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How early sensory experience during "critical periods" of postnatal life affects the organization of the mammalian neocortex at the resolution of neuronal cell types is poorly understood. We previously reported that the functional and molecular profiles of layer 2/3 (L2/3) cell types in the primary visual cortex (V1) are vision-dependent (Tan et al., Neuron, 108 (4), 2020; Cheng et al., Cell, 185 (2), 2022). Here, we characterize the spatial organization of L2/3 cell types with and without visual experience. Spatial transcriptomic profiling based on 500 genes recapitulates the zonation of L2/3 cell types along the pial-ventricular axis in V1. By applying multi-tasking theory (Adler et al., Cell Systems, 8, 2019), we suggest that the spatial zonation of L2/3 cell types is linked to the continuous nature of their gene expression profiles, which can be represented as a 2D manifold bounded by three archetypal cell types ("A", "B", and "C"). By comparing normally reared and dark reared L2/3 cells, we show that visual deprivation-induced transcriptomic changes comprise two independent gene programs. The first, induced specifically in the visual cortex, includes immediate-early genes and genes associated with metabolic processes. It manifests as a change in cell state that is orthogonal to cell type-specific gene expression programs. By contrast, the second program impacts L2/3 cell type identity, regulating a subset of cell type-specific genes and shifting the distribution of cells within the L2/3 manifold, with a depression of the B-type and C-type and a gain of the A-type. Through an integrated analysis of spatial transcriptomic measurements with single-nucleus RNA-seq data from our previous study, we describe how vision patterns L2/3 cortical cell types during the postnatal critical period., Significance Statement: Layer 2/3 (L2/3) glutamatergic neurons are important sites of experience-dependent plasticity and learning in the mammalian cortex. Their properties vary continuously with cortical depth and depend upon experience. Here, by applying spatial transcriptomics and different computational approaches in the mouse primary visual cortex, we show that vision regulates orthogonal gene expression programs underlying cell states and cell types. Visual deprivation not only induces an activity-dependent cell state, but also alters the composition of L2/3 cell types, which are appropriately described as a transcriptomic continuum. Our results provide insights into how experience shapes transcriptomes that may, in turn, sculpt brain wiring, function, and behavior., Competing Interests: Declaration of interests The authors declare no competing interests.

Mouse whisker somatosensory cortex (wS1) is a major model system to study the experience-dependent plasticity of cortical neuron physiology, morphology, and sensory coding. However, the role of sensory experience in regulating neuronal cell type development and gene expression in wS1 remains poorly understood. We assembled and annotated a transcriptomic atlas of wS1 during postnatal development comprising 45 molecularly distinct neuronal types that can be grouped into eight excitatory and four inhibitory neuron subclasses. Using this atlas, we examined the influence of whisker experience from postnatal day (P) 12, the onset of active whisking, to P22, on the maturation of molecularly distinct cell types. During this developmental period, when whisker experience was normal, ~250 genes were regulated in a neuronal subclass-specific fashion. At the resolution of neuronal types, we found that only the composition of layer (L) 2/3 glutamatergic neuronal types, but not other neuronal types, changed substantially between P12 and P22. These compositional changes resemble those observed previously in the primary visual cortex (V1), and the temporal gene expression changes were also highly conserved between the two regions. In contrast to V1, however, cell type maturation in wS1 is not substantially dependent on sensory experience, as 10-day full-face whisker deprivation did not influence the transcriptomic identity and composition of L2/3 neuronal types. A one-day competitive whisker deprivation protocol also did not affect cell type identity but induced moderate changes in plasticity-related gene expression. Thus, developmental maturation of cell types is similar in V1 and wS1, but sensory deprivation minimally affects cell type development in wS1.

