Visual acuity losses in pigeons with lesions of the nucleus of Edinger-Westphal that disrupt the adaptive regulation of choroidal blood flow

Choroidal blood flow (ChBF) in birds is regulated by a neural circuit whose components are the retina, the suprachiasmatic nucleus, the medial division of the Edinger-Westphal nucleus (EWM), the ciliary ganglion, and the choriod. We have previously shown that lesions of EWM appear to result in pathological alterations in the retina. To determine whether EWM lesions also lead to altered visual functions, we have examined the effects of EWM lesions on visual acuity in pigeons. Bilateral lesions of EWM were made electrolytically, and visual acuity for high-contrast, square-wave gratings was determined behaviorally about 1 year later and compared to that of a group of pigeons that had received sham lesions of EW about 1 year prior to acuity testing. Because lesions targeting EWM invariably resulted in damage to the adjoining lateral part of the Edinger-Westphal nucleus (EWL), which controls pupillary constriction and accommodation, two additional control groups were studied. In one such control group, bilateral lesions in the area pretectalis (AP), which innervates the pupillary control part of EWL and thereby controls pupillary constriction, were made and the effects on visual acuity determined about 1 year later. In the second such control group, the effects of acute accommodative and pupillary dysfunction on acuity were studied in pigeons made cycloplegic. The accuracy of all lesions was later confirmed histologically. The mean acuities of birds with AP lesions (9.1+/-1.4 cycles/deg) and sham lesions (7.1+/-1.5 cycles/deg) were not significantly different from normal, based on published normative data on pigeons. In contrast, pigeons with lesions that completely destroyed EW bilaterally showed visual acuity (2.7+/-0.1 cycles/deg) that was well below the acuity of the sham and AP-lesion control groups. The acuity of the cycloplegic pigeons (4.8+/-0.3 cycles/deg) and one pigeon with a nearly complete bilateral EWL but a unilateral EWM lesion (6.4 cycles/deg) indicated that only about half of the loss with a bilateral EW lesion could be attributed to accommodative dysfunction. Thus, bilateral destruction of EWM appears to have led to a loss in visual acuity. This conclusion suggests that disruption of adaptive neural regulation of ChBF may impair visual function. Destruction of EWM was, however, associated with damage to the somatic components of the oculomotor and trochlear nuclei. The possibility cannot be excluded that such damage also contributed to the acuity loss.     

Nd:YAG laser removal of pupillary membranes developed after ECCE with PC-IOL implantation

PURPOSE: To define the frequency of development of pupillary membranes after ECCE with PC-IOL implantation, and to remove the pupillary membranes using the Nd:YAG laser. METHODS: From 400 patients who had undergone ECCE and were free from local or systemic illness affecting the blood-ocular barrier, 20 eyes developed pupillary membranes Nd:YAG laser was used to remove these pupillary membranes. RESULTS: The frequency of pupillary membranes was found to be 5% (9.8% in pex eyes and 3.3% to the non-pex eyes). Visual acuity improved in 17 eyes by 2 to 5 Snellen lines. No serious complications were observed, endothelium inclusive. CONCLUSION: Pseudoexfoliation might play a significant role in the development of postoperative pupillary membranes which could be successfully treated with the use of Nd:YAG laser. The safety of the procedure has to be evaluated in relation to the corneal endothelium damage in long-term.     

Sato needling for pupillary membranes

Dense pupillary membranes are resistant to needle-knife incision. Trauma to attached intraocular structures may be produced during discission techniques that stretch the membrane. The Sato discission technique produces membrane stabilization on a fixation needle. This allows controlled incision of the pupillary membrane at a right angle to the direction of the fibers without tension on surrounding structures. The Sato technique is not difficult, and surgical complications are minimal. Using this technique, adequate pupillary openings were produced in 62 of 65 eyes, with an average follow-up of 50 months. Postoperative visual acuity was 6/24 or better in 43 (74%) eyes. No long-term surgical complications were encountered.     

