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A further subdivision of functions during vitrectomy surgery has been enabled. By means of a separate, suture-secured fiberoptic endoilluminator and a modified infusion cannula located in the inferior quadrants, two superior sclerotomies are kept free for the use of a variety of simple and complex instruments, alone or in combination. Included among these are vitreous scissors, forceps, picks, spatulas, diathermy probes, and endophotocoagulators.
The continuous-infusion air pump offers the advantages of rapid and accurate adjustment of the intraocular pressure at vitrectomy and may be used to provide either fluid or air infusion.
The final visual acuities and prognostic factors predictive of these results were analyzed in 353 eyes that had pars plana vitrectomy for nonclearing diabetic vitreous hemorrhage. Eighty-one percent of the eyes had improved visual acuities on final examination. The percentage of eyes that achieved a visual acuity of 20/100 or better and the percentage that achieved 5/200 or better increased during the study period. Preoperative factors associated with a favorable visual prognosis included the following: preoperative visual acuity of 5/200 or better, absence of iris neovascularization, absence of neovascular glaucoma, clear lens or minimal cataract, and panretinal photocoagulation of at least one fourth of the fundus. Intraoperative factors associated with a favorable visual prognosis included retaining the crystalline lens and absence of an intraocular gas bubble.
We prospectively studied 36 consecutive premature infants with the diagnosis of retinopathy of prematurity stage V with total traction retinal detachment who underwent lensectomy/vitrectomy and epiretinal membrane delamination. The first 26 patients underwent vitrectomy using thrombin mixed with Balanced Salt Solution Plus at a concentration of 100 U/mL and the remaining ten patients had pure Balanced Salt Solution Plus used. Intraoperative and postoperative bleeding were monitored. The overall intraoperative bleeding rate was 92% (33/36). Intraoperative bleeding (19% vs 80%) and bleeding at the time of wound closure (4% vs 30%) were both significantly reduced in the thrombin vs no thrombin group.
A small group of eyes with proliferative diabetic retinopathy develop progressive macular traction characterized by partial vitreous detachment with vitreo-retinal traction along the arcades and disc, retinal traction lines extending through the fovea, and progressive visual loss. Vitrectomy may be helpful in stabilizing selected eyes and actually improving visual acuity.
Pars plana vitrectomy was performed in 16 eyes to release vitreomacular traction. All patients had a symptomatic preoperative decrease in visual acuity, most often to 20/200. Partial detachment of the posterior vitreous surface was associated with vitreoretinal attachment remaining in the area of the macula and sometimes to the optic nerve head. The posterior vitreous traction on the macula was released by tangential traction on the posterior vitreous surface, causing it to separate from the retina. The postoperative vision was the same or improved in each case. No operative complications occurred, but progressive nuclear sclerosis developed postoperatively in five of the 15 phakic eyes.
Traumatic retinal incarceration into a scleral wound may prevent successful surgical rehabilitation of eyes with severe posterior segment injury. We managed 15 consecutive eyes with traumatic retinal incarceration and associated retinal detachment with vitrectomy techniques. We based our approach on the anteroposterior location of the incarceration site and the amount of retina incarcerated into the wound. Despite successful anatomic reattachment in six of seven eyes with retinal incarceration posterior to the vortex vein ampullae, only two of seven eyes achieved visual acuity of 5/200 or better. In eyes with more peripheral retinal incarceration, anatomic reattachment was achieved in five of eight eyes and visual acuity of 5/200 or better was achieved in four eyes. Overall, a visual acuity of 5/200 or better was achieved in six (40%) of 15 eyes with a minimum follow-up of six months.
We review our experience and present an analysis of 119 consecutive cases of macular pucker treated by vitrectomy and removal of the epiretinal tissue following treatment for acute retinal tears (16 eyes) or rhegmatogenous retinal detachment (103 eyes). Vision improved postoperatively in 104 (87%) of the 119 eyes. Final visual acuity of 20/60 or better was achieved in 38 (75%) of 51 cases in which the macula had not been detached previously and in 12 (24%) of 52 cases with prior macular detachment. Two preoperative factors were associated with a final visual acuity of 20/100 or better: (1) macula not involved by the original retinal detachment, and (2) thin epiretinal membrane.
