Fundus Appearance Research Articles

Retinal astrocytic hamartoma and Stargardt's disease: unusual association in a patient with ABCR mutation without phacomatosis

We report the unusual association of a retinal astrocytic hamartoma and Stargardt's disease in a patient with ABCR mutation. A healthy 24-year-old man exhibited the typical fundus appearance of Stargardt's disease in both eyes, associated with a white, well-circumscribed, elevated lesion in the inferotemporal area of the right eye. Molecular genetic examination of the ABCR gene detected three heterozygous missense mutations, described in the literature in association with Stargardt's disease. Optical coherence tomography, fluorangiography, electroretinography and B scan ultrasonography were performed. The clinical findings were consistent with the diagnosis of retinal astrocytic hamartoma. The connection between Stargardt's disease and this tumour has never been previously reported. The astrocytic hamartoma of our patient showed unusual clinical features. This association is probably incidental.

Early Bevacizumab Treatment of Central Retinal Vein Occlusion

To evaluate the change in visual acuity and retinal appearance in patients after early initiation of intravitreal bevacizumab treatment for central retinal vein occlusion (CRVO). Retrospective, interventional case series. Patients with CRVO of fewer than three months' duration receiving intravitreal bevacizumab as primary treatment were evaluated. Patients received an intravitreal 1.25 mg (0.05 ml) bevacizumab injection. Changes in visual acuity, central macular thickness, venous tortuosity and diameter, and optic disk edema were noted. Six eyes of five consecutive patients with CRVO treated with intravitreal bevacizumab injection were reviewed retrospectively. The patients did not have other ocular conditions that could have compromised visual acuity. The mean baseline visual acuity was 20/428 (logarithm of the minimum angle of resolution [logMAR] units, 1.33). The mean follow-up period was 12 months (range, seven to 15 months), and the number of bevacizumab injections ranged from four to 10. The patients showed a statistically significant decrease in optic nerve head swelling, venous tortuosity, and venous diameter, with the largest proportion of change occurring within one month of the first bevacizumab injection. The mean visual acuity at last follow-up was 20/53 (logMAR units, 0.42; P = .035, as compared with baseline). In no patient did collateral vessels at the optic nerve head develop. The patients experienced a dramatic improvement in the visual acuity and clinical fundus appearance, without collateral vessel formation. These findings are difficult to explain with current theories of the pathophysiologic features of CRVO. These findings also suggest early initiation of anti-vascular endothelial growth factor (VEGF) treatment should be studied in a larger trial for CRVO.

ACTA lecture: The retinal pigment epithelium, friend or foe?

Abstract Purpose: To review the physiology and pathophysiology of the retinal pigment epithelium, RPE, with focus on some of the work of myself and my wonderful collaborators and students during the last 20 years. Methods: In vitro studies of RPE preparations from frogs and of cultured human and porcine RPE cells. In vivo studies of experimental surgery in pigs using histopathology, immunohistochemistry and functional testing by multifocal electoretinograhpy. Results: There are active fluid transport mechanisms in the RPE, which are capable of transporting water aganist an osmotic gradient. This has important bearings on the fundus appearance in states of macular oedema.RPE cell physiology is dependent on the surface on which they grow, and the maturity of the cells. Older RPE cells are more stress resistant than younger RPE cells. This has important bearings on studies where cultured RPE cells are used to assess toxicity of substances used in the clinic.In vivo RPE cells are non‐dividing under normal circumstances. Posterior injury to the epithelium induces proliferation of the peripheral, but not the posterior RPE. This indicates that a g zone of putative RPE stem cells might exist in the peripheral retina.The functional consequences of experimental posterior RPE injury can be assessed by multifocal electroretinography Conclusions: The RPE plays an important role in the normal physiology og the outer retina, as well as in the pathogenesis of retinal diseases. The development of animal models of RPE injury increase our understanding of the role of RPE in health and disease.

