Corneal shape changes after pars plana vitrectomy

BACKGROUND: The modern practice of using artificial light to extend waking activities into the nighttime hours might be expected to precipitate or exacerbate bipolar illness, because it has been shown that modifying the timing and duration of sleep can induce mania in susceptible individuals. With this possibility in mind, we treated a patient with rapidly cycling bipolar illness by creating an environment that was likely to increase and to stabilize the number of hours that he slept each night. METHODS: We asked the patient to remain at bed rest in the dark for 14 hours each night (later this was gradually reduced to 10 hours). Over a period of several years, his clinical state was assessed with twice-daily self-ratings, once-weekly observer ratings, and continuous wrist motor activity recordings. Times of sleeping and waking were recorded with sleep logs, polygraphic recordings, and computer-based event recordings. RESULTS: The patient cycled rapidly between depression and mania and experienced marked fluctuations in the timing and duration of sleep when he slept according to his usual routine, but his sleep and mood stabilized when he adhered to a regimen of long nightly periods of enforced bed rest in the dark. CONCLUSIONS: Fostering sleep and stabilizing its timing by scheduling regular nightly periods of enforced bed rest in the dark may help to prevent mania and rapid cycling in bipolar patients.     

Pars plana vitrectomy with pars plana tube implantation in eyes with intractable glaucoma

Fas Ligand (FasL) can induce apoptosis of Fas-bearing cells. It is expressed on the cell surface of many tumor cells, immune-privileged tissues and activated lymphocytes. We report here that FasL can itself transduce signals, leading to cell-cycle arrest and cell death in CD4+ T cells. In vitro, FasL engagement inhibited CD4+ T-cell proliferation, cell-cycle progression, and IL-2 secretion. In vivo, FasL engagement prevented superantigen-mediated CD4+, but not CD8+, T-cell expansion. These findings demonstrate that FasL engagement regulates cell-cycle progression, and show that FasL engagement in vivo has a potent anti-inflammatory effect specific for CD4+ T cells.     

Early indications for pars plana vitrectomy in idiopathic macular holes

Soluble Fc gamma-binding components were detected in gingival fluid from periodontal lesions by incubation with biotinylated human Fc gamma fragments. Fc gamma III receptor was identified by incubation of gingival fluid with monoclonal antibody. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western transfer showed that most of the Fc gamma-binding components had minimal mobility in a 4-15% gradient gel under nonreducing conditions. Under reducing conditions, the main band of Fc gamma-binding components in gingival fluid migrated corresponding to protein A of 49 kDa. The pattern of Fc gamma-binding components was similar in serum and gingival fluid except for the observation in gingival fluid of Fc gamma-binding components migrating like standard proteins of 19 to 20 kDa, a size that corresponds to the polypeptide part of Fc gamma II receptor and Fc gamma III receptor.     

Fluorescein angiography of the fundus after pars plana vitrectomy

In diabetic patients with massive vitreous hemorrhage, fluorescein angiography after pars plana vitrectomy demonstrated varying degrees of vascular involvement depending on the stage of the basic disease process. Arteriolar occlusions, capillary bed drop-out, microaneurysms, and neovascularization were common findings. We concluded that diabetic retinopathy continued its course behind the cloudy vitreous, sometimes leading to retinal ischemia and subsequent spontaneous involution, macular disease, or retinal detachment. In addition, some of these patients were also subject to nondiabetic diseases, such as senile macular degeneration, that could not be detected preoperatively, but that reduced visual acuity postoperatively. In the nondiabetic patients with vitreous hemorrhage, visual acuity after vitrectomy usually depended on the degree of coincident macular disease.     

