OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY STUDY OF CHOROIDAL NEOVASCULARIZATION ASSOCIATED WITH EARLY-ONSET DRUSEN

PURPOSE

To report three middle-aged cases with choroidal neovascularization (CNV) associated with early-onset drusen documented with optical coherence tomography angiography (OCTA).

METHODS

Three patients with bilateral early-onset drusen were referred to our hospital. Fundus examination, fluorescein angiography, indocyanine green angiography, OCTA, and other multimodal imaging were performed.

RESULTS

Case 1 involved a 47-year-old woman who presented with sudden unilateral anorthopia. She had no previous systemic pathologies. Funduscopic examination and fluorescein angiography revealed bilateral large colloid drusen accompanied by unilateral mild subretinal hemorrhage. Indocyanine green angiography revealed CNV, although it was unclear in fluorescein angiography. Optical coherence tomography angiography also showed interconnecting CNV beneath the retinal pigment epithelium. Case 2 involved a 40-year-old woman with membranoproliferative glomerulonephritis Type 3 who presented with unilateral anorthopia. On fluorescein angiography, cuticular drusen secondary to membranoproliferative glomerulonephritis were seen in both eyes. An interconnecting vascular network was revealed with OCTA and indocyanine green angiography indicating Type 1 CNV in the affected eye. Case 3 involved a 47-year-old man without any medical or family history. Predominant large colloid drusen associated with cuticular drusen were seen in both eyes. Unilateral mild serosanguinous changes were accompanied in the macula, where Type 1 CNV was detected with OCTA.

CONCLUSION

All our cases with early-onset drusen showed Type 1 CNV that was detected by indocyanine green angiography or OCTA. Optical coherence tomography angiography has a potential to help noninvasively diagnose CNV in the cases of EOD.

Vasa Vasorum Lumen Narrowing in Brain Vascular Hyalinosis in Systemic Hypertension Patients Who Died of Ischemic Stroke

Ischemic stroke is a major cause of death among patients with systemic hypertension. The narrowing of the lumen of the brain vasculature contributes to the increased incidence of stroke. While hyalinosis represents the major pathological lesions contributing to vascular lumen narrowing and stroke, the pathogenic mechanism of brain vascular hyalinosis has not been well characterized. Thus, the present study examined the postmortem brain vasculature of human patients who died of ischemic stroke due to systemic hypertension. Hematoxylin and eosin staining and immunohistochemistry showed the occurrence of brain vascular hyalinosis with infiltrated plasma proteins along with the narrowing of the vasa vasorum and oxidative stress. Transmission electron microscopy revealed endothelial cell bulge protrusion into the vasa vasorum lumen and the occurrence of endocytosis in the vasa vasorum endothelium. The treatment of cultured microvascular endothelial cells with adrenaline also promoted the formation of the bulge as well as endocytic vesicles. The siRNA knockdown of sortin nexin-9 (a mediator of clathrin-mediated endocytosis) inhibited adrenaline-induced endothelial cell bulge formation. Adrenaline promoted protein-protein interactions between sortin nexin-9 and neural Wiskott–Aldrich syndrome protein (a regulator of actin polymerization). Spontaneously hypertensive stroke-prone rats also exhibited lesions indicative of brain vascular hyalinosis, the endothelial cell protrusion into the lumen of the vasa vasorum, and endocytosis in vasa vasorum endothelial cells. We propose that endocytosis-dependent endothelial cell bulge protrusion narrows the vasa vasorum, resulting in ischemic oxidative damage to cerebral vessels, the formation of hyalinosis, the occurrence of ischemic stroke, and death in systemic hypertension patients.

Primary megalocornea: Case report

The neonate has a horizontal diameter of the cornea, usually up to 10mm with growth up to 2mm in the first 2 years of life. We report a case of megalocornea, a rare, recessive, X-linked disorder in a 3-month-old child, seeking to review what the medical literature brings information about the condition, as well as diagnostic and follow-up parameters, of its main differential diagnoses.