To see or not to see

Abstract Purpose: “Sighted C3H” mice with a normal Pde6b gene, were compared to wild‐type C3H/HeH mice with the strain‐specific Pde6b(rd1) mutation causing retinal degeneration, BALB/c and C57BL/6 mice. Methods: All mice were screened for morphological and visual alterations by funduscopy, slit lamp biomicroscopy, laser interference biometry, ERG and optokinetic drum. Results: In “sighted C3H” mice the mutated Pde6b(rd1) allele of C3H/HeH mice was replaced by the normal Pde6b allele from BALB/c mice. The presence of the normal Pde6b gene was verified by PCR analysis.Slit lamp biomicroscopy revealed no abnormalities in the anterior segments of the eye in all mice. In the fundus of C3H/HeH (Pde6b‐/‐) mice the typical pigment patches and vessel attenuation caused by the retinal degeneration were observed, while the “sighted C3H” (Pde6b+/+) mice showed a normal fundus appearance, comparable to C57BL/6 mice. The albino BALB/c mice had a red‐shining fundus, due to the lack of pigmentation. Scotopic ERG was performed with our screening setup for mice, where BALB/c and C57BL/6 mice showed good responses with well developed a‐ and b‐waves, while C3H/HeH (Pde6b‐/‐) mice showed no response. Unexpectedly, all “sighted C3H” (Pde6b+/+) mice did not show any b‐wave response in the scotopic ERG, but scored at least once within 6 trials in the optokinetic drum. As expected C3H/HeH (Pde6b‐/‐) mice did not respond to the moving stripes of the optokinetc drum, as did the BALB/c mice. A good response to the rotating drum was obtained from C57BL/6 mice. Conclusions: "Sighted C3H" mice have a normal Pde6b gene and responded to the rotating stripes in the optokinetc drum, but do not have normal vision due to the lack of the b‐wave in the ERG.This work is supported by the NGFN.

Clinical and Functional Findings in Choroideremia Due to Complete Deletion of the CHM Gene

To report the clinical, functional, and in vivo microanatomic characteristics of a family with choroideremia with a deletion of the entire gene that encodes for the Rab escort protein 1 (CHM). We performed clinical examination, flash electroretinography (ERG), light- and dark-adapted perimetry, and optical coherence tomography; reviewed medical records; and obtained the medical history of the proband and 3 other family members. At 4 years of age, the proband had a hypopigmented fundus and retinal pigment epithelium mottling, and dark-adapted ERGs were reduced. Severe retinal pigment epithelium and choriocapillaris atrophy developed by 6 years of age, paralleled by a lesser ERG decline. Optical coherence tomography findings showed normal neural retinas overlying mild changes in the retinal pigment epithelium and thinned neural retina with impaired lamination, yet the neural retina was fairly preserved over retinal pigment epithelium and choriocapillaris atrophy. The carrier mother had diffuse elevation of 650-nm dark-adapted thresholds. Deletion of the CHM gene causes severe choroideremia. Results of serial ERGs and fundus examinations documented progression first of rod and then of cone disease. Fundus appearance deteriorated rapidly, in excess of the severity of the ERG decline. Optical coherence tomography findings explained this observation, at least in part. To our knowledge, this is the earliest clinical, microanatomic, and ERG longitudinal phenotypic documentation in molecularly characterized choroideremia and the first documentation of impaired dark-adapted cone function in carriers. The preservation of the neural retina has mechanistic, prognostic, and therapeutic implications.

Aicardi Syndrome: Follow-Up Investigation of Swedish Children Born in 1975-2002

Aicardi syndrome has been defined by the triad of agenesis of the corpus callosum, early seizure onset and lacunar chorioretinopathy. In a nation-wide survey a total of 18 Swedish cases were found. Fourteen girls were re-examined by one of the authors at the ages of 1-27 years. One was seizure free following epilepsy surgery operation, 13 were drug resistant. Two were on ketogenic diet. Most of the girls had multifocal EEG discharges. All except one were severely disabled with severe mental retardation and total dependency on helpers for activities of daily life. Communication, nutrition, and motor function were severely affected areas. Visual function was difficult to evaluate because of mental retardation and lack of co-operation and varied from severely impaired to normal. In one case the appearance of the ocular fundus was documented to have changed with time. One girl was exceptional and seizure free with mild mental retardation. An update by March 2006 showed that 12/18 patients were still alive, at a median age of 13.5 years (range: 3-31 years). Six had died between the ages of 3-10 years. They had all suffered from intractable epilepsy and belonged to the most disabled group. Surprisingly two had died from malignant brain tumours.

