Seeing into the future. Vision and aging

The leading causes of visual impairment in North Americans are age-related, but appropriate care can preserve useful vision for most older adults. Cataract surgery is highly successful. Early detection and treatment of glaucoma can prevent vision loss. Laser treatment is remarkably effective against diabetic retinopathy. Vision loss due to macular degeneration cannot be delayed in all patients, but low-vision rehabilitation can maximize the usefulness of remaining sight.

Pigmentary retinopathy in long chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency

PURPOSE

To define the ophthalmologic findings in long chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency, an inborn error of mitochondrial beta-oxidation.

METHOD

Case report.

RESULTS

A 5-year-old girl with long chain 3-hydroxyacyl-CoA dehydrogenase deficiency had a bilateral acquired disturbance of the retinal pigment epithelium consisting of a central macular spot and regularly spaced peripheral spots. Central and peripheral vision and dark adaptation appeared to be mildly compromised. Electroretinography showed abnormalities of the cone system.

CONCLUSIONS

An excess of long chain and very long chain fatty acid intermediates has been postulated as the cause of the retinopathy in long chain 3-hydroxyacyl-CoA dehydrogenase deficiency and the biochemically related peroxisomal disorders. Dietary management may slow or halt progression. Ophthalmoscopic detection of regularly spaced pigment spots could help identify long chain 3-hydroxyacyl-CoA dehydrogenase deficiency in future cases.

Facio-oculo-acoustico-renal (FOAR) syndrome: case report and review

We report on an 11-year-old boy with distinct facial anomalies, iris coloboma, iris hypoplasia, cataract, high myopia, retinal detachment, moderate sensorineural hearing loss, and proteinuria. He appears to have the facio-oculo-acoustico-renal (FOAR) syndrome, a rare familial disorder reported only 4 times previously. In contrast to the other patients, he has normal intellect.

Normal and pathological mechanisms in retinal vascular development

Angiogenesis is a complex biologic process that occurs normally in development and in turnover and remodeling of mature vascular networks. Pathological angiogenesis and neovascularization occur in association with retinal and ocular ischemic diseases, in retinopathy of prematurity and other developmental disorders, and in tumor growth and metastasis. We describe current understanding of cellular and molecular mechanisms of retinal vascular development, highlighting aspects that relate to eye diseases, that provide sites of therapeutic intervention in ophthalmology and that are potential avenues for research.

Recommendations for the use of routine bone marrow aspiration and lumbar punctures in the follow-up of patients with retinoblastoma

PURPOSE

Patients with metastatic retinoblastoma have a poor outcome. Hope that early detection of extraocular spread will improve survival has led to routine monitoring with bone marrow and cerebrospinal fluid (CSF) examinations. In light of cost and patient morbidity, the clinical utility of this practice is questioned.

PATIENTS AND METHODS

We have performed 254 serial bone marrow aspirations and 164 lumbar punctures in 60 children with retinoblastoma.

RESULTS

Two patients with extensive intraocular disease at diagnosis developed positive bone marrow aspirations, although no patient died of distant metastasis. Three patients developed positive CSF examinations. All had neurologic symptoms at the time of CSF positivity.

CONCLUSIONS

We recommend performing staging bone marrow and CSF evaluations only in patients with clinical, histologic, or radiologic evidence of local or systemic extension (Pratt stage III-IV), or in patients presenting with one Reese-Ellsworth group V eye and retrolaminar or extrascleral extension of their tumor. We recommend limiting follow-up bone marrow and CSF evaluations to patients who develop objective signs and symptoms of metastatic or regionally recurrent disease.

Visual outcomes of macular retinoblastoma after external beam radiation therapy

PURPOSE

To determine the risk factors that influence the visual outcomes of patients with macular retinoblastoma who are treated with radiation therapy.

METHODS

The medical records of all patients with macular retinoblastoma treated with radiation therapy between 1980 and 1990 were reviewed. Ten patients were entered into the study. Features analyzed included patient age, laterality of eye involvement, location and size of macular tumor(s) at the time of diagnosis, treatment course, and most recent visual acuity.

