Lower Temporal Quadrant Research Articles

Optical coherence tomography in the diagnosis of primery neurodegenerative diseases

AbstractBackgroundThe priority task of the world community of neurologists is the early diagnosis of dementia, which is associated with an increase in life expectancy of the population. Among all dementias, Alzheimer’s disease occupies a leading position. Existing criteria for Alzheimer’s disease do not allow a diagnosis at the stage of predementia. New predictors of cognitive deficits, as such a method, scientists hope for optical coherence tomography.Method90 patients were examined, divided into 3 groups: the first group ‐ patients with Alzheimer’s disease (AD), meeting the NINCDS ADRDA criteria, the second ‐ patients with vascular dementia (VD), meeting the NINDS‐AIREN criteria. According to the criteria, each group of BA and DM consisted of 21 (70%) women and 9 (30%) men, mean age 65 years [61; 67] ∖ 66 [60; 69] years respectively. The third group included patients with open‐angle glaucoma (POAG) ‐ 20 (66.7%) women and 10 (33.3%) men, mean age 70 years [62; 76] years.ResultAccording to the results of OCT in the area of the optic disc, there were no statistically significant differences in the width of the neuroretinal rim between the groups. In the VAD group, the thickness of the peripapillary layer of nerve fibers in the upper and lower temporal quadrants was greater than in the DA and POAG groups. OCT in the macular region revealed a decrease in the thickness of the retina and the inner plexiform layer in the upper and lower quadrant of the peripheral region, as well as a decrease in the thickness of the nerve fibers, the ganglionic layer in the lower quadrant of the peripheral region in the OP and POAG groups compared with the VAD group.ConclusionBased on the data obtained, it can be concluded that in AD, degenerative changes in the retina are observed in the peripheral region, while in VD, the process is more pronounced in the foveal (central) region of the retina. In conclusion, it should be noted that a comprehensive ophthalmological examination can become one of the key and affordable methods for the early diagnosis of BA.

Особенности течения ретиношизиса у пациентов Республики Бурятия

It is known that the formation of retinoschisis occurs at any age, the senile form is more common, with the same probability in men and women. However, data on the nature of retinoschisis and their prevalence in patients over 18 years of age are fragmentary and unsystematic. Material and methods. A retrospective analysis of the occurrence of retinoschisis in patients older than 18 years was carried out. Results. Retinoschisis was diagnosed in 263 patients (372 eyes), which was 1.1 % of the number of examined patients. Group I included patients with uncomplicated retinoschisis, and group II included patients with complicated retinoschisis. In group I, bilateral changes were observed in 35 % of cases, and unilateral changes were observed in 65 %. In group II, bilateral changes were diagnosed in 44.5 % of cases, unilateral – 55.5 %. The distribution by type of ametropia was equal in both groups: 21.5 % of patients had myopia and emmetropia, in 57 % of cases – hypermetropia. According to the location in both groups, retinoschisis was diagnosed more often in the lower temporal quadrant in 58 % of cases. Conclusion. Retinoschisis is almost 2 times more common in female patients, mainly with hypermetropia and at the age of 50–70 years. In all types of ametropia, retinoschisis was localized in the lower temporal quadrant in 58 % of cases. Keywords: retinoschisis, retinal detachment, retinal hole, laser coagulation

Tuberculous scleritis

Tuberculosis is a multifaceted disease, it is called the great imitator because it can take many appearances, especially in the eye. Ocular manifestations in tuberculosis are rare, since they are observed in only 1 to 2% of cases. It can accompany the general manifestations of the disease or be isolated. We report a case of a 64-year-old patient, who consulted the emergency room for the impaired general condition with fever. The onset of symptoms dates back to two months, marked by the appearance of a pulmonary infection on day 7 after surgery for the anal abscess put on antibiotic therapy without improvement. Clinical examination found asthenia, anorexia, weight loss of 12 kg in 2 months with fever at 41 °C and headache. The pleuro-pulmonary examination and for tuberculin were positive. An ophthalmological opinion was requested following a painful red eye reported by the patient. The ophthalmological examination found on inspection a red scleral nodule of the prelimbic right eye richly vascularized in the lower temporal quadrant, more or less painful (A, C, E). Visual acuity is 10/10 in both eyes and slit-lamp examination shows slight conjunctival hyperemia, a richly vascularized scleral nodule per limbic inferior temporal, fixed on the deep planes. The rest of the ophthalmologic examination is unremarkable. When pulmonary tuberculosis was confirmed, anti-tuberculosis treatment was instituted. Evolusion on d-15 is marked by a good evolution on the general plan and on the plan ophthalmologic with regression of inflammatory signs with almost disappearance of the scleral noduleand persistence of a small conjunctival uplift next to the lesion (B, D, F).