Catch me if you scan: ultrasound diagnosis of ectopic pregnancy

In recent years, ultrasound has become an essential tool in the assessment of women with suspected early pregnancy complications1. A large number of studies has already been published, describing the value of ultrasound in the diagnosis of ectopic pregnancy2,3. So, why write yet another review on this topic? We run a busy Early Pregnancy Unit in the area with the highest prevalence of ectopic pregnancy in the UK, which also receives many referrals from other hospitals of women with an uncertain diagnosis of ectopic pregnancy. The most interesting fact that we have learned over the years is that the majority of women referred with suspected ectopic pregnancies in fact had intrauterine ones that were either missed on ultrasound examination or misinterpreted as ectopics. This may sound surprising to many, as ultrasound diagnosis of intrauterine pregnancy is considered to be relatively simple and accurate. In many cases, ultrasound examination failed to identify a small amount of retained products of conception, due in part to inconsistencies in the sonographic diagnosis of incomplete miscarriage; this is often based on the use of arbitrary cut-off levels for endometrial thickness4. In other cases, however, sonographers were unable to decide whether a visible gestational sac represented an intrauterine or an ectopic pregnancy. In some cases with uncertain diagnosis, women had already received medical treatment with methotrexate prior to referral, leading to the loss of wanted normal intrauterine pregnancies. Another common problem is difficulty in differentiating between the various types of ectopic pregnancy. An accurate differential diagnosis is important in ectopics, as the management often differs depending on the type and exact location of the pregnancy. The purpose of this review is to summarize the sonographic criteria for the diagnosis of both intrauterine and ectopic pregnancies and to describe the principles of differential diagnosis of various types of ectopic pregnancy. We will not cover management of pregnancies of unknown location, as this issue has been covered extensively in recent publications5.

Negative Electroretinogram in the Differential Diagnosis of Malingering of Night Blindness in the Military

We evaluated the value of unusual electroretinogram (ERG) findings (negative ERG, which is selective reduction in the amplitude of the b-wave) in the differential diagnosis of night blindness in the military. We surveyed 3 years of data. Presumptive and final clinical diagnoses before and after negative ERG recordings were evaluated. A total of 495 ERGs were included. The mean age was 22 +/- 2.5 years (range, 20-33 years). Twenty-two patients (4.4%) had negative ERG. Final clinical diagnoses could be made for all except two patients (9%). The diagnoses were congenital stationary night blindness (CSNB) (14 patients), X-linked juvenile retinoschisis (five patients), and muscular dystrophy (one patient). Seven (50%) of 14 patients with CSNB had normal fundal appearance, symptoms of night blindness, and a presumptive clinical diagnosis of malingering before the ERG test. Negative ERG may prevent misdiagnosis of malingering for patients with CSNB with normal fundal appearance in the military.

Glomerulonefritis mesangiocapilar tipo II y degeneración macular

We report a 34-year-old woman with biopsy proven type II mesangiocapillary glomerulonephritis (MCG II) who had an ophthalmic fundal appearance similar to that seen in patients with age-related macular degeneration (ARMD). All patients with MCG II should be reviewed regularly by an ophthalmologist to assess and treat any retinal complications.