A randomised prospective comparison of operative peripheral iridectomy and Nd:YAG laser iridotomy treatment of acute angle closure glaucoma: 3 year visual acuity and intraocular pressure control outcome

AIM: To compare visual acuity and intraocular pressure outcomes 3 years after treatment of acute angle closure glaucoma (AACG) by operative peripheral iridectomy (PI) or Nd:YAG laser iridotomy (YAG PI). METHODS: A prospective study of consecutive patients presenting to one ophthalmology department with uniocular AACG during a 2 year period. Following informed consent patients were randomised to bilateral PI or bilateral YAG PI. Three years after treatment the mean Snellen visual acuity converted to logMAR scores of the two groups was compared using the unpaired Student's t test. The number of patients with normal intraocular pressure with no further treatment in each group was compared using the chi 2 test with Yates's correction. RESULTS: 21 patients underwent bilateral PI and 27 bilateral YAG PI. Three years after treatment visual acuity was 0.30 (SD 0.28) log MAR units for PI eyes and 0.57 (0.67) logMAR units for YAG PI eyes (p = 0.08, NS). 15 (70.4%) PI eyes and 19 (71.8%) YAG PI eyes had an intraocular pressure less than 21 mm Hg with no further treatment (NS). CONCLUSIONS: There was no significant difference in visual acuity or intraocular pressure control 3 years after treatment of AACG with PI or YAG PI.     

Results of bilateral cataract extraction with posterior chamber intraocular lens implantation in children

OBJECTIVE: A retrospective study was undertaken to evaluate long-term anatomic and visual outcomes in eyes of children who underwent bilateral intraocular lens implantation. DESIGN: The study design was a review of medical records of 24 children operated on for bilateral cataracts and posterior chamber-intraocular lenses. PARTICIPANTS: Twenty-four children operated on for bilateral cataracts by 1 surgeon between February 1980 and February 1995 were studied. INTERVENTION: Cataract extraction with bilateral posterior chamber-intraocular lens implantation was performed. MAIN OUTCOME MEASURES: Best-corrected visual acuity, visual acuity without correction, intraocular pressure, manifest refraction, and any intraoperative or postoperative complications were measured. RESULTS: At last follow-up (mean follow-up, 50.8 months; range, 10-149 months), the intraocular lens was in good position and the intraocular pressure was normal without medication in all eyes. Four years after surgery, 79.2% (19 of 24) of first eyes achieved a best-corrected visual acuity of 20/40 or better compared to 66.7% (16 of 24) of second eyes. No eye had any loss in best-corrected visual acuity. In first eyes of 3- to 8-year olds at the time of surgery, 73.3% (11 of 15) achieved a spherical equivalent within 2 diopters of the intended at 4 years after surgery compared to 80% of second eyes. In the 9- to 18-year-old group, 88.9% (8 of 9) of first eyes and 100% of second eyes achieved a spherical equivalent within 2 diopters of the intended at 4 years after surgery. Intraoperative and postoperative complications were minimal. CONCLUSIONS: Long-term anatomic and visual results have been gratifying in this series of patients with bilateral implants.     

Visual outcomes following lensectomy and vitrectomy for combined anterior and posterior persistent hyperplastic primary vitreous

OBJECTIVE: To determine the visual outcome after surgery for persistent hyperplastic primary vitreous using modern vitreoretinal techniques. DESIGN: Retrospective medical record review during a 5-year period (June 1992 to June 1997). Information recorded for each patient included age, medical history, sex, results of preoperative ocular examination, age at diagnosis, procedure performed, intraoperative and postoperative complications, location and number of sclerotomy sites, type of aphakic rehabilitation, amblyopic therapy given, final visual acuity, and length of follow-up. RESULTS: Fourteen patients who underwent surgical management of combined anterior and posterior persistent hyperplastic primary vitreous were identified. Eleven patients underwent aphakic rehabilitation and aggressive amblyopic therapy consisting of occlusive therapy for several waking hours each day. One additional older patient received aphakic rehabilitation only. Ten eyes (71%) achieved a visual acuity of 20/300 or better, and 8 (57%) obtained a final visual acuity of 20/100 or better. Average length of follow-up was 22 months (range, 4-57 months). Nine patients were fitted with an aphakic soft contact lens, 2 older patients had a posterior chamber intraocular lens placed at the time of vitrectomy, and 1 patient wore aphakic spectacles. CONCLUSIONS: With modern vitreoretinal techniques, aphakic rehabilitation, and aggressive amblyopic therapy, useful vision can be obtained in the majority of patients with combined anterior and posterior persistent hyperplastic primary vitreous.     