Rare CD4 T cells that contain HIV under antiretroviral therapy represent an important barrier to HIV cure 1-3 , but the infeasibility of isolating and characterizing these cells in their natural state has led to uncertainty about whether they possess distinctive attributes that HIV cure-directed therapies might exploit. Here we address this challenge using a microfluidic technology that isolates the transcriptomes of HIV-infected cells based solely on the detection of HIV DNA. HIV-DNA + memory CD4 T cells in the blood from people receiving antiretroviral therapy showed inhibition of six transcriptomic pathways, including death receptor signalling, necroptosis signalling and antiproliferative Gα12/13 signalling. Moreover, two groups of genes identified by network co-expression analysis were significantly associated with HIV-DNA + cells. These genes (n = 145) accounted for just 0.81% of the measured transcriptome and included negative regulators of HIV transcription that were higher in HIV-DNA + cells, positive regulators of HIV transcription that were lower in HIV-DNA + cells, and other genes involved in RNA processing, negative regulation of mRNA translation, and regulation of cell state and fate. These findings reveal that HIV-infected memory CD4 T cells under antiretroviral therapy are a distinctive population with host gene expression patterns that favour HIV silencing, cell survival and cell proliferation, with important implications for the development of HIV cure strategies., (© 2023. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

The development and connectivity of retinal ganglion cells (RGCs), the retina's sole output neurons, are patterned by activity-independent transcriptional programs and activity-dependent remodeling. To inventory the molecular correlates of these influences, we applied high-throughput single-cell RNA sequencing (scRNA-seq) to mouse RGCs at six embryonic and postnatal ages. We identified temporally regulated modules of genes that correlate with, and likely regulate, multiple phases of RGC development, ranging from differentiation and axon guidance to synaptic recognition and refinement. Some of these genes are expressed broadly while others, including key transcription factors and recognition molecules, are selectively expressed by one or a few of the 45 transcriptomically distinct types defined previously in adult mice. Next, we used these results as a foundation to analyze the transcriptomes of RGCs in mice lacking visual experience due to dark rearing from birth or to mutations that ablate either bipolar or photoreceptor cells. 98.5% of visually deprived (VD) RGCs could be unequivocally assigned to a single RGC type based on their transcriptional profiles, demonstrating that visual activity is dispensable for acquisition and maintenance of RGC type identity. However, visual deprivation significantly reduced the transcriptomic distinctions among RGC types, implying that activity is required for complete RGC maturation or maintenance. Consistent with this notion, transcriptomic alternations in VD RGCs significantly overlapped with gene modules found in developing RGCs. Our results provide a resource for mechanistic analyses of RGC differentiation and maturation, and for investigating the role of activity in these processes., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

We describe a computational workflow to analyze single-cell RNA-sequencing (scRNA-seq) profiles of axotomized retinal ganglion cells (RGCs) in mice. Our goal is to identify differences in the dynamics of survival among 46 molecularly defined RGC types together with molecular signatures that correlate with these differences. The data consists of scRNA-seq profiles of RGCs collected at six time points following optic nerve crush (ONC) (see companion chapter by Jacobi and Tran). We use a supervised classification-based approach to map injured RGCs to type identities and quantify type-specific differences in survival at 2 weeks post crush. As injury-related changes in gene expression confound the inference of type identity in surviving cells, the approach deconvolves type-specific gene signatures from injury responses by using an iterative strategy that leverages measurements along the time course. We use these classifications to compare expression differences between resilient and susceptible subpopulations, identifying potential mediators of resilience. The conceptual framework underlying the method is sufficiently general for analysis of selective vulnerability in other neuronal systems., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

The genesis of broad neuronal classes from multipotential neural progenitor cells has been extensively studied, but less is known about the diversification of a single neuronal class into multiple types. We used single-cell RNA-seq to study how newly born (postmitotic) mouse retinal ganglion cell (RGC) precursors diversify into ~45 discrete types. Computational analysis provides evidence that RGC transcriptomic type identity is not specified at mitotic exit, but acquired by gradual, asynchronous restriction of postmitotic multipotential precursors. Some types are not identifiable until a week after they are generated. Immature RGCs may be specified to project ipsilaterally or contralaterally to the rest of the brain before their type identity emerges. Optimal transport inference identifies groups of RGC precursors with largely nonoverlapping fates, distinguished by selectively expressed transcription factors that could act as fate determinants. Our study provides a framework for investigating the molecular diversification of discrete types within a neuronal class., Competing Interests: KS, IW, SB, YP, JS No competing interests declared, (© 2022, Shekhar et al.)

