Aqueous concentrations of fluorouracil after intravitreal injection. Normal, vitrectomized, and silicone-filled eyes.

Treatment of postoperative vitreoretinopathy with combined intravitreal fluorouracil and liquid silicone may result in increased corneal and retinal toxicity. We therefore investigated the movement of carbon 14-labeled fluorouracil from the vitreous into the anterior chamber in normal rabbit eyes and in eyes filled with either balanced salt solution or silicone after vitrectomy and lensectomy, with or without preservation of the anterior capsule. Only 0.56% of intravitreally injected fluorouracil was recovered from the anterior chamber over a four-hour period in normal eyes. This impermeability was partly maintained if the anterior capsule was retained (9.98%), particularly if the eye contained silicone (2.52%). The greatest amount was recovered when both lens capsules were removed (43.7%). Corneal toxicity is most likely to occur in this situation.

Relative permeability of retina and retinal pigment epithelium to the diffusion of tritiated water from vitreous to choroid.

The movement of intravitreally injected tritiated water from the vitreous to the choroid was accelerated by the removal of intervening retina. Both rate of transfer and peak choroidal levels of the tracer were increased, but the proportion of the intravitreal dose recovered was unaltered. In contrast, the movement of tritiated water after diffuse damage to the retinal pigment epithelium by sodium iodate was similar to that of control eyes. The main resistance to the diffusion of this tracer from the vitreous to the choroid is the retina. The differential permeability of the retina and the retinal pigment epithelium may have a role in normal retinal adhesion.

Intravitreal expanding gas bubble. A morphologic study in the rabbit eye.

The morphologic changes induced by an expanding bubble of perfluoropropane (C3F8) gas in the vitreous body have been studied in the rabbit eye by dissecting microscopy and scanning and transmission electron microscopy. Initial expansion of the gas displaces water from the vitreous; the remaining vitreous forms a compressed layer on the retinal surface. Subsequent absorption and contraction of the gas bubble is associated with gradual detachment of the compressed vitreous from the retina. Eventually, vitreous detachment is complete, except for residual attachments posteriorly to the medullary rays and anteriorly to the ciliary processes. The plane of vitreous separation is predominantly at the anatomic vitreoretinal junction, although scattered islands of outer cortical vitreous are found on the surface of the retina.

Posterior chorioretinopathy and retinal detachment after organ transplantation.

Four patients, three after renal transplantation and one after heart-lung transplantation, developed visual loss in both eyes associated with geographic zones of disruption and coarse clumping of the pigment epithelium in the posterior fundi. Secondary retinal detachment occurred bilaterally in three patients. Localized choroidal intravascular coagulation is the suspected but unproven cause.

Massive suprachoroidal hemorrhage with central retinal apposition. A clinical and echographic study.

We reviewed the charts of 18 patients diagnosed with a massive suprachoroidal hemorrhage (MSCH) with central retinal apposition (kissing configuration). Four cases occurred intraoperatively (expulsive), eight after a surgical procedure (delayed), and six associated with blunt or perforating injury (traumatic). In this study, echography was used to monitor the course of MSCH; the mean time for clot lysis was 14 days, and the mean duration of central retinal apposition was 15 days. The expulsive MSCHs were all allowed to resolve spontaneously, with good initial visual outcome in three of the four eyes in which they occurred. In the delayed MSCH group, the majority of patients attained their prehemorrhage visual acuity, with or without early surgical intervention. In the traumatic MSCH group, retinal detachment was a constant complication in all patients. All six patients in the traumatic MSCH group had a poor visual outcome, despite early surgical intervention in five patients. The results of this study suggest that not all MSCHs need to be drained surgically and that, when surgical drainage is indicated, echography may be a useful adjunct in determining the optimal time of drainage.

Intraoperative argon endophotocoagulation for recurrent vitreous hemorrhage after vitrectomy for diabetic retinopathy.

