Syndrome with an Unusual Form of ERG

Some unusual forms of retinal dysfunction have been reported that involve the cone and the rod photoreceptor systems in an extraordinary way. With the rod-cone dysfunction syndrome, there is decreased sensitivity to light while at the same time its responsiveness to superthreshold light stimuli is enormously augmented 1-3 . This unusual combination is illustrated in three of our patients 4 . A 15-year-old girl (case 1), an 11-year-old girl (case 2), and a 32-year-old woman (case 3) had low...

Diffuse Unilateral Subacute Neuroretinitis

Diffuse unilateral subacute neuroretinitis (DUSN) 8 is caused by an unidentified species of nematodes that may wander in the subreti-nal space for 4 years or longer and cause progressive ocular damage. DUSN is characterized by early visual loss, vitritis, papillitis, retinal vasculitis, and recurrent crops of evanescent, grayish white outer retinal lesions that may develop in one eye of an otherwise healthy individual. At a late stage, there is severely reduced vision, optic atrophy, retinal...

Macular Translocation Surgery

Although surgical removal of a subfoveal CNV can be performed in some patients with AMD, the main disadvantage of the procedure is reduced visual function that results from damage to the RPE underneath the macula. Foveal or macular translocation surgery is an operative procedure in which the fovea is moved from diseased RPE onto healthy RPE 5 . This surgery has the potential to improve or preserve central visual function in eyes after removing a subfoveal CNV. One common technique of macular...

Focal Macular ERGs and Diabetic Maculopathy

Diabetic maculopathy is one of the leading causes of blindness in diabetic retinopathy. The functional and morphological analysis of diabetic maculopathy is thus important for prognostic evaluation and treatment indications. The OCT images and the focal macular ERGs obtained from representative patients with diabetic maculopathy are shown in Fig. 3.9. Normal control (A), mild maculopathy (B), or focal macular edema (C) often show an Fig.3.9. Fluorescein angiograms (F AG),optical convergence...

Diabetic Vitreous Hemorrhage

When massive vitreous hemorrhage prevents ophthalmoscopic examination of the fundus in patients with proliferative diabetic retinopathy, it makes it difficult to predict the surgical and visual outcome after vitrectomy. In these eyes, the amplitudes of the ERGs may be markedly reduced by various factors pathological changes induced by the diabetic retinopathy earlier PRP vitreous hemorrhage. As mentioned, the PRP reduces the ERG amplitude, but the b a ratios are unchanged (Fig. 3.3). Because...

How Does Subretinal Hemorrhage Damage the Retina

A thick subretinal hemorrhage situated under the fovea occasionally has a natural course that leads to severely decreased visual function even in those without choroidal neovascularization. Animal experiments have shown that the photoreceptors can be damaged by the toxic effects of the iron released by red blood cells as well as by mechanical blockage by the hemorrhage, which hinders metabolic exchange between the photoreceptors and the RPE cells 1 . Subretinal macular hemorrhages can be...

Aphakic or Pseudophakic Cystoid Macular Edema

Cystoid Macular Edema Oct

Cystoid macular edema (CME), a common complication of cataract surgery, manifests as leakage of plasma from the perifoveal capillaries, formation of macular cystoid spaces, and marked visual impairment 1, 2 . The disease may or may not resolve spontaneously, and vit-rectomy leads to successful resolution of the edema in some patients with CME. Fluorescein angiograms and OCT images of a patient with typical CME before and after vitrectomy are shown in Fig. 4.4. The fluorescein angiogram (Fig....

Are Complete and Incomplete Cases of CSNB Really Nonprogressive

Long-term follow-up of the corrected visual acuity in patients with complete and incomplete CSNB 24 is shown in Fig. 2.76. For both types of CSNB, most patients do not show significant changes or even slight improvement in their visual acuity during the long follow-up period. This strongly indicates that both types of CSNB are nonprogressive, at least when assessed by visual acuity. The full-field ERGs also show little decrease in amplitude during long-term follow-up an example is shown in Fig....

Occult Macular Dystrophy

Occult macular dystrophy is an unusual, inherited macular dystrophy characterized by progressively decreased visual acuity due to macular dysfunction, but the fundus and fluorescein angiograms are essentially normal. In 1989 we reported three patients in one family with hereditary macular dystrophy without a visible fundus abnormality 1 . Since then we have diagnosed 43 patients (26 men and 17 women) with this disease from 14 families and termed the disorder occult macular dystrophy (occult...

Preface

Soon it will be time for me to retire from my position as professor of ophthalmology in the Department of Ophthalmology, Nagoya University School of Medicine. I have therefore decided to summarize my experience of more than 30 years of studies on the clinical electrophysiology of vision. These studies were performed in our department through the hard work and good ideas of many co-workers, and the chapters of this book cover the rationale and results of our studies. Because excellent textbooks...