CUTICULAR DRUSEN: Risk of Geographic Atrophy and Macular Neovascularization

PURPOSE

Cuticular drusen (CD) have been associated with manifestations of age-related macular degeneration such as atrophy and neovascularization in the macula. In this study, eyes with CD were followed and investigated for the estimated 5-year risk of progression to sequelae of age-related macular degeneration such as geographic atrophy (GA) and macular neovascularization (MNV).

METHODS

A consecutive series of patients with CD were followed for the development of GA and MNV. Whenever possible, they were also studied retrospectively. The patients with CD were categorized into three phenotypic groups. Phenotype 1: eyes had concentrated, densely populated CD in the macular and paramacular area, Phenotype 2: eyes showed scattered CD in the posterior fundus, and Phenotype 3: involved eyes with CD mixed with large drusen (>200 µm). The 5-year incidence of progression was then estimated using a Kaplan-Meier estimator.

RESULTS

A total of 63 eyes from 38 patients (35 women with a mean age at presentation of 58.9 ± 14.2 years) were studied and followed for a mean of 40 ± 18 months. Thirteen patients had single eyes with GA (84.5%; 11/13) or MNV (15.5%; 2/13) in one eye at presentation and were subsequently excluded. Geographic atrophy developed in 19.0% (12/63) of eyes and MNV in 4.8% (3/63) of eyes. The cumulative estimated 5-year risk of GA and MNV was 28.4% and 8.7%, respectively. The estimated 5-year incidence of MNV or GA was 12.6%, 50.0%, and 51.6% in Phenotype 1, Phenotype 2, and Phenotype 3, respectively (P = 0.0015, log-rank test). No difference in risk was found in the development of GA or MNV (P = 0.11) between the subgroup of patients presenting with GA or MNV in their fellow eye and those with both eyes included.

CONCLUSION

When patients with CD are followed longitudinally, there was a significant risk of progression to GA or MNV for Phenotype 2 and Phenotype 3. Patients with CD are commonly first diagnosed in the fifth decade of life, and there is a female predominance. Clinicians should use multimodal imaging to detect and be aware of the risk of progression to manifestations of GA and MNV. These risks of GA and MNV suggest that patients with CD may be part of the overall spectrum of age-related macular degeneration.

Peripheral Persistent Fetal Vasculature: A Report of Three Cases

The authors report three cases of persistent fetal vasculature (PFV) presenting with an atypical peripheral fibrovascular stalk. A 5-month-old with congenital exotropia with a vitreous hemorrhage in the right eye underwent vitrectomy, and a mid-peripheral vitreal vascular stalk was visualized within the area of hemorrhage. The second case is of an 8-year-old with two fetal vascular remnants in the right eye: (1) a stalk superotemporally extending from the pars plana to the mid-peripheral retina that was associated with a retinal break and (2) a focal lens opacity. The third case is a 12-year-old with a history of familial exudative vitreoretinopathy and peripapillary choroidal neovascular membrane found to have a peripheral vitreal stalk in the right eye. These cases demonstrate a rare form of PFV with primarily peripheral remnants. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:e83-e88.].

Electrophysiological verification of enhanced S-cone syndrome caused by a novel c.755T>C NR2E3 missense variant

BACKGROUND

Nuclear hormone receptor gene, NR2E3, plays a critical role in retinogenesis and determination of the rod photoreceptor phenotype. Mutations in NR2E3 typically lead to recessive enhanced S-cone syndrome (ESCS), where affected individuals show higher sensitivity to short wavelength light and early onset rod dysfunction. Patients with ESCS present in early childhood with nyctalopia, enhanced sensitivity to blue light and display a very heterogeneic retinal phenotype with varying degrees of clumped pigmentation and occasional retinoschisis.

PURPOSE

To confirm the pathogenicity of a novel mutation in NR2E3 using electrophysiological studies.

MATERIALS AND METHODS

Patient underwent detailed clinical evaluation and ophthalmic imaging followed by next generation sequencing analysis and electrophysiological studies.

RESULTS

We describe a case of a young man of Greek descent with a family history of retinal degeneration. His fundal features at presentation were atypical of ESCS, with striking macular involvement in both eyes, including fibrotic subretinal material overlying the pigment epithelial detachment in one eye and schisis in the other. Genetic testing revealed a novel homozygous variant in NR2E3 gene of uncertain pathogenicity. Instead of performing further genetic analyses, electrophysiological studies showed pathognomonic changes in the S-cone response.

