Correlation of gene expression with magnetic resonance imaging features of retinoblastoma: a multi-center radiogenomics validation study

OBJECTIVES

To validate associations between MRI features and gene expression profiles in retinoblastoma, thereby evaluating the repeatability of radiogenomics in retinoblastoma.

METHODS

In this retrospective multicenter cohort study, retinoblastoma patients with gene expression data and MRI were included. MRI features (scored blinded for clinical data) and matched genome-wide gene expression data were used to perform radiogenomic analysis. Expression data from each center were first separately processed and analyzed. The end product normalized expression values from different sites were subsequently merged by their Z-score to permit cross-sites validation analysis. The MRI features were non-parametrically correlated with expression of photoreceptorness (radiogenomic analysis), a gene expression signature informing on disease progression. Outcomes were compared to outcomes in a previous described cohort.

RESULTS

Thirty-six retinoblastoma patients were included, 15 were female (42%), and mean age was 24 (SD 18) months. Similar to the prior evaluation, this validation study showed that low photoreceptorness gene expression was associated with advanced stage imaging features. Validated imaging features associated with low photoreceptorness were multifocality, a tumor encompassing the entire retina or entire globe, and a diffuse growth pattern (all p < 0.05). There were a number of radiogenomic associations that were also not validated.

CONCLUSIONS

A part of the radiogenomic associations could not be validated, underlining the importance of validation studies. Nevertheless, cross-center validation of imaging features associated with photoreceptorness gene expression highlighted the capability radiogenomics to non-invasively inform on molecular subtypes in retinoblastoma.

CLINICAL RELEVANCE STATEMENT

Radiogenomics may serve as a surrogate for molecular subtyping based on histopathology material in an era of eye-sparing retinoblastoma treatment strategies.

KEY POINTS

• Since retinoblastoma is increasingly treated using eye-sparing methods, MRI features informing on molecular subtypes that do not rely on histopathology material are important. • A part of the associations between retinoblastoma MRI features and gene expression profiles (radiogenomics) were validated. • Radiogenomics could be a non-invasive technique providing information on the molecular make-up of retinoblastoma.

A Multicenter Study Validates the WHO 2022 Classification for Conjunctival Melanocytic Intraepithelial Lesions With Clinical and Prognostic Relevance

Several nomenclature and grading systems have been proposed for conjunctival melanocytic intraepithelial lesions (C-MIL). The fourth "WHO Classification of Eye Tumors" (WHO-EYE04) proposed a C-MIL classification, capturing the progression of noninvasive neoplastic melanocytes from low- to high-grade lesions, onto melanoma in situ (MIS), and then to invasive melanoma. This proposal was revised to the WHO-EYE05 C-MIL system, which simplified the high-grade C-MIL, whereby MIS was subsumed into high-grade C-MIL. Our aim was to validate the WHO-EYE05 C-MIL system using digitized images of C-MIL, stained with hematoxylin and eosin and immunohistochemistry. However, C-MIL cases were retrieved from 3 supraregional ocular pathology centers. Adequate conjunctival biopsies were stained with hematoxylin and eosin, Melan-A, SOX10, and PReferentially expressed Antigen in Melanoma. Digitized slides were uploaded on the SmartZoom platform and independently scored by 4 ocular pathologists to obtain a consensus score, before circulating to 14 expert eye pathologists for independent scoring. In total, 105 cases from 97 patients were evaluated. The initial consensus diagnoses using the WHO-EYE04 C-MIL system were as follows: 28 benign conjunctival melanoses, 13 low-grade C-MIL, 37 high-grade C-MIL, and 27 conjunctival MIS. Using this system resulted in 93% of the pathologists showing only fair-to-moderate agreement (kappa statistic) with the consensus score. The WHO-EYE05 C-MIL system (with high-grade C-MIL and MIS combined) improved consistency between pathologists, with the greatest level of agreement being seen with benign melanosis (74.5%) and high-grade C-MIL (85.4%). Lowest agreements remained between pathologists for low-grade C-MIL (38.7%). Regarding WHO-EYE05 C-MIL scoring and clinical outcomes, local recurrences of noninvasive lesions developed in 8% and 34% of the low- and high-grade cases. Invasive melanoma only occurred in 47% of the cases that were assessed as high-grade C-MIL. This extensive international collaborative study is the first to undertake a comprehensive review of the WHO-EYE05 C-MIL scoring system, which showed good interobserver agreement and reproducibility.