FINDINGS

Ten of 11 eyes (10 patients) were successfully treated with external beam radiation. Eight patients obtained visual acuities ranging from 20/25 to 20/100; two patients had visual acuities of 20/200 or less. The best visual acuities were noted in patients whose tumor(s) did not involve the fovea and were relatively small. The worse visual acuities were noted in patients with binocular vision whose tumors invaded the fovea and were larger in size. In two of three patients in whom both eyes were retained, superimposed amblyopia developed in the eye with macular retinoblastoma.

CONCLUSION

The authors' findings indicate that most patients with macular retinoblastoma who are treated with external beam radiation have favorable visual outcomes, but final visual acuity depends on the size of the tumor and involvement of the fovea. Patients in whom both eyes are retained are predisposed to further visual loss from amblyopia.

Aging of the human photoreceptor mosaic: evidence for selective vulnerability of rods in central retina

PURPOSE

Because previous studies suggested degeneration and loss of photoreceptors in aged human retina, the spatial density of cones and rods subserving the central 43 degrees of vision as a function of age was determined.

METHODS

Cones and rods were counted in 27 whole mounted retinas from donors aged 27 to 90 years with macroscopically normal fundi. Photoreceptor topography was analyzed with new graphic and statistical techniques.

RESULTS

Changes in cone density throughout this age span showed no consistent relationship to age or retinal location, and the total number of foveal cones was remarkably stable. In contrast, rod density decreased by 30%, beginning inferior to the fovea in midlife and culminating in an annulus of deepest loss at 0.5 to 3 mm eccentricity by the ninth decade. Space vacated by dying rods was filled in by larger rod inner segments, resulting in a similar rod coverage at all ages. At the temporal equator, cone density declined by 23%, but rods were stable throughout adulthood.

CONCLUSIONS

The stability of both rod coverage and rhodopsin content despite decreasing cell number suggests plasticity of the adult rod system and that age-related declines in scotopic sensitivity may be due to postreceptoral factors. There is no evidence for the massive loss of foveal cones required to explain even modest decrements in acuity, consistent with evidence that visual deficits at high photopic levels may be largely due to optical factors. Why the rods of central retina, which share a common support system and light exposure with the neighboring cones, are preferentially vulnerable to aging remains to be determined.

Effects of povidone-iodine chemical preparation and saline irrigation on the perilimbal flora

PURPOSE

To analyze the effects of 5% povidone-iodine preparation and saline irrigation on the species composition of perilimbal flora.

METHODS

Cultures were taken from the perilimbal conjunctiva in 100 eyes before preparation for ophthalmic surgery, after instillation of povidone-iodine solution, and after saline irrigation.

RESULTS

Bacteria were isolated in 75% of eyes before preparation, in 28% after povidone-iodine instillation, and in 24% after saline irrigation. Fifty-one culture-positive eyes became negative with povidone-iodine, while only four culture-negative eyes became culture-positive (P < 0.001). The number of eyes yielding coagulase-negative staphylococci, Staphylococcus aureus, and Propionibacterium were significantly decreased after povidone-iodine instillation. Twenty-three culture-positive eyes became negative after saline irrigation, while 19 culture-negative eyes became culture-positive (P > 0.25).

CONCLUSION

Povidone-iodine solution is effective in reducing bacterial recovery from the perilimbal conjunctiva, where most incisions for intraocular surgery occur. Saline irrigation after povidone-iodine preparation has no significant effect.