Prevalence of Retinitis Pigmentosa in Urban and Rural Adult Chinese: The Beijing Eye Study

To determine the prevalence of retinitis pigmentosa in the elderly Chinese population. The Beijing Eye Study is a population-based, cross-sectional cohort study and included 4439 subjects out of 5324 subjects invited to participate (response rate 83.4%) with an age of 40+ years. Readable fundus photographs were available for 4027 (90.7%) subjects. Diagnostic criteria for retinitis pigmentosa were visual field defects on frequency doubling perimetry, typical ophthalmoscopic abnormalities such as retinal pigment deposits, retinal arteriole attenuation, and pigment epithelial atrophy, and no other reason for perimetric defects and fundus abnormalities. Retinitis pigmentosa was diagnosed in four subjects (all men). Its prevalence was 0.099+/-3.15% (95% CI: 0.00, 0.2). Retinitis pigmentosa with typical fundus appearance and functional loss may be present in about 1 out of 1000 elderly Chinese in Northern China. Calculated for the whole population in China, the figure would be 1.3 million patients with retinitis pigmentosa.

A Novel Homozygous GRK1 Mutation (P391H) in 2 Siblings with Oguchi Disease with Markedly Reduced Cone Responses

The only mutations reported to date in Japanese patients with Oguchi disease, a rare form of stationary night blindness with autosomal recessive transmission, have been in the SAG (arrestin) gene. The objective of this study was to describe the ophthalmic features and a novel mutation in the GRK1 (rhodopsin kinase) gene in 2 Japanese patients with Oguchi disease. Molecular genetic and observational case study. A consanguineous family including 2 siblings with Oguchi disease (a 35-year-old man and a 31-year-old woman). Best-corrected visual acuity (BCVA), fundus examinations, Goldmann perimetry, color vision tests, and full-field electroretinograms (ERGs) were evaluated. Mutation screening of the SAG and GRK1 genes was performed with polymerase chain reaction amplification and direct sequencing. Mutations in the GRK1 gene, BCVA, color vision, fundus photographs, visual fields, and ERG findings. Molecular analysis revealed a novel homozygous missense mutation (p.P391H) in the GRK1 gene in both patients. Proline 391 is not only within the functionally important catalytic domain, but is also a phylogenetically conserved amino acid residue among GRK1 orthologs and homologs. No mutation was found in the SAG gene. The unaffected parents were heterozygous carriers of the mutation. Both patients had night blindness, 1.5 BCVA for each eye, normal color vision, and typical fundus appearance with golden-yellow discoloration. The visual fields were normal in the male sibling. The ERGs showed no rod B waves, reduced standard combined responses, and markedly reduced single-flash cone and 30-Hz flicker responses in both patients. A novel homozygous GRK1 mutation (p.P391H) was found in 2 Japanese siblings with Oguchi disease. Visual function in the 2 patients has not deteriorated with age, indicating that the disease is stationary. This is the first report of any patient with GRK1-associated Oguchi disease with markedly reduced cone responses.

Can we predict which patients are at risk of having an ungradeable digital image for screening for diabetic retinopathy?

We aimed to determine the reasons for, and variables which predicted, ungradeable retinal photographs during screening patients for diabetic retinopathy. Age, duration of diabetes, visual acuity, and HbA1c were recorded. Following dark adaptation, a single 45 degrees nonmydriatic photograph was taken of each fundus. The pupils were then dilated and the photograph repeated. Using slit lamp biomicroscopy, lenticular changes (LOCS III), and fundus appearance were recorded. In ungradeable photographs the fovea could not be visualised in 98% of cases of images from nonmydriatic photography, and in 88% if mydriasis was used. Poor definition in the nonmydriatic image was associated with a subsequent ungradeable mydriatic photograph (P=0.001), however, the positive predictive value was poor (34%). Age, posterior subcapsular cataract, and near vision predicted ungradeable status of nonmydriatic photographs (P<0.001, P=0.004, P=0.006, respectively; regression analysis). Nuclear colour and poor definition of the nonmydriatic photograph predicted ungradeable status of mydriatic photographs (P=0.006 & P=0.001, respectively). Inability to visualise the fovea is the commonest cause of an ungradeable image from digital retinal photography. Age and posterior subcapsular cataract were best predictors of ungradeable status of nonmydriatic fundus photographs. Nuclear colour was the strongest predictor for ungradeable mydriatic photography.