Rapidly growing interest in the nanoparticle-mediated delivery of DNA and RNA to plants requires a better understanding of how nanoparticles and their cargoes translocate in plant tissues and into plant cells. However, little is known about how the size and shape of nanoparticles influence transport in plants and the delivery efficiency of their cargoes, limiting the development of nanotechnology in plant systems. In this study we employed non-biolistically delivered DNA-modified gold nanoparticles (AuNPs) of various sizes (5-20 nm) and shapes (spheres and rods) to systematically investigate their transport following infiltration into Nicotiana benthamiana leaves. Generally, smaller AuNPs demonstrated more rapid, higher and longer-lasting levels of association with plant cell walls compared with larger AuNPs. We observed internalization of rod-shaped but not spherical AuNPs into plant cells, yet, surprisingly, 10 nm spherical AuNPs functionalized with small-interfering RNA (siRNA) were the most efficient at siRNA delivery and inducing gene silencing in mature plant leaves. These results indicate the importance of nanoparticle size in efficient biomolecule delivery and, counterintuitively, demonstrate that efficient cargo delivery is possible and potentially optimal in the absence of nanoparticle cellular internalization. Overall, our results highlight nanoparticle features of importance for transport within plant tissues, providing a mechanistic overview of how nanoparticles can be designed to achieve efficacious biocargo delivery for future developments in plant nanobiotechnology., (© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)

The role of postnatal experience in sculpting cortical circuitry, while long appreciated, is poorly understood at the level of cell types. We explore this in the mouse primary visual cortex (V1) using single-nucleus RNA sequencing, visual deprivation, genetics, and functional imaging. We find that vision selectively drives the specification of glutamatergic cell types in upper layers (L) (L2/3/4), while deeper-layer glutamatergic, GABAergic, and non-neuronal cell types are established prior to eye opening. L2/3 cell types form an experience-dependent spatial continuum defined by the graded expression of ∼200 genes, including regulators of cell adhesion and synapse formation. One of these genes, Igsf9b, a vision-dependent gene encoding an inhibitory synaptic cell adhesion molecule, is required for the normal development of binocular responses in L2/3. In summary, vision preferentially regulates the development of upper-layer glutamatergic cell types through the regulation of cell-type-specific gene expression programs., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022. Published by Elsevier Inc.)

Retinal ganglion cells (RGCs) form an array of feature detectors, which convey visual information to central brain regions. Characterizing RGC diversity is required to understand the logic of the underlying functional segregation. Using single-cell transcriptomics, we systematically classified RGCs in adult and larval zebrafish, thereby identifying marker genes for >30 mature types and several developmental intermediates. We used this dataset to engineer transgenic driver lines, enabling specific experimental access to a subset of RGC types. Expression of one or few transcription factors often predicts dendrite morphologies and axonal projections to specific tectal layers and extratectal targets. In vivo calcium imaging revealed that molecularly defined RGCs exhibit specific functional tuning. Finally, chemogenetic ablation of eomesa + RGCs, which comprise melanopsin-expressing types with projections to a small subset of central targets, selectively impaired phototaxis. Together, our study establishes a framework for systematically studying the functional architecture of the visual system., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Though inflammatory bowel disease (IBD) has a specific predilection for the intestinal tract, it is a systemic inflammatory disorder affecting multiple organs, including the eye. Ocular complications directly related to IBD are categorized as primary and secondary. Primary complications are usually temporally associated with IBD exacerbations and tend to resolve with systemic treatment of the intestinal inflammation. These include keratopathy, episcleritis, and scleritis. Secondary complications arise from primary complications. Examples include cataract formation due to treatment with corticosteroids, scleromalacia due to scleritis, and dry eye due to hypovitaminosis A following gut resection. Some ocular manifestations of IBD can lead to significant visual morbidity and temporally associated complications can also be a herald of disease control. Furthermore, ocular manifestations of IBD can occasionally manifest before the usual intestinal manifestations, leading to an earlier diagnosis. Thus, it is important to understand the clinical presentation of possible ocular manifestations in order to initiate appropriate treatment and to help prevent significant visual morbidity.

Ectrodactyly-ectodermal dysplasia-clefting syndrome, the result of a mutation in the gene encoding tumor protein p63, causes ocular surface disease. It is typically progressive, with vision loss in adulthood. We present a case of severe corneal disease, glaucoma, and blindness related to ectrodactyly-ectodermal dysplasia-clefting syndrome in a 3-year-old female patient., (Copyright © 2011 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.)

The authors describe a girl with congenital symblephara, progressive corneal pannus, and skin defects caused by focal dermal hypoplasia. Her corneal neovascularization progressed to full pannus and blindness.

