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PubMed1999

Motility and binocularity outcomes in vitrectomy versus scleral buckling in retinal detachment surgery.

BACKGROUND: Ocular motility defects and loss of binocularity are well-recognised problems following retinal detachment surgery. It is presumed that scleral buckling is primarily responsible for these effects. The increasing use of vitrectomy in the management of retinal detachment might be expected to reduce the incidence of these defects. METHOD: Two groups of patients presenting with primary uncomplicated rhegmatogenous retinal detachments were examined following a single surgical repair. The first group underwent vitrectomy (n = 17), the second group, scleral buckling/external surgical techniques (n = 23). RESULTS: Heterotropia was present in 24% (n = 4) of the vitrectomy group and 30% (n = 7) of the "external" group, with suppression reported clinically in 8 of these and diplopia by the other 3. While ocular movements were frequently full (vitrectomy 59%, external 61%), restricted vertical movements were observed in 35% of the vitrectomy group and 26% of the external group, with horizontal and general restrictions being rare (6% and 13% respectively). True motor fusion was more common for the external group (44%) than the vitrectomies (24%), while superimposition was more frequent in the vitrectomies (64%; external 39%). The latter was achieved only with correcting prisms in 18% of vitrectomies and 9% of the external group. The remainder did not demonstrate any potential for binocularity. Visual symptoms were more frequent among the vitrectomy group, with aniseikonia and torsion significantly more common. CONCLUSIONS: The findings confirm that ocular motility problems are not exclusive to scleral buckling, with the incidence being similar in both groups. Slinging of the extraocular muscles and the accompanying dissection, resulting in the 'fat adherence syndrome', must be considered as contributory factors. The visual deficits which inevitably occur as the result of retinal detachment seem to play a more major role in the disruption of binocularity in these cases.

Adolescent↗

PubMed2001

Outcome of vitrectomy for retained lens fragments after phacoemulsification.

PURPOSE: To evaluate the incidence of complications and the visual outcome of pars plana vitrectomy in patients with retained lens fragments in the vitreous cavity after phacoemulsification. METHODS: A retrospective chart review of 85 patients who underwent vitrectomy for removal of retained lens fragments at the Barnes Retinal Institute/Washington University Medical Center between 1990 and 1998. RESULTS: At the time of presentation, uveitis (n = 57, 67.1%), increased intraocular pressure >25 mmHg (n = 44, 51.8%), and corneal edema (n = 42, 49.4%) were frequently observed. The initial visual acuity was 20/200 or worse in 61 (71.8%) eyes. However, the final visual acuity after vitrectomy, with 10.1 months follow-up, was 20/40 or better in 44 (51.8%) eyes. The major complication observed was retinal detachment, which was present in seven (8.2%) eyes: four before vitrectomy and three after vitrectomy. Visual outcome after vitrectomy and cataract extraction was compared among three groups based on the timing of the second surgery: < or =7 days postcataract extraction; 8-30 days postcataract extraction; and >30 days postcataract extraction. No statistically significant difference in final visual acuity was observed between the three intervals. CONCLUSIONS: The major complication associated with vitrectomy for retained lens fragments in the vitreous cavity after phacoemulsification was retinal detachment. The timing of vitrectomy did not affect the final visual acuity outcome. Visual prognosis was most closely related to the presence of age-related macular degeneration and cystoid macular edema. The type of intraocular lens did not influence the visual outcome. Management with vitrectomy yielded favorable visual results in most patients with retained lens fragments.

Aged↗

PubMed2006

25-Gauge pars plicata vitrectomy for stage 4 and 5 retinopathy of prematurity.

PURPOSE: To describe the authors' technique and initial experience using the 25-gauge vitrectomy system for stage 4 and 5 tractional retinal detachment in retinopathy of prematurity (ROP). METHODS: Consecutive patients with stage 4 or 5 ROP treated with 25-gauge vitrectomy surgery between July 2003 and May 2004 were studied retrospectively. Eyes with prior vitrectomy surgery were excluded. A modified three-port 25-gauge approach was used in which conjunctival dissection and suturing of sclerotomies was necessary. The primary outcome was anatomic success defined as retinal reattachment. Secondary outcomes were intra- and postoperative complications. RESULTS: Fifteen eyes in 12 infants were identified that had 25-gauge vitrectomy for stage 4 or 5 ROP: 11/15 (73%) had stage 4A; 2/15 (13%), stage 4B; and 2/15 (13%), stage 5. All 15/15 (100%) were referred with incomplete anterior laser ablation of threshold ROP. Six of 15 (40%) required lensectomy at the time of initial pars plicata vitrectomy. Seven of 15 (47%) required more than one retinal surgery for persistent retinal detachment and/or vitreous hemorrhage. Eleven of 15 (73%) eyes had documented retinal reattachment after one or more surgeries at the last follow-up. Complications included vitreous hemorrhage (2) and postoperative cataract (1). CONCLUSIONS: Twenty-five gauge vitrectomy is a safe and effective treatment approach for tractional retinal detachments in stage 4 and 5 ROP. Complications may be comparable to vitrectomies performed with two-port 20-gauge vitrectomy. Modifications of the 25-gauge vitrectomy system included conjunctival dissection and suturing of conjunctiva and sclerotomies at the conclusion of the case.

Equipment Design↗

PubMed2003

Primary vitrectomy for pseudophakic retinal detachment: a prospective non-randomized study.

PURPOSE: To compare the anatomic and functional results of primary vitrectomy alone or vitrectomy-scleral buckling for pseudophakic retinal detachment (RD). Vitrectomy permits a detailed view of the peripheral retina, so otherwise undetectable holes or additional small lesions can be found which, left untreated, may cause a residual RD. PATIENTS AND METHODS: Twenty-four consecutive pseudophakic eyes with pseudophakic RD were operated by vitrectomy and encircling band (Group I) and 27 additional cases were operated on by vitrectomy alone (Group II). Internal subretinal fluid drainage, using liquid perfluoro-n-octane, endolaser, and/or cryocoagulation and fluid-air exchange with SF6 20%, was applied in all cases. Preoperative findings and intraoperative and postoperative complications as well as final results were analyzed. RESULTS: Preoperatