Pituitary adenylate cyclase-activating peptide-immunoreactive nerve fibers in the cat eye

Purpose: To study the occurrence and distribution of the neuropeptide pituitary adenylate cyclase-activating peptide (PACAP) in ocular and orbital structures of the cat. Methods: Immunocytochemistry to localize PACAP and double immunostaining to detect co-localization of PACAP with other neuropeptides. Results: Numerous PACAP-immunoreactive nerve fibers were observed in the lacrimal gland, choroid and retroocular arteries. There was a sparse supply of PACAP-containing nerve fibers in the iris, ciliary body and conjunctiva. Subpopulations of PACAP-containing nerve fibers stored vasoactive intestinal peptide (VIP) or calcitonin gene-related peptide (CGRP). Around 10% of the ganglion cells in the sphenopalatine ganglion harbored PACAP immunoreactivity. In the trigeminal ganglion around 5% of the neuronal cell bodies and in the ciliary ganglion only occasional ganglion cells contained PACAP immunoreactivity. PACAP immunoreactivity co-localized with VIP in the sphenopalatine ganglion and with CGRP in the trigeminal ganglion. Conclusion: PACAP-containing nerves in the eye and associated structures demonstrate a distribution pattern resembling that of VIP. Subpopulations of nerve fibers containing PACAP immunoreactivity store VIP or CGRP immunoreactivity. Neuronal PACAP in the eye and orbit may take part in regulation of smooth muscle tone, glandular secretion and sensory processing.     

Differential distribution of neuronal markers and neuropeptides in the human lacrimal gland

Background: The present study was untertaken in an attempt to broaden the spectrum of known neuronal markers and neuropeptides in the main lacrimal gland of the human by light-microscopic immunohistochemistry. Methods: Using antisera against the neuronal markers protein gene product (PGP) and S-100 protein (S-100), the distribution of nerve fibers in the human main lacrimal gland was studied. Vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY) and tyrosine hydroxylase (TH) were identified by their specific antisera. Results: The nerve fibers are distributed throughout the interstice between the glandular tubules. Associations were also found between nerve fibers and both the interlobular ductal system and blood vessels (mainly arterioles). Within the glandular lobules isolated groups of secretory cells stained positive for S-100 protein. Nerve fibers situated in the glandular interstice between the tubules showed predominantly positive immunoreactions for the neuropeptide VIP, while only very few fibers stained positive for CGRP, NPY and the catecholamine marker TH. Nerve fibers associated with interlobular blood vessels were mainly CGRP and NPY positive and stained only very rarely for VIP. The epithelia of interlobular ducts and excretory ducts were associated with CGRP-immunoreactive nerve fibers. Conclusion: The neuropeptides identified in the lacrimal gland indicate the complexity with which a variety of biologic signals regulate and modulate the lacrimal gland.Presented in part at the Joint European Research Meetings in Ophthalmology and Vision (JERMOV), 15–19 October 1994, Montpellier, France     

Optic nerve fiber count and diameter of the retrobulbar optic nerve in normal and glaucomatous eyes

Background: The caliber of the retrobulbar optic nerve and the count of optic nerve fibers vary considerably in normals. The diameter of the retrobulbar optic nerve also decreases with optic nerve atrophy. This study aimed to determine the relationship between the caliber of the optic nerve and the optic nerve fiber count. Methods: We counted the optic nerve fibers and measured the diameter of histological cross sections of the optic nerve for 56 normal subjects and 23 patients with absolute glaucoma. Results: The optic nerve fiber count increased significantly (P<0.0001) by 777 000 fibers for every millimeter increase in retrobulbar optic nerve diameter, starting at a baseline diameter of 1.89 mm. Conclusion: Using this linear regression equation, the optic nerve fiber count can be estimated in routine histology by measuring the optic nerve diameter. Taking into account a fixation-induced tissue shrinkage, this method may also give some indication of the optic nerve fiber count intravitally, when, for eyes with opaque optic media, the diameter of the retrobulbar optic nerve has been measured by imaging techniques. Greater retrobulbar optic nerve caliber may indicate greater structural reserve capacity.     

Course of the optic nerve fibers through the lamina cibrosa in human eyes

Background: This study investigated whether regional variations in the course of the optic nerve fibers through the lamina cribrosa may be one of the reasons why the local susceptibility for glaucomatous optic nerve fiber loss differs among the various regions of the optic disc. Methods: The study included 34 human eyes enucleated because of a malignant melanoma of the peripheral choroid without involvement of the anterior chamber angle or the optic nerve. Anterior-posterior sections through the pupil and the optic disc were histomorphometrically evaluated. In the central region and the peripheral part of the optic disc, we measured the thickness of the lamina cribrosa and the length of the lamina cribrosa channels through which the nerve fibers pass. Results: In the peripheral parts of the disc, compared with its central region, the lamina cribrosa was significantly thicker (P<0.0001, Wilcoxon test), the lamina cribrosa channels with the nerve fibers passing through were significantly longer (P<0.0001), and the ratio of length of the fiber channels to the thickness of the lamina cibrosa was significantly higher (P=0.0001). Conclusion: The lamina cribrosa is thicker and the course of the optic nerve fibers through the lamina cribrosa is more curvilinear in the disc pheriphery than in the disc center. These variations in the anatomy of the lamina cribrosa may be one of several factors influencing the regional susceptibility for glaucomatous optic nerve fiber loss within the optic nerve head.     

Unusual retinal pigment epitheliopathy and choroidopathy in carcinomatosis: A rare case of cancer-associated retinopathy

Background: Cancer-associated retinopathy is a syndrome causing ocular symptoms. It is a rare entity and only a few cases have been reported. Methods: A 67-year-old woman with small-cell endometrial carcinoma suffering from deterioration of visual acuity is presented. Results: The patient presented with extensive mottled changes of the retinal pigment epithelium, accompanied by diffuse subretinal fluid in the posterior pole and exudative retinal detachments inferior in both eyes. Conclusion: This patient suffered from a rare variety of cancer-associated retinopathy.     

The effect of nasolacrimal occlusion on drug-induced mydriasis

Background: Nasolacrimal occlusion has been shown to improve the efficacy of some topically applied ocular drugs. The aim of this study was to investigate the effect of nasolacrimal occlusion on tropicamide-induced mydriasis. Methods: We compared pupillary dilatation by 0.125% tropicamide with and without nasolacrimal occlusion in 40 healthy volunteers. Results: Analysis of variance with repeated measures failed to show any advantage due to nasolacrimal occlusion in drug-induced mydriasis. Conclusion: Nasolacrimal occlusion did not increase the mydriasis obtained with 0.125% tropicamide.     

HLA antigens in a Japanese family with Behçet's disease

Background: Familial Behçet's disease is rare. Methods: HLA antigens in a Japanese family with Behçet's disease were examined. Results: The affected patients had HLA B51, and unaffected family members also had the same antigen. Conclusion: It is likely that not only HLA B51 but also other factors may be involved in the pathogenesis of Behçet's disease in Japanese patients.     

Ophthalmological and neuro-ophthalmological involvement in Churg-Strauss syndrome: a case report

Background: It is well known that different types of eye involvement may develop during the course of systemic vasculitides. Methods: We report here a case of Churg-Strauss syndrome (allergic granulomatous angiitis) characterized by the presence of multiple ophthalmological and neuro-ophthalmological lesions, i.e., mononeuritis of the fourth cranial nerve, multifocal choroidal ischaemia, and bilateral ischaemic optic neuropathy. Results: Ischaemic lesions in the posterior ciliary plexus and chorio-retinal circulation, which appeared simultaneously after a phase of disease activity, were documented. Conclusion: The simultaneous occurrence of multiple ocular features in a patient with Churg-Strauss syndrome suggests that regional vasculitis may be the pathological mechanism underlying the multiple ophthalmological lesions in this disorder.     

Pressure sore in a patient who underwent repair of a retinal tear with gas injection

Purpose: To demonstrate a pressure sore following strict head positioning in a patient who underwent encircling band, vitrectomy and gas injection. Methods: A male patient was admitted to the hospital with a large posterior horseshoe tear in the inferior temporal retina with severe vitreous traction and retinal detachment. Encircling band, vitrectomy cryotherapy and gas injection was performed. After surgery the patient was instructed to sit in a facedown position. Results: A pressure sore resulted from prolonged immobility of the right elbow due to face-down positioning following encircling band, vitrectomy and gas injection. Conclusion: A patient injection. Conclusion: A patient may rarely have compulsive personality traits that result in extreme compliance to the physician's recommendations; therefore, general instructions given for head positioning should include permission for a change in position when required, at least for brief periods of time.     

The use of tissue plasminogen activator in post-traumatic total hyphaema

Background: We wanted to evaluate whether intracameral injection of tissue plasminogen activator (tPA) is useful in managing traumatic hyphaema. Methods: Two eyes with total hyphaema after a severe penetrating injury were treated with a single intracameral injection of 25 g of tPA 5 and 14 days after the injury, respectively. Results: Most of the blood coagulum dissolved within 24 h, and in one of the two eyes the intraocular pressure decreased from 45 to 8 mmHg. The other eye was hypotonic. No re-bleeding or complications related to the use of tPA were noticed. Conclusion: The results in these two cases suggest that tPA is a useful adjunct in managing total hyphaema.     