Ocular allergy is a common hypersensitivity disorder that affects 15%-20% of the population in developed nations. This disorder can be divided into several categories: seasonal and perennial allergic conjunctivitis, atopic keratoconjunctivitis, vernal keratoconjunctivitis, and drug-induced allergic conjunctivitis. Giant papillary conjunctivitis often is included among these classifications of allergy; however, it is not a true allergy, but rather the result of a chronic mechanical irritation. This article reviews these subtypes of ocular allergy, with particular emphasis on the pathophysiology, diagnosis, and treatment of seasonal and perennial allergic conjunctivitis. These are the most common varieties, representing more than 95% of the ocular allergy cases in the United States.

Purpose: Olopatadine hydrochloride 0.1% ophthalmic solution is a topical antiallergy agent indicated for treatment of the signs and symptoms of allergic conjunctivitis. The purpose of this study was to evaluate the comfort of olopatadine used for contact lens wearers in the conjunctival allergen-challenge (CAC) model., Methods: This was a single-center, randomized, double-masked, parallel-controlled CAC study. Contact lens-wearing subjects with a history of allergic conjunctivitis were randomized to receive olopatadine or placebo bilaterally. Fifteen minutes after study medication instillation, subjects inserted contact lenses. Allergen challenge was performed 10 minutes after contact lens insertion. Subjective evaluations of ocular comfort were obtained immediately and every minute after CAC, up to and including 10 minutes. Thereafter, comfort evaluations were made every 5 minutes up to and including 60 minutes. Subjects evaluated itching at 3, 7, and 10 minutes and redness was graded at 5, 10, and 20 minutes. All evaluations were graded on standardized scales. Subjects were given diaries in which to rate comfort at 2, 4, 6, 9, 12, and 13 hours and the time of contact lens removal., Results: At post-study medication instillation, post-lens insertion, and at time points from 1 to 10 minutes post-allergen challenge, ocular comfort evaluations were statistically superior in subjects receiving olopatadine as compared with those receiving placebo (P < 0.05). The difference in time until contact lens removal was clinically significant, with subjects who were treated with olopatadine wearing lenses for an average of 2.1 hours longer than placebo group., Conclusions: As evidenced by significantly greater comfort and longer duration of lens wear, olopatadine provides superior comfort to contact lens wearers suffering from the signs and symptoms of seasonal allergic conjunctivitis, as induced by the CAC model.

An infant born with bilateral corneal clouding diagnosed clinically as congenital anterior staphyloma and Peters' anomaly was confirmed histopathologically. This case report demonstrates one clinical spectrum of Peters' anomaly. The clinical course and histopathologic findings are detailed as is a unique surgical approach of corneoscleral graft used to perserve the right globe.

Purpose: We present a case of peripheral corneal ulceration in a patient with hepatitis C, which rapidly and dramatically responded to intravenous steroid treatment., Methods: Clinical examination and photographs were obtained to document initial presentation and therapeutic response of Mooren's-type ulcers to steroids., Results: Bilateral peripheral corneal ulceration with documented progression responded to intravenous administration of steroids within 5 days., Conclusion: Previous reports of Mooren's-type ulcers in patients with chronic hepatitis C have shown a response to interferon alfa-2b, but not to oral corticosteroid therapy. Given the medical contraindications to interferon use in selected patients and the cost, we suggest a trial of high-dose systemic steroids as a possible therapy.

This study investigates a gelfoam disc device as an alternative topical ophthalmic drug delivery system for pupillary dilation in humans. Gelfoam (Pharmacia & Upjohn) discs were impregnated with 0.60 mg of tropicamide racemate and 1.7 mg of 1-phenylephrine hydrochloride by an ethanol solvent evaporation method. Twenty randomly selected human subjects received baseline examinations, including blood pressure, pulse rate and biomicroscopy of the ocular surface. One impregnated gelfoam disc was placed in the inferior fornix of a randomly selected eye. Simultaneously, the fellow eye was treated with two topically administered drops, one from a phenylephrine hydrochloride 2.5% solution and one from a tropicamide 1% solution. A single, masked observer measured the pupillary diameter in both eyes at various time intervals under constant ambient conditions. Administration of the topical drops was repeated in the fellow eye. At maximum pupillary dilation, the disc was removed, and a post-dilation biomicroscopic exam was performed. Blood pressure and pulse rate were rechecked. The gelfoam-treated eyes' median change in dilation diameter was approximately 25% greater (a two-fold increase in pupillary area) (p< 0.001) at 15.2 min (median time to maximum dilation) than the topically treated fellow eyes. The median change in systolic blood pressure (+1.0 mmHg) and diastolic blood pressure (-1.0 mmHg) was not statistically significant (p>0.1). The average pulse rate was decreased 7 beats per minute (p=0.004). A gelfoam disc may serve as an ophthalmic drug delivery system for pupillary dilation or as a model for other multiple-dose topical drugs.