Clinical Features of Iris Cysts in Long-Term Follow-Up.

This study evaluated the characteristics and clinical course of patients with iris cysts in the long-term follow-up (24–48 months). We retrospectively analyzed the medical records of 39 patients with iris cysts (27 women and 12 men). Age, visual acuity, intraocular pressure (IOP), slit-lamp evaluation, and ultrasound biomicroscopy images were assessed. The mean age at diagnosis was 40.6 ± 17.48 years. Thirty (76.9%) cysts were peripheral, five (12.8%) were located at the pupillary margin, two (5.1%) were midzonal, and two (5.1%) were multichamber cysts extending from the periphery to the pupillary margin. A total of 23 (59%) cysts were in the lower temporal quadrant, 11 (28.2%) were in the lower nasal quadrant, and 5 (12.8%) were in the upper nasal quadrant. Cyst size was positively correlated with patient age (rs = 0.38, p = 0.003) and negatively correlated with visual acuity (rs = −0.42, p = 0.014). Cyst growth was not observed. The only complication was an increase in IOP in three (7.7%) patients with multiple cysts. The anatomical location of the cysts cannot differentiate them from solid tumors. The vast majority of cysts are asymptomatic, do not increase in size, and do not require treatment during long-term follow-up.

Structural Characterization of Glaucoma Patients with Low Ocular Blood Flow

ABSTRACT Purpose: There is an unclear relationship between ocular blood flow (OBF) and the structural characteristics of the optic nerve head (ONH) in glaucoma, a multifactorial disease. This study used laser speckle flowgraphy (LSFG) to identify low-OBF glaucoma patients and investigated the ONH in these patients. Materials and Methods: In 533 eyes with glaucoma, we determined confounding factors for LSFG-measured OBF (tissue-area mean blur rate: MT) and corrected MT with a linear mixed-effects model (LMM). Structural ONH data (from fundus stereo photography), OCT data, and clinical characteristics were then compared in patients with corrected MT in the upper and lower quartiles using the LMM. Results: Single regression showed significant correlations between MT and age, spherical equivalent (SE), central corneal thickness (CCT), and a weighted count of retinal ganglion cells (wRGC), but not axial length or systemic blood pressure. Gender also significantly influenced MT; MT was corrected for these correlated factors and also glaucoma type with the LMM. The lower-quartile MT group had a significantly larger cup area and cup-disc area ratio and lower temporal quadrant circumpapillary retinal nerve fiber layer thickness (cpRNFLT) and macular ganglion cell complex (GCC) than the upper-quartile group. Conclusions: Low-OBF glaucoma patients were characterized by a larger cup-disc ratio, and higher susceptibility to damage in the temporal disc and the macular area.

Regional Patterns of Retinal Oxygen Saturation and Microvascular Hemodynamic Parameters Preceding Retinopathy in Patients With Type II Diabetes.