We reviewed the medical records of 103 consecutive cases of vitrectomy performed for complications of diabetic retinopathy to determine if the introduction of argon laser endophotocoagulation had reduced the incidence of recurrent vitreous hemorrhage. Twenty-six eyes (48%) treated with endophotocoagulation and 35 (71%) eyes not receiving laser treatment had a recurrent hemorrhage. Follow-up was shorter for the eyes treated with endophotocoagulation, but a log-rank analysis to allow for this variable confirmed the benefit of laser photocoagulation (P less than .05). The proportion of eyes requiring surgical removal of the hemorrhage was also significantly lower in the group receiving endophotocoagulation (P less than .05). The beneficial effect of intraoperative laser treatment was independent of the amount of preoperative laser treatment, aphakia, and indications for the original vitrectomy surgery.

An updated classification of retinal detachment with proliferative vitreoretinopathy.

The Retinal Society classification on proliferative vitreoretinopathy of 1983 has been updated to accommodate major progress in understanding of this disease. There are three grades describing increasing severity of the disease. Posterior and anterior location of the proliferations have been emphasized. A more detailed description of posterior and anterior contractions has been made possible by adding contraction types such as focal, diffuse, subretinal, circumferential contraction, and anterior displacement. The extent of the abnormality has been detailed by using clock hours instead of quadrants.

The Sylvian aqueduct syndrome and neurofibromatosis.

A 23-year-old man initially presented with the Sylvian aqueduct syndrome and subsequently developed cutaneous neurofibromata. The case is reported and the possibility that these represent manifestations of the same genetic abnormality is discussed.

Sclerotomy forceps.

Forceps to facilitate the drainage of subretinal fluid are described.

The acute vitreous haemorrhage.

One hundred cases of acute vitreous haemorrhage have been analysed prospectively. It was possible to identify the cause of the haemorrhage at presentation in 79% of the cases. 40% were due to retinal tears and only 6% were associated with diabetic retinopathy.

Infection following retinal detachment surgery.

Since the introduction of gentamicin (given both as a soaked sponge and as an injection below Tenon's capsule at the end of surgery) no case of early infection either with or without intraocular signs after operation for retinal detachment has occurred in a series of 206 cases comprising 243 operations. However, late infection many months after operation has appeared in 3 cases (1-5%), though this rate appears to have been favourably influenced by the administration of gentamicin. Local or systemic side effects from the administration of gentamicin have not been seen, and therefore the sub-Tenon injection in the quadrant where the sponge has been placed is strongly advocated in all cases of surgery for retinal detachment when such sponges are used.

Experimental model of proliferative vitreoretinopathy (PVR) in the vitrectomised eye: effect of silicone oil.

Silicone oil alone or as an adjunct to vitrectomy is widely used for the treatment of retinal detachment complicated by proliferative vitreoretinopathy (PVR). It appears to reduce the tendency for recurrent traction detachment, but the mechanism of this action is obscure. We have studied the effects of silicone oil in an experimental animal model. Twenty five thousand homologous fibroblasts were injected into the aphakic vitrectomised rabbit eye, and traction detachment of the vascularised retina (medullary rays) regularly resulted. Intraocular silicone oil did not influence the development of this experimental detachment.

Effect of preoperative posture and binocular occlusion on retinal detachment.

In an unselected series of retinal detachments a 24-hour period of binocular occlusion and posture with a retinal hole dependent produces some resolution of subretinal fluid in 13% of cases. If only patients with acute, freely mobile detachments and retinal holes above the horizontal meridian were selected the proportion of detachments showing some resolution rose to 30%. In 8% of cases a paradoxical response occurred, the detachment increasing in depth or extending to involve an additional area of retina.

Vitrectomy and fluid/silicone-oil exchange for giant retinal tears: results at six months.