An evaluation of saline irrigation and comparison of povidone-iodine and antibiotic in the surface decontamination of donor eyes

We evaluated the effect of saline irrigation on 38 pairs of donor eyes and determined the relative efficacy of antibiotic rinse/storage (neomycin-polymyxin B-gramicidin) and povidone-iodine immersion. Microbial growth was found in 49 (64.5%) of 76 eyes from which cultures were taken before irrigation, and only four (8.2%) became culture negative after irrigation. Of 27 eyes culture negative before irrigation, 15 (55.6%) became positive after irrigation. One eye of each pair was then assigned randomly to antibiotic rinse/storage and the other eye to 3-minute immersion in 1% povidone-iodine. Both antimicrobial treatments decreased the numbers of positive cultures, with povidone-iodine showing an advantage that did not reach significance. These results demonstrate that saline irrigation of donor eyes in situ does not reduce surface contamination and that povidone-iodine immersion should be considered as an alternative for donor eye decontamination.

Computerized tomography fails to show calcification in diffuse retinoblastoma

A suspected diagnosis of retinoblastoma can almost always be supported by intraocular calcification detected by computerized tomography. We report two patients with diffuse unilateral opacification of the ocular media who failed to demonstrate calcification on a CT scan.

Cone dysfunction in a subgroup of patients with autosomal dominant cerebellar ataxia

Four patients with autosomal dominant cerebellar ataxia and retinal degeneration underwent neurologic and ophthalmologic examinations and computer-assessed corneal electroretinography. Previous reports described progressive panretinal degeneration initially involving the cones and subsequently spreading to the rods. By contrast, all our patients displayed evidence of selective dysfunction of the cone system in one or two successive electroretinograms, irrespective of their age or duration of visual symptoms. Color vision testing, funduscopy, and fluorescein angiography suggested a cone dystrophy. Within the period of observation only one patient showed progression of cone dysfunction. In patients with hereditary ataxias, quantitative electroretinography provides an objective and sometimes early indication of retinal degeneration and helps to characterize it.

Human photoreceptor topography

We have measured the spatial density of cones and rods in eight whole-mounted human retinas, obtained from seven individuals between 27 and 44 years of age, and constructed maps of photoreceptor density and between-individual variability. The average human retina contains 4.6 million cones (4.08-5.29 million). Peak foveal cone density averages 199,000 cones/mm2 and is highly variable between individuals (100,000-324,000 cones/mm2). The point of highest density may be found in an area as large as 0.032 deg2. Cone density falls steeply with increasing eccentricity and is an order of magnitude lower 1 mm away from the foveal center. Superimposed on this gradient is a streak of high cone density along the horizontal meridian. At equivalent eccentricities, cone density is 40-45% higher in nasal compared to temporal retina and slightly higher in midperipheral inferior compared to superior retina. Cone density also increases slightly in far nasal retina. The average human retina contains 92 million rods (77.9-107.3 million). In the fovea, the average horizontal diameter of the rod-free zone is 0.350 mm (1.25 degrees). Foveal rod density increases most rapidly superiorly and least rapidly nasally. The highest rod densities are located along an elliptical ring at the eccentricity of the optic disk and extending into nasal retina with the point of highest density typically in superior retina (5/6 eyes). Rod densities decrease by 15-25% where the ring crosses the horizontal meridian. Rod density declines slowly from the rod ring to the far periphery and is highest in nasal and superior retina. Individual variability in photoreceptor density differs with retinal region and is similar for both cones and rods. Variability is highest near the fovea, reaches a minimum in the midperiphery, and then increases with eccentricity to the ora serrata. The total number of foveal cones is similar for eyes with widely varying peak cone density, consistent with the idea that the variability reflects differences in the lateral migration of photoreceptors during development. Two fellow eyes had cone and rod numbers within 8% and similar but not identical photoreceptor topography.

Retinal oxalosis. A clinicopathologic report

A 55-year-old woman with chronic renal failure treated with hemodialysis had severe bilateral visual loss develop due to retinal ischemia. Ophthalmoscopy showed crystals in the distribution of the retinal arteries, but not veins, and this led to a diagnosis of systemic oxalosis. Factors contributing to systemic oxalosis in addition to renal failure were ascorbic acid dietary supplementation, pyridoxine deficiency, and ileal resection. Histopathologic findings showed ocular calcium oxalate deposition limited nearly entirely to the walls of retinal blood vessels.