Retinal detachments due to traumatic tears in the pars plana ciliaris

Hypothermia during orthotopic liver transplantation (OLT) is common despite measures to prevent this complication. We retrospectively analyzed two groups of patients; those managed with (n = 113) or without (n = 109) a heat exchanger (HE) incorporated in the venovenous bypass (VVB) circuit to test the hypothesis that normothermia before liver reperfusion minimizes hypotension during reperfusion and decreases neohepatic transfusion requirements. Use of the HE resulted in significantly warmer patients during reperfusion and at the end of surgery (P < .001). An increase in neohepatic transfusion requirement was observed in patients with HE use: packed red blood cells, 4 +/- 4 versus 3 +/- 3 units; fresh-frozen plasma, 5 +/- 5 versus 4 +/- 4 units; platelets, 8 +/- 8 versus 6 +/- 7 units; and cryoprecipitate, 5 +/- 7 versus 3 +/- 5 units. There was no difference between the two groups in the untoward hemodynamic events during reperfusion of the liver (P = .31). We conclude that during OLT, the use of an HE in a nonheparinized VVB circuit helps maintain normothermia. Our limited experience suggests that its use is safe but does not improve hemodynamic stability during reperfusion or decrease blood loss during the neohepatic period.     

Combined endocapsular phacoemulsification, pars plana vitrectomy, and intraocular lens implantation

OBJECTIVE: To determine whether a combined vitrectomy and phacoemulsification is a safe and feasible approach in patients requiring a vitrectomy who have a concomitant significant lens opacity. SETTING: Royal Victoria Eye and Ear Hospital, Dublin, Ireland. METHODS: This retrospective study comprised five patients with significant lens opacities who had combined trans pars plana vitrectomy and phacoemulsification with intraocular lens implantation. Main outcome measures were visual acuity and intraoperative and postoperative complications. RESULTS: The combined surgical approach resulted in minimal complications, and postoperative visual acuity was satisfactory. CONCLUSION: In the hands of experienced phacoemulsification and vitrectomy surgeons, combined trans pars plana vitrectomy and phacoemulsification can be a safe approach in treating patients requiring a vitrectomy who have significant lens opacities precluding a view of the posterior segment.     

Glaucoma after pars plana vitrectomy and silicone oil injection for complicated retinal detachments

OBJECTIVE: To determine the incidence and associations of glaucoma after pars plana vitrectomy (PPV) and silicone oil injection (SOI) for complicated retinal detachments and the response to treatment. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: A total of 150 eyes of 150 patients who had completed a minimum of 6 months of follow-up were included in this study. Analysis included clinical records of all consecutive cases of complicated retinal detachment that underwent PPV with SOI between July 1991 and February 1996. INTERVENTION: Surgical intervention for vitreoretinal pathology included standard three-port PPV and additional procedures as appropriate for the retinal pathology, and SOI. Procedures for the control of glaucoma were silicone oil removal (SOR), trabeculectomy with mitomycin C, cyclocryotherapy, semiconductor diode laser contact transscleral cyclophotocoagulation (TSCPC) and anterior chamber tube shunt to encircling band (ACTSEB). MAIN OUTCOME MEASURES: Presence of glaucoma (predefined as intraocular pressure [IOP] > or = 24 mmHg, which also was > or = 10 mmHg over the preoperative level, sustained for > or = 6 weeks) and the result of medical and surgical management were the main outcome measures. Demographic, preoperative, intraoperative, and postoperative parameters including the age of the patient, etiology of retinal detachment, refractive status, pre-existing glaucoma, aphakia, diabetes mellitus, presence of silicone oil (SO) in the anterior chamber, emulsification of SO, rubeosis iridis, and anatomic success were evaluated by univariate and multivariate logistic regression analyses to assess their predictive value in the causation of glaucoma and to determine factors prognosticating response to treatment. RESULTS: The main indications for PPV+SOI were proliferative vitreoretinopathy (57%; 85 of 150), proliferative diabetic retinopathy (15%; 23 of 150), and trauma (14%, 21 of 150). Glaucoma occurred in 60 eyes (40%) at 14 days median (range, 1 day-18 months). Elevation of IOP could be attributed directly to SO in 42 (70%) eyes. Glaucoma was controlled in 43 (72%) of 60 eyes on treatment (with medicines alone in 30%; SOR and medicines in 25%; trabeculectomy with mitomycin C/ACTSEB/cyclocryotherapy or TSCPC in 17%); 28% (17 of 60) remained refractory. Independent predictive factors for glaucoma on multivariate analysis were rubeosis iridis (odds ratio, 10.76), aphakia (odds ratio, 9.83), diabetes (odds ratio, 6.03), SO in anterior chamber (odds ratio, 4.74), and anatomic failure (negative risk factor; odds ratio, 0.11). Poor prognostic factors for the control of glaucoma were SO emulsification (odds ratio, 15.34) and diabetes (odds ratio, 6.03). CONCLUSION: Glaucoma is a frequent and often a refractory complication of PPV with SOI and has a multifactorial etiology. Aggressive medical and surgical management with SOR, trabeculectomy with mitomycin C, glaucoma shunts, and cyclodestructive procedures shows modest success in controlling IOP.     