Alterations in retinal oxygen metabolism and retinal microcirculation are signs of impending diabetic retinopathy (DR). However, if specific retinal regions are primarily affected is so far unknown. The purpose of this study was to investigate if retinal oxygen saturation (SO2) and microvascular hemodynamic parameters follow a distinct regional pattern in patients with diabetes but no DR. Patients with type II diabetes without clinically apparent DR were imaged as follows: SO2 in peripapillary vessels was assessed with dual-wavelength oximetry. Optical coherence tomography angiography (OCTA) scans were acquired with a prototype system using a swept-source laser with an effective 400 kHz A-scan rate and 16° field of view. Regional flow indices termed "flux" were calculated for the peripapillary microvasculature. Parafoveal capillary density was evaluated with the commercially available AngioVue OCTA. Twenty-nine eyes of 16 consecutive patients (59 ± 10 years, 6 females) were included in this study. SO2 differed significantly between quadrants (P < 0.001), with a decreasing pattern from the upper nasal through the lower nasal, the upper temporal and the lower temporal quadrant in arterioles and venules. In contrast, peripapillary flux followed an increasing trend from nasally to temporally. Peripapillary and parafoveal microvascular hemodynamic parameters demonstrated no significant regional variability as observed for retinal oxygenation. Metabolic imaging identified regional differences in retinal SO2 without an associated topographic variance in microvascular hemodynamics in type II diabetes without DR. Future studies should focus on the mechanisms causing this heterogeneity in metabolic demand.

Pseudoexfoliation syndrome and episcleral venous pressure

Introduction. Pseudoexfoliation syndrome (PEX) is a relatively widespread generalized age-related disease, in which abnormal fibrillar extracellular material is produced and accumulates in many tissues including vessels. Glaucoma occurs more commonly in eyes with PEX than in those without it. Episcleral venous pressure (EVP) is an important determinant of intraocular pressure (IOP). It seems reasonable to evaluate episcleral venous pressure in patients with PEX. Purpose. To evaluate episcleral venous pressure in patients with PEX. Methods. 540 eyes of 270 patients were enrolled in the prospective study. We evaluated episcleral venous pressure. Results. EVP in total vein compression in lower-nasal quadrant (mmHg) in main group(with PEX) was 14.0±3.29, in control group No. 1 (non PEX, adults) - 14.38±3.77, in control group No. 2 (non PEX, young) - 10.91±2.34. EVP in total vein compression in lower-temporal quadrant (mmHg) in main group was 15.1±3.31, in control group No. 1 - 15.76±3.45, in control group No. 2 - 11.00±2.16. Difference in episcleral venous pressure between main group and age-matched control group No. 1 was not significant, and between main group and control group No. 2 was significant. Conclusion. EVP level is not influenced by PEX, but is influenced by age.

Transient cortical blindness after spinal surgery as initial presenting sign of hereditary thrombophilia