Full Field Electroretinograms

The development and advancement of clinical electroretinography (ERG) were the consequence of a better understanding of the cellular origins of the major components of the ERG initially demonstrated by Granit in 1934 1 the progressive improvement of the recording devices, as shown by introduction of the contact lens electrode by several investigators such as Riggs 2 , Karpe 3 , and Burian and Allen 4 and the development of computers for improving the signal-to-noise ratio by averaging...

Focal Macular ERGs

The design and development of the instrument required for recording focal macular ERGs from normal subjects and patients with macular diseases have been major accomplishments in my life. I first took part in the study of focal macular ERGs in 1976 with Tatsuo Hirose in Boston 1 and have continued to refine the various aspects of this technique up to the present. The principle of recording a focal macular ERG includes presenting a small stimulus to the macula and recording the response from the...

Age Related Macular Degeneration

Age-related macular degeneration (AMD) is a chronic degenerative disease that affects primarily the choriocapillaris, Bruch's membrane, and the RPE. It is the most common cause of legal blindness in the United States and Europe, and the incidence of AMD in Japan has been increasing during the past 20 years. AMD is classified into two types dry and exudative. The exudative form, also called disciform macular degeneration, is characterized by the development of choroidal neovascularization, which...

Fundus Findings

The characteristic features of the fundus of patients with XLRS (Fig. 2.31) are schisis in the foveal area (foveoschisis) with either a wheellike configuration with radiating spoke-like striations (Fig. 2.31A) or clearly visible micro-cysts (Fig. 2.31B) an absence of vascular leakage in the macula as seen by fluorescein angiography (Fig. 2.31C) cystic spaces in the macula revealed by OCT (Fig. 2.31D) and peripheral retinoschisis in about 50 of the eyes, often with inner retinal breaks (Fig....

Bests Disease

Knot Tying Cheat Sheet Printable

Best's disease (vitelliform macular dystrophy) is an autosomal dominant, pleomorphic, progressive disease of the RPE with an onset early in life 1 . The unique fundus appearance (Fig. 2.143) is used to classify the stages previtelli-form, vitelliform, pseudohypopyon, vitellirup-tive, and atrophic 2 . The OCT images show a solid substance underneath the RPE in the macula (Fig. 2.143). The visual prognosis is relatively good, and most patients retain reading vision in at least one eye throughout...

Nettleship Falls XLinked Ocular Albinism

Nettleship-Falls ocular albinism is an X-linked recessively inherited retinal disease characterized by reduced visual acuity, translucent irides, congenital nystagmus, photophobia, hypopig-mentation of the fundi, and foveal dysplasia (Fig. 2.49) 1, 2 . Full-field ERGs and EOGs are normal (Fig. 2.50), and focal macular ERGs are moderately reduced because of the foveal dysplasia (Fig. 2.51). Histopathological examination of the retina has revealed evidence of foveomacular dyspla-sia 3 , including...

Central or Peripheral Cone Dystrophy

Progressive Cone Dystrophy

The concept of regional cone dystrophy has been suggested by some clinicians 14 , and these eyes were thought to have central or peripheral cone dystrophy. With central or peripheral cone dystrophy, the central or peripheral cone system is predominantly impaired and the rod system is completely preserved, even in the area where the cone system is impaired. Occult macular dystrophy 5 is an example of a central cone dystrophy and is described later. We have reported that some patients with occult...

Fundus Appearance

Retinal Hypopigmentation

The fundus photographs of patients with complete and incomplete CSNB, which was verified by molecular genetics 10, 11 , are shown in Figs. 2.54 and 2.55. The fundus in both types of CSNB is essentially normal. However, because complete CSNB is often associated with high myopia, most patients with this disorder display the characteristics of a myopic fundus and may show slight temporal pallor of the optic disk and or a tilted disk. Incomplete CSNB has been suggested to be the same clinical...

Luetic Chorioretinitis

Chorioretinitis

Congenital or acquired syphilis can present as pigmentary retinopathy that resembles, in some aspects, advanced retinitis pigmentosa 13 . However, the retinal pigmentary changes are more varied and patchy, and the pigment deposits are in clumps with large patches of black pigment associated with the chorioretinal scars Fig. 3.30 . Interstitial keratitis is often associated with congenital syphilis Fig. 3.30 . The prognosis for vision with congenital luetic choroiditis is better than that with...

Golden Tapetallike Fundus Reflex

The ophthalmoscopic appearance of the fundi of patients with XLRS is either a homogeneous or streaked tapetal-like reflex in the mid-peripheral retina. The appearance has been described as flaking gold, gold-dusted, golden-yellow, grayish white, or yellowish white Fig. 2.31H . The mechanism underlying this reflex remains to be determined. This reflex in the eyes of patients with XLRS closely resembles the color of the fundus of eyes with Oguchi's disease. The abnormal reflex in Oguchi's disease...

Batten Disease

The late infantile and juvenile forms of neuronal ceroid-lipofuscinosis are known as Batten disease 1 . The mode of inheritance of this disease is autosomal recessive. Although many cases of Batten disease have been reported worldwide, only a few patients have been reported to be Japanese 2 , suggesting that the incidence of the disease is lower among the Japanese population. Patients with Batten disease have a lysosomal storage disease that results in the accumulation of insoluble fluorescent...