Do routine antibiotics after loop diathermy excision reduce morbidity?

AIMS: To determine functional results after unilateral and bilateral cataract surgery in children with different aphakic optical correction. METHODS: In this retrospective study, we evaluated visual acuity and binocular vision in 107 children who underwent cataract surgery during the 10 year period from 1985 to 1995. Aphakia was corrected by an intracapsular intraocular lens (IOL), spectacles or contact lenses. RESULTS: Mean visual acuity was > 20/40 (< 0.3 log MAR) with normal binocular vision in 58 children over 7 months of age operated on for bilateral cataracts. Pseudophakic eyes regained visual acuity > 20/63 (< 0.5 log MAR) more often (90%) than aphakic eyes (46%) (p < 0.001). Binocular vision was also achieved more often after IOL implantation (p < 0.001). Visual outcome of early bilateral cataracts was less satisfactory in children with abnormal foveolar function. For 49 children who had surgery for unilateral cataracts, prognosis was poor when surgery was performed before the age of 7 months. For cataract surgery in older children (> or = 7 months) mean visual acuities were better with IOL implantation (p < 0.05). CONCLUSION: Cataract surgery with unilateral and bilateral IOL implantation can provide a beneficial effect on final visual outcome in children who are operated on before abnormal foveolar function develops.     

Discovery of left-sided superior vena cava during central venous catheterization

PURPOSE: To report a child with the mitochondrial cytopathy of Pearson syndrome and zonular cataract. METHOD: Case report. We describe a 6-year-old boy with Pearson syndrome. RESULTS: At age 3 years, the boy developed secondary strabismus caused by bilateral zonular cataract. Subsequently, he underwent successful bilateral cataract extraction with intraocular lens implantation. Postoperative visual acuity with best correction was RE, 20/25 and LE, 20/40. CONCLUSIONS: Children with Pearson syndrome should be examined ophthalmologically to rule out zonular cataract and possible amblyopia. Mitochondrial cytopathies such as Pearson syndrome should be included in the differential diagnosis of congenital and early juvenile cataract.     

Optic disc pallor: a false localizing sign

A 20-year-old pregnant woman was referred with bilateral mild visual acuity loss and optic disc pallor. Because of profound color vision deficits out of proportion to her acuity loss, an abnormality of the cone photoreceptors was suspected. An electroretinogram confirmed the diagnosis of a cone dystrophy and precluded further costly and invasive testing. Cone dystrophy should be considered in the differential diagnosis of any patient with bilateral, nonrefractive visual loss, especially if color vision is disproportionately affected, even with a normal retinal appearance and no significant family history.     

Vitrectomy for traction macular detachment in diabetic retinopathy

BACKGROUND: A small number of eyes with proliferative diabetic retinopathy develop massive central fibrovascular membranes characterized by vitreoretinal tractions along the arcades and optic disk and retinal traction lines extending through the macula. The aim of our study was first to present the results of vitrectomy for removal of these central membranes and second to determine the correlation between preoperative parameters and postoperative visual outcome. SUBJECTS AND METHODS: We treated 28 eyes with severe central fibrovascular diabetic membranes by a modified bi-manual en bloc excision technique during vitrectomy. Preoperative examination included general status, visual acuity, slit-lamp investigation, binocular funduscopy, ultrasound investigation and visual evoked potentials (VEP). Further, we analyzed intraoperative complications and postoperative anatomic and functional outcomes. RESULTS: The retinas of 27 eyes with central traction retinal detachments were reattached by surgery. With a minimum of 6 months' follow-up, the macula remained attached in 24 eyes, while the retinas were completely attached in 22 eyes. Preoperative visual acuity was defective light perception to 0.1; an increase in visual acuity to maximal 0.1 was seen in 50% of the patients postoperatively. Preoperative visual acuity of light perception was associated with no functional improvement. Preoperative ultrasound investigation gave information about the real anatomic situation of the retina, especially if funduscopy was not possible. The other preoperative parameters could not predict correctly the functional outcome of vitrectomy in diabetics with severe central fibrovascular membranes because of the damage of the optic nerve and the retina. CONCLUSIONS: The high rate of anatomical reattachment after vitrectomy in diabetic eyes with severe central fibrovascular membranes is associated with a slight improvement of function; only preoperative visual acuity of hand motions or better was associated with an improvement of function.     