CONCLUSIONS

With the recent clinical endorsement of a gene therapy for RPE65 related-inherited retinal degeneration it is of paramount importance to correctly identify the pathogenic genetic mutation. In this particular syndrome, we highlight the value of electrophysiology to confirm the pathogenicity of a novel mutation in NR2E3 and aid the diagnosis of ESCS, with potential for gene therapy in the future.

[Guidance of Medical Care for Familial Exudative Vitreoretinopathy：Research on Rare and Intractable Diseases, Health and Labour Sciences Research Grants]

Familial exudative vitreoretinopathy is a hereditary insufficiency of retinal vascularture, which manifests a variety of vitreoretinal abnormalities, including nonvascularlized retina, abnormality of retinal vessel growing, dragged retina, retinal folds and total retinal detachment. While causative genes have been identified, cases are often sporadic. Periodic examination is necessary to find recurrence of the disease and late complications, including rhegmatogenous retinal detachment, cataract and glaucoma.

Novel membrane frizzled-related protein gene mutation as cause of posterior microphthalmia resulting in high hyperopia with macular folds

PURPOSE

We present a genetic and clinical analysis of two sisters, 3 and 4 years of age, with nanophthalmos and macular folds.

METHODS

Ophthalmological examination, general paediatric examination and molecular genetic analysis of the MFRP gene were performed in both affected siblings.

RESULTS

Clinical analysis showed high hyperopia (+11 D and +12 D), short axial lengths (15 mm) and the presence of macular folds and optic nerve head drusen. Autofluorescence of the retina was generally normal with subtle macular abnormalities. Sequence analysis showed compound heterozygosity for severe MFRP mutations in both sisters: a previously reported p.Asn167fs (c.498dupC) and a novel stop codon mutation p.Gln91X (c.271C>T).

CONCLUSION

These are the youngest nanophthalmos patients in the literature identified with severe loss of MFRP function, showing already the known structural abnormalities for this disease. Adult patients affected by homozygous or compound heterozygous MFRP mutations generally show signs of retinal dystrophy, with ERG disturbances and RPE abnormalities on autofluorescence imaging. ERG examination could not be performed in these children, but extensive RPE abnormalities were not seen at this young age.

Department-related tasks and organ-targeted therapy in Fabry disease: an interdisciplinary challenge

Fabry disease is a rare X-linked storage disorder leading to an accumulation of globotriaosylceramides in all cells carrying lysosomes. As the accumulation occurs in most organs, different medical specialties are involved in the diagnostics and therapy of Fabry disease. With this review of the 3 main specialties (cardiology, nephrology, and neurology) and, in addition, the adjacent specialties (ophthalmology and dermatology), we aim to discuss the division-related responsibilities and want to suggest an organ-related additional therapy besides enzyme replacement therapy.

Ocular and orbital manifestations of the inherited bone marrow failure syndromes: Fanconi anemia and dyskeratosis congenita

PURPOSE

The inherited bone marrow failure syndromes (IBMFS) are a heterogeneous group of genetic disorders that share the inability of the bone marrow to produce an adequate number of blood cells. The 4 most frequent syndromes are Fanconi anemia (FA), dyskeratosis congenita (DC), Diamond-Blackfan anemia (DBA), and Shwachman-Diamond syndrome (SDS). All 4 syndromes have been associated with various physical abnormalities. As part of a genotype/phenotype/cancer susceptibility study, we determined the prevalence of ophthalmic manifestations in these 4 syndromes.

DESIGN

Cross-sectional study of a patient cohort.

PARTICIPANTS

Seventy-five patients with an IBMFS and 121 of their first-degree relatives were seen in the National Eye Institute, National Institutes of Health, from 2001 to 2007. The patient group included 22 with FA, 28 with DC, 19 with DBA, and 6 with SDS.

