Pressure sore in a patient who underwent repair of a retinal tear with gas injection

Purpose: To demonstrate a pressure sore following strict head positioning in a patient who underwent encircling band, vitrectomy and gas injection. Methods: A male patient was admitted to the hospital with a large posterior horseshoe tear in the inferior temporal retina with severe vitreous traction and retinal detachment. Encircling band, vitrectomy cryotherapy and gas injection was performed. After surgery the patient was instructed to sit in a facedown position. Results: A pressure sore resulted from prolonged immobility of the right elbow due to face-down positioning following encircling band, vitrectomy and gas injection. Conclusion: A patient injection. Conclusion: A patient may rarely have compulsive personality traits that result in extreme compliance to the physician's recommendations; therefore, general instructions given for head positioning should include permission for a change in position when required, at least for brief periods of time.     

Communication between the subretinal space and the vitreous cavity in the morning glory syndrome

Background: The aim was to describe a pathogenic mechanism for a rhegmatogenous retinal detachment in a 69-year-old man with the morning glory syndrome. Methods: During vitreous surgery for a retinal detachment, a membrane was removed that covered the optic disc anomaly and produced traction on the peripapillary retina. A retinal hole was found in tissue lying within the optic cup, and the hole was sealed using a autologous plasma —thrombin mixture. Silicone oil was used for retinal tamponade. Results: A retinal hole in tissue lying within the optic cup provided a fluid pathway between the vitreous cavity and the subretinal space. Following vitrectomy surgery, bubbles of silicone oil passed through the retinal hole into the subretinal space of the macula. Conclusion: This case demonstrates that a retinal hole in tissue lying within the optic disc anomaly of the morning glory syndrome provides a communication for fluid between the subretinal space and the vitreous cavity, resulting in a rhegmatogenous retinal detachment. Vitreous replacement with silicone oil resulted in the migration of silicone bubbles into the subretinal space.     

Iatrogenic choroidal neovascularisation following argon laser photocoagulation for choroidal malignant melanoma

Background: Choroidal neovascularisation is known to occur following photocoagulation for choroidal melanomas. Its occurrence rate, possible causes and clinical impact were studied. Methods: Post-treatment fluorescein angiograms were reviewed from 18 patients who had received argon laser photocoagulation as sole treatment of their small choroidal melanomas, to look for choroidal neovascularisation. Where it was found an assessment of its clinical impact was made. Results: choroidal neovascularisation was found in 50% of cases. Choroidoretinal neovascularisation, found in five patients, caused vitreous haemorrhage in one patient but was otherwise benign. Choroidovitreal neovascularisation was found in four patients. It occurred early and altered their clinical management. Three of these patients had a vitreous haemorrhage, one of whom also suffered a retinal detachment. The three diabetic patients in the series all developed aggressive choroidovitreal neovascularisation. Tumour size, tumours location and number of treatment sessions did not appear to affect the occurrence of choroidal reovascularisation, nor did other medical or ocular conditions except for diabetes. Conclusion: Choroidal neovascularisation occurs commonly after melanoma photocoagulation. Although sometimes benign, it can be aggressive, particularly in diabetic patients, in whom it might be better to consider different forms of tumour treatment.     

Preoperative vitreous hemorrhage associated with rhegmatogenous retinal detachment: a risk factor for postoperative proliferative vitreoretinopathy?