Psychogenic visual disorders in an abused child: a case report

A 17-yr-old female, classified as retarded educable, was found to have uncorrected visual acuity of 20/800 in both eyes, unimproved by a pinhole disc. A low myopic correction determined objectively did not improve her visual acuity. Tangent-screen studies uncovered neurasthenic spiral fields superimposed on hysterical tubular contractions of both eyes. Investigation uncovered a history of child abuse since infancy. To rule out organic lesions of the oculocalcarine visual pathways, the patient was referred for electrodiagnostic evaluation. Her visual evoked responses were found to be normal. With the use of strong suggestion, her visual fields were brought out to normal limits and her visual acuity with correction was improved to 20/20 in each eye. With the cooperation of her school counselor, the patient was referred for psychiatric evaluation and therapy.     

A clinical analysis of pupillary membrane formation after intraocular lens implantation

In 540 cases having undertaken extracapsular cataract extraction and intraocular lens implantation, a pupillary membrane developed in 76 cases, the rate of occurrence being 14%. Generally, the membrane appears on the fifth post-operative day and corticosteroids are effective in its treatment. After treatment no significant sequela is left and the corrected postoperative visual acuity is not affected. The pathogenesis, treatment and prognosis of the pupillary membrane are briefly discussed in the report.     

Radiotherapy of exudative senile macular degeneration. A prospective controlled study

Despite the successful therapy of subretinal neovascular membranes by laserphotocoagulation there are many problems to be overcome. In the case of subfoveolar neovascularization, photocoagulation leads to a sudden decrease in visual acuity. Recently radiotherapy is considered as an alternative. Complications and effectivity were evaluated in this prospective and randomized trial. The initial results are presented. PATIENTS AND METHODS: There are 76 patients (51 women, 25 men, average age 77.7 +/- 8.6 years) included in the prospective randomized study. All of them show subfoveolar neovascular membranes in FLA and a decrease in visual acuity between 0.05 and 0.5. They were randomly assigned to either the radiotherapy or the control group. Radiotherapy was done within 6 days by 6 x 2 Gy (6 MV photons). The follow-up was at 4 weeks, after 3 months, after 6 months and then every 6 months after the end of radiotherapy. On average the follow-up is at 15.1 months. RESULTS: Concerning age and visual acuity before therapy, the control group and the radiotherapy group were not significantly different. At 4 weeks after radiotherapy, visual acuity was 0.13 +/- 0.46 (LogMAR). After 12 months, visual acuity at a distance was 0.11 +/- 0.30 in the therapy group and 0.09 +/- 0.13 (P = 0.838) in the control group. Patients with a preoperative visual acuity better than 0.2 improved more after radiotherapy. Metamorphopsy improved in 75% of the therapy group. The following complications could be observed: In the control group 3 patients suffered subretinal bleeding, in the radiotherapy group 3 patients, respectively. CONCLUSIONS: At present, the follow-up is too short to recommend radiotherapy as a standard procedure in the case of subfoveolar neovascularization. The results in patients with a better preoperative visual acuity encourage us to continue this study.     