MRI Features for Identifying MYCN-amplified RB1 Wild-type Retinoblastoma

Background MYCN-amplified RB1 wild-type (MYCNARB1+/+) retinoblastoma is a rare but clinically important subtype of retinoblastoma due to its aggressive character and relative resistance to typical therapeutic approaches. Because biopsy is not indicated in retinoblastoma, specific MRI features might be valuable to identify children with this genetic subtype. Purpose To define the MRI phenotype of MYCNARB1+/+ retinoblastoma and evaluate the ability of qualitative MRI features to help identify this specific genetic subtype. Materials and Methods In this retrospective, multicenter, case-control study, MRI scans in children with MYCNARB1+/+ retinoblastoma and age-matched children with RB1-/- subtype retinoblastoma were included (case-control ratio, 1:4; scans acquired from June 2001 to February 2021; scans collected from May 2018 to October 2021). Patients with histopathologically confirmed unilateral retinoblastoma, genetic testing (RB1/MYCN status), and MRI scans were included. Associations between radiologist-scored imaging features and diagnosis were assessed with the Fisher exact test or Fisher-Freeman-Halton test, and Bonferroni-corrected P values were calculated. Results A total of 110 patients from 10 retinoblastoma referral centers were included: 22 children with MYCNARB1+/+ retinoblastoma and 88 control children with RB1-/- retinoblastoma. Children in the MYCNARB1+/+ group had a median age of 7.0 months (IQR, 5.0-9.0 months) (13 boys), while children in the RB1-/- group had a median age of 9.0 months (IQR, 4.6-13.4 months) (46 boys). MYCNARB1+/+ retinoblastomas were typically peripherally located (in 10 of 17 children; specificity, 97%; P < .001) and exhibited plaque or pleomorphic shape (in 20 of 22 children; specificity, 51%; P = .011) with irregular margins (in 16 of 22 children; specificity, 70%; P = .008) and extensive retina folding with vitreous enclosure (specificity, 94%; P < .001). MYCNARB1+/+ retinoblastomas showed peritumoral hemorrhage (in 17 of 21 children; specificity, 88%; P < .001), subretinal hemorrhage with a fluid-fluid level (in eight of 22 children; specificity, 95%; P = .005), and strong anterior chamber enhancement (in 13 of 21 children; specificity, 80%; P = .008). Conclusion MYCNARB1+/+ retinoblastomas show distinct MRI features that could enable early identification of these tumors. This may improve patient selection for tailored treatment in the future. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Rollins in this issue.

Cytopathology of Vitreous Specimens in Acute Retinal Necrosis

PURPOSE

To report the cytopathology of vitreous biopsy samples in patients with acute retinal necrosis (ARN) who underwent pars plana vitrectomy (PPV). We also describe two patients with unique clinical courses, cytopathologic findings, and immune response.

METHODS

A retrospective review of patients with ARN who developed retinal detachment (RD) and underwent PPV from 22011 to 2019 at the Emory Eye Center was performed to assess cytopathology findings of vitreous biopsy samples. Patient demographics and laboratory testing including aqueous humor PCR for viral pathogens were recorded. Additional clinical details abstracted included intravitreal injections, surgical procedures, and vitreous cytopathological reports including immunohistochemistry findings.

RESULTS

Fourteen eyes of 12 patients with RD were reviewed. Ten eyes showed HSV DNA (71%) and 4 demonstrated VZV DNA (29%). All eyes received intravitreal antivirals (i.e. ganciclovir or foscarnet) with a median of 8.5 intravitreal injections per eye. Diagnoses prompting PPV included tractional RD in 14 eyes (100%), rhegmatogenous RD in 8 eyes (57%), vitreous hemorrhage in 4 eyes (29%) and vitreous opacity in 4 (29%). Ophthalmic pathology reports showed lymphocyte populations in 10 eyes (71%) with a CD3 + T-cell predominance in two patients where immunohistochemistry of CD3+ and CD20+ for T- and B-cell populations was performed. Observed immune cell populations included macrophages or histiocytes (11 eyes, 79%) and polymorphonuclear cells in 4 eyes (29%). Initial median VA was 2.5 (IQR 2.0-3.0) and improved to 2.0 (IQR 1.48-3.00, p = .48) at 6-months and 1.8 (IQR 1.2-3.0, p = .45) at 12 months follow-up.

CONCLUSIONS

Our cohort of ARN patients undergoing PPV show a spectrum of immunologic findings with the majority demonstrating a lymphocytic response. Histiocytes, macrophages, and PMNs were also observed. Cytopathologic and immunologic studies suggest that both innate and adaptive immunity are responsible for the clinical disease findings observed in ARN. The variability of the response to treatment in patients with ARN may reflect patient-to-patient differences in their antigen-specific immune response. Understanding the immunologic response associated with ARN may provide valuable information regarding the dosing and timing of treatment.

Isolated hemangiopericytoma of the conjunctiva

PURPOSE

To report a unique presentation of hemangiopericytoma and discuss the clinical course, pathological features, and management of this tumor.