Background: We conducted a prospective clinical study to elucidate the role of preoperative vitreous hemorrhage in the development of postoperative proliferative vitreoretinopathy (PVR) in primary rhegmatogenous retinal detachment. Materials and methods: We prospectively evaluated 409 eyes of 390 patients affected by primary rhegmatogenous retinal detachment referred before any failed attempt to reattach the retina. Single and multiple logistic regression analysis were used to test 14 categories of variables. Results: Postoperative PVR occurred in 48 (11.7% of 409 eyes). Postoperative PVR developed in 41 (11.8%) of the 347 eyes with no preoperative vitreous hemorrhage, and 7 (11.3%) of the 62 eyes with preoperative vitreous hemorrhage (P=0.90). The results of multiple logistic regression analysis showed that only four variables were significant factors which had independently and jointly an effect on the risk of postoperative PVR: (1) 90° or greater circumferential extent of the retinal tears; (2) preoperative PVR grade B; (3) preoperative PVR grade C-D; and (4) the use of cyrotreatment as the method of retinopexy. Conclusion: With the surgical techniques currently used, mild preoperative vitreous hemorrhage is not an independent risk factor for postoperative PVR in primary rhegmatogenous retinal detachment. The role of moderate and severe vitreous hemorrhage remains to be fully evaluated in a larger series of eyes.     

The role of inner wall retinectomy in the management of juvenile retinoschisis

Purpose: The purpose of this paper is to describe the technique and application of relief of vitreous traction and inner wall retinectomy in the management of juvenile retinoschisis (JRS). In addition, during the course of this study a previously undescribed form of tractional retinal detachment associated with retinal schisis was observed. Methods: Six eyes of four children with visual field and/or central vision loss underwent vitrectomy (in five of the six eyes the lenses were preserved), inner wall retinectomy and photocoagulation for rhegmatogenous/schisis retinal detachment, tractional retinal detachment and reduced central vision secondary to intraschisis hemorrhage overhanging the macula. Results: The children were followed up for 1 to 4 years. All eyes showed anatomic reattachment. Three of the four eyes that could be tested for vision showed improved visual function postoperatively. One eye showed marked enlargement of visual field and central visual acuity improvement from 20/200 preoperatively to 20/50 postoperatively. Conclusion: Inner wall retinectomy can be a useful adjunct in the management of the retinal complication of JRS. Appropriate case selection of eyes with associated central traction retinal detachment can result in improved visual field and central visual acuity. The success of this technique suggests that the mechanical and/or pharmacological relief of vitreous traction may be able to alter the clinical course of JRS.     

Pars plana lensectomy in cases of cataract with juvenile chronic uveitis

Background: Classical cataract extraction in young patients with secondary cataract following juvenile chronic uveitis often is complicated by serious problems such as severe postoperative uveitis, hypotonia oculi and phthisis bulbi. Lensectomy with partial anterior vitrectomy might be a less inflammatory way of handling these cases. Methods: Over a 15-year period we have treated 10 eyes of 9 young patients (age from 8 to 30 years) with secondary cataract after chronic uveitis by pars plana lensectomy with partial anterior vitrectomy. A classical two-port technique was used with incisions at 4 mm from the limbus. The follow-up period varied from 3 to 12 years with an average of 8 years. There were five patients with chronic iridocyclitis, two with Fuch's heterochromic iridocyclitis, one with sympathetic ophthalmia and one with idiopathic panuveitis. Results: Seven eyes were corrected with contact lenses. During the entire follow-up period six had 20/20 visual acuity and one, 20/40. None of these patients reported tolerance problems with the contact lens. One patient has 20/20 visual acuity with spectacles. One patient who initially had 20/20 visual acuity with a contact lens developed retinal detachment 2 years after surgery, during pregnancy, and now has 20/40 vision after retinal surgery. She prefers not to wear the contact lens any longer because of diplopia. The visual acuity of one patient was no better than hand movement and his aphakia was never corrected. Complications included one vitreous haemorrhage necessitating a second vitrectomy, one retinal detachment during pregnancy and one retinal detachment with proliferative vitreoretinopathy. One patient with sympathetic ophthalmia has 20/20 vision after 9 years' follow-up but still needs systemic steroids and cyclosporine. Conclusion: Pars plana lensectomy, with anterior vitrectomy appears to be a relative safe way to treat secondary cataract in patients during the first 30 years of life.     