Corneal complications after closed vitrectomy were analyzed in patients treated by the same surgeon from January 1980 through December 1986. Of 428 eyes (400 patients), 64 (15%) had corneal complications, 58 (13.6%) had epithelial defects, and 12 (2.8%) had corneal edema. Among 206 diabetic eyes, 41 (19.9%) had corneal complications. Of 222 nondiabetic eyes, only 23 (10.4%) showed complications. Multiple regression analysis of possible contributing factors was performed. Diabetes, intraoperative lensectomy, and history of vitreous surgery were related significantly to the occurrence of all corneal complications combined. Our series showed a significantly decreased complication rate when compared with a previous study. Improved preoperative surgical preparation and intraoperative technique to minimize corneal trauma may have accounted for the decrease.
Seventy-six consecutive patients with total rhegmatogenous retinal detachments and severe proliferative vitreoretinopathy underwent combined pars plana vitrectomy, lensectomy, panretinal photocoagulation, perfluoropropane gas (C3F8)/fluid exchange, and scleral buckling. Sixty-two (82%) of the patients had successful, sustained (greater than 12 months) posterior retinal reattachments at last examination. Of these 62 patients, 40 (65%) had complete retinal attachment, with no evidence of regrowth of periretinal membranes or redetachments following the initial procedure. In the remaining 22 cases with successful reattachment of the retina posterior to the equator, partial peripheral retinal detachments were observed. In 16 of the 22 cases, the detachments occurred entirely anterior to the boundary of the previously placed photocoagulation lesions. The posterior retina remained uninvolved, and no further treatment was needed. Reoperation was required in the other six patients to achieve sustained posterior retinal reattachment. Postoperative visual acuity ranged from 20/40 to bare light perception, with 69% of the anatomically successful cases obtaining functional visual acuity (greater than 20/400). Failures were related to reproliferation of fibrous membranes.
Ten patients (11 eyes) with sickle-C hemoglobinopathy with complications of proliferative sickle retinopathy were treated using pars plana vitrectomy with or without the use of a scleral buckle. Postoperative visual acuity was improved in ten of 11 cases. Three cases of retinal detachment were managed by internal vitreoretinal techniques alone without the use of a scleral buckle. Although exchange transfusions were used in only five of the 11 cases, no cases of recognized anterior segment ischemia occurred during the postoperative course of these patients. Because of exchange transfusion risks and awareness of intraoperative and postoperative measures to reduce this complication, the use of exchange transfusions probably should be discontinued as prophylaxis for vitreoretinal surgery in these patients.
In a retrospective review of 30 cases of complex retinal detachment, which had been managed by pars plana vitrectomy techniques together with silicone oil injection, we found that two patients developed marked postoperative anterior chamber fibrin and hypopyon. In all 30 cases, the same silicone oil was used: purified and heat-sterilized trimethylsiloxy-terminated, polydimethylsiloxane of 1000-centistoke viscosity. Although the silicone oil itself remained clear and without emulsification, the differential diagnosis of this postoperative inflammation included microbial endophthalmitis. These two cases were treated with frequent topical steroids and antibiotics while we closely monitored the retraction of the anterior chamber fibrin. In both cases, clinical improvement and long-term retinal reattachment with satisfactory visual function were achieved. The use of intense scatter laser endophotocoagulation and the presence of impurities in the silicone oil may have contributed to the excessive postoperative inflammation in these cases.
The dynamics of pressure, flow, and ocular volume relationships were examined with respect to extrusion needle use in simulated vitrectomy. Glass-stoppered bottles used with infusion lines with drip chambers lowered the intraocular pressure 4 to 7 inches below the fluid level in the bottle, varying with the amount of fluid in the bottle. Compared with flow rates using the regular tip needle with the steel infusion cannula, the disposable infusion cannula lowered the flow rate by about 25% and the tapered tip extrusion needle decreased outflow by 40% to 50%. Tracer dilution rates were decreased by the use of the disposable infusion port or the aphakic model eye; however, 2 minutes of infusion at a 30-inch bottle height dilution was still sufficient to wash out the tracer to less than 5% of the original concentration.