OBSERVATIONS

An otherwise healthy 54-year-old Caucasian female presented with a painless conjunctival mass. The lesion gradually enlarged over a three-week period and was unresponsive to corticosteroid treatment. The mass was surgically removed, and histopathologic findings were consistent with hemangiopericytoma.

CONCLUSIONS AND IMPORTANCE

Conjunctival hemangiopericytoma should be considered in patients with conjunctival lesions unresponsive to medical management. Surgical excision is diagnostic and therapeutic and is the strongest predictor of clinical course. Incompletely excised lesions are at a greater risk of local recurrence and subsequent metastasis. Given the neoplasm's malignant potential, patients should be followed in the outpatient setting.

Targeting integrin αvβ3 by a rationally designed protein for chronic liver disease treatment

Chronic Liver Diseases (CLD) are characterized by abnormal accumulation of collagen fibrils, neo-angiogenesis, and sinusoidal remodeling. Collagen deposition along with intrahepatic angiogenesis and sinusoidal remodeling alters sinusoid structure resulting in portal hypertension, liver failure, and other complications. Efforts were made to develop treatments for CLDs. However, the success of such treatments is limited and unpredictable. We report a strategy for CLD treatment by induction of integrin αvβ3 mediated cell apoptosis using a rationally designed protein (ProAgio). ProAgio is designed to target integrin αvβ3 at a novel site. Integrin αvβ3 is highly expressed in activated Hepatic Stellate Cells (HSC), angiogenic endothelium, and capillarized Liver Sinusoidal Endothelial Cells (LSEC). ProAgio induces apoptosis of these disease causative cells. Tests with liver fibrosis mouse models demonstrate that ProAgio reverses liver fibrosis and relieves blood flow resistance by depleting activated HSC and capillarized LSEC. Our studies demonstrate an effective approach for CLD treatment.

Approach to Cataract Surgery in an Ebola Virus Disease Survivor with Prior Ocular Viral Persistence

A 46-year-old patient with previously documented Ebola virus persistence in his ocular fluid, associated with severe panuveitis, developed a visually significant cataract. A multidisciplinary approach was taken to prevent and control infection. Ebola virus persistence was assessed before and during the operation to provide safe, vision-restorative phacoemulsification surgery.

Intravitreous Cutaneous Metastatic Melanoma in the Era of Checkpoint Inhibition: Unmasking and Masquerading

PURPOSE

Cutaneous melanoma metastatic to the vitreous is very rare. This study investigated the clinical findings, treatment, and outcome of patients with metastatic cutaneous melanoma to the vitreous. Most patients received checkpoint inhibition for the treatment of systemic disease, and the significance of this was explored.

DESIGN

Multicenter, retrospective cohort study.

PARTICIPANTS

Fourteen eyes of 11 patients with metastatic cutaneous melanoma to the vitreous.

METHODS

Clinical records, including fundus photography and ultrasound results, were reviewed retrospectively, and relevant data were recorded for each patient eye.

MAIN OUTCOME MEASURES

Clinical features at presentation, ophthalmic and systemic treatments, and outcomes.

RESULTS

The median age at presentation of ophthalmic disease was 66 years (range, 23-88 years), and the median follow-up from diagnosis of ophthalmic disease was 23 months. Ten of 11 patients were treated with immune checkpoint inhibition at some point in the treatment course. The median time from starting immunotherapy to ocular symptoms was 17 months (range, 4.5-38 months). Half of eyes demonstrated amelanotic vitreous debris. Five eyes demonstrated elevated intraocular pressure, and 4 eyes demonstrated a retinal detachment. Six patients showed metastatic disease in the central nervous system. Ophthalmic treatment included external beam radiation (30-40 Gy) in 6 eyes, intravitreous melphalan (10-20 μg) in 4 eyes, enucleation of 1 eye, and local observation while receiving systemic treatment in 2 eyes. Three eyes received intravitreous bevacizumab for neovascularization. The final Snellen visual acuity ranged from 20/20 to no light perception.

CONCLUSIONS

The differential diagnosis of vitreous debris in the context of metastatic cutaneous melanoma includes intravitreal metastasis, and this seems to be particularly apparent during this era of treatment with checkpoint inhibition. External beam radiation, intravitreous melphalan, and systemic checkpoint inhibition can be used in the treatment of ophthalmic disease. Neovascular glaucoma and retinal detachments may occur, and most eyes show poor visual potential. Approximately one quarter of patients demonstrated ocular disease that preceded central nervous system metastasis. Patients with visual symptoms or vitreous debris in the context of metastatic cutaneous melanoma would benefit from evaluation by an ophthalmic oncologist.