Scleral Buckling With Macular Plombe for Eyes With Myopic Macular Retinoschisis and Retinal Detachment Without Macular Hole

To determine the effectiveness of scleral buckling with a macular plombe in eyes with myopic macular retinoschisis and retinal detachment without a macular hole. A prospective, consecutive interventional case series. Clinical practice at university hospitals. Six eyes of five consecutive patients with myopic macular retinoschisis and retinal detachment without a macular hole. Intervention Procedure: Scleral buckling with a macular plombe. The best-corrected visual acuity (BCVA), ophthalmoscopic appearance of fundus, and optical coherence tomographic images were recorded preoperatively, and at two weeks, at one, three, and six months, and then every three months thereafter. The mean retinal thickness was reduced significantly by the macular plombe (P < .05). The BCVA was improved by 2 lines or more in four eyes (66%), and remained within 2 lines of the preoperative BCVA in two eyes (34%). The complications were subretinal hemorrhage without choroidal neovascularization in one eye, and a progression of choroidal neovascularization with subretinal hemorrhage, which caused a transient visual impairment in one eye. We recommend that macular scleral buckling with a macular plombe be considered for eyes with myopic macular retinoschisis and retinal detachment without a macular hole.

Comparison of Visual Acuity Loss in Patients with Different Stages of Stargardt’s Disease

To investigate a previously reported observation that the presence of diffuse, as compared with localized, fundus flecks is an indicator of a more severe course for visual acuity (VA) loss beyond 20/200 in patients with Stargardt's disease. Retrospective clinic-based cross-sectional study. Four hundred five patients with Stargardt's disease. Visual acuity in 405 patients with Stargardt's disease was analyzed at their initial and most recent visits. The stage of Stargardt's disease and appearance of the macula were recorded. The diagnosis and stage of Stargardt's disease were based on the extent and appearance of fundus flecks. Best-corrected VA, stage of Stargardt's disease, and appearance of the macula at the initial and most recent visits were used in the cross-sectional analysis. At their initial visit, 199 patients were identified as having stage 1 Stargardt's disease, of whom 97.5% maintained 20/200 or better VA in at least one eye. One hundred eighty-five were identified as having stage 2 or stage 2-3 Stargardt's disease combined, of whom 83.2% maintained 20/200 VA or better. Patients with stage 1 were more likely to maintain 20/200 or better VA in at least one eye when compared with patients with stage 2/stage 2-3 Stargardt's disease (chi2(1) = 21.25, P<0.001). Ninety-nine percent of stage 1 patients and 94.1% of stage 2/stage 2-3 patients maintained 20/400 or better VA in at least one eye (chi2(1) = 5.72, P = 0.017). Patients with stage 1 Stargardt's disease exhibiting fundus flecks limited to the posterior pole are more likely to maintain a level of VA at 20/200 or better when compared with patients with stage 2/stage 2-3 disease who have diffuse fundus flecks. Nevertheless, over 80% of the patients with stage 2/stage 2-3 Stargardt's disease still maintained VA of 20/200 or better. Only 5.9% of patients with stage 2/stage 2-3 had VA levels worse than 20/400. In our cohort of patients with Stargardt's disease and diffuse fundus flecks, the majority of patients did not lose VA to a greater extent than those with localized flecks.