The results of vitrectomy combined with fluid/silicone-oil exchange in 73 eyes with giant retinal tears are reported at six months after surgery. Initial anatomical success was achieved in 71 out of 73 eyes (97%) and, prior to removal of silicone-oil, in 66 out of 73 eyes (90%). In 63 eyes (86%) the retina remained attached six months after surgery. Of these visual acuity was 6/60 or better in 44 (70%). The high proportion of eyes with macular detachment before surgery and the frequency of macular abnormalities are thought to account for reduced vision in many of the anatomically successful cases.

Changing attitudes in United States to use of intravitreal silicone.

The use of intravitreal silicone oil injection to separate preretinal membranes from the retinal surface in proliferative vitreoretinopathy (PVR) was pioneered in the United States. The anatomical results obtained were encouraging but complications of cataract, glaucoma and keratopathy frequently occurred. This method was therefore discontinued in the United States once the techniques of pars plana vitrectomy and membrane dissection had been developed. More recently, however, it has become clear that in severe PVR treated by vitrectomy procedures, recurrent traction is almost inevitable and prolonged vitreous substitution is required to limit the associated retinal detachment. Silicone has been selectively re-introduced for this purpose. Improved techniques and oil removal in some cases have reduced the incidence of complications. Insoluble gases have also been widely used in the United States to achieve the same objective but have generally been found to be less effective. The comparative merits of these alternative forms of vitreous substitution remain controversial. A randomized clinical trial is currently being conducted in the United States to address this issue. The trial embodies features of multicenter clinical trials used successfully in other prospective clinical studies. Silicone oil is still used less frequently than in Europe or in Japan for the management of diabetic traction detachment and giant tears.

Origin of simple glial epiretinal membranes in an animal model.

Severe vitreous hemorrhage was simulated by the injection of 0.2 ml fresh uncoagulated autologous blood into the vitreous cavity of eight rabbits. Four weeks later, hemoglobin released from lysis of the original intravitreal clot had formed a thick layer on the retina. At this stage, many macrophages were conspicuous on the retinal surface and, in addition, in seven of the eight eyes, small cellular membranes were found by scanning electron microscopy. Light and transmission electron microscopy showed these membranes to be derived from accessory glial cells and their progeny. The membranes resembled the simple epiretinal membranes that occur in human eyes.

Management of giant retinal tears using vitrectomy and silicone oil/fluid exchange. A preliminary report.

The long-term management of giant retinal breaks presents a difficult problem. A surgical method is described in which removal of the vitreous and complete filling of the preretinal space with silicone oil is used to close the giant tear and re-attach the retina. The silicone oil is removed from the eye after 2 to 3 months in most cases. The results are reported of using this technique in a consecutive series of seventeen eyes with giant retinal breaks.

Vertical supranuclear gaze palsy with secondary syphilis.

A 48-year-old man presented with a vertical gaze palsy associated with secondary syphilis. It is suggested that the eye movement disorder is due to syphilitic endarteritis in the mesodiencephalic region.

Variations in clinical features of the Vogt-Koyanagi-Harada syndrome.

Forty-eight cases of the Vogt-Koyanagi-Harada (VKH) syndrome occurring in patients residing in southern California were reviewed. Thirty-six patients were Hispanic and 12 of other racial groups. Symptoms of meningismus, predominantly headache, were present in 32 (67%) cases, but the other characteristic neurologic symptoms, i.e., tinnitus and dysacusis, were present in only eight (17%) and six (13%) cases, respectively. Dermatologic changes were rare; vitiligo occurred in five (10%) patients, alopecia in six (13%), and poliosis in three (6%). In this patient population, extraocular signs and symptoms of the VKH syndrome, other than headache, were unusual. The ocular manifestations of the VKH syndrome are more constant and include iridocyclitis, vitritis, diffuse swelling of the choroid, serous retinal detachment, and optic disc hyperemia. Procedures that may aid in the diagnosis include lumbar puncture, fluorescein angiography, and standardized echography. The ophthalmologist must be prepared to make this diagnosis and initiate treatment with high-dose systemic steroids based on the typical ocular findings even in the absence of other (extraocular) manifestations of this disease.