Increased survival of low birth weight infants: impact on the incidence of retinopathy of prematurity

Retinopathy of prematurity is a retinal vascular disease that occurs only in premature infants. Because of concern that the occurrence of this potentially blinding disease is increasing, a retrospective chart review was undertaken to compare the incidence of retinopathy of prematurity at the University of Washington during the years 1981 to 1984 with previously published data collected at the same institution during the years 1968 to 1980. During 1981 to 1984, there was an increase in the annual numbers of admissions and survivors weighing 1750 g at birth; the survival rate increased significantly (P less than .000001). A trend toward an increased risk for proliferative retinopathy of prematurity (P = .057) during 1981 to 1984 period was noted, but the number of "excess cases" was calculated to be only 6 per year. The remainder of the additional cases, 19 annually, were due to increased survival of infants at risk. Thus, the "second epidemic" of retinopathy of prematurity is largely due to improved survival of low birth weight infants rather than to new iatrogenic factors. In infants with proliferative retinopathy of prematurity, there was a previously unreported association between increased severity of disease and lower birth weight (P = .015). There were four children with severe bilateral visual loss due to retinopathy of prematurity identified during the 1981 to 1984 period, whereas only one bilaterally blind infant was noted during the preceding 12.7 years.

Ocular complications of arteriovenous communications of the retina

Primary arteriovenous communications of the retina (AVCR) are usually considered to be stable retinal lesions. Complications were documented in seven cases of AVCR, including intraretinal macular hemorrhage, central and peripheral retinal vein occlusions, neovascular glaucoma, and vitreous hemorrhage. To explain these developments, a hypothesis is presented that AVCR are associated with localized decreased retinal arterial pressure, increased retinal venous pressure, increased turbulence of blood flow, and decreased perfusion of adjacent retinal tissues.

Acute macular neuroretinopathy following intravenous sympathomimetics

Three young women developed acute macular neuroretinopathy with persistent paracentral scotomas following acute hypertension caused by intravenous sympathomimetics. The temporal relationship of the acute onset of symptoms suggests either acute hypertension or a direct retinal effect of sympathomimetics as the cause of the retinal changes.

Acute retinal pigment epitheliitis

Acute retinal pigment epitheliitis is an infrequently described macular disorder of unknown cause that affects healthy young adults. Acute symptoms include either reduced visual acuity or central scotoma. Ophthalmoscopy discloses discrete pigment clumps with surrounding hypopigmented halos in the center of the macula. Inflammatory signs are mild or absent. The hypopigmented areas show transmission hyperfluorescence without leakage on fluorescein angiography. Symptoms subside spontaneously although retinal pigment epithelial (RPE) changes are usually permanent. Central serous choroidopathy, macular edema, or permanently decreased vision have not developed in any of the eight patients we have followed for up to 8 years. Accurate identification of retinal pigment epitheliitis as a specific clinical entity is important because of the good prognosis without treatment.

Choroidal involvement in systemic necrotizing vasculitis

Wegener's granulomatosis and lymphomatosis are systemic necrotizing vasculitides of unknown cause. We report similar involvement of the choriocapillaris in these two diseases. A presumed choriocapillaritis caused ischemia and infarction of the choriocapillaris-retinal pigment epithelium-outer neurosensory retina complex. Systemic corticosteroid and immunosuppressive agents were successful in controlling systemic disease and preserving useful vision. At the time of this study, one patient had not had a recurrence for 12 years, and the other patient had been asymptomatic for seven years.

Distribution of cones in human and monkey retina: individual variability and radial asymmetry

The distribution of photoreceptors is known for only one complete human retina and for the cardinal meridians only in the macaque monkey retina. Cones can be mapped in computer-reconstructed whole mounts of human and monkey retina. A 2.9-fold range in maximum cone density in the foveas of young adult human eyes may contribute to individual differences in acuity. Cone distribution is radially asymmetrical about the fovea in both species, as previously described for the distribution of retinal ganglion cells and for lines of visual isosensitivity. Cone density was greater in the nasal than in the temporal peripheral retina, and this nasotemporal asymmetry was more pronounced in monkey than in human retina.