In situ analysis of Her2 DNA and RNA in retinoblastoma and adjacent retina

Retinoblastoma (RB) is an ocular tumor of early childhood. Current treatments attempt to preserve visual function, but may spare chemoresistant tumor cells. One potential therapeutic target for RB is HER2, (ERBB2), expressed in RB in truncated form. In this study, we tested the hypothesis that Her2 DNA and RNA are expressed in RB tumors and adjacent retina. We examined 24 human RB tumors as well as normal-appearing adjacent retinal tissues for Her2 DNA and RNA expression by in situ hybridization. We also examined 28 RB tumors for HER2 protein immunoreactivity. 21/22 RB tumors expressed Her2 DNA and 14/19 tumors expressed Her2 RNA. In 17 paired cases, there were three cases in which Her2 DNA was detected, but not RNA. We also saw Her2 RNA signal in six instances of "normal" adjacent retinal tissue. Heterogeneous HER2 protein expression in specific tumor regions also was confirmed by quantitative HER2 immunohistochemistry. In summary, Her2 DNA and RNA are expressed in many RB tumors, and in some adjacent ocular tissues, with hetereogenous protein expression throughout. These results may provide important insights regarding RB tumor progression, and drug targeting approaches designed to spare the eye, preserve vision and improve quality of life for RB patients.

GNAQ Mutations in Diffuse and Solitary Choroidal Hemangiomas

PURPOSE

GNAQ mutations have been identified in port wine stains (both syndromic and nonsyndromic) and melanocytic ocular neoplasms. This study investigates the presence of GNAQ mutations in diffuse (those associated with Sturge-Weber syndrome [SWS]) and solitary choroidal hemangiomas.

PARTICIPANTS

Tissue from 11 patients with the following diagnoses: port wine stain (n = 3), diffuse choroidal hemangioma (n = 1), solitary choroidal hemangioma (n = 6), and choroidal nevus (n = 1).

METHODS

Ten specimens were interrogated with Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets, a hybridization capture-based next-generation sequencing assay for targeted deep sequencing of all exons and selected introns of 468 key cancer genes in formalin-fixed, paraffin-embedded tumors. Digital polymerase chain reaction was used to detect GNAQ Q209 mutation in 1 specimen.

MAIN OUTCOME MEASURES

Detection of GNAQ codon-specific mutation.

RESULTS

Activating somatic GNAQ mutations (c.547C > T; p.Arg183Cys) were found in 100% (3 of 3) of the port wine stain and in the diffuse choroidal hemangioma. Somatic GNAQ mutations (c.626A > T; p.Gln209Leu) were found in 100% (6 of 6) of the solitary choroidal hemangiomas and (c.626A > C; p.Gln209Pro) in the choroidal nevus.

CONCLUSIONS

GNAQ mutations occur in both diffuse and solitary hemangiomas, although at distinct codons. An R183 codon is mutant in diffuse choroidal hemangiomas, consistent with other Sturge-Weber vascular malformations. By contrast, solitary choroidal hemangiomas have mutations in the Q209 codon, similar to other intraocular melanocytic neoplasms.

Ring-Shaped Leiomyoma of the Ciliary Body

Purpose

Ciliary body mesectodermal leiomyoma is a rare, benign smooth muscle tumor that typically presents in women in the second to fourth decade of life. The diagnosis is typically based on clinical color, funduscopic appearance, transillumination properties, and B-scan ultrasonography.

Methods

We present a patient with a 360° ciliary body mass with transillumination and ultrasonographic properties consistent with a ring melanoma.

Results

This case emphasizes the difficulty in differentiating the benign leiomyoma from similar appearing malignant tumors such as melanoma.

Conclusion

The eye was enucleated and the diagnosis was ring-shaped leiomyoma.

Epstein-Barr virus associated smooth muscle tumors in post transplant pediatric patients two cases of rare locations, and review of the literature

Epstein-Barr virus (EBV) may present few or no symptoms in immunocompetent individuals; however, in immunocompromised patients as in the case of AIDS and post-transplant patients, the virus occasionally stimulates neoplastic transformations. Epstein-Barr virus may play a role in the development of smooth muscle tumors (SMT). In the case of Epstein-Barr associated smooth muscle tumors (EBV+SMT), the virus is thought to be the leading factor to the tumorigenic pathway. We report two pediatric patients (6 and 13 years old) who underwent liver transplantation and developed EBV+SMT in the colon and orbit. These two cases represent rare locations for this kind of lesion.

Analysis of the RPE sheet in the rd10 retinal degeneration model

BACKGROUND

The normal RPE sheet in the C57BL/6J mouse is subclassified into two major tiling patterns: a regular generally hexagonal array covering most of the surface and a “soft network” near the ciliary body made of irregularly shaped cells. Physics models predict these two patterns based on contractility and elasticity of the RPE cell, and strength of cellular adhesion between cells.