The Scotopic Sensitivity Tester‐1 and the detection of early age‐related macular degeneration1

Previous research shows that dark adaptation is a marker of early age-related macular degeneration (ARMD), even when visual acuity remains good. This study evaluates whether a commercially available, off-the-shelf device for measuring dark adaptation, the Scotopic Sensitivity Tester-1 (SST-1), which uses a full-field stimulus, detects early ARMD as defined by fundus appearance. Fundus appearance is the gold standard method for defining the presence of ARMD. Dark adaptation was measured using the SST-1 in 12 young adults (mean age 23 years), 17 old adults with normal retinal health (mean age 69) and 19 old adults with early ARMD (mean age 74). Normal retinal health and presence of early ARMD were defined by masked grading of dilated fundus photographs using the Wisconsin Age-Related Maculopathy Grading System. Older adults in normal retinal health exhibited slower dark adaptation as compared with young adults. No difference in the rate of dark adaptation was found between early ARMD patients and older adults in normal retinal health. Although the SST-1 differentiated between young and older adults, it failed to detect dark adaptation abnormalities in early ARMD when referenced against older adults in normal retinal health. This may be attributable to the full-field stimulation used by the SST-1, which may be better suited for characterizing retinal degenerations affecting large retinal areas than for focal macular diseases like ARMD.

Association Between Severity of Inflammation in CNS and Development of Sunset Glow Fundus in Vogt-Koyanagi-Harada Disease

To investigate the association between central nervous system (CNS) inflammation at disease onset and the appearance of sunset glow fundus (SGF) in Vogt-Koyanagi-Harada (VKH) disease. Retrospective case series. Charts of 102 patients with VKH disease followed from from initial onset were reviewed. The frequency of cerebrospinal fluid (CSF) pleocytosis and the number of cells in the CSF were compared among the patients who eventually developed SGF and the patients who had not developed SGF as of final follow-up. SGF was observed in 69 (67.6%) of 102 patients. The frequency of CSF pleocytosis was 77 (82.7%) of 93 patients examined. The frequency of CSF pleocytosis and the number of cells in CSF were significantly higher in patients who eventually developed SGF (both P = .0029). Severe inflammatory response in CNS sites at disease onset may influence the development of SGF in VKH disease.

Giant congenital melanocytic nevus with neurofibroma‐like changes and spina bifida occulta

A 12‐year‐old Iranian girl presented with a bathing trunk congenital melanocytic nevus. Multiple other pigmented lesions were present. The nevi were distributed over the entire body including the oral mucosa. There were also bilateral, soft, pendulous tumors and nodules in the area covered by the giant congenital melanocytic nevus. The tumors had been present since birth and showed continuous growth during childhood. She was otherwise healthy. Her parents were not consanguineous. There was no family history of similar lesions.Physical examination revealed a large dark‐brown circumferential plaque extending evenly from the upper back and abdomen down to the lumbar region, buttocks, and thighs (Fig. 1). It had a smooth surface, with excessive growth of hair. There were soft, redundant, exuberant folds of skin overhanging the back and buttock, localized to the area covered by the bathing trunk nevus. On palpation, they appeared as deep, multilobulated masses mimicking giant neurofibromas. There were also several smaller dark‐ or skin‐colored, soft, dermal nodules in this area. On other parts of the integument, there were numerous pigmented nevi of different sizes and colors, including speckled nevi, café‐au‐lait spots, and some clinically dysplastic nevi. There was hypertrichosis over some of the nevi. Mucosal examination revealed dark‐brown macules on the hard palate and conjunctiva. General physical examination was otherwise normal. There was no axillary freckling. Ophthalmologic examination was negative for Lisch nodules, and the fundal appearance was normal. Neurological examination revealed no abnormalities. Spinal X‐ray showed spina bifida occulta in the fifth lumbar vertebra. Brain and spinal magnetic resonance imaging (MRI) with gadolinium contrast was performed to detect neurocutaneous melanosis, which was negative. Two deep incisional biopsies were performed of the proliferative nodules over the hips, with the clinical impression of giant neurofibroma. Histologic examination revealed superficial nests of melanocytes with focal involvement of the dermo‐epidermal junction, extending into the dermis (Fig. 2). The melanocytes became spindle shaped within the reticular dermis (Fig. 3). Immunohistochemical techniques showed strong positive staining for both S100 protein and MART‐1 in both the superficial and deep portions of the proliferation, consistent with a melanocytic nevus.Bathing trunk melanocytic nevus with large, pendulous skin lesions mimicking neurofibromas over the buttocks and lower back and multiple other melanocytic nevi of variable size distributed all over the bodyimageHistologic examination of a pendulous pigmented mass reveals nests of melanocytes extending from the superficial into the deep dermis (low power, hematoxylin and eosin)imageThere is focal involvement of the dermo‐epidermal junction; melanocytes become spindle shaped within the reticular dermis (medium power, hematoxylin and eosin)imageAs the pathological examination was consistent with proliferative nodules in a giant congenital melanocytic nevus, excision of the tumors was planned to improve the cosmetic appearance of the patient and to decrease the possibility of malignant transformation via debulking of the melanocytic mass.