Congenital iris cysts

Unilateral, spontaneous, non-pigmented iris cysts appeared before the age of 2 years in four patients. Histopathological specimens obtained in three cases showed stratified to cuboidal, non-pigmented, epithelial lined cysts. Goblet cells were recognised in two of the three specimens. The clinical features and histopathological findings indicate that these cysts are derived from surface ectoderm and may be congenital.

A whole mount method for sequential analysis of photoreceptor and ganglion cell topography in a single retina

Photoreceptors (PR) in human and monkey retina are visible in whole mounts cleared with glycerol or dimethyl sulfoxide and viewed with Nomarski differential interference contrast microscopy. These preparations substantially decrease the large tissue volume changes associated with dehydration and sectioning and reveal many details of PR organization and cytology with great clarity. Tissue may be subsequently stained to reveal ganglion cells so that the topography of both cell types may be studied in the same retina.

CT of acquired hyperopia with choroidal folds

Seven patients with an ophthalmologic diagnosis of acquired hyperopia with choroidal folds were evaluated by high-resolution axial CT of the orbits. Coronal, oblique coronal, and parasagittal reformations were obtained and the thickness of the optic nerve and morphologic appearance of the globes were assessed by measurement and subjective appearance. Flattening of the globe, which caused the globe to assume an ellipsoid shape, was seen in all 11 affected eyes. Mild to moderate optic nerve enlargement was also demonstrated in most patients. In six of 11 affected eyes a visible space was noted between the optic nerve and its sheath, implying expansion of the subarachnoid perineural compartment. These findings were not demonstrated in a control group of five patients scanned in a similar manner. Scans of a phantom revealed no evidence of CT-generated distortion. These findings may help to identify hyperopia with choroidal folds as a benign disease and eventually help to establish its cause.

The natural history and CT appearance of acquired hyperopia with choroidal folds

Seven healthy adults with acquired hyperopic change in refractive error had choroidal folds in affected eyes. High resolution computerized tomographic scanning techniques used to obtain coronal, oblique coronal, and parasagittal reformations revealed flattening of the posterior globes and mild to moderate optic nerve enlargement. In 5 of 11 eyes, a space was noted between the optic nerve and its sheath, implying expansion of the sub-arachnoid perineural compartment. The clinical findings and natural history of this syndrome, based on an average follow-up of 4.5 years, are discussed.

Visual loss from choroidal ischemia

Six patients with visual loss showed decreased perfusion of the choroid during fluorescein angiography. The most commonly associated systemic abnormality in these patients was severe hypertension. Other associated diseases included toxemia of pregnancy, renal failure, systemic lupus erythematosus, disseminated intravascular coagulation, and thrombotic thrombocytopenic purpura. Two patients had permanently decreased vision in one or both eyes whereas the other four regained normal vision. Known anatomic and physiologic differences between the retinal and choroidal vessels explained the pronounced choroidal vascular disturbances in the presence of minimal or no observed retinal vascular abnormalities in these patients.

Progressive inherited retinal arteriolar tortuosity with spontaneous retinal hemorrhages

Tortuosity of the retinal arterioles complicated by spontaneous retinal hemorrhages is inherited as an autosomal dominant trait. Even when hemorrhages involve the fovea, spontaneous clearing with recovery of normal vision is the rule. We have studied members of three families in which arteriolar tortuosity increases with age. Tortuosity increases most dramatically during adolescence and affects small arterioles in the macular area. Retinal hemorrhages in children from two pedigrees led to extensive laboratory investigation because arteriolar tortuosity, later unmistakeable, was not recognized initially. Inherited retinal arteriolar tortuosity may be overlooked easily, particularly in children. Patients with spontaneous retinal hemorrhages and their relatives should be examined for retinal arteriolar tortuosity before being subjected to cardiovascular or hematologic studies.