METHODS

Every participant underwent a complete ophthalmic evaluation and digital facial photography with an adhesive paper ruler on the patient's forehead for an internal measure of scale. Interpupillary distance (IPD), inner canthal distance (ICD), outer canthal distance (OCD), palpebral fissure length (PFL), and corneal diameter (CD) were measured. Thirteen of the 22 patients with FA underwent axial length (AL) measurements by A-scan ultrasonography.

MAIN OUTCOME MEASURES

Type and prevalence of ophthalmic manifestations.

RESULTS

Ninety-five percent of patients with FA had at least 1 abnormal parameter, and 25% of patients had at least 4 abnormal parameters. Eighty-two percent of patients had small palpebral fissures, 69% of patients had simple microphthalmia, 64% of patients had small OCD, 55% of patients had microcornea, 28% of patients had ptosis, and 6% of patients had epicanthal folds. In patients with DC, abnormalities of the lacrimal drainage system (29%) were the most prevalent findings, followed by retinal abnormalities (pigmentary changes, retinal neovascularization, retinal detachment, exudative retinopathy) in 21%, cicatricial entropion with trichiasis and blepharitis in 7% each, and sparse eyelashes and congenital cataract in 3.5% each. No significant ophthalmic abnormalities were seen in patients with DBA or SDS.

CONCLUSIONS

Syndrome-specific ocular findings are associated with FA and DC and may antedate diagnosis of the specific syndrome. Early recognition of these abnormalities is important for optimal management.

Pfeiffer syndrome: Systemic and ocular implications

BACKGROUND

In 1964, Pfeiffer described a three-generation family in which eight individuals had a syndrome consisting of craniosynostosis, broad thumbs and great toes, and partial syndactyly of the hands and feet. Pfeiffer syndrome affects males and females equally, and is most commonly a result of de novo mutations, but can be inherited in an autosomal dominant fashion. Pfeiffer syndrome is considered Type V of the five acrocephalosyndactly syndromes (ACS), a group of rare genetic diseases that involve premature closure of the cranial sutures. Cohen, in 1993, further described Pfeiffer syndrome and it's various expression patterns by creating three subgroups of the syndrome.

CONCLUSIONS

While Pfeiffer syndrome is clearly a rare disorder, affecting 15 of every 1 million births, there has been a series of publications reviewing the difficult differential diagnosis among Pfeiffer types and between the other acrocephalosyndactly syndromes. While these publications individually focus on a variety of specific systemic and ocular implications of the syndrome, together they encompass the scope of the syndrome. Since Pfeiffer syndrome mainly affects the craniofacial regions, the eye care professional plays an essential role in diagnosis and management. What follows are guidelines to aid in the diagnosis, ophthalmic and functional testing, and management of this disorder.

Inherited eye disease: cause and late effect

Molecular genetics has provided relatively few insights into late-onset eye disorders, but epidemiological data indicate that genetic factors are important in some late-onset eye disorders that cause major health burdens. Much clinical genetic research is based on the belief that developmental and late-onset disorders are not necessarily the result of defects in different genes, but are often caused by different mutations in the same collection of genes. Thus, mutations that either abolish or radically change gene function might cause early-onset disorders, whereas more-subtle changes in gene expression might underlie late-onset diseases. We present arguments and examples that indicate that this principle might be a fruitful guide to investigating the causes of late-onset eye disorders.

Multiple factors contribute to inefficient prenylation of Rab27a in Rab prenylation diseases

Post-translational geranylgeranylation of Rab GT-Pases is essential for their membrane association and function as regulators of intracellular vesicular transport. The reaction is catalyzed by Rab geranylgeranyltransferase (RGGT) and is assisted by the Rab escort proteins (REP), which form stable complexes with newly synthesized GDP-bound Rabs. Two genetic diseases involve the Rab geranylgeranylation machinery: choroideremia, an X-linked retinal degeneration resulting from loss-of-function mutations in REP1, and gunmetal, a mouse model of Hermansky-Pudlak syndrome resulting from mutations in the alpha-subunit of RGGT. A small subset of Rab proteins is selectively under-prenylated in both diseases, most notably Rab27a. Here we analyze why Rab27a is selectively affected in diseases of Rab geranylgeranylation. Semi-quantitative immunoblotting suggests that mass action, i.e. the amount of Rab27a relative to other Rabs, is unlikely to be a factor as the expression level of Rab27a is similar to other Rabs not affected in these diseases. In vitro binding assays and fluorescence resonance energy transfer detected by fluorescence lifetime imaging microscopy in intact cells demonstrate that Rab27a binds equally well to both REP1 and REP2, suggesting differential affinity of Rab27a for REP isoforms is not an important factor. However, steady-state kinetic analysis of the geranylgeranylation reaction indicates that REP2-Rab27a has lower affinity for RGGT compared with REP1-Rab27a. Furthermore, we show that Rab27a has relatively low GTPase activity, presumably decreasing the affinity of the REP interaction in vivo. We suggest that the restricted phenotypes observed in these diseases result from multiple contributing factors.