Sir, Cortical blindness is a rare complication of spine surgery,[1] and is followed by a period of recovery due to resolution of inflammation and edema around the lesion and to the re-activation of partially damaged perilesional tissue.[2,3] Bilateral occipital abnormalities caused by hypotension, ischemia and infarction are associated with poor prognosis. Herein, we report complete recovery of a case with cortical blindness, despite having an ischemic infarct. A 33-year-old female patient who was otherwise healthy underwent uneventful simple discectomy operation. In the immediate postoperative period, she had a syncopal attack and was hypotensive for 5-6 min. After emergency aid, she regained consciousness and complained that she could not see. On neurologic examination, both pupils were isocoric and equally reactive to light and accomodation. There was perception of hand motion. Fundoscopic examination was normal. Cranial magnetic resonance imaging (MRI) revealed hypodense areas involving the occipital lobes bilaterally [Figs. ​[Figs.1,1, ​,2a2a and ​andb].b]. D-dimer test was positive. Deep vein thrombosis in the right popliteal vein was detected ultrasonographically. In spiral computerized tomography (CT) of the thorax scan, there were patchy consolidation areas. Her electrocardiogram showed sinusal tachycardia with an incomplete right bundle-branch block. There were moderate tricuspid insufficiency and mild pulmonary hypertension echocardiographically. She was diagnosed to have massive pulmonary embolism and cortical blindness, and was admitted to the intensive care unit. Treatment was started with continuous intravenous heparin infusion. The patient's vision gradually began to improve within 24 h. Radiological cure with normal thoracal CT was seen on the seventh day. Her vision restored to its preoperative level on the 25th day. After 2 months, there were relative deficits in the right lower temporal quadrant and in the left lower hemifield in visual field examination. Contrast sensitivity evaluation showed losses at high frequencies in the right eye and at all spatial frequencies in the left eye. Color vision assessment revealed low pattern discrimination. For excluding any prothrombotic state, a haemotologic evaluation revealed heterozigousity for factor V Leiden R506Q, protrombin G20210A and MTHFRC677T. Anticoagulant therapy was initiated. In the 3rd year follow-up of the patient, near-complete regression of the infarct area was found in the MRI and improvement of visual field defects was observed [Fig. 3]. Color vision was near-perfect in both eyes. Contrast sensitivity was slightly improved. Figure 1 Diffusion-weighted image showing diffusion restriction compatible with the acute infarct involving the striate and extrastriate cortex (arrows) Figure 2 (a and b) Axial T2-weighted images showing hyperintense areas compatible with the acute infarct involving the striate and extrastriate cortex (arrows) Figure 3 Axial T2-weighted control image showing near-complete regression. There is an encephalomalasic area in the anterior part of the right occipital lobe Visual impairment in cortical blindness is highly variable, and deficits between the hemifields may be different.[4] In our patient, the infarct area was mainly in the cuneus, and corresponding visual field defects were in the lower hemifields. Besides, infarct area comprised both striate and extra-striate visual cortex initially and corresponding abnormalities in color vision and contrast sensitivity recovered with regression of the infarct area. Occipital lobe infarcts were reported to be frequently associated with a prothrombotic state, and were seen more frequently in younger patients and in patients of the female sex.[5] In young patients with cortical blindness, screening for thrombophilia should be made. Because visual loss may be reversible with initiation of immediate anticoagulation therapy, awareness, evaluation and prompt management of this rare complication is critical.

Do microvascular retinal changes improve cardiovascular risk estimation?

Do microvascular retinal changes improve cardiovascular risk estimation?

Surgical Management of Congenital Pupillary-Iris-Lens Membrane

To describe the surgical interventions in congenital pupillary-iris-lens membrane. Six patients with congenital pupillary-iris-lens membrane presented with partial or totally occluded pupils, or increased intraocular pressure (IOP). We describe the value of creating 2 paracenteses. The first one is made in the lower temporal quadrant and accommodates a 20-gauge anterior chamber maintainer (ACM). The second paracentesis is made in an upper quadrant and serves to cut the membrane with a vitrectomy probe. The technique was performed in 6 eyes of 6 children aged 4 to 10 months from March 2007 to July 2008 at Southwest Eye Hospital. These patients had congenital pupillary-iris-lens membrane with partial or totally occluded pupils, or increased IOP due to iris bombe or angle closure. No secondary glaucoma has been detected in the follow-up period. The visual acuity before the operations was less than 0.05 with preferential looking (PL), while the visual acuity was improved to 0.5 in 4 out of 6 eyes and 0.3 in 2 eyes in the last follow-up. The ACM and vitrectomy probe are important tools in the surgical management of congenital pupillary-iris-lens membrane because they facilitate the surgical procedure and reduce iatrogenic damage to the lens. Timely surgical intervention can abort the progressive pupillary occlusion or angle closure glaucoma.

Cataract frequency and light scattering profiles in retired members of light protected communities ‐ The Irish Nun Eye Study (INES)