HYPOTHESIS

We hypothesized and identified major changes in RPE regular hexagonal tiling pattern in rd10 compared to C57BL/6J mice.

RESULTS

In rd10 mice, RPE sheet damage was extensive but occurred later than expected, after most retinal degeneration was complete. RPE sheet changes occur in zones with a bullseye pattern. In the posterior zone, around the optic nerve, RPE cells take on larger irregular and varied shapes to maintain an intact monolayer. In mid periphery, RPE cells have a compressed or convoluted morphology that progress into ingrown layers of RPE under the retina. Cells in the periphery maintain their shape and size until the late stages of the RPE reorganization. The number of neighboring cells varies widely depending on zone and progression. RPE morphology continues to deteriorate after the photoreceptors have degenerated.

CONCLUSIONS

The RPE cells are bystanders to photoreceptor degeneration in the rd10 model, and the collateral damage to the RPE results in changes in morphology as early as 30 days old. Quantitative measures of the tiling patterns and histopathology detected here were scripted in a pipeline written in Perl and Cell Profiler (an open source MatLab plugin) and are directly applicable to RPE sheet images from noninvasive fundus autofluorescence (FAF), adaptive optics confocal scanning laser ophthalmoscope (AO-cSLO), and spectral domain optical coherence tomography (SD-OCT) of patients with early stage AMD or RP.

The Zimmerman-McLean-Foster hypothesis: 25 years later

It is now 25 years since the publication of the landmark article by Zimmerman, McLean, and Foster, in which they cast doubts on the benefit of enucleation, which was the prevailing management of choroidal melanoma at that time. Over the past 25 years several advances have been made in the management of uveal melanoma. Research in the pathobiology of cancer metastasis in general and uveal melanoma in particular has also provided new insights. In this review, the Zimmerman-McLean-Foster hypothesis is explored in the light of current clinical, epidemiological, statistical, and experimental evidence.

Increased oxidant-induced apoptosis in cultured nondividing human retinal pigment epithelial cells

PURPOSE

To determine whether long-term cultured nondividing human retinal pigment epithelial (hRPE) cells are sensitive to oxidant-induced apoptosis and whether the Fas pathway is involved in the process.

METHODS

Confluent hRPE cells were maintained for 2 to 3 months in the basal medium (DMEM containing 2% fetal bovine serum) with one medium change per week. DNA synthesis was measured by incorporation of bromodeoxyuridine (BrdU) and the cell cycle was analyzed by flow cytometry. Intracellular glutathione (GSH) and glutathione disulfide (GSSG) were measured by HPLC. Apoptosis was triggered with the oxidant tert-butylhydroperoxide (tBH), recombinant soluble Fas ligand (sFasL), or agonistic anti-Fas antibody (CH-11). Cell viability was assessed by tetrazolium salt (WST-1) assay, and apoptosis was determined by measuring DNA cleavage or phosphatidylserine exposure. FasL and Fas proteins were detected by flow cytometry and Western blot. FasL and Fas transcripts were analyzed by RT-PCR.

RESULTS

After incubation in basal medium for more than 2 months, hRPE cells were largely nondividing and accumulated autofluorescent granules identified by electron microscopy to be lysosomes. Compared with proliferating hRPE cells, the nondividing cells had lower intracellular GSH, GSSG, and GSH/GSSG and a more oxidized redox potential (E(h)). Downregulation of Fas but upregulation of FasL was observed in these cells. The nondividing hRPE cells appeared more susceptible to tBH-induced apoptosis. Similar to proliferating hRPE cells, the apoptosis induced by tBH was preceded by induction of FasL, and antioxidants inhibited both FasL increase and apoptosis. Apoptosis was also inhibited with the antagonistic anti-Fas antibody ZB4. However, the nondividing hRPE cells had decreased sensitivity to apoptosis triggered by sFasL or CH-11.

CONCLUSIONS

Long-term hRPE culture created cells that were nondividing and accumulated autofluorescent granules. The increased sensitivity to tBH-induced apoptosis in these cells was associated with intracellular oxidation and upregulation of FasL. These results suggest that an increase in FasL may contribute to the vulnerability of nondividing hRPE cells to oxidant-induced apoptosis.

Interleukin-18 expression and modulation in human corneal epithelial cells

PURPOSE

The interferon-gamma-inducing factor Interleukin-18 (IL-18) is a recently described cytokine that appears to have multiple important pro-inflammatory effects including the induction of interferon-gamma (IFN-gamma) by activated T-cells. The expression of IL-18 by human cornea has not been previously reported. In the present study, we examine the possibility that human corneal epithelial cells are capable of producing this leukocyte-activating factor which may play an important role in IFN-gamma-dependent inflammation responses in the cornea.