The effect of chemical stability and purification of perfluorocarbon liquids in experimental extended-term vitreous substitution

Background: To determine the importance of chemical stability and purification of perfluorocarbon liquids (PFCLs) in experimental retinal tolerance, we tested four different substances as long-term vitreous tamponade: purified and nonpurified perfluorodecalin (PFD) and perfluoro-octylbromide (PFOB) Method: After mechanical vitrectomy we replaced the vitreous of 65 rabbit eyes. Five groups were formed; four of them received the four PFCLs, while one served as control and received Ringer solution. The eyes were observed clinically every week and examined histologically after 1, 2, 4 and 8 weeks Results: After 1 week we observed foam cells and intraretinal macrophages in all eyes with PFCLs. Purified PFD caused retinal lesions in the photoreceptor, ganglion cell and outer nuclear layers after only 2 weeks in the lower part of the eyes. In eyes filled with purified PFOB we observed more pronounced damage of the same nature. Unpurified substances caused severe inflammation and retinal detachment Conclusion: Our study demonstrates that purification and chemical stability are important factors in retinal tolerance of PFCLs for vitreous replacement. Although purified PFD was tolerated by the rabbit eyes for 1 week, we cannot recommend this substance for short-term clinical use as a vitreous substitute.     

Unusual retinal pigment epitheliopathy and choroidopathy in carcinomatosis: A rare case of cancer-associated retinopathy

Background: Cancer-associated retinopathy is a syndrome causing ocular symptoms. It is a rare entity and only a few cases have been reported. Methods: A 67-year-old woman with small-cell endometrial carcinoma suffering from deterioration of visual acuity is presented. Results: The patient presented with extensive mottled changes of the retinal pigment epithelium, accompanied by diffuse subretinal fluid in the posterior pole and exudative retinal detachments inferior in both eyes. Conclusion: This patient suffered from a rare variety of cancer-associated retinopathy.     

Epidemiologic characteristics of rhegmatogenous retinal detachment in Kumamoto,Japan

Background: The epidemiology of rhegmatogenous retinal detachment in Asians is not well known. We studied the epidemiologic characteristics of rhegmatogenous retinal detachment in Kumamoto, Japan. Methods: The study was based on a retrospective chart review of hospital patients who were treated for primary rhegmatogenous retinal detachment in 1990. The data were collected from seven hospitals in the Kumamoto area. Results: From a population of 1 840000, 192 residents developed retinal detachment. The annual incidence was therefore 10.4 per 100000 population (9.6 for males, 11.2 for females). The incidences of three types of detachment — nontraumatic phakic, aphakic, and blunt trauma — were 9.8, 0.5, and 0.2 per 100000 population, respectively. In 109 of 180 patients (60.6%) with nontraumatic phakic detachment, retinal breaks were associated with lattice degeneration. In females, 14 of 106 nontraumatic phakic cases (13.2%) were secondary to macular holes. Conclusion: Compared with previously published studies from other countries, the incidence of detachments associated with lattice degeneration and macular hole was higher, while the incidences of aphakic detachment and detachment due to blunt trauma were lower in Japan. Racial factors and living habits may affect the development of retinal detachment.     

Primary vitrectomy without scleral buckling for rhegmatogenous retinal detachment

Background: Pars planta vitrectomy has evolved as an alternative method in the treatment of more complicated rhegmatogenous retinal detachments. We report a series of patients who underwent primary vitrectomy with gas tamponade without the use of additional scleral buckling. Methods: A retrospective study of 53 patients with a follow-up of 6–45 months (mean 17.8 months) was carried out. Preoperative findings included unusual, multiple or large breaks, vitreous haemorrhage, proliferative vitreoretinopathy and bullous retinal detachment. Preoperative visual acuity was between light perception and 1.0, with 30% (16/53) of patients with 0.4 or better. Results: Retinal reattachment was achieved in 64% of cases (34/53) with one and in 92% (49/53) with one or more operations. Final visual acuity was between light perception and 1.0, with 41% (22/53) of patients with 0.4 or better. Cataract formation occurred in 86% (37/43) of all patients with a clear lens preoperatively. Macular pucker was noted in 11 % (6/53) and postoperative proliferative vitreoretinopathy causing redetachment in 6% (3/53). Conclusion: With primary vitrectomy, a high final anatomical success rate with few intraoperative complications can be achieved in more complicated forms of rhegmatogenous retinal detachment. The major drawback of the procedure is the high incidence of post-operative cataract formation.     