Combined phacoemulsification and pars plana vitrectomy were performed in eight eyes with cataract and vitreoretinal disease. Six eyes had tractional retinal detachment and/or nonclearing vitreous hemorrhage, one eye had a retained metallic intraocular foreign body, and one eye had a traumatic retinal detachment. In six eyes, a posterior chamber lens implant was placed in the capsular bag. Postoperative visual acuity improved in each case and ranged between 20/15 and 6/200. There were no perioperative complications, and the posterior chamber lens implant appeared well tolerated during an average follow-up interval of 8 months (range, 3 to 30 months). This technique allows endocapsular fixation of a posterior chamber lens and provides rapid visual rehabilitation with a single operation.
We reviewed 14 consecutive cases of subretinal hemorrhage involving the macula, in which surgery to remove the hemorrhage was performed by the authors between February 1984 and January 1989. All patients underwent pars plana vitrectomy and internal subretinal hemorrhage drainage. The causes of subretinal hemorrhages in group 1 were primary rhegmatogenous retinal detachments (three eyes), complications from scleral buckling procedures (three eyes), traumatic retinal detachments (two eyes), and sickle cell retinopathy associated with anticoagulation therapy after a pulmonary embolus (one eye). Group 2 consisted of five eyes with massive subretinal hemorrhage associated with age-related macular degeneration. In group 1, recurrent postoperative retinal detachment occurred in five eyes but reattachment was achieved in eight of the nine eyes, and final visual acuities were 20/400 or better in those eight eyes. In group 2, marked subretinal fibrosis occurred in two eyes. Although three eyes had improved visual acuities, final visual acuities were 5/200 or worse in all five eyes.
Traumatic hemorrhagic retinal detachment may prevent successful visual rehabilitation of eyes with severe posterior segment injury. We managed 19 consecutive cases of traumatic hemorrhagic retinal detachment with pars plana vitrectomy, scleral buckling, and fluid-gas exchange, with or without internal drainage of subretinal hemorrhage. We based our approach on the amount of subretinal hemorrhage present and the location of associated retinal breaks. Internal drainage of subretinal hemorrhage was performed in 16 eyes to allow adequate retinopexy to hemorrhagically elevated retinal breaks (9 eyes), to remove massive subretinal hemorrhage (4 eyes), and to allow intraoperative reattachment when the retina exhibited bullous retinal detachment (3 eyes). Overall, with a minimum of 6 months of follow-up, anatomic reattachment was achieved in 13 (68%) of 19 eyes, and functional success (visual acuity 5/200 or better) was achieved in 6 (32%) of 19 eyes. Anatomic failure resulted from proliferative vitreoretinopathy (4 eyes) and globe atrophy (2 eyes). Drainage of subretinal blood appeared to be beneficial for hemorrhagically elevated retinal tears to allow adequate retinopexy and may help to accomplish long-term anatomic attachment in eyes with massive subretinal hemorrhage or bullous retinal detachment.
We describe herein a two-stage technique of intraoperative fluid-gas exchange following pars plana vitrectomy. The first stage is a complete fluid-air exchange using an air pump and intraocular linear suction. The air pump then maintains the intraocular pressure at the desired level during adjunctive procedures, such as laser endophotocoagulation. The second stage is an air-gas mixture exchange in which the desired gas, premixed in air to the desired final intraocular concentration, is manually flushed through the eye. This technique allows the attainment of an accurate concentration of intraocular gas if the air-gas mixture exchange is complete. In vitro and in vivo experiments in aphakic human eyes demonstrated that an effectively complete air-gas mixture exchange occurs with a 25-mL flush volume. This result compares favorably with the theoretical prediction derived from a "pharmacokinetic approximation" equation.
We studied the inhibition of intraocular fibrin formation following infusion of 5 IU/mL of low-molecular-weight heparin sodium (Fragmin, KabiVitrum AB, Stockholm, Sweden) during lensectomy, vitrectomy, and retinotomy in the rabbit model. Surgery was performed on 18 eyes, with nine receiving low-molecular-weight heparin and nine serving as controls. Masked postoperative examinations assessed fibrin quantity, corneal clarity, media clarity, and amount of vitreous hemorrhage. Five (56%) of nine eyes receiving low-molecular-weight heparin did not show fibrin exudation development, with the remainder demonstrating a minimal fibrin response. Eight (89%) of nine control eyes demonstrated prominent fibrin exudation, with five (56%) showing development of a fibrin clot that obscured two or more quadrants of the posterior chamber. No significant difference in the degree of vitreous hemorrhage was noted between groups. Corneal clarity was improved in the heparin-treated group.