Contamination of corneal tissue from infected donors

Thirty-two corneas with scleral rims were cultured from the eyes of 17 cadavers that harbored systemic infection at the time of death. Twelve (71%) of 17 cadavers demonstrated corneal contamination from one or both corneas. Eleven (92%) of 12 donors with positive postmortem blood cultures had positive corneal cultures from at least one eye. Six of these 12 had the same organism isolated from both the blood and corneal tissue. Bacterial corneal cultures were negative in the five donors with negative postmortem blood cultures. Control cultures were obtained from 19 eyes of ten donors without evidence of infection at death. Four (21%) of 19 control eyes yielded Staphylococcus epidermidis. There was a significantly higher incidence of corneal contamination in donors who died with systemic infections. Eye banks should continue to screen donors carefully for documented or suspected sepsis in an effort to reduce the incidence of postkeratoplasty infections.

Retinal lesions following long bone fractures

Patients with long bone fractures are at risk for the fat embolism syndrome (FES). Although an estimated 50% of patients with overt FES have retinal abnormalities, the overall incidence of fundus lesions in patients with long bone fractures has not been studied. We examined 100 consecutive patients who had suffered long bone or pelvic fractures in the absence of head, abdominal, or thoracic injury, and who had no other diseases associated with retinopathy. Only one patient had visual symptoms. Cotton-wool spots and retinal hemorrhages were observed in four patients, none of whom were suspected of FES prior to our examination. Subclinical FES may be found by ophthalmoscopy in patients with long bone fractures.

Degenerative retinoschisis with giant outer layer breaks and retinal detachment

Five unusual cases of retinal detachment were caused by giant (more than 90 degrees) posterior breaks in the outer layer of degenerative retinoschisis. All retinas were successfully reattached by a variety of surgical techniques. The two cases managed with scleral buckling required subsequent buckle removal because of macular distortion. Treatment with cryotherapy or laser, together with intraocular air and postoperative positioning, gave better anatomic results.

Fleck retina in Kjellin's syndrome

We examined members of two families with Kjellin's syndrome, an autosomal recessive disorder characterized by spastic paraparesis, dementia, and macular changes. Although the retinal lesions resemble the flecks of fundus flavimaculatus by ophthalmoscopy, they appear distinct from previously reported retinal flecks by fluorescein angiography.

Radiation Retinopathy After Orbital Irradiation for Graves' Ophthalmopathy

Recent reports indicate that orbital irradiation for Graves' ophthalmopathy is sometimes beneficial, particularly for dysthyroid optic neuropathy, and is not associated with serious complications. We are aware, however, of four patients who were found to have radiation retinopathy after orbital irradiation for Grave's ophthalmopathy. All four patients have decreased central acuity, and three of the four are legally blind in one or both eyes. Computer reconstruction of the dosimetry, based on computed tomography and beam profiles, shows that errors in dosage calculations and radiotherapy technique probably account for the radiation retinopathy in three of the four patients. Radiotherapy for Graves' ophthalmopathy should be administered only by competent radiotherapists who are experienced in the treatment of this disease. Similar errors in dosage calculations and treatment techniques may account for other reports of radiation retinopathy after reportedly safe dosages.

Separation of retinoblastoma and esterase D loci in a patient with sporadic retinoblastoma and del(13)(q14.1q22.3)

A chromosome 13 deletion in a patient with sporadic retinoblastoma appears to have separated the loci for retinoblastoma and esterase D. This study indicates that: (1) the retinoblastoma locus is distinct from the esterase D locus; and (2) the linear order of these genes is centromere-esterase D-retinoblastoma.