The retinal depression sign in diabetic retinopathy

Background: The retinal depression sign, an abnormal light reflex due to ischemia-induced focal inner retinal atrophy, was initially described in patients with sickle cell retinopathy. We undertook this study to characterize the finding in diabetic retinopathy. Methods: The fundus photographs of 97 consecutive patients with diabetic retinopathy seen in the Penn State University Ophthalmology Department were reviewed. We recorded age, sex, type of retinopathy, visual acuity and photographic details, including the presence or absence of the retinal depression halo. Results: The retinal depression sign was present in 9 of 22 patients age 45 years or under, versus 1 of 75 patients age 46 or older (P<0.0001, two-tailed Fisher's exact test). The presence or absence of retinal depression sign did not predict the type of retinopathy in a given patient. Eleven (70%) of the affected eyes had visual acuity 20/40. Conclusion: The retinal depression sign is common in younger patients with diabetes and should be distinguished from other macular lesions associated with diabetic retinopathy.     

Familial exudative vitreoretinopathy: surgical intervention and visual acuity outcomes

Background: Familial exudative vitreoretinopathy (FEVR) is a hereditary condition that may lead to vitreous hemorrhage and traction retinal detachment necessitating surgical intervention. In this paper we review the results of surgery on seven such patients (eight eyes). Methods: Seven patients (eight eyes) were followed up after surgery that had been performed because of vitreous hemorrhage and/or traction retinal detachment due to FEVR, in an effort to evaluate outcomes. Parameters that were noted were the current age, gender, age at the time of first surgery, length of follow-up and postoperative retinal status and visual acuity. Results: Seven patients (eight eyes) ranging in age from 6 months to 44 years with a mean of 24.7 and a median of 26 years were followed. There were three females and four males. The lowest age at which surgery was first performed was 6 months and the highest was 28 years, with a mean of 14.7 and a median of 17 years. Six of the 8 eyes were reattached following surgery, although some required multiple procedures. Conclusion: Vitreoretinal surgery may be of benefit in helping to preserve some degree of vision in eyes of patients with FEVR who develop vitreous hemorrhage and/or retinal detachment.Presented at the combined meeting of the Club Jules Gonin and the Retina Society, 3 September 1996     

Anterior chamber inflammation after transconjunctival cryosurgery

Background: Inflammation caused by transconjunctival cryotherapy for prophylactic retinal detachment surgery was measured in various conditions. Methods: Thirty-four eyes of 28 patients with peripheral retinal lesions predisposing to retinal detachment were studied by laser flare cell meter before and after treatment. Results: The mean flare value for 34 eyes was 4.06 ± 1.45 photon counts/ms before surgery and 5.72 ± 2.52 pc/ms after surgery (p < 0.05). Flare value was elevated at 1, 2, and 3 weeks after treatment, peaking at 2 weeks (p < 0.05), and normal again at 4 weeks. There were no significant differences in flare increase between eyes with and without retinal breaks, eyes with and without limited retinal detachment, eyes with myopia more and less than – 8.0 D, and eyes with a treatment area limited to one quadrant and extending over more than one quadrant. Conclusion: Transconjunctival cryosurgery caused mild inflammation in the anterior chamber of the eye for 3 weeks. The inflammation was not affected by the presence of retinal break or limited retinal detachment, the degree of myopia, or the extent of the treatment area.     