Idiopathic Epimacular Membranes

Epimacular membranes Fig. 4.13 can be caused by trauma, inflammation, retinal vascular disease, and retinal detachment surgery. We have studied the focal macular ERGs of patients with unilateral idiopathic epimacular membrane IEM to determine how the altered retinal function correlates with visual acuity and OCT images 1, 2 . We found that the changes in the focal macular ERG while the macula was altered and after recovery of the macula closely resemble those seen in the presence of aphakic...

Hereditary Retinal and Allied Diseases

Chorioretinal Atrophy

The diagnostic value of electroretinograms ERGs in the assessment and pathophysiolog-ical changes seen on the ERGs in the presence of hereditary retinal and allied diseases are presented in this section. The focus is on clinical findings in patients, but the chapter also touches briefly on the present status of research, if any, for each disease. Retinitis pigmentosa RP is an inherited rod-cone dystrophy in which the onset of symptoms, rate of progression, severity, and mode of inheritance are...

Fullfield ERGs

It is conceivable that the full-field ERGs may be within the normal limits in cases of simple aphakic or pseudophakic CME without an associated systemic disease such as diabetes. This is true because the abnormal fundus and fluorescein angiographic findings are limited to the macula or within the posterior pole. The full-field ERGs should be normal because the peripheral retina contributes more significantly than the macula to the full-field ERGs. However, our study of full-field ERGs showed...

Cone Dystrophy

Patients with cone dystrophy belong clinically and genetically to a heterogeneous group of patients with inherited retinal dystrophies. They are characterized by widespread degeneration of the cone photoreceptors, leading to impaired central vision, loss of color vision, and photophobia 1, 2 . The disease process is progressive. At the advanced stage, most patients with cone dystrophy also have abnormal sco-topic vision cone-rod dystrophy 2, 3 . Because impairment of the cones is widespread,...

Enhanced SCone Syndrome

Enhanced S-cone syndrome ESCS is a newly identified hereditary retinal disorder with several unique functional properties 1,2 . Initially, this disorder was classified as a type of congenital stationary night blindness, but it was later found that most of the cones in these eyes were the short-wavelength-sensitive cones S-cones 3,4 . The syndrome is caused by mutations in the PNR photoreceptor-specific nuclear receptor gene 5 . The PNR gene is a retinal orphan nuclear receptor that determines...

Mewds Azoor Acute Idiopathic Blind Spot Enlargement Syndrome

Azoor Syndrome

Multiple evanescent white dot syndrome MEWDS 4 , acute zonal outer retinopathy AZOOR 5 , and acute idiopathic blind spot enlargement syndrome 6 have several similar ophthalmological and demographic findings unilateral, blurred vision, multiple paracentral scotomas usually including a temporal scotoma, photopsia, and blind spot enlargement and it affects young women. These symptoms usually develop soon after a flu-like illness. Among these disorders, only MEWDS has ophthalmoscopic abnormalities,...

Macular Pseudohole

A macular pseudohole resembles a full-thickness macular hole in terms of its shape, but the pathophysiology is quite different. The pseudohole is created by spontaneous contraction of an epiretinal membrane surrounding the fovea. The pseudohole is not a retinal hole but a round defect of the epimacular membrane over the fovea. The natural course of a macular pseudohole is generally good, with preservation of near-normal visual acuity 1 . In some cases, however, further contraction of the...

Peripheral Schisis Without Foveoschisis

Retina Schisis

As mentioned above, foveoschisis or nonspecific macular degeneration is always present in patients with XLRS. We have studied one patient who had a peripheral schisis with normal maculas. This 15-year-old boy had visual acuity of 1.0 in both eyes also visual field defects in both eyes. His maternal brother was reported to have poor visual acuity but was not available for examination. A peripheral schisis with inner retinal breaks in the inferior retina was present in both fundi, but...

Retinal and Choroidal Detachment

Retinal detachment is separation of the sensory retina from the retinal pigment epithelium RPE Fig. 3.15 . The ERG cannot be recorded when the retinal detachment is complete. Therefore in cases of rhegmatogenous retinal detachments, the reduction of the ERG amplitude corresponds roughly to the extent of retinal detachment Fig. 3.16 . The EOG is usually quantified by the L D ratio, which reflects not only the function of the RPE but also the photoreceptors and neurons in the middle retinal...

Initial Complaints of Patients

Pictures Retinal Disorders

The chief complaints at the initial visit of our 49 complete CSNB and 41 incomplete CSNB patients are listed in Table 2.1. Most of our patients had an initial complaint of blurred vision. Because of the normal fundus appearance, the correct diagnosis was not easy unless electroretinography was performed. It should be noted that only 1 of the 41 patients with incomplete CSNB complained of night blindness. The absence of a complaint of night blindness is important because if it was not reported...