Dehydration injury as a possible cause of visual field defect after pars plana vitrectomy for macular hole

PURPOSE: To present the hypothesis that a visual field defect after pars plana vitrectomy for macular hole may be caused by dehydration injury to the nerve fiber layer during the fluid-air exchange. METHODS: In a consecutive nonrandomized series of 45 operations on 35 eyes of 34 patients with full-thickness macular hole, the surgical method was changed with postoperative visual field testing performed. RESULT: The incidence and location of the post-operative visual field defect was affected only by changing the location of the infusion cannula. CONCLUSION: Dehydration injury of the nerve fiber layer during the fluid-air exchange should be considered as a possible cause of visual field defect after pars plana vitrectomy for macular hole.     

Combined pars plana vitrectomy, lens removal and intraocular lens implantation for complications of diabetic retinopathy. Surgical results in 120 cases

We performed combined vitrectomy, lens removal and posterior chamber intraocular lens implantation for proliferative diabetic retinopathy in 120 eyes of 101 patients. Follow-up periods ranged from 3 to 63 months, with a mean of 17 months. Three lens removal methods were used: extracapsular cataract extraction (14 eyes), phacoemulsification and aspiration (49 eyes), and pars plana phacoemulsification (57 eyes). Preoperative rubeosis iridis or neovascular glaucoma was found in 21 eyes. Gas or temporary silicone oil tamponade was employed in 32 eyes. Surgical results were good, and the postoperative vision was finger counts or below only in 13 eyes. Thus the combined surgery proved to have no serious problems. Our results indicate two important points. (1) It is best to chose either of the following two methods for the lens surgery: phacoemulsification with continuous circular capsulorhexis, self sealing sclerocorneal incision, and in-the-bag fixation of the posterior chamber lens, or pars plana phacoemulsification leaving the anterior capsule, rub off and aspirating the lens epithelial cells, continuous circular capsulorhexis, and posterior chamber lens implantation in front of the anterior capsule from a self-sealing sclerocorneal wound. (2) It is mandatory to do complete vitrectomy and cut out the vitreous gels incarcerated in the sclerotomy site.     

Retinal detachment in an infant with the ring chromosome 13 syndrome

A 6-year-old fit girl experienced convulsions 44 h after an otherwise uneventful anaesthesia with propofol, alfentanil and nitrous oxide. As an underlying pathology was suspected, the child was kept sedated for 6.5 h for further investigations. During this period she received a continuous infusion of propofol amounting in total to 1600 mg. After having regained consciousness, she was strikingly ataxic and remained so for 5 days. During this period she also experienced two episodes of hallucinations lasting about 2 h. Investigations including lumbar puncture, EEG, cerebral CT and MR scan could not explain the neurological symptoms. She recovered without long-term sequelae.     

Retinal detachment in the rat

Retinal detachment is uncommon in the rat. Retinal atrophy, rosette formation and folding of the retina are some of the sequelae following reattachment.     