METHODS

Northern blot analysis and ELISA were used to investigate the in vitro expression of IL-18 mRNA and protein respectively in primary (HCEC) and transformed human corneal epithelial cells (HCET). To determine if IL-18 expression was modulated by pro-inflammatory mediators, cells were treated with lipopolysaccharide (LPS), phorbol 12-myristate 13-acetate (PMA) or synthetic double stranded RNA (poly dI : dC). IL-18 bioactivity was determined in a leukocyte interferon-gamma induction assay and IL-18 was immunolocalized in whole human cornea by immunohistochemistry using a specific anti-IL-18 antibody.

RESULTS

IL-18 mRNA and bioactive protein was constitutively expressed by human corneal epithelial cells and upregulated by PMA, LPS and poly dI : dC. The constitutive expression of IL-18 protein immunoreactivity was also demonstrated in the epithelial cells of whole human cornea tissue.

CONCLUSIONS

This is the first study demonstrating that corneal epithelial cells are capable of producing the IFN-gamma inducing factor IL-18. Increased bioactive corneal IL-18 production can be induced by a number of pro-inflammatory agents and may play an important role in initiating gamma-interferon-mediated inflammatory responses in the cornea.

Infantile lensectomy and intraocular lens implantation with long-term follow-up in a monkey model

PURPOSE

To report the long-term clinical and histopathologic findings in infant monkeys following a lensectomy and intraocular lens (IOL) implantation using two different surgical techniques.

METHODS

A lensectomy and IOL implantation was performed on the right eye of 10 infant monkeys. A posterior capsulotomy was performed using a limbal approach in 5 monkeys (Group 1), and a pars plana approach in 5 other monkeys (Group 2). The residual refractive error in the pseudophakic eye was then corrected with a contact lens and the fellow eye was occluded for 70% of the daylight hours. The monkeys were then examined at regular intervals for 2 to 4 years. Visual acuity was assessed using operant testing and sweep visual evoked potentials (VEPs). At the end of the study, the pseudophakic eyes were studied histopathologically.

RESULTS

The only complications that required reoperation were diaphanous fibrin membranes on the lens optic (n=10) and lens reproliferation into the pupillary space (n=5). The visual outcome was similar in Groups 1 and 2, with better acuities in the phakic eyes compared with the pseudophakic eyes. A higher percentage of both haptics were found in the capsular bag for the monkeys in Group 2 (n=3) than in Group 1 (n=1).

CONCLUSIONS

Although haptic placement was superior using a pars plana approach to perform the primary posterior capsulotomy, no clinically discernable difference was noted in IOL centration between the monkeys undergoing a limbal versus a pars plana posterior capsulotomy and no difference was noted in the visual outcome.

Surgical management of subfoveal neovascularization in children

OBJECTIVE

To report the authors' clinical experience with submacular surgery for subfoveal membranes in children and to evaluate the histopathologic findings of membranes in children with various etiologies of choroidal neovascularization.

DESIGN

Retrospective, noncomparative, interventional case series.

PARTICIPANTS

Twelve eyes of 12 consecutive children with subfoveal choroidal neovascularization treated by vitrectomy and excision of the choroidal neovascular complex.

INTERVENTION

Vitrectomy, excision of the choroidal neovascular complex, and air-fluid exchange.

MAIN OUTCOME MEASURES

Visual acuity and recurrence of choroidal neovascular membrane.

RESULTS

Preoperative visual acuities ranged from 20/60 to 20/800 (median, 20/300). Postoperative visual acuities ranged from 20/25 to 20/400 (median, 20/80) after an average follow-up of 20 months (range, 7-62 months). Ten of 12 eyes improved from immediate preoperative visual acuity, and four eyes developed recurrence of neovascular membranes over a mean follow-up of 18 months. Histopathologic examination of six excised membranes showed that the most common components of the membranes were retinal pigment epithelium, fibrocytes, vascular endothelium, and collagen.

CONCLUSION

Selected eyes of children with subfoveal neovascular membranes and no evidence of membrane regression may benefit from submacular surgery. The histopathologic findings were similar to adult choroidal neovascularization not associated with age-related macular degeneration.

Tumors of the cornea and conjunctiva

This article reviews the literature published in 1996 regarding conjunctival and corneal tumors. There is an increased incidence of squamous cell carcinoma of the conjunctiva in patients with HIV infection, especially in young individuals and Africans. Presumed causative factors for conjunctival squamous cell carcinoma include ultraviolet light, HIV infection, human papillomavirus and other unknown factors. Metastatic tumors to the conjunctiva appear at an advanced stage of the disease, and metastases to the conjunctiva are a poor prognostic sign for survival. Reviews of premalignant lesions of the conjunctiva, including diagnosis, treatment, and recurrence, are discussed. Spindle cell and mucoepidermoid variants of squamous cell carcinoma of the conjunctiva have a worse prognosis for intraocular extension compared with usual conjunctival squamous cell carcinoma.