Clinical features of comitant strabismus related to family history of strabismus or abnormalities in pregnancy and delivery

PURPOSE

To elucidate the genetic or environmental background for clinical features in the three major types of comitant strabismus.

METHODS

Interview based on a questionnaire asking background factors such as family history of strabismus and abnormalities in pregnancy and delivery was conducted with 101 consecutive patients with infantile esotropia (5-180 months of age), 83 with accommodative or partially accommodative esotropia (6-201 months of age), and 143 with intermittent exotropia (3-216 months of age) seen during 7 months from May to November 1998. The clinical features of strabismus obtained from medical records were analyzed statistically by logistic regression to determine their relation with these background factors.

RESULTS

In infantile esotropia, patients with family history of strabismus had a significantly higher chance of showing latent nystagmus (odds ratio, 3.553; 95% confidence interval [CI], 1.077-11.717; P =.0373, logistic regression analysis). In a subgroup of 40 patients with infantile esotropia whose birth followed no abnormalities in pregnancy or delivery, patients with family history of strabismus had a significantly higher chance of showing inferior oblique muscle overaction (odds ratio, 7.714; 95% CI, 1.246-47.761; P =.0280), dissociated vertical deviation (odds ratio, 6.667; 95% CI, 1.176-37.787; P =.0321), and latent nystagmus (odds ratio, 7.333; 95% CI, 1.168-46.060; P =.0336). In accommodative or partially accommodative esotropia and intermittent exotropia, no relation was found between the clinical features and the background factors.

CONCLUSIONS

Inferior oblique muscle overaction, dissociated vertical deviation, and latent nystagmus in infantile esotropia might have a genetic background.

Corneoscleral transplantation in congenital corneal staphyloma and Peters' anomaly

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.

Heredity versus abnormalities in pregnancy and delivery as risk factors for different types of comitant strabismus

PURPOSE

To elucidate risk factors for different types of comitant strabismus, the incidence of heredity and abnormalities in pregnancy and delivery was compared among different types of strabismus.

METHODS

Between May 1998 and January 1999, a prospective clinical study of 500 consecutive patients with comitant strabismus at a referral-based university hospital was performed using data collected from questionnaires and interviews. Inclusion criteria were infantile esotropia (168 patients), accommodative and partially accommodative esotropia (97 patients), microesotropia (15 patients), acquired esotropia (12 patients), intermittent or constant exotropia (205 patients), and congenital exotropia (3 patients). Exclusion criteria were strabismus associated with systemic and central nervous system abnormalities and organic eye diseases.

RESULTS

Family history was significantly more prevalent in intermittent or constant exotropia and accommodative or partially accommodative esotropia than in infantile esotropia (P<.0001 and P=.0267, respectively, Fisher's exact test). In contrast, abnormalities in pregnancy and delivery were noted at a significantly higher rate in infantile esotropia than in accommodative or partially accommodative and in intermittent or constant exotropia (P=.003 and P=.0215, respectively). Patients with infantile esotropia were significantly younger at the survey than those with the other two types of strabismus (P=.0004 and P<.0001). No significant difference was found in the number of siblings, birthweight, maternal age at delivery, or maternal cigarette smoking or alcohol drinking among these three types of strabismus.