Vitreoretinal complications in cataract surgery. I. Retinal detachment

OBJECTIVE: We raise the issue of scanning multifetal pregnancies of higher order as early as possible. A rare case of monochorionic/quadramniotic pregnancy seeking multifetal pregnancy reduction and its clinical management is presented. METHODS: Transabdominal scanning at 16 weeks was performed correctly diagnosing the monochorionic quadruplet pregnancy. RESULTS: Suspecting vascular connections between the placentae, the fetal reduction was declined. The patient was delivered at 31 weeks. The 4 female neonates survived with slight ventilatory assistance. CONCLUSION: Multifetal pregnancies in general, but those of higher order in particular, have to be scanned as early as 8-10 weeks to correctly and easily assign their chorionicity and amnionicity. The case of a monochorionic/quadramniotic pregnancy and its clinical course are presented.     

Retinal detachment in a battered infant

A 12-week-old battered infant boy had bilateral retinal detachments. The retina in the left eye was considered inoperable, but retinal detachment surgery was performed in the right eye. This retina was reattached and limited vision was restored. The history, the location of the retinal pathology, and the absence of a lens coloboma helped differentiate this result of physical abuse from a congenital retinal detachment.     

Ehlers-Danlos syndrome type I. Ultrastructural study

Ehlers-Danlos syndrome comprises a very heterogeneous group of collagen diseases characterised in clinical terms by fragility and cutaneous hyperextensability, ligamentous hyperlaxity, ecchymosis, scarring, visceral and neurological manifestations. Having been described in detail by Ehlers in 1899 and Danlos in 1908, it was subsequently classified into various clinical types. At present at least 11 forms are recognised on the basis of their clinical characteristics, methods of transmission and biochemical defect; the first four types of the syndrome account for approximately 95% of cases. Almost all forms are transmitted with a dominant autosomic character. Specific genetic mutations have been ascertained whereas the biochemical defect has been identified in numerous types. Ehlers-Danlos type 1 syndrome is the most frequent and most severe form. The biochemical anomaly underlying the altered deposition of collagen fibre is still unknown and this is responsible for the "storiform" appearance of collagen fibre on ultrastructural examination. The authors have described a typical case of "Ehlers-Danlos type 1 syndrome" in which the diagnosis was confirmed by comparing clinical data and the results of ultrastructural tests which revealed the characteristic "pattern" of collagen fibres.     

Ehlers-Danlos syndrome type II in pregnancy

The Allen test was performed by four physician examiners on 200 hands of healthy volunteers. Positive results were found in 5.5% of hands. There was not a single case in which all four observers agreed. Considerable inter-observer disagreement is associated with the Allen test.     

Retinal irradiation from an operating microscope during vitrectomy: observation by endoscopy

Phototoxic retinopathy due to light from the operating microscope has been reported during cataract surgery, as well as during vitreous surgery. A neutral density filter for the coaxial light or coverage of the cornea with various materials has been advocated to prevent retinal complications. However, it is difficult to actually monitor the fundus during surgery with usual methods. The author used an endoscope to demonstrate how intensively the light from the operating microscope is focused on the retinal surface during vitreous surgery.     

Retinal detachment following congenital cataract surgery. I. Preoperative findings in 114 eyes

One hundred fourteen eyes of patients with retinal detachment occurring after congenital cataract surgery were studied. Retinal detachment was typified by high incidences of men, myopia, preference for the second and fourth decades of life, and a fairly long interval after cataract surgery. Frequently found were the following: (1) undetected retinal breaks, (2) high incidences of small oval or round holes in the upper nasal quadrant near the ora serrata, (3) retinal detachment in more than one quadrant, and (4) extensive vitreous and preretinal traction. Preoperative examination was often hampered by a small, bound-down pupil, nystagmus, extreme photophobia, and an inability to move the eye in desired directions. The major factor in the pathogenesis of retinal detachment after congenital cataract surgery appears to be chronic vitreoretinal traction in the anterior vitreous caused by cataract removal.