Background: Anaphylaxis is a potentially fatal complication of fluorescein angiography. It is diagnosed by clinical signs. Serum beta-tryptase serves as a specific indicator of mast cell activation and of anaphylactic shock that can be detected by radioimmunoassay., Method: This is a report on a 48-year-old woman who developed anaphylaxis during fluorescein angiography. This study investigates the role of beta-tryptase in anaphylactic shock resulting from intravenous fluorescein angiogram., Results: A serum sample of beta-tryptase collected at the time of an adverse reaction to fluorescein angiography was determined by radioimmunassay to be elevated above 20 ng/ml (normal level <1 ng/ml). This indicates massive mast cell activation and anaphylactic shock., Conclusion: This case is the first in which elevated levels of beta-tryptase in serum indicated that the systemic adverse reaction to fluorescein was mast cell dependent. Additionally, beta-tryptase levels can be assayed to detect anaphylactic reactions several hours after a precipitating event.

Purpose: To report two patients with ocular burns from explosion of microwaved eggs that caused direct vision-threatening corneal damage., Methods: The initial examination and treatment of both patients are described., Results: Both patients were initially examined with severe decrease in the visual acuity of both eyes. The first patient required limbal conjunctival transplantation and a subsequent penetrating keratoplasty in the right eye and prolonged treatment of superficial keratitis in the left eye. The second patient sustained bilateral corneal epithelial defects and unilateral intrastromal hemorrhage., Conclusions: Exploding microwaved eggs can cause notable thermal injury to the eyes. The public should be educated about the dangers of cooking eggs in the microwave oven.

A 31-year-old man with the acquired immunodeficiency syndrome presented with herpes zoster ophthalmicus on the right. Five days after he began treatment for the zoster pseudodendrites and skin lesions, he developed superficial punctate keratitis, uveitis, and crusting skin lesions in the left eye. After treatment, the ocular lesions resolved in both eyes without incident. The bilateral manifestation of herpes zoster ophthalmicus is a result of the increased severity associated with immunosuppression caused by the human immunodeficiency virus.

Background: Anterior segment findings in AIDS patients presenting with cytomegalovirus (CMV) retinitis have not been specifically addressed in the American literature., Methods: Our study evaluated 21 AIDS patients with CMV retinitis., Results: Nineteen (90%) of these patients exhibited corneal endothelial deposits concurrent with CMV retinitis. The endothelial deposits were microscopic, opaque, linear flecks arranged in a reticular-like fashion. Of 42 eyes evaluated, 32 (76%) demonstrated active CMV retinitis. Corneal endothelial deposits were noted in 26 (81%) of the 32 eyes with retinitis. These corneal endothelial deposits were absent in the eyes which did not have CMV retinitis., Conclusion: Meticulous examination of the retina of an HIV-positive or AIDS patient who presents with reticularly arranged, linear, flecked corneal endothelial deposits should be performed to ensure that the diagnosis of CMV retinitis can be ruled out.

Purpose/methods: We examined the mast cells in 12 pterygium specimens of patients who underwent primary excisions and the conjunctival specimens of ten normal age-matched control subjects., Results/conclusion: The mean mast cell count per cubic millimeter was twice as high in the pterygium specimens as in the control specimens. Mast cell proliferation and activation may contribute to the pathogenesis of pterygium formation.

Bilateral exudative macular detachments were present on a 64-year-old diabetic Caucasian male who presented with bilateral blurring of vision. Besides the exudative macular detachments there was no diabetic retinopathy or congestive retinopathy, and a previous fluorescein angiogram revealed no focal leakage. Laboratory investigation, bone marrow biopsy, and a bone survey revealed the diagnosis of multiple myeloma.