Increased Corneal Scarring after Phototherapeutic Keratectomy in Fuchs' Corneal Dystrophy

PURPOSE

A 63-year-old female with Fuchs' endothelial corneal dystrophy, stromal edema and subepithelial scarring was inappropriately treated with phototherapeutic keratectomy, leading to a central focal circular corneal scar and decreased visual acuity that required penetrating keratoplasty.

METHOD

The host corneal button was bisected and fixed in 10% formaldehyde and in glutaraldehyde immediately after its removal.

RESULTS

Light microscopy demonstrated a central area of absent Bowman's layer with a thin layer of subepithelial fibrosis, stromal corneal edema, and thickened Descemet's membrane.

CONCLUSION

Correct estimation of differential ablation rates of tissue and shallow, repeated ablations followed by slit-lamp microscopy and/or videokeratography help prevent over-treatment.

Comparative treatment of experimental Staphylococcus aureus endophthalmitis

PURPOSE

To compare treatment strategies for Staphylococcus aureus endophthalmitis, we created an animal model in an aphakic rabbit eye and tested six different approaches to treatment.

METHODS

Rabbit eyes were rendered aphakic, and three weeks postoperatively, S. aureus organisms were injected into the vitreous cavity. One group was maintained as a control. Twenty-four hours after bacterial injection, six different treatment groups were created for comparison. Clinical inflammation scores, culture results 48 hours after treatment, histopathologic gradings, and development of total corneal opacity three weeks after treatment were assessed.

RESULTS

Injection of vancomycin hydrochloride into the vitreous cavity was more effective than injection of cefazolin sodium (P = .01) in reducing the percentage of eyes that had positive culture results and also resulted in lower inflammation scores. Vitrectomy plus injection of either antibiotic was more effective than injection of the same antibiotic alone in reducing culture-positive results and reducing clinical inflammation scores. addition of systemic corticosteroids to intravitreal antibiotic injection did not improve any measure of outcome. Vitrectomy and injection of intravitreal vancomycin was the most effective strategy to sterilize the vitreous cavity, resulting in the lowest inflammation scores and the smallest percentage of eyes with opaque corneas.

CONCLUSION

In an animal model of S. aureus endophthalmitis, the combination of vitrectomy and injection of intraocular vancomycin was the most effective strategy for rapidly controlling the infective process and improving the outcomes measured three weeks after treatment.

Evaluation of a delivery system providing long-term release of cyclosporine

OBJECTIVES

To examine the clearance of cyclosporine after intravitreal injection and to assess the kinetics and toxic effects of an intravitreal device that provides sustained delivery of cyclosporine.

METHODS

Rabbits were divided into two groups to evaluate (1) the elimination kinetics after 1-microgram and 10-microgram intravitreal injections of cyclosporine and (2) the levels produced after implantation of a device that contained cyclosporine over 6 months. The toxic effects of the intravitreal device over 6 months were assessed in rabbits and cynomolgus monkeys.

RESULTS

After the 10-microgram injection, the half-life was longer (10.8 hours vs. 4.2 hours) and the distribution volume was smaller (1.7 mL vs 3.2 mL) than after the 1-microgram injection. This difference can be attributed to saturable partitioning of the drug. The device resulted in a vitreous concentration of approximately 500 ng/mL throughout the study period. In the rabbit it resulted in reversible lens opacification and decreased b-wave amplitude. This toxic effect was not detected in the monkey.

CONCLUSIONS

The device produces sustained intravitreal levels of cyclosporine. Although it was associated with reversible toxic effects in the rabbit, it was well tolerated in primates. Sustained-release implants are a promising new treatment for chronic uveitis.

Climatic proteoglycan stromal keratopathy, a new corneal degeneration

PURPOSE

To characterize a previously undescribed corneal disorder, climatic proteoglycan stromal keratopathy.

METHODS

We prospectively characterized the disorder in 58 eyes of 29 patients (ages 41 to 84 years) at the El Maghraby Eye Hospital, Jeddah Saudi Arabia. Light and transmission electron microscopy were performed on six corneal specimens.

