Pars plana vitrectomy

We describe our first 127 vitrectomies through the pars plana performed on 120 eyes for a variety of indications. The success rate in anterior segment disorders was 45% and in those of the posterior segment 34%. While in some cases the results were encouraging, in others they were disastrous. Some 12 eyes (10%) went on to lose perception of light.     

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.     

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 detachment in Ehlers-Danlos syndrome. Treatment by pars plana vitrectomy

Ehlers-Danlos syndrome (EDS) is an hereditary connective tissue disorder caused by defective collagen synthesis, the main features being hyperelasticity and vulnerability of the skin, recurrent bleeding from fragile blood vessels, and secondary deformities of the joints. Ocular involvement is a rare occurrence, e.g., corneal and scleral rupture from minor blunt injury, lens displacement, rhegmatogenous retinal detachment. To date, few reports exist concerning the treatment of retinal detachment in Ehlers-Danlos syndrome, all of them dealing exclusively with conventional scleral buckling surgery. PATIENT AND METHODS: We report on a 47-year-old male patient suffering from EDS type VI (so-called ocular type, lysine-hydroxylase deficiency). He presented with rhegmatogenous retinal detachment in his only eye. A scleral buckling procedure was not feasible because of marked scleral atrophy. A three-port vitrectomy was therefore carried out. RESULTS: During the operation, pronounced choroidal detachment and bleeding developed, subsiding within weeks postoperatively. Closure of the sclerotomies was difficult due to scleral thinning. Two revitrectomies were necessary because anterior PVR with traction retinal detachment occurred. The last revitrectomy was performed 18 months ago, and the retina has been completely reattached under 5000 cs silicone oil since then. Visual acuity is 0.1. CONCLUSION: Primary vitrectomy permits successful treatment of retinal detachment in EDS patients if a buckling procedure cannot be performed because of scleral atrophy. However, serious complications may occur. Surgical procedures other than primary vitrectomy should therefore always be carefully considered, e.g., pneumatic retinopexy, temporary balloon, dura patch with episcleral pocket.     

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.     

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.     

Endophthalmitis in eyes following vitrectomy

The authors describe two patients who underwent pars plana vitrectomy for nonclearing vitreous hemorrhage. Both patients had severe pain, increased intraocular pressure, and orbital swelling. The anterior chamber became flat in a phakic eye. The infection progressed rapidly, and ultimately evisceration was required in both cases. The presence of a flat anterior chamber in gas-filled, phakic eyes and a severe orbital inflammatory reaction in the early postoperative period should alert the physician to the possibility of endophthalmitis.     

Phaco-emulsification of cataract in eyes with glaucoma

Previous observations on the dissemination of Coxiella burnetii between laboratory animals strongly support the hypothesis of venereal transmission. Serum and semen samples, from 57 bulls used for artificial insemination, were assayed for specific C. burnetii phase II antibodies and the presence of the organism respectively. Viable C. burnetii were detected in the semen of seropositive bulls. These findings indicate the possibility of sexual transmission of C. burnetii between cattle and further our knowledge of the epidemiology of the organism. The procedures used for investigations into the source of infection and route of tran-mission should be modified to take these findings into account.     

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.     

Cataract and implantation in the vitrectomized eyes

The SOS Chromotest was carried out on leachates of ten industrial wastes with the standard procedure and a miniaturized version with microplates. The two methods gave identical results in nine samples (eight negative and one positive). A simple additional manipulation is described for the identification of the false positive response that is frequently observed with complex mixtures. It involves challenging the SOS Chromotest bacteria with samples (having previously shown a positive genotoxic response) just before the enzymatic activities (i.e. beta-galactosidase and alkaline phosphatase) are estimated colorimetrically. This additional step eliminates discrepancies between the results for the standard and the miniaturized procedures.     

Distribution of proteoglycans in the trabecular tissue of eyes with neovascular glaucoma

We investigated histo-chemically the composition and distribution of proteoglycans in the trabecular tissue of eyes with neovascular glaucoma. Cupromeronic blue in combination with a series of enzyme digestions and nitrous acid treatment were used. The spaces between the trabecular beams were lined by a single layer of vascular endothelium and were filled with red blood cells. A basal lamina and microfibrils were detected just beneath the newly formed vascular endothelial cells. Chondroitin-sulfate- and dermatan-sulfate-type proteoglycans were present in association with collagen fibrils in the extracellular matrix. Heparan-sulfate-type proteoglycans were present in association with the basal lamina of both the vascular endothelial cells and the trabecular cells. It is unlikely that these abnormalities in the type or distribution of proteoglycans in the trabecular meshwork have a major role in the pathogenesis of glaucoma.     