Abstract Purpose Investigation of cataract frequencies, yellow discoloration and light scattering profiles in the lenses of a subset of nuns from the Irish Nun Eye Study (INES) correlated to age and outdoor activity. Methods After obtaining informed consent, the anterior eye segment of 144 retired nuns from contemplative and missionary convents in Northern Ireland and the Republic of Ireland were monitored with a Scheimpflug camera (Pentacam HR®, Oculus, Wetzlar, Germany). Images of the cornea and lens were recorded automatically in 25 meridians in mydriasis, using the recording algorithm of the camera. In addition retro‐images of the lenses were recorded using the Neitz Cataract screener and lens discoloration was recorded using a manual slitlamp and the LOCS III grading system. Image analysis was performed using special analytical software (BIOM®) and cataract classification was done using the Bonn cataract classification system. Results Age‐related light scattering increase is most pronounced in the anterior deep cortex and the anterior nuclear shell of the lenses and is generally lowest in the posterior nuclear shell. Cortical cataracts were the most frequent type in this study, the highest frequency found in the lower nasal quadrant followed by the lower temporal quadrant. Pure subcapsular cataracts have not been found in this study. The increase in yellow discoloration correlated to the increase in nuclear light scattering. Nuns with cortical cataracts had less discoloration, but were also younger. Conclusion The frequency of nuclear cataracts was lower in the INES cohort was lower, but the amount of cortical cataracts was similar to other studies like Beaver Dam Eye Study. The increases in nuclear light scattering and discoloration correlated with age and exposure index. The data from the INES study support the hypothesis that light protection has a positive effect on the frequencies of nuclear and subcapsular cataracts as well as on lens discoloration. The Pentacam HR® provided better documentation of lens transmission characteristics than the Neitz cataract scanner.

Desprendimiento hemorrágico de la membrana de Descemet tras viscocanalostomía

Introduction Viscocanalostomy is an option in the surgical treatment of glaucoma. This non-penetrating technique favours aqueous drainage through the Schlemm channel while avoiding filtering blebs and their related pathologies. Complications associated to this surgery are unusual, one of which is Decemet's membrane detachment (DMD). Clinical case A 64 year-old female diagnosed with open-angle chronic glaucoma, whose had undergone a viscocanalostomy of the left eye. In the immediate postoperative period we noticed a hemorrhagic DMD in the lower temporal quadrant. After adopting a wait and see attitude, we did not find improvement 15 days after surgery and corneal edema was established with vision decrease. We proceeded to a surgical reapplication by means of Descemet's membrane micropuncture and SF6 injection into the anterior chamber and achieving an anatomical and functional improvement. Discussion We believe that the intrusion of viscoelastic material into the supradescemetic was a consequence of the high-pressure during the high-density hyaluronate injection. Hemorrhagic DMD management is mainly determined by its location, size and evolution. In our case, the posterior endothelial micropuncture and descematopexy by means of 20% SF6 injection into the anterior chamber was useful in resolving this complication.

Hemorrhagic Descemet's membrane detachment after viscocanalostomy

IntroductionViscocanalostomy is an option in the surgical treatment of glaucoma. This non-penetrating technique favours aqueous drainage through the Schlemm channel while avoiding filtering blebs and their related pathologies. Complications associated to this surgery are unusual, one of which is Decemet's membrane detachment (DMD) Clinical caseA 64 year-old female diagnosed with open-angle chronic glaucoma, whose had undergone a viscocanalostomy of the left eye. In the immediate postoperative period we noticed a hemorrhagic DMD in the lower temporal quadrant. After adopting a wait and see attitude, we did not find improvement 15 days after surgery and corneal edema was established with vision decrease. We proceeded to a surgical reapplication by means of Descemet's membrane micropuncture and SF6 injection into the anterior chamber and achieving an anatomical and functional improvement DiscussionWe believe that the intrusion of viscoelastic material into the supradescemetic was a consequence of the high-pressure during the high-density hyaluronate injection. Hemorrhagic DMD management is mainly determined by its location, size and evolution. In our case, the posterior endothelial micropuncture and descematopexy by means of 20% SF6 injection into the anterior chamber was useful in resolving this complication

Use of an anterior chamber maintainer in the surgical management of traumatic hyphaemas

Surgical intervention in traumatic hyphaemas becomes necessary when high intraocular pressure (IOP) is intractable and there is persistent corneal staining. Anterior chamber (AC) washout and elimination of blood clots have been described previously using one paracentesis. We describe the value of creating two paracenteses. The first one is made in the lower temporal quadrant and accommodates a 20-gauge anterior chamber maintainer (ACM) that is connected to a bottle of Balanced Salt Solution. The second paracentesis is made in an upper quadrant and serves to evacuate liquefied blood and blood clots. With an ACM in place, the fluctuations of intraoperative IOP are minimized and the AC depth is stabilized throughout the operation. The risk of renewed bleeding is reduced because of the continuous positive intraoperative IOP. The ACM is an important tool in the surgical management of traumatic hyphaemas because it facilitates AC washout and reduces iatrogenic damage to the iris and corneal endothelium.