Retinal ganglion cell layer and visual function in a patient with optic disc drusen

BACKGROUND: To correlate the retinal ganglion cell pattern to visual acuity and visual field data in a patient with bilateral optic disc drusen, a quantitative clinicopathological study was carried out. METHODS: Both retinae of a patient with optic drusen were whole-mounted. Retinal ganglion cell counts were made using a sampling scheme covering the whole retina and compared to the findings in 10 normal retinae. Relative ganglion cell reduction in the drusen retinae was correlated to clinical data. RESULTS: The total retinal ganglion cell count was reduced from 1244858+/-98736 in normal retinae to 305319 on the right and 527571 on the left eye with optic disc drusen. Large ganglion cells had a better chance of survival. Parafoveal ganglion cell loss was 57% for the right and 36% for the left eye, while visual acuity was 0.8 and 1.0 respectively. The mean light sensitivity loss increased from the centre (6.2 dB) to paracentral (9.9 dB), mid-peripheral (13.7 dB) and outer peripheral (15.0 dB) retina, while ganglion cell losses were smallest in outer peripheral retina (21.9%), followed by central (53.0%), mid-peripheral (70.9%) and paracentral retina (87.7%). CONCLUSION: These data validate Frisén's theory on central retinal resolution and provide the structural basis for the clinical rule that low visual acuity should not be attributed to disc drusen. Automated light sense perimetry gives an inadequate picture of retinal damage caused by optic disc drusen.     

Neuro-ophthalmology, for the pediatrician

The pediatrician needs to develop some skills in evaluating afferent visual functions and ocular motor abnormalities. He must know some fundamental neuro-ophthalmologic facts to prevent his patients from undergoing unnecessary diagnostic and surgical procedures. In addition, he needs to understand the fundamentals of strabismus and amblyopia, which are briefly considered in this article but are explored thoroughly elsewhere in this issue of PEDIATRIC ANNALS. First, the most common type of nystagmus in children is congenital nystagmus. These children often have a head turn or tilt. Also, it should be remembered that numerous drugs may cause nystagmus. Second, any child with a head turn or tilt must be considered to have some ocular motor abnormality until a complete ophthalmologic evaluation has eliminated this possibility. In addition, before a child is considered to have an isolated sixth-nerve palsy, Duane's retraction syndrome should be looked for. Also, before an inferior oblique palsy is diagnosed, a Brown's tendon sheath syndrome should be considered. Thus, any ocular muscle abnormality deserves an ophthalmologic evaluation. Third, when bilateral swollen optic nerves are noted as an incidental finding, drusen of the optic nerve head should be suspected. A unilateral swollen disk with decreased visual acuity and a Marcus Gunn pupil should bring to mind a papillitis, which is a local inflammatory condition of the optic nerve head. Remember, papilledema is a bilateral condition secondary to increased intracranial pressure with normal vision. Children with papilledema usually have other signs of increased intracranial pressure. If the article has convinced you of only two facts -- that head tilts and turns are usually ocular in origin, and that bilaterally swollen optic nerves in an otherwise asymptomatic child may be optic nerve drusen -- it has accomplished its purpose.     

Impact of cerebral visual impairment on the everyday life of cerebral palsied children

A group of 43 patients suffering from cerebral palsy and cerebral visual impairment was compared with a group of 24 cerebral palsy patients with normal visual acuity, with regard to a functional level in daily life. Four categories were considered: communication, emotional contact, self-care and intelligence. Cerebral visual impairment-cerebral palsy patients scored significantly lower in all categories than cerebral palsy patients with normal visual acuity. In the cerebral visual impairment-cerebral palsy group, there was a higher frequency of tetraplegia compared with the group with normal acuity, but even after this predominance had been excluded, a significant difference remained. When dealing with cerebral palsy patients, occurrence of cerebral visual impairment must be taken into account. By initiating intervention programmes, one can prevent extra handicaps due to the consequences of diminished visual acuity.     