Early detection of P-VEP and PERG changes in opthalmic Graves' disease

Background: In Graves' disease the optic neuropathy (ON) is due to direct compression of the nerve and/or of its blood supply. The aim of the present study was to detect early changes in the visual functions of patients affected by ophthalmic Graves' disease (OGD) by using electrophysiological tests (P-VEP and PERG). Methods: We studied 50 OGD patients who were in a range between class 2 and class 5 according to the Donaldson-American Thyroid Association classification, i.e. had no evident ON and normal visual acuity. We recorded transient reversal PERG and P-VEP in response to the stimulation of one eye at three spatial frequencies (2.2, 1.1 and 0.5 c/d). Results: Our results showed a statistically significant reduction in PERG amplitude in class 5, while the P-VEP amplitude was already reduced in class 2. Conclusion: The electrofunctional tests were useful to detect small changes in the visual function of patients affected by initial stages of OGD. Therefore, P-VEP and PERG recordings appear to be a useful tool for early diagnosis of the optic nerve involvement in Graves' disease.     

Application of eye drops to the medial canthus

Background: Our purpose was to investigate the efficacy of instillation of eye drops in the medial canthus with the lids closed at the time of application. Methods: The pupils of 50 healthy volunteers were dilated with tropicamide 0.125%. The effect of the drug on pupillary dilatation when instilled in one eye with the lids closed was compared to its effect when instilled in the conventional mode in the other eye. Results: Maximal mydriasis achieved was 2.75 ± 0.76 mm in the eye with closed lids and 2.8 ± 0.77 mm in the eye in which eye drops were instilled in the conventional mode. Conclusion: Eye drop instillation in the medial canthus with the lids closed at the time of application seems to be an effective means of ophthalmic drug delivery.     

Sebaceous gland adenoma of the palpebral conjunctiva in a patient with Muir-Torre-syndrome: a case report

Background: MuirTorre syndrome (NITS) is a hereditary genodermatosis associated with internal malignancies. Methods: We report the histological case of an atypical sebaceous gland adenoma of the palpebral conjunctiva in a 42-year-old female patient. Results: The combination of this adenoma with atypical adenomatous hyperplasia of the endometrium and a strong family history of gastrointestinal and urogenital cancers led to the diagnosis of NITS. Conclusion: We present a case where the diagnosis of an atypical solitary sebaceous gland adenoma of the palpebral conjunctiva combined with a conspicuous personal and family history led to the diagnosis of NITS.     

Ocular findings in Japanese women with nevus of Ota

Background: Nevus of Ota is common in Japanese women, but most patients are not examined ophthalmologically. Methods: We performed ophthalmologic examinations on 16 Japanese women who had had bluish pigmentation in the periorbital region, sclera, and conjunctiva since birth. Results: Fifteen patients had unilateral involvement, and one had bilateral lesions. The visual acuities were good, and the intraocular pressures were within normal range. All patients had a negative family history. Three patients had light pigmentation in the optic disc in the affected eye. Conclusion: We believe that optic disc pigmentation associated with nevus of Ota, as found in these three patients, may be common but have been rarely described.     

Histopathology of episcleral fibrosis after trabeculectomy with and without mitomycin C

Background: The aim of the study was to investigate the histopathologic features of scar tissue which have proliferated at the site of trabeculectomy of surgical failures after procedures with and without the use of the antimetabolite mitomycin C (MMC). Methods: We obtained seven surgical specimens after trabeculectomy without MMC and five specimens after trabeculectomy with MMC, which were compared with 23 controls. Sections were stained with hematoxylin and eosin, Verhoeff-van Gieson, Grocott methenamine silver, and alcian blue. An immunohistochemical stain was performed for -smooth muscle actin. Results: Specimens from eyes operated without MMC showed dense scar tissue with many fibroblasts, much ground substance, parallel-oriented collagen fibers, and contractile intracellular proteins within the fibroblasts. Specimens from eyes operated with MMC consisted of tissue with only few fibroblasts which did not exhibit contractile proteins. Collagen fibers were arranged randomly with less ground substance. Conclusion: Even after 1–10 months, the scar tissue was distinctly different in the two groups. These results suggest that the use of MMC has long-term effects in vivo. Surgical failures related to scar formation are possible and not reduced to zero.Presented in part at the Association for Research in Vision and Ophthalmology (ARVO) Meeting, Fort Lauderdale, USA, 14–19 May 1995     

Double contour of the lens capsule edges after continuous curvilinear capsulorhexis