Expression of mRNA coding for TNFα, IL-1β and IL-6 by cells infiltrating retinal membranes

Background: Cellular mechanisms of inflammation are thought to be involved in the pathogenesis of proliferative vitreoretinopathy, and cytokines, which are products of cell activation, are known to play an important role in the development and maintainance of inflammatory reactions. It was the aim of this work to investigate the presence of cells expressing cytokine mRNA within retinal membranes. Methods The presence of mRNA coding for the cytokines interleukin 1 (IL-1), interleukin 6 (IL-6) and tumour necrosis factor (TNF) was investigated in 19 epiretinal membranes obtained from eyes undergoing vitrectomy for the treatment of retinal detachment complicated by proliferative vitreoretinopathy. Results Cells expressing mRNA for IL-1 were observed in 7 membranes, cells positive for IL-6 mRNA were seen in 12 membranes, and cells exhibiting mRNA for TNF were present in 9 specimens. Only three membranes contained cells expressing mRNA for all the cytokines investigated. Four membranes possessed positive cells for IL-6 and TNF, two contained cells expressing mRNA for IL-6 and IL-1, and two others exhibited cells expressing mRNA for TNF and IL-1. Five membranes contained IL-6 mRNA-positive cells only, whilst two exhibited cells expressing mRNA for IL-1, or TNF only. Conclusion The present findings indicate that cellular activation may occur during the development of PVR, and suggest that these cytokines may be locally produced by cells infiltrating epiretinal membranes. The presence of IL-1, IL-6 and TNF mRNA-positive cells within retinal membranes provides further evidence of a pathogenic role of these cytokines in proliferative vitreoretinopathy.     

Fixation of whole eyes: the role of fixative osmolarity in the production of tissue artifact

Background: Whole eyes fixed in 4% buffered formaldehyde (10% neutral buffered formalin) demonstrate a variety of artifacts, including separation of the neurosensory retina from the retinal pigment epithelium. We postulate that the osmolarity of 4% buffered formaldehyde causes contraction of the internal compartments of the eye leading to several artifactual changes commonly observed in routine histologic sections. Methods: In part I of the study, enucleated animal eyes were examined histologically after immersion in different concentrations of formaldehyde. The variables of fixation and processing were kept constant except for the concentration and osmolarity of formaldehyde. In part II, enucleated animal eyes were used to empirically determine the optimal mixture of formaldehyde and glutaraldehyde for fixation based on subjective assessment of histologic sections. Results: In the first part of the study, the post-fixed volume of the anterior chamber and vitreous increased as the concentration (and osmolarity) of formaldehyde decreased. In part II of the study, fixation of whole eyes was optimal with a mixture of 1% buffered formaldehyde and 1.25% glutaraldehyde. The neurosensory retina was less likely to detach from the retinal pigment epithelium, and the anterior chamber retained a more normal shape with this fixative. Conclusions: Volume contraction of whole eyes fixed in 4% buffered formaldehyde is caused by the relatively high osmolarity of the fixative. Immersion fixation of whole eyes for 36 h (or longer) in 1% buffered formaldehyde/1.25% glutaraldehyde reduces tissue distortion without compromising cellular preservation.     

Exotropia secondary to vitreous hemorrhage

Background: Diplopia after cataract surgery has been reported by several authors, but diplopia after recovery from vitreous hemorrhage (VH) has not been described. Methods: We examined eight patients with manifest exotropia and binocular diplopia after recovery from dense VH by vitreous surgery. VH was bilateral in three patients and unilateral in five, and lasted for an average of 7.7 years. Results: Visual acuity before vitrectomy ranged from 20/200 to light perception; that after vitrectomy ranged from 20/20 to 20/60. Exotropia was present in all patients after vitrectomy. Additionally, seven out of eight patients had vertical strabismus with an average deviation of 6 prism diopters (). Fusion was confirmed in four patients with an average amplitude of 13 . Four patients underwent horizontal strabismus surgery. Fusion was present in two before strabismus surgery and in all four after surgery; however, unstable diplopia persisted in three of the four after surgery. Conclusion: Diplopia after vitrectomy for longstanding VH may occur due to fusion impairment comparable to that occasionally seen after surgery for traumatic cataract.     