Glutamine immunoreactivity in Müller cells of monkey eyes with experimental glaucoma

Irritable bowel syndrome (IBS), a chronic disorder that includes symptoms such as abdominal pain and altered bowel habits, affects up to 22% of people in Western populations. The causes of IBS are not well understood, but are believed to be multifactorial. Although stress is widely believed to be implicated, empirical evidence in support of this is lacking, perhaps because a typical between-participants analysis ignores individual differences and therefore may obscure any link. The present study used a within-person, lagged time-series approach to investigate the links between everyday stress and symptomatology in 31 IBS sufferers. Both everyday stress and symptomatology exhibited serial dependence for a statistically significant proportion of sufferers. Multiple regression analysis carried out on same-day and lagged relationships up to and including 4 days found that, for over half the participants, everyday stress and symptoms were related. The best regression model was one in which symptoms were a function of hassles and symptoms on the previous 2 days, and hassles on the same day, fitting the data for 67% of participants. This prospective study confirms other studies that have suggested stress is a significant factor in IBS, and concludes that stress management programs may be both useful and cost-effective in the treatment of IBS.     

Long tube implants in the management of glaucoma

The design, surgical insertion and results of a plastic draining implant for severe glaucoma are reported. The need for pharmacological control of bleb inflammation is stressed and the favourable long-term outlook for patients with such implants is discussed.     

Extracapsular cataract extraction with posterior chamber lens implantation in primary angle-closure glaucoma

PURPOSE: To evaluate long-term intraocular pressure (IOP) control after extracapsular cataract extraction (ECCE) with posterior chamber intraocular lens (IOL) implantation in patients with primary angle-closure glaucoma. SETTING: Ophthalmology Department, Groote Schuur Hospital, Cape Town, South Africa. METHODS: This retrospective study comprised 17 patients (19 eyes) with primary angle-closure glaucoma who had ECCE and posterior chamber IOL implantation. Four presented initially with acute glaucoma, 5 with subacute angle-closure glaucoma, and 8 (10 eyes) with chronic angle-closure glaucoma. In all, less than half the circumference of the angle was permanently closed. The drainage angle was evaluated preoperatively and postoperatively to monitor changes in the amount of angle closure. Intraocular pressure was measured in the early and late postoperative periods. RESULTS: On the first postoperative day, mean IOP was 17.2 mm Hg, although 5 patients (26%) had an IOP rise above 21 mm Hg despite the use of perioperative topical pilocarpine gel. After a mean follow-up of 19 months, IOP remained below 22 mm Hg without medication in 13 eyes (68%) and with topical medication in 5 eyes (26%). Mean number of glaucoma medications was reduced from 1.5/eye preoperatively to 0.5/eye postoperatively. CONCLUSION: Cataract extraction with IOL implantation resulted in good long-term IOP control in patients with primary angle-closure glaucoma, suggesting that combined cataract and trabeculectomy surgery may not be necessary to achieve long-term IOP control in these patients.     

Influence of refraction on the visual field defects in normal tension glaucoma and primary open angle glaucoma eyes

The prevalence of normal tension glaucoma (NTG) or primary open angle glaucoma (POAG) is higher in myopic populations and the prevalence of myopia and NTG is relatively high in the Japanese. To evaluate the influence of myopic refractive error on the central visual field defect in NTG eyes, the data obtained from NTG eyes with the Humphrey Visual Field Analyser were analysed in comparison with those from POAG eyes. One hundred and twenty NTG eyes and one hundred and ninety-seven POAG eyes were included. All of them had clear ocular media, but no myopic degeneration in the fundus. Multiple linear regression analysis was performed with a dependent variable of the deviation of the measured threshold value from normal reference value (total deviation, STATPAC) and independent variables of refractive error and mean deviation (STATPAC). Myopic power was found to be positively correlated with the depression in the lower papillo-macular area in both NTG and POAG eyes, and it was negatively correlated with the depression in an upper arcuate area extending just nasal to the fixation only in NTG eyes.     

Intracapsular foldable posterior chamber lens implantation in eyes with posterior capsule tears or zonular fiber instability

A surgical technique is described for foldable posterior chamber intraocular lens implantation in the capsular bag in the presence of a posterior capsule tear or weakened zonular fiber support. Haptics are compressed by suturing before endocapsular insertion, minimizing capsular and zonular fiber stress.