Long-term fluctuation of retinal sensitivity during pregnancy

Background: We investigated the effect of pregnancy on the long-term fluctuation of retinal sensitivity in healthy women. Methods: Candidates for the study were healthy women who were likely to become pregnant. A complete ocular examination of both eyes was performed in 41 women, and 1 eye each was chosen at random for the study.This initial examination included 2 sets of visual field measurements consisting of 5 individual measures done at least a day apart. After pregnancy, ocular examinations were repeated once between 10 and 15 weeks of gestation and once between 29 and 34 weeks. The mean threshold sensitivity (MS) of the visual field and the coefficient of variation of MS measurements for upper temporal, upper nasal, lower temporal, and lower nasal quadrants were calculated in each series. Results: The visual field MS of the subjects increased significantly in the third trimester ( p < 0.01).The coefficient of variation of the visual field MS measurements did not change significantly in the nasal quadrants. However, it decreased significantly in both upper and lower temporal quadrants. Interpretation: Visual field MS and the reproducibility of MS measurements for temporal visual field increased significantly in the third trimester of the pregnancy. Further studies on the role of pregnancy-related ocular hemodynamic changes may provide insight into the etiopathogenesis of hormone-related processes.

Número, tipo e topografia dos pontos de vazamento em pacientes com coriorretinopatia serosa central

To evaluate the number, shape and topography of leakage points in patients with central serous chorioretinopathy (CSC). Digital photographic files of fluorescein angiography with the diagnosis of CSC were reviewed by the author. The cases considered in remission and the examinations related to the same episode were excluded. The author filled out a form containing medical record number, initials, sex, age, date of the examination and leakage point characteristics (number, shape, and topography) of the selected cases. The examinations of 418 patients (455 eyes) were included, with a male:female ratio of 2.32:1. Ninety-one point fifteen percent of the patients presented the disease unilaterally and 8.85% bilaterally. The mean age was 43.04 years (range, 19-68 years). Among the 455 selected eyes, 88.35% presented typical forms of CSC while 10.11% decompensation of the retinal pigment epithelium and 1.54% with isolated retinal pigment epithelium (RPE) detachment. The evaluation of typical forms of CSC showed a leakage point with uniform dye spread (inkblot) in 88.81% and 11.19% with a smoke-stack phenomenon. Regarding the leakage points, 46.01% were located in the upper nasal quadrant, 23.27% in the upper temporal quadrant, 19.18% in the lower nasal quadrant, 11.01% in the lower temporal quadrant and 0.53% in the subfoveal area. In our series men were affected approximately two times more often then women, most of them with a unilateral involvement and in around the fourth decade of life. About 90% of the patients presented the typical forms, with 1 or 2 inkblot points or leakage. The superior nasal quadrant was the most affected. The isolated RPE detachment rarely occurred. Decompensation of RPE affected about 10% of the patients.

Les décollements de rétine post contusifs: Étude rétrospective à propos de 48 cas

Analysis of the epidemiological, clinical and therapeutic characteristics of retinal detachment after ocular blunt trauma. We retrospectively reviewed 48 patients with isolated retinal detachment after ocular blunt trauma, studying their epidemiological characteristics (age, sex and trauma circumstances), their clinic details and the surgical techniques used. The average age of our patients was 39.3 Years; most were male (75%). Assault and home accidents were the most common cause of ocular trauma (83.2%). Total retinal detachment was noted in 47.9%. Of the retinal breaks found, dialysis at the ora serrata was observed in 22%, atrophic holes in 33.9%, retinal breaks in 40.6% and giant tears in 4.2%. Most of the breaks were situated at the lower temporal quadrant. Forty one out of the 48 patients were operated on, with surgical treatment consisting in episcleral surgery in 38 cases and vitreoretinal surgery in three cases. Complete anatomical success was achieved in 92.7%. This survey shows that the prognosis of retinal detachment after ocular blunt trauma remains favorable given the young age and the absence of advanced vitreoretinal proliferation, but this should not affect the importance of prevention.