An 8-year-old boy presented with symptoms compatible with a right internuclear ophthalmoplegia. Magnetic resonance imaging showed a high-intensity signal on T2-weighted images at the level of the medial longitudinal fasciculus. Laboratory evaluation was positive only for sickle cell trait. Sickle cell trait is an uncommon cause for brainstem infarction.

We report a patient with AIDS who developed rapidly progressive, acute outer retinal necrosis. Cytomegalovirus etiology was proposed as a possibility in view of the histopathologic identification of the virus in the fellow concomitantly affected eye. Treatment with ganciclovir resulted in disappearance of the posterior pole lesions and inactivation of the peripheral lesions. We suggest that ganciclovir be used as soon as this condition is suspected in order to optimize the outcome.

Wegener's granulomatosis is a life-threatening condition characterized by the triad of necrotizing granulomatous inflammation of the respiratory tract, vasculitis, and glomerulonephritis. During early stages of the disease, some patients may present with only one or two components of the triad. Other patients may be affected by the limited form of Wegener's which lacks the renal involvement. We report an 18-year-old female who initially presented with bilateral dacryoadenitis. A lacrimal gland biopsy was consistent with Wegener's granulomatosis. A few months later she developed glomerulonephritis and responded well to cyclophosphamide treatment. Wegener's granulomatosis remains a diagnostic challenge and is frequently underdiagnosed. Early diagnosis is crucial in saving many lives because the disease is potentially curable with cytotoxic therapy. Dacryoadenitis may be one of the initial presentations of Wegener's granulomatosis.

Tryptase, a neutral endoprotease, is secreted by activated mast cells in human tissues. Tryptase levels in various body fluids have been used as an indicator of mast cell activation. The authors determined tryptase levels in unstimulated tears collected from the following groups of patients: (1) normal control, (2) nonallergic ocular inflammation, (3) asymptomatic seasonal allergic conjunctivitis, (4) symptomatic seasonal allergic conjunctivitis, (5) vernal conjunctivitis, and (6) contact lens-associated giant papillary conjunctivitis. They also assessed the release of tryptase into the tear fluid after provoking the conjunctiva with (7) allergens, (8) compound 48/80, and (9) rubbing. Tryptase levels were elevated in tears of patients with active ocular allergy and also increased after provoking the conjunctiva with allergens in atopic subjects and with compound 48/80 and rubbing in nonatopic subjects. Tryptase levels in tear fluid may prove useful as a clinical indicator of mast cell involvement in ocular allergic disorders. In provocation experiments, tryptase levels may be used to evaluate and compare different mast cell stabilizing agents.

Soft contact lenses are bathed with tear components during wear and surface deposits accumulate. This report shows that Pseudomonas aeruginosa adheres to the surface of worn extended wear contact lenses in direct proportion to the amount of lens surface deposits as determined by the Rudko method (P less than .05). More hydrophobic bacteria adhered 10 times greater than bacteria which were relatively hydrophilic (P less than .005). The effect upon bacterial adhesion of enzyme and surfactant cleaning of worn extended wear contact lenses was investigated by two independent methods: one involving a high inoculum and the other a low inoculum of Pseudomonas. Treatment of worn lenses with commercially available enzymes such as papain and pork pancreatin as well as treatment with neuraminidase, mannosidase, glucosidase and alkylcarboxylic acid for as long as 48 hours failed to reduce subsequent bacterial adhesion in both the high and low inoculum experiments. We conclude that soft contact lens surface deposits are a major determinant in the adhesion of Pseudomonas aeruginosa to the worn lens surface and that enzyme cleaning of worn lenses does not significantly reduce bacterial adhesion.