CONCLUSION

Heredity and abnormalities in pregnancy and delivery are two major risk factors for comitant strabismus and contribute at different levels to the development of infantile esotropia, accommodative or partially accommodative esotropia, and intermittent or constant exotropia.

Essential iris atrophy, pigment dispersion, and glaucoma in DBA/2J mice

PURPOSE

To characterize ocular abnormalities associated with iris atrophy in DBA/2J mice and to determine whether mice of this strain develop elevated intraocular pressure (IOP) and glaucoma.

METHODS

Different approaches, including slit-lamp biomicroscopy, ophthalmoscopic examination, ultrasound backscatter microscopy, and histology were used to examine the eyes of DBA/2J mice ranging from 2 to 30 months old. IOP was measured in DBA/2J mice of different ages.

RESULTS

DBA/2J mice were found to develop pigment dispersion, iris transillumination, iris atrophy, anterior synechias, and elevated IOP. IOP was elevated in most mice by the age of 9 months. These changes were followed by the death of retinal ganglion cells, optic nerve atrophy, and optic nerve cupping. The prevalence and severity of these lesions increased with age. Optic nerve atrophy and optic nerve cupping was present in the majority of mice by the age of 22 months.

CONCLUSIONS

DBA/2J mice develop a progressive form of secondary angle-closure glaucoma that appears to be initiated by iris atrophy and the associated formation of synechias. This mouse strain represents a useful model to evaluate mechanisms of pressure-related ganglion cell death and optic nerve atrophy, and to evaluate strategies for neuroprotection.

Hereditary external ophthalmoplegia synergistic divergence, jaw winking, and oculocutaneous hypopigmentation: a congenital fibrosis syndrome caused by deficient innervation to extraocular muscles

BACKGROUND

The congenital fibrosis syndrome is a hereditary form of external ophthalmoplegia that is considered to be a primary myopathy.

PURPOSE

To document the coexistence of two distinct forms of ocular motor synkinesis in a subgroup of patients with congenital fibrosis syndrome.

METHODS

Clinical and intraoperative examination results and extraocular muscle biopsy specimens from four patients with congenital fibrosis syndrome were studied.

RESULTS

Three patients displayed a variant of synergistic divergence characterized by simultaneous abduction with intorsion and depression of the synkinetically abducting eye. Three patients had variant of Marcus Gunn jaw winking characterized by elevation of a ptotic eyelid during mouth opening. Three patients had oculocutaneous hypopigmentation.

CONCLUSIONS

A subgroup of patients with congenital fibrosis syndrome display two distinct synkinetic ocular movements in conjunction with oculocutaneous hypopigmentation. The patterns of neuronal misdirection implicate a regional innervational disturbance involving cranial nerves III through VI as the underlying cause of diffuse hereditary ophthalmoplegia in these patients.

Peters' anomaly associated with protruding corneal pseudo staphyloma

PURPOSE

To describe a new manifestation of Peters' anomaly.

METHODS

We managed four infants with an unusual form of Peters' anomaly. One eye of each patient had a thickened and scarred cornea, mimicking a corneal staphyloma, protruding anteriorly from the corneal plane. The other eye of each patient ranged from normal to having severe ocular anomalies. A corneal transplant was performed in each case.

RESULTS

Follow-up ranged from 1 to 3 years. Three eyes maintained graft clarity for at least 1 year. Each of these eyes developed vision. Two of these eyes developed glaucoma. The one eye with graft failure developed an inoperable retinal detachment. The histopathology of each corneal button showed changes consistent with Peters' anomaly.

CONCLUSIONS

These corneas demonstrated characteristics of both Peters' anomaly and congenital anterior staphyloma. Despite their severe anomalies, surgery successfully restored a more normal cosmetic appearance in all four eyes and vision in three eyes.

Exclusion of PPEF as the gene causing X-linked juvenile retinoschisis

X-linked juvenile retinoschisis (RS) is a progressive vitreoretinal degeneration localised in Xp22.1-p22.2. A human homologue of the retinal degeneration gene C (rdgC), a gene that in Drosophila melanogaster prevents light-induced retinal degeneration, was localised in the RS obligate gene region. We have tested the gene, designated PPEF in humans, as a candidate gene in RS patients using RT-PCR and the protein truncation test on RNA and SSCP on DNA. No mutations were identified, making it highly unlikely that PPEF is the gene implicated in RS. The data presented facilitate mutation analysis of the PPEF gene in other diseases which have been or will be localised to this region.