Schisis-like rhegmatogenous retinal detachment associated with choroidal colobomas

Background: The breaks that cause retinal detachments in colobomatous eyes are often hidden within the lesion and difficult to find. Method: To elucidate the pathoanatomy and possible pathomechanism of such detachments, histological sections of eight choroidal colobomas were reviewed. Results: Sections of the margin showed central continuation of the inner neuroblastic layer (the intercalary membrane) and eversion and separation of the outer neuroblastic layer. The opposite direction of continuity of the neuroblastic layers created a schisis-like configuration between the intercalary membrane and the everted outer retina. The zone of duplication was a point of retinal adhesion, but also a locus minoris resistentiae due to vitreous attachments and variable glial support at the margin. Conclusion: The subset of coloboma-associated retinal detachments requires both a central break in the inner layer and a break in the outer layer at the margin of the coloboma. The inner layer break may be precipated by retinovascular ischemia or scleral stretching; that in the outer layer may be caused by vitreous traction on the margin of the coloboma or extension of the formerly isolated detachment through the outer marginal zone of decreased glial support.Presented at the Annual Meeting of the Retina Society, San Francisco, California, 20 October 1993     

Evidence of cross-link formation of vitreous collagen during experimental ocular inflammation

Purpose: To determine the mechanisms of vitreous changes during ocular inflammation. Methods: We investigated vitreous changes, with special emphasis on collagen, in an experimental model of ocular inflammation induced by intravitreal injection of endotoxin (Escherichia coli) in rabbits. Results: Inflammation caused gel contraction and loss of elasticity, accompanied by release of a water-like liquid from the gel, and increases in the amount of insoluble material and highmolecular-weight components of vitreous collagen, presumably due to extensive cross-links of the collagen molecules. Those changes were partially inhibited by intravitreal injection of superoxide dismutase. Conclusions: The crosslinks of vitreous collagen may promote vitreous gel contraction and release of a water-like liquid from the gel. Superoxide anion may play a role in this process.     

Type VI collagen is present in human and bovine vitreous

Background. Heterotypic (mixed) collagen fibrils that contain collagen types II, IX and V/XI have previously been identified in vitreous gel. The purpose of this study was to determine whether vitreous gel also contains type VI collagen microfibrils, as they are widely distributed in other tissues where they may play an important structural role. Methods. Bovine and human vitreous gel was analysed by rotary shadowing electron microscopy after bacterial collagenase digestion and gel filtration chromatography. Bovine vitreous was extracted in 4 M guanidine hydrochloride, and following isopycnic centrifugation fractions were analysed by western blotting. Results. Type VI collagen microfibrils were identified by electron microscopy in human and bovine vitreous. Type VI collagen was identified by western blot analysis. Conclusion. Type VI collagen is present in vitreous and may participate in the structural assembly of the vitreous gel.Presented in part at the XIXth meeting of the Club Jules Gonin in Versailles. France, September 1994.     

Isovolemic hemodilution increases retinal tissue oxygen tension

Background: Therapeutic isovolemic hemodilution has been reported to improve blood flow and oxygen delivery. Few reliable measurements have been made, however, showing the effect of hemodilution on tissue oxygen tension. Methods: We measured retinal oxygen tension during experimental isovolemic hemodilution in normal cats. Polarographic oxygen microelectrodes were placed in the vitreous humor within 100–200 m of the retinal surface.Results: Tissue oxygen tension increased initially during isovolemic hemodilution to a maximum approximately 50% above baseline at approximately two thirds of the original hematocrit level. Hemodilution beyond this point to lower hematocrits caused a steady decline in tissue oxygen tension. Cardiac output measured in one cat undergoing isovolemic hemodilution increased as hematocrit was lowered, but the cardiac erythrocyte flux actually decreased steadily.Conclusion: The observed increase in tissue oxygen tension with hemodilution appears to be explained by a lesser reduction in capillary than in systemic hematocrit, coupled with an increased capillary blood flow. The increase in tissue oxygen tension we observed could in part explain the clinically beneficial effects of hemodilution.