Extended wear soft contact lenses are associated with an increased incidence of Pseudomonas aeruginosa keratitis. Because the first step in the pathogenesis of this disease is adherence of the microorganism to the corneal surface, we studied the effect of soft contact lens wear on the adherence of P. aeruginosa to the cornea. Rabbits were fitted for extended wear soft contact lenses in the left eye, and the right eye served as a control. Both eyes were then closed with a partial tarsorrhaphy. After 1-5 days of wear, the lenses were removed and the corneas of the left and right eye were removed. Differences in the number of adherent Pseudomonas and in lectin binding to lens-wearing corneas and non-lens-wearing corneas were determined. After 1, 3, and 5 days of soft contact lens wear, there was a significant increase in the number of P. aeruginosa adherent to the lens-wearing cornea. Three to eight times as many bacteria adhered to the lens-wearing eye as compared with the control eye (p less than 0.05). In addition, a soft contact lens placed in the eye followed by the immediate application of P. aeruginosa resulted in an eightfold increase in adherence of bacteria to the lens-wearing cornea (p less than 0.05). Lens wear also led to an increase in binding of concanavalin A (Con A), wheat germ agglutinin (WGA), and Maclura pomifera agglutinin (MPA) to surface epithelium covered by the lens. These corneal epithelial changes induced by extended wear soft contact lenses may provide some insight as to why soft contact lens wearers are predisposed to Pseudomonas keratitis.

The distribution and concentration of human tryptase-positive, chymase-negative mast cells (MCTS) and tryptase-positive, chymase-positive mast cells (MCTCS) were examined in conjunctival biopsy specimens from subjects with active vernal conjunctivitis (VC; n = 7), giant papillary conjunctivitis (GPC; n = 6), and allergic conjunctivitis (AC; n = 5), and from asymptomatic soft-contact lens wearers (SCL; n = 6) and normal control individuals (n = 19). Carnoy's fixed tissue sections were stained by a double immunohistochemical method using a biotinylated mouse monoclonal antichymase antibody with immunoperoxidase, followed by an alkaline phosphatase-conjugated mouse monoclonal antitryptase antibody. Epithelial mast cells (MCs) were found in all VC specimens (96% MCTCs) and in three GPC specimens (100% MCTCS) but in none of the other groups. In the substantia propria, MCTCS were the predominant type of MC observed in all specimens, accounting for 95% of the total MCs in the normal control group and 100% of the total MCs in the subjects with GPC, AC, and SCL. No significant differences were found in the total MC concentration of the substantia propria among the normal control subjects (11,054 +/- 6327 MCs per cubic millimeter), subjects in the SCL group (13,168 +/- 4685 MCs per cubic millimeter), subjects with GPC (17,313 +/- 8500 MCs per cubic millimeter), and subjects with AC (15,380 +/- 5660 MCs per cubic millimeter). In subjects with VC, the percentage of MCTs (18% +/- 13%) and the total MC concentration (24,689 +/- 18,978 MCs per cubic millimeter) in the substantia propria were significantly increased as compared to the normal control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Commercial preparations of two topical ophthalmic vasoconstrictors were evaluated for whitening ability, duration of action, tolerance, and rebound vasodilation in 11 normal volunteers. Both 0.02% naphazoline HCI and 0.05% tetrahydrozoline HCI significantly reduced baseline redness after a single use (Part I); however, naphazoline produced significantly more whitening than did tetrahydrozoline. Only naphazoline retained its whitening ability after ten days (Part II). The level of redness remained significantly below baseline for eight hours after a single use of either vasoconstrictor and for six hours after multiple use of naphazoline. The diminished effectiveness of tetrahydrozoline after the ten-day test period may encourage its overuse. Neither vasoconstrictor produced rebound vasodilation after discontinuation of use.

We present three adult patients having classic symptoms of ocular allergy with findings confined to the limbus in all eyes. Findings in the cornea and the rest of the bulbar and tarsal conjunctivae were within normal limits. Case 1 had numerous limbal follicles; Case 2 had limbal chemosis 360 degrees; and Case 3 had superior perilimbal conjunctival injection, chemosis, and micropannus formation. Limbal scrapings from all patients revealed abundant eosinophils. There was marked clinical improvement after topical cromolyn sodium 4% treatment. Since the limbus was the only structure involved, the diagnosis of "allergic limbitis" was made. We feel that the limbus is an overlooked structure during ocular examination. As in our three cases, the limbus may be the only area involved in ocular allergy. A careful examination of the limbus may provide important clues for the diagnosis of many ocular inflammatory conditions.