Ocular manifestations of genetic and developmental diseases

Ophthalmic genetics is a rapidly expanding field that includes both clinical and basic sciences. Clinical descriptions of syndromes and new diagnostic testing both reflect the increase in knowledge and technology of molecular biology. Technologic advances have resulted in old diseases being described in new ways and being attributed to new pathophysiologic mechanisms. This review is intended to update the past year's contributions in ophthalmic genetics. Discussion is by disease type, which is familiar to most clinicians.

Ocular manifestations in a father and son with EEC syndrome

BACKGROUND

The ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome is a rare disease which follows an autosomal-dominant pattern of inheritance. Due to the ectodermal dysplasia there is atresia of the lacrimal duct system and aplasia of the meibomian glands with a defective tear film. Therefore, vascularized corneal scars often form during early adult life.

PATIENTS

Father aged 41 years, and son aged 23 months. Both patients: stenosis/atresia of lacrimal duct systems (the father had twice undergone dacryocystorhinostomy externally) with epiphora, lip-palate clefting, syndactylies of fingers and toes, lobster deformities of hands. Additional ophthalmological findings in the father: bilaterally extracted juvenile cataracts with implantation of intraocular lenses, bilateral extensive vascularized corneal scars. Additional dermatological findings in the father: malignant melanoma of the calf, now in complete remission following several operations on the melanoma and several cycles of chemotherapy for the metastases.

DISCUSSION AND THERAPEUTIC CONCLUSIONS

Father and son show the full clinical picture of the EEC syndrome with clefting, lobster-like deformities of the hands and ectodermal dysplasia with tear duct atresia and aplasia of the meibomian glands with defective tear film. During childhood, the main handicapping features are the clefting and the hand deformities with their respective multiple operative revisions. During early adulthood, however, the ocular problems become the predominantly handicapping aspects of the EEC syndrome; due to the ectodermal dysplasia, vascularized corneal scarring develops. Tearing and secondary inflammation due to lacrimal duct atresia has to be treated by early dacryocystorhinostomy. As secondary infections promote the development of corneal scars, one should not postpone the operation too long. Infections have to be treated promptly by local antibiotics. Because of the aplasia of the meibomian glands, artificial tear substitution should be given on a regular basis to support the defective tear film. Thus, the development of vascularized corneal scars can perhaps be delayed. Once corneal scarring has developed, perforating keratoplasty has a poor prognosis due to the ectodermal dysplasia, the absence of the meibomian glands and the defective tear film. Three factors lead to the formation of vascularized corneal scars: recurrent infections of lid margins and conjunctiva due to obstructed tear ducts; defective tear film with insufficient lipid phase due to the aplasia of the meibomian glands; and primary corneal epithelial defects in the course of the generalized ectodermal dysplasia.

Ocular manifestations of genetic and developmental diseases

Although ophthalmic involvement in developmental and genetic abnormalities has been recognized for centuries, it is only recently, due to new discoveries in molecular biology, that our classification and pathophysiology of congenital eye diseases have been advanced. In the next few years these advances will increasingly influence aspects of diagnosis classification, and therapy in ophthalmology. Tests for acquired and inherited diseases in opthalmology are being revolutionized by biotechnical innovations. The molecular genetics of ocular diseases is currently undergoing changes in classification due to intense investigations using advanced biotechnology. The potential for new treatment modalities, such as gene therapy, for molecular eye diseases, once thought to be pure fiction, is now a reality. This paper will outline recent changes in classification, organization, and general knowledge regarding inherited eye diseases.

A histopathological, ultrastructural and immunohistochemical study of congenital hereditary retinoschisis

OBJECTIVE

To confirm our earlier histopathological and electron microscopic findings in congenital hereditary retinoschisis (CHRS) in two additional globes and to further evaluate the nature and origin of the intraretinal filaments by means of immunohistochemical analysis.