Residual symptoms and signs after untreated acute optic neuritis. A one-year follow-up

PURPOSE: To study the symptoms and signs one year after optic neuritis. METHODS: Seventy population-based untreated patients, (44F, 26M; median age 35 years, range 14-48 years) were eligible for study, but the 11 bilateral cases were excluded. Among 59 patients participating in a one-year follow-up of the visual function, 58 answered a questionnaire. RESULTS: At follow-up 59% of the patients complained of visual impairment, though 49% of these patients had a Snellen visual acuity of 6/9 or better. The affected eyes showed decreased visual acuity in 34%, decreased contrast sensitivity in 63%, an abnormal score in 40% with the Lanthony D-15 desaturated panel, and in 13% with the Ishihara test, prolonged latencies of VEP in 58%, and decreased amplitudes of VEP in 41%. CONCLUSIONS: All tests except for VEP correlated significantly to the degree of perceived visual impairment. Subjective visual complaints and more sensitive tests than visual acuity should be used to evaluate the visual function following optic neuritis.     

Central serous chorioretinopathy. Clinical, fluorescein angiography and demographic aspects

The purpose of this retrospective study was to analyze the demographic characteristics of central serous chorioretinopathy (CSC). METHODS: Findings of 100 consecutive subjects with CSC were evaluated. Clinical and fluorescein angiographic findings, demographic characteristics, and visual acuity were analyzed. RESULTS: The age of the patients ranged from 28 to 68 years with a mean of 43 years. No significant sex differences were found concerning age and other parameters. The highest age peak was in the group of women. The male to female ratio was 5:1. Patients with chronic CSC were significantly older (P = 0.015) than patients with the other angiographic findings. Median visual acuity was 0.5. In 40% bilateral characteristics of CSC were found. Clinical and fluorescein angiographic findings showed no significant correlation with visual acuity. CONCLUSION: The range of age distribution in CSC is wide. In older patients distinguishing CSC from age-related macular degeneration can be difficult.     

Rearranging the deck chairs on the Titanic

BACKGROUND: The aim of the study was to evaluate results of visual acuity and binocularity and complications after cataract surgery with primary capsular bag-fixated IOL implantation in children. MATERIALS AND METHODS: Thirty-three children [mean age (+/- SEM) 6.9 +/- 2.9 years, range 3-12 years] accounting for 43 eyes, were examined before and after surgery (15 traumatic, 19 developmental, and 9 congenital cataracts, of the latter two groups 9 unilateral and 19 bilateral cataracts). RESULTS: All eyes had a best corrected postoperative visual acuity of 0.5 +/- 0.05. The postoperative visual acuity of the traumatic cataracts was 0.6 +/- 0.07, of the developmental cataracts 0.5 +/- 0.07, and of the congenital cataracts 0.2 +/- 0.05. Of the 43 eyes, 17 (40%) showed a best corrected visual acuity of 0.5 or better. There was a positive correlation between morphology (lamellar versus subcapsular opacification) and visual acuity (0.7 +/- 0.07 versus 0.5 +/- 0.05; P < 0.05). Bilateral cataracts had a better postoperative visual acuity than unilateral cataracts (0.7 +/- 0.07 versus 0.2 +/- 0.05 P< 0.001) Stereopis was found postoperatively in 62% of the children. In one eye a capsular bag-fixated IOL implantation was not possible, and so the IOL was inserted in the sulcus. Four children presented with postoperative fibrin formation. Posterior capsule opacification occurred in 19% of the eyes in which a primary posterior capsulotomy had been performed. CONCLUSIONS: The prognosis of visual acuity and the results of stereopsis in children older than 3 years following capsular bag-fixated IOL implantation are very good. Both the intraoperative and postoperative complication rates were low.     

Differential inhibition of human prostaglandin endoperoxide synthase-1 and -2 by nonsteroidal anti-inflammatory drugs

PURPOSE: The authors determined the effect of photocoagulation of drusen on visual acuity and progression to subretinal neovascular membranes (SRNV). METHODS: One of paired eyes was randomized to photocoagulation with other eye to control in 27 patients having symmetrical maculopathy and visual acuities, aged 46 to 81 years (mean, 69.7 years); follow-up 1 to 6 years (mean, 3.2 years). RESULTS: Final visual acuity was improved in treated eye or decreased in control eye in 12 patients, equal in 13 patients, and decreased in treated eye in 2 patients (P < 0.006). Progression to SRNV was less with treatment. CONCLUSION: Laser photocoagulation of confluent soft macular drusen may improve long-term visual prognosis.