Clinical-ultrastructural study of a retinal dystrophy

An ultrastructural and cytochemical study was performed on the retina and retinal pigment epithelium of an eye surgically enucleated for choroidal melanoma from an otherwise healthy 31-year-old man. The patient and his identical twin show a retinal dystrophy that, based on clinical appearance, visual fields, amd electrophysiology, is most likely autosomal recessive retinitis pigmentosa. Rod and cone photoreceptors were reduced in numbers and outer segments were virtually absent in the region corresponding to the patient's poorest vision. In the region from approximately 20 degrees to 60 degrees (best field of vision), the outer segments of rods and cones were shortened and disorganized. The retinal pigment epithelium showed reactive changes in areas of most severe photoreceptor pathology, including re-duplication, loss of melanin, increased melanolysosomes, and migration of individual cells into the retina. The acid phosphatase reactivity of both the retinal pigment epithelium and photoreceptor cells appeared normal, as were the photoreceptor cilia and inner layers of the retina. This study thus provides improved ultrastructural documentation of a relatively early case of retinitis pigmentosa that may provide a foundation for further functional studies aimed at elucidation of this enigmatic retinal dystrophy.

Ocular effects following the volcanic eruptions of Mount St Helens

Three hundred thirty-two ophthalmologists examined 1,523 patients with immediate ocular complaints following the 1980 eruptions of Mount St Helens. Loggers working up to 18 months in environments with high concentrations of volcanic ash were compared with a control group of loggers without volcanic ash contact. Although the ash particles acted as ocular foreign bodies, the small particles were apparently well tolerated for the most part, except for acute irritation. Patients with contact lenses or sicca syndrome had the most frequent ocular complaints. To date, no long-term ocular effects have been noted secondary to volcanic ash exposure.

Acute macular neuroretinopathy following adverse reaction to intravenous contrast media

Two young women noted acutely altered vision while suffering an adverse reaction to an intravenous injection of contrast agent for computerized tomography. One patient initially showed swollen maculas with subtle opacification of the parafoveal retina. Deep retinal lesions typical of acute macular neuroretinopathy were present later in both cases. Paracentral scotomas corresponding to the fundus lesions were present in both patients but subsequently improved. The temporal relationship of the onset of symptoms and the retinal abnormalities to the adverse reaction suggests that acute macular neuroretinopathy in these patients was caused either by the adverse reaction or its treatment.

Clinical-ultrastructural study of thioridazine retinopathy

Advanced thioridazine retinopathy was observed clinically and histopathologically in a 61-year-old man with progressive, severe loss of vision who had received thioridazine in high dosages 18 years previously. The ocular fundi showed multiple confluent, nummular areas of hypopigmentation and choroidal atrophy posterior to the equator. Atrophy and disorganization of the photoreceptor outer segments appeared to be the initial degenerative event, followed by loss of the retinal pigment epithelium and choriocapillaris.

Retrolental fibroplasia. Experience over two decades in one institution

We examined 1,849 consecutively admitted premature infants weighing 2000 gm or less at birth for retrolental fibroplasia (RLF). Proliferative RLF was diagnosed frequently in low birth weight infants who were more likely to survive with modern neonatal intensive care. Cicatricial RLF was more likely to result from proliferative RLF and to be more severe in lower birth weight infants, but most affected eyes retained useful vision. Comparison of cases diagnosed over the 20 years of this study suggest that cicatricial RLF in recent years is less likely to result in severe visual disability. Improving survival rates for lower birth weight infants mandate continued surveillance for RLF and study of improved oxygen monitoring techniques.

Epithelial implantation cyst of the iris

Following a penetrating eye injury, a 12-year-old girl presented with an enlarging epithelial cyst of the iris. The cyst was excised completely. Epithelial cysts arise after injury or operation from implantation or ingrowth of corneal or conjunctival epithelium. The cyst wall is composed of corneal or conjunctival epithelium, and the cyst contents may be clear or turbid. While generally more benign than the sheet-like epithelial ingrowth, cysts may lead to visual loss by growth into the visual axis, effects upon the lens, or by causing uveitis and glaucoma. Although excision is the preferred treatment, therapeutic alternatives include photocoagulation and chemical cautery.