Background: After curvilinear capsulorhexis in cataract surgery often a double-ring shape of the remaining capsular margins can be observed. In order to better understand this phenomenon we performed a histological study of excised capsules after continuous curvilinear capsulorhexis. Methods: Ten anterior capsular specimens from cases with double-ring structure of the capsular margins after continuous curvilinear capsulorhexis (D-group) were examined light microscopically and compared with 10 normal cases (N-group) and 10 cases with pseudoexfoliation (P-group). Three cases from each group were also examined electron microscopically. Results: A characteristic step formation in the capsular edges and in addition horizontal capsular splits in the border zone between the zonular lamella of the anterior capsule and the capsule proper could be demonstrated histologically in the D-group. Conclusions: There seems to be a weak point of the capsular tissue in the border zone between zonular lamella of the lens and the capsule proper. The superficial splits that we found histologically in this region might be a precursor or forme fruste of true exfoliation. The outward-directed traction force exerted by the zonular fibers seems to lead to further disruption in this weakened layer of the lens capsule during capsulorhexis, producing a double-ring contour of the capsular margins.     

Cytochemical localization of guanylate cyclase in photoreceptor cells of the mouse

Background: Light-stimulated excitation causes a decrease of the cGMP concentration in vertebrate photoreceptor cells. The cGMP content is restored by the catalytic action of a guanylate cyclase (EC 4.6.1.2). Methods: The spatial distribution of guanylate cyclase was determined cytochemically in rod visual cells of the mouse. Results: In retinal tissue of the mouse guanylate cyclase was found throughout the photoreceptor cells, in the outer and the inner segments, and was especially prominent in the cilia and in elongations of cilia extending into the outer segments. A reaction product of adenylate cyclase (EC 4.6.1.1) could not be demonstrated in vertebrate rod outer segments. Conclusion: The relatively high amount of guanylate cyclase in the inner segments and the cilia may contribute — at least in part — to the actual concentration and the time course of concentration changes of the cGMP concentration in rod outer segments.     

Explorative study of interleukin levels in the human cornea

Background: The presence of interleukins has been demonstrated in the cornea and other ocular tissues. Although pathogenic mechanisms are unknown, interleukins seem to be involved in inflammatory disorders of the cornea. The present study was undertaken to analyse concentrations of interleukin- I (IL-1) and interleukin-6 (IL-6) in human corneas with various clinical diagnoses. Methods: Immediately after keratoplasty 127 explanted human corneas with various corneal diseases were snap frozen and cryosections were prepared for histological examination. Furthermore, the protein content was measured according to the method of Bradford and the concentration of IL-1 and IL-6 were determined using a specific immunosorbent test (ELISA). Results: It was found that IL-1 and IL-6 level were clearly higher in corneas with ulcerations and distinct inflammatory signs. Lower levels of both interleukins were found in corneas with a weak expression of inflammatory signs. Conclusions: Keratitis, keratoconus with inflammatory signs, and ulcerating processes showed higher interleukin levels than corneas with non-inflammatory disorders like scar formation, corneal dystrophy and keratoconus. The results could show that, depending on the clinical diagnosis, the inflammatory status of the cornea may be evaluated by the interleukin levels determined in the corneal tissue.     

Evidence of cross-link formation of vitreous collagen during experimental ocular inflammation

Purpose: To determine the mechanisms of vitreous changes during ocular inflammation. Methods: We investigated vitreous changes, with special emphasis on collagen, in an experimental model of ocular inflammation induced by intravitreal injection of endotoxin (Escherichia coli) in rabbits. Results: Inflammation caused gel contraction and loss of elasticity, accompanied by release of a water-like liquid from the gel, and increases in the amount of insoluble material and highmolecular-weight components of vitreous collagen, presumably due to extensive cross-links of the collagen molecules. Those changes were partially inhibited by intravitreal injection of superoxide dismutase. Conclusions: The crosslinks of vitreous collagen may promote vitreous gel contraction and release of a water-like liquid from the gel. Superoxide anion may play a role in this process.     

Evolution of ocular clinical and electrophysiological findings in pediatric Bardet-Biedl syndrome

Bardet-Biedl syndrome (BBS) is ahereditary autosomal-recessive disorder,characterized by mental retardation, obesity,pigmentary retinopathy,polydactyly and, only in males, hypogenitalism.Even though genetic studies haverevealed five different forms of BBS correlatedto distinct loci on differentchromosomes, a diagnosis of BBS is stillprimarily based on clinical data. Thepresent study discusses the evolutionof clinical ophthalmological andelectrophysiological characteristics ofBBS patients in developmental age.The main results obtained on asample of 13 pediatric patients are thefollowing: progressive loss of visualacuity arised early in the first decade of life ophthalmoscopic signs of pigmentaryretinopathy were present only in 46%of the children studied striking anomalies in theelectroretinogram were also detectedin the cases without pigmentary retinopathy the electroretinographic results, whendetectable, suggested a greater involvement of thephotopic system as against the scotopic system.