonstrated. These observations suggest that argon-laser irradiation to the iris leads to a breakdown of the blood-aqueous barrier mainly in the laser-treated iris, and that deposition of blood plasma with fibrin in the anterior chamber angle tissue may cause transient intraocular pressure elevations after laser iridotomy in rabbits.

Transformation and cytotoxicity of iron in siderosis bulbi

Ocular tissues from two enucleated and one trabeculectomized human eyes with siderosis bulbi were studied by electron microscopy. Ferritin particles were demonstrated in various cell types of the three eyes. Other types of iron were not identifiable. The ferritin particles were scattered throughout the cytoplasm, with a few particles in the nucleus and extracellular space. More ferritin particles were seen in tissues near the iron foreign body. The cells which contained numerous ferritin particles also had siderosomes, most of which were thought to be conglomerates of the ferritin particles in the secondary lysosomes. Cells with numerous ferritin particles, particularly in the siderosomes, showed vacuolar degeneration. The present study indicated that in siderosis bulbi, iron released from the iron foreign body is deposited as ferritin scattered throughout the cytoplasm and is sometimes accumulated as siderosomes, in the affinitive cells. In siderosis bulbi, the cells become damaged by the deposition of ferritin in the cytoplasm, especially in the form of siderosomes.

Developmental immaturity of the trabecular meshwork in juvenile glaucoma

We used light and electron microscopy to compare ten specimens of anterior chamber angle tissue obtained by trabeculectomy from seven patients with juvenile glaucoma (primary glaucoma with open iridocorneal angle in young humans with specimens of normal trabecular meshwork from humans of the same ages. In all cases of juvenile glaucoma, we observed a thick compact tissue consisting of cells with fine processes and extracellular substances at the anterior chamber side of Schlemm's canal and abnormal deposits of ground substances in the thick tissue. These observations strongly suggest that the thick compact tissue represents an immature development of the trabecular meshwork and may be one of the primary causes of increased intraocular pressure in juvenile glaucoma. Our studies indicate that both congenital and juvenile glaucoma occur because of developmental immaturity of the trabecular meshwork in anterior chamber angle tissue and that the more extensive the immaturity, the earlier the glaucoma will become manifest.

Developmental immaturity of the trabecular meshwork in congenital glaucoma

We examined nine specimens of anterior chamber angle tissue obtained by trabeculectomy from seven patients with early-onset congenital glaucoma and one patient with late-onset congenital glaucoma by light and electron microscopy and compared them with specimens of trabecular meshwork from normal human and monkey eyes. One eye with early-onset congenital glaucoma had no Schlemm's canal. In all cases of congenital glaucoma, we observed a thick subcanalicular tissue with a structure similar to that seen in the endothelial meshwork beneath the inner wall of Schlemm's canal. There were abnormal deposits of ground substances that resembled basement membrane. Additionally, histologic studies of eyes from premature infants obtained at autopsy showed that trabecular sheet-formation initially occurs on the anterior chamber side of the trabeculum and advances gradually toward Schlemm's canal and that the undifferentiated portion of the trabeculum remains as endothelial meshwork beneath the inner wall of Schlemm's canal. Our observations strongly suggest that the existence of the thick subcanalicular tissue, which is considered to be endothelial meshwork, indicates an immature stage of the trabecular meshwork and may be one of the primary causes of increased intraocular pressure in congenital glaucoma.