Strabismus as a Complication of “Cuba Therapy” for Retinitis Pigmentosa

Purpose:We studied a case of instant consecutive strabismus in a patient who had undergone “Cuba Therapy” for Retinitis Pigmentosa (RP).Method:We compared the pre- and postoperative orthoptic examinations of a patient complaining of diplopia immediately after she underwent orbital surgery in Havana.Results:A previous small exophoria without diplopia changed into a left exotropia of 20D with constant heteronymous diplopia. Strabismus surgery revealed limited adduction caused by an orbital pedicle flap in the lower temporal quadrant of the left eye. The patient did not regain binocular single vision after corrective orbital and strabismus surgery.Conclusion:This case demonstrates an irreversible strabismus complication after the controversial “Cuba Therapy”.

Microanatomy of the dopaminergic system in the rainbow trout retina

We have investigated the morphology of dopaminergic interplexiform cells as well as the distribution of two classes of dopamine receptors in the retina of the rainbow trout. Interplexiform cells were visualized using an antiserum against tyrosine hydroxylase and PAP immunocytochemistry. In whole amounts, these cells have a density of between 91 and 182 cells per mm2 with highest values in the lower temporal quadrant. Their cell bodies lie at the inner margin of the inner nuclear layer with only 12-17 cells per retina displaced to the ganglion cell layer. There are three levels of stratification in the inner plexiform layer, one at the distal and proximal borders respectively, and one in the middle. They arise mostly from a radially oriented, stout primary dendrite. Tangential processes are about 1 micron in diameter and show a number of varicosities. The density of processes is greatest in sublayer 5, but no major difference in the general organization is apparent between the three sublayers. In the outer retina, there are two levels of dense ramification confined to the layer of horizontal cells. Light and electron microscopic analysis shows synaptic input to horizontal cells, but not to photoreceptors. The distribution of D1 receptors was assessed by studying the binding pattern of a specific, fluorescent-labelled antagonist, SCH 23390, in unfixed frozen sections. We found displaceable binding in the inner and outer plexiform layers and in the region of horizontal cell perikarya. We used an anti-peptide antibody directed to an extracellular domain of the rat D2 receptor and a fluorescent secondary antiserum to study the localization of D2 receptors. In addition to marked label in both plexiform layers, the outer, and especially the inner segments of rods and cones show specific immunoreactivity. In addition, there is distinct label at the level of the horizontal cell bodies; in the inner retina, specific fluorescence is found in somata of some amacrine cells. The significance of the connectivity pattern and the distribution of the two receptor types is discussed with respect to the role of dopamine in controlling adaptational processes in the outer retina, such as retinomotor movements and changes in horizontal cell morphology and physiology.

Traumatic retinal detachment.

Seventy-seven patients developed retinal breaks following an episode of ocular contusion, and 65 (84.4%) of these developed rhegmatogenous retinal detachment. Surgical treatment successfully restored or maintained retinal apposition in 74 (96.1%) of the eyes. Thirty-six (46.8%) eyes recovered visual acuity of 6/9 or better. Of the retinal breaks recognised dialysis at the ora serrata was observed in 49 eyes, of which 28 were situated at the lower temporal quadrant. Seventeen eyes had irregular breaks arising within necrotic retina at the site of scleral impact. Twenty-four (31.2%) patients had retinal break or retinal detachment diagnosed within 24 hours of injury and 49 (63.6%) within six weeks. Immediate retinal detachment was a feature of necrotic retinal breaks, while inferior oral dialyses led to a slow accumulation of subretinal fluid. Delayed diagnosis of retinal detachment was due either to opaque media or to failure to examine the retina after injury. Visual prognosis was good when retinal break or detachment were diagnosed within six weeks of injury. However, those patients who escaped initial retinal examination and were lost to follow-up had a less favourable visual outcome.