Severe combined hyperlipidaemia and retinal lipid infiltration in a patient with Type 2 diabetes mellitus

Severe combined hyperlipidaemia has occasionally been associated with infiltration of tissues in addition to arteries and the skin. We report a woman with Type 2 diabetes mellitus (DM) and severe combined hyperlipidaemia who developed retinal lipid infiltration, resulting in blindness. A 61-year-old woman with a 15-year history of Type 2 DM was admitted following a two-week history of progressive visual loss. Examination identified lipid infiltration into the retina. Phenotypically she had severe combined hyperlipidaemia with elevated IDL cholesterol and a broad beta band on lipoprotein electrophoresis, raising the possibility of familial dysbetalipoproteinaemia. However, gene sequencing analysis indicated that the patient was homozygous for the E3/E3 allele of the ApoE gene with no mutations detected in either the coding region or intron-exon boundaries. Her lipid profile improved following dietary therapy and gemfibrozil treatment, but this had little effect on either her fundal appearances or her visual acuity. Type 2 DM plays a vital role both in allowing expression of severe combined hyperlipoproteinaemia, in addition to serving as a risk factor for complications such as tissue infiltration.

Retinitis pigmentosa, pigmentary retinopathies, and neurologic diseases

Retinitis pigmentosa (RP) refers to a group of inherited retinal diseases with phenotypic and genetic heterogeneity. The pathophysiologic basis of the progressive visual loss in patients with RP is not completely understood but is felt to be due to a primary retinal photoreceptor cell degenerative process mainly affecting the rods of the peripheral retina. In most cases RP is seen in isolation (nonsyndromic), but in some other cases it may be a part of a genetic, metabolic, or neurologic syndrome or disorder. Nyctalopia, or night blindness, is the most common symptom of RP. The classic fundus appearance of RP includes retinal pigment epithelial cell changes resulting in retinal hypo- or hyperpigmentation ("salt-and-pepper"), retinal granularity, and bone spicule formation. The retinal vessels are often narrowed or attenuated and there is a waxy pallor appearance of the optic nerve head. Electroretinography will demonstrate rod and cone photoreceptor cell dysfunction and is a helpful test in the diagnosis and monitoring of patients with RP. A detailed history with pedigree analysis, a complete ocular examination, and the appropriate paraclinical testing should be performed in patients complaining of visual difficulties at night or in dim light. This review discusses the clinical manifestations of RP as well as describing the various systemic diseases, with a special emphasis on neurologic diseases, associated with a pigmentary retinopathy.

Bilateral CRAO and CRVO From Thrombotic Thrombocytopenic Purpura: OCT Findings and Treatment With Triamcinolone Acetonide and Bevacizumab

A patient with thrombotic thrombocytopenic purpura secondary to adult-onset Still's disease presented with bilateral combined central retinal artery occlusion and central retinal vein occlusion, a rare complication reported only once before. Fundus appearance and fluorescein angiography were similar to the previous case. Optical coherence tomography findings demonstrated aspects consistent with both central retinal artery occlusion and central retinal vein occlusion. Treatment of one eye with intravitreal triamcinolone acetonide (4 mg) was not effective in improving visual acuity. Treatment of both eyes with intravitreal bevacizumab (1.25 mg) and panretinal photocoagulation was effective in eliminating iris neovascularization, although the patient lost all visual function.