RESULTS

Clinical criteria for the diagnosis included a central, horizontally oval, corneal stromal haze with a ground glass appearance, a uniform or lamellar pattern, greater extent anteriorly and involvement of 50% to 100% of stromal thickness. It occurred bilaterally but sometimes asymmetrically. Density varied from mild to moderate and seldom decreased visual acuity. Sixteen (28%) of 58 corneas had additional degenerative lesions (spheroidal degeneration, mild calcific band keratopathy, and Salzmann's nodular degeneration). Refractile stromal lines or posterior white dots were present in six (10%) of 58 eyes. Videokeratography in 11 (29%) of 38 eyes demonstrated flat areas that overlay the stromal haze. Pathologic analysis demonstrated focal intracellular and extracellular deposits of excess proteoglycans. One specimen showed amyloid. We postulate that climatic factors play a pathogenic role because the disorder occurs in individuals who were exposed to the sunny, dry, dusty environment of the Middle East and because other corneal degenerative disorders were present concomitantly.

CONCLUSIONS

Climatic proteoglycan stromal keratopathy is a corneal degeneration that appears as an oval, central, gray, ground-glass haze associated with central corneal flattening on videokeratography and as excess proteoglycans on histologic examination. It seldom severely decreases visual function.

Inflammatory pseudotumor of the eyelid

We present three patients whom we believe developed idiopathic inflammatory pseudotumors confined to the eyelid tissues with no evidence of orbital involvement. All three patients were misdiagnosed initially as having lesions of an infectious etiology. All three patients responded completely and rapidly to oral steroid therapy after the correct diagnosis was confirmed by biopsy. We believe that pseudotumor of the eyelid is a distinct subtype of idiopathic inflammatory pseudotumor.

Neonatal lensectomy and intraocular lens implantation: effects in rhesus monkeys

PURPOSE

To compare the effects of a lensectomy with and without intraocular lens (IOL) implantation on a neonatal rhesus monkey eye.

METHODS

A lensectomy and anterior vitrectomy was performed on 75 monkeys during the first 16 days of life; 21 of these monkeys also had an IOL implanted into the posterior chamber. The eyes were examined at regular intervals using biomicroscopy, applanation tonometry, and ophthalmoscopy.

RESULTS

The pseudophakic monkeys were studied until they were 92.5 +/- 5.8 weeks of age and the aphakic monkeys until they were 80.4 +/- 5.7 weeks of age. Pupillary membranes (100% versus 55.5%; P < 0.01) and lens regeneration into the pupillary aperture (28.6% versus 5.6%; P = 0.02) occurred more often in the pseudophakic than the aphakic eyes. As a result, the pseudophakic eyes required more reoperations than the aphakic eyes to keep the visual axis clear (P < 0.01). There was not a significant difference in the incidence of ocular hypertension between the pseudophakic and aphakic eyes (9.5% versus 12.7%; P = 0.34). Pupillary capture of the IOL optic occurred in 52% and haptic breakage in 33% of the pseudophakic eyes. All of the eyes with broken haptics had a prominent Soemmerring's ring varying in maximum thickness from 0.6 to 2 mm. Nine of the haptics from the seven eyes with broken IOLs had eroded into the iris, two into the ciliary body, and one into the anterior chamber.

CONCLUSIONS

Implanting an IOL into a neonatal monkey eye after a lensectomy and anterior vitrectomy increases the likelihood of a reoperation being necessary. Haptics frequently erode into the iris and ciliary body and may break because of stress placed on the optic-haptic junction by forward movement of the IOL.

Sclerosing syringoma

Syringoma, a benign sweat gland tumor which may occur in the eyelid, commonly presents as multiple lesions in young women. We had an unusual case of a sclerosing syringoma found as a single lesion in the lower eyelid of a man.

Nonsimultaneous primary choroidal and cutaneous melanomas. Report of a case

The authors report a patient with nonsimultaneous choroidal and cutaneous melanomas. The patient did not display the dysplastic nevus syndrome phenotype, and there was a negative family history for cutaneous or uveal melanomas. This sporadic case might suggest a common etiologic factor in the pathogenesis of multicentric malignant melanomas.

Acute monocytic leukemia presenting in the eyelid. An immunohistochemical and electron microscopic study

A 28-year-old woman was evaluated for a firm subcutaneous nodule of the left upper eyelid. Results from the examination showed multiple red to brown subcutaneous nodules on her upper extremities and thorax. An excisional biopsy specimen showed the nodules to be cutaneous involvement of acute monocytic leukemia. Acute monocytic leukemia should be considered in the differential diagnosis of a subcutaneous nodule in the eyelid.

Computed axial tomography in ophthalmology

Diagnostic accuracy of computed axial tomography (CT) of the eye and orbit is limited by resolving power and interpretation. Indiscriminate use of the scan is limited by radiation exposure and cost of the modality. The use of CT should be reserved in the ophthalmologist's supply of diagnostic modalities and be used as part of an orderly, logic scheme of diagnostic testing. The scheme proposed advises ordering a B-mode ultrasound before CT.