PATIENTS

Three white men with CHRS, aged 83 years (patient I) (two globes), 55 years (patient 2) (two globes) and 33 years (patient 3, nephew of patient 2) (one globe).

OUTCOME MEASURES

Findings on histopathological study and electron microscopy (patient I) and immunohistochemical analysis (all five globes).

RESULTS

Histopathological examination showed extensive extracellular deposition of amorphous material positive for periodic acid-Schiff reagent in the outer schisis layer and focally in the macula. Ultrastructurally, the amorphous material represented filaments measuring 8 to 12 nm in diameter within degenerated Müller cells, with accumulation of these filaments in adjacent extracellular spaces. Similar, less severe changes were seen in the superonasal retina. Immunohistochemical studies showed focal reactivity for glial fibrillary acidic protein (GFAP) in the retina adjacent to the schisis cavity in all five globes, focal reactivity for S-100 protein in four retinas, rare focal staining for vimentin and neurofilaments in two retinas each and no reactivity for type I keratin or actin.

CONCLUSIONS

The present study corroborates our previous work and provides pathological evidence that the retinal disorder extends beyond the limits of the schisis. The results of the immunohistochemical analysis are consistent with a glial cell origin of the filaments. We postulate that defective Müller cells produce GFAP and possibly S-100 protein, which accumulate within the retina and secondarily result in degeneration of these cells and schisis formation.

A unification hypothesis of pigment dispersion syndrome

PURPOSE

To synthesize recent findings regarding pigment dispersion syndrome in order to arrive at a hypothesis concerning the nature of an underlying genetic predisposition.

METHODS

The literature on the subject was reviewed and analyzed.

RESULTS

Eyes with pigment dispersion syndrome differ from normal in that they have a larger iris, a midperipheral posterior iris concavity that increases with accommodation, a more posterior iris insertion, increased iridolenticular contact that is reversed by inhibition of blinking, possibly an inherent weakness of the iris pigment epithelium, and an increased incidence of lattice degeneration of the retina.

CONCLUSION

A gene affecting some aspect of the development of the middle third of the eye early in the third trimester appears at the present time to be the most likely cause.

Familial exudative vitreoretinopathy

PURPOSE

To evaluate the natural history of Familial Exudative Vitreoretinopathy (FEVR) with emphasis on the effect of the age of onset on its severity and on the development of late complications such as cataract and retinal detachment. Also, to evaluate affected patients for DNA abnormalities.

METHODS

The records of thirty-nine patients with FEVR were studied. All were asked to come in for a final follow-up examination. The referring physician was asked to provide the latest findings for those who could not. On 10 patients, karyotypes were prepared.

RESULTS

Only 2 of 28 patients whose onset of symptoms was prior to their third birthday had a final visual acuity of 20/200 or better. Older patients had a better prognosis, because they were more likely to have asymmetrical retinal deterioration with only one eye deteriorating. Preservation of good visual acuity into the teens and later was no guarantee that deterioration would not occur. In 3 eyes of 4 patients who were asymptomatic until 15 years of age, the final visual acuity was counting fingers or worse. In 5 patients, retinal detachment developed 6 to 17 years after apparent stabilization. The karyotype of 10 patients showed no evidence for rearrangement, altered size, translocations or deletions of chromosome 11 or any other chromosome. Of the 31 eyes in patients older than 15 years, 10 (32%) had a significant cataract. Three eyes underwent cataract surgery.

CONCLUSIONS

The prognosis for infants with FEVR is extremely poor and the long-term prognosis for patients with a later onset of the condition is guarded. Retinal detachment, macular dragging, and cataract are common late complications which can develop even in patients whose eye findings appear to be stable. Karyotype studies ruled out involvement of chromosome 11 or others at a gross level, but did not exclude them at the location for some genetic defect related to FEVR because single base changes and small deletions or insertions may be undetectable by the methods utilized.

Bilateral juxtapapillary subretinal neovascularization and pseudopapilledema in a three-year-old child

A case of bilateral pseudopapilledema associated with serous and hemorrhagic detachment of the juxtapapillary sensory retina in a 35-month-old girl was thought to be secondary to optic nerve drusen.