Ten isolates of Pseudomonas aeruginosa obtained from the corneas of patients with Pseudomonas keratitis adhered to soft contact lenses in significantly greater numbers than did six isolates from other body sites (P less than .05). However, there was no predominant serotype among the 10 corneal isolates tested. Isolates grown statically in broth at 37 degrees C formed a pellicle and adhered two times as much to contact lenses as did isolates grown in broth while shaking which did not form a pellicle (P less than .01). The more adherent isolates (grown at 37 degrees C) were shown to be more hydrophobic than the less adherent bacteria (grown at 26 degrees C) by their propensity to accumulate at the interface between hexadecane and saline and their movement into polyethylene glycol from dextran. These corneal isolates agglutinated erythrocytes, a process that was inhibited by dilute solutions (as low as 0.01%) of three commonly used surfactants. These same surfactants inhibited the adherence of Pseudomonas aeruginosa to soft contact lens surfaces by as much as 52%. It is concluded that hydrophobic interactions may significantly contribute to the ability of Pseudomonas aeruginosa to adhere to contact lenses.

Products of arachidonic acid metabolism, prostaglandins and leukotrienes, play an important role in ocular inflammation. In this study, we investigated the efficacies of the cyclo-oxygenase inhibitors (aspirin, indomethacin, and piroxicam) and the lipoxygenase inhibitors (N-hydroxy-arachidonamide (AH) and phenidone) in reducing ocular inflammation induced by arachidonic acid. Administering arachidonic acid topically (0.50% for rabbits and 0.25% for humans) produced a simple model for evaluating the effects of inhibitors on prostaglandins. In rabbits, aspirin, piroxicam and indomethacin all blocked lid closure and chemosis significantly. In humans, aspirin and indomethacin significantly blocked arachidonic acid-induced conjunctival injection. Neither AH nor phenidone blocked any of the signs of ocular inflammation in rabbits or humans. Further testing of phenidone in the presence of the calcium ionophore, ionomycin, also proved negative. Species specificity in arachidonic acid metabolism may account for the different results in humans and rabbits. This model may be a useful tool for comparing the relative efficacies of topical cyclo-oxygenase inhibitors in treating ocular problems.

The adherence of microorganisms to contact lenses may be an important initial step in the pathogenesis of contact lens-associated infectious keratitis. Using a strain of Candida albicans whose interaction with various polymers has been well characterized we systematically investigated the adherence of this pathogen to hard hydrophobic and soft hydrophilic extended-wear contact lenses. Yeasts adhere to the hydrophobic lenses in direct proportion to the wetting angle of the lens whereas yeasts adhere to the hydrophilic lenses in direct proportion to the water content of the lens. Tear proteins such as albumin, lactoferrin, and lysozyme in addition to fibronectin enhance yeast adherence to both types of lenses (P less than 0.01). Concanavalin A reduces adherence of yeasts to both lens types (P less than 0.01). Among tear components however, only mucin (0.5%) consistently reduced yeast adherence to both lens types. Hydrophilic extended wear lenses worn for at least 28 days by normal patients consistently had greater adherence of yeasts than unworn lenses of the same type, often as much as ten-fold or greater yeasts/mm2 of lens surface area (P less than 0.05). These investigations indicate that tear components both in solution and adsorbed to the lens surface enhance microorganism adherence to contact lenses.

Hyper-IgE syndrome (HIE) appears to be related to an immunoregulatory imbalance characterized by severe deficiency of suppressor T cells, elevated levels of IgE antibodies, and repeated infection of various organ systems. We report the association of HIE syndrome in two definite cases and one probable case of vernal conjunctivitis. This association suggests that T cell-mediated imbalance may be one factor in the pathogenesis of vernal conjunctivitis.

Prostaglandin D2 is a secondary mast cell mediator that causes redness, chemosis, mucous discharge, and eosinophil chemotaxis in the eye. It may play an important role in allergic ocular disease. Although histamine is a key mediator of allergic inflammation, antihistamine therapy provides only symptomatic relief. We added aspirin therapy to the treatment regimen of three patients with vernal conjunctivitis. Aspirin acetylates the enzyme cyclooxygenase, thereby preventing the formation of prostaglandin D2. Within two weeks after initiation of aspirin therapy, we noted dramatic improvement in conjunctival and episcleral redness and resolution of keratitis and limbal infiltration. We recommend a trial of oral aspirin as adjunctive therapy for intractable cases of vernal conjunctivitis.

The eye is a mirror that reflects pathologic changes occurring in many organs. The present paper presents eye changes in renal disease including hereditary progressive nephritis, cystic disease of the kidney, cystinosis, and diffuse mesangial sclerosis. It also touches on these changes in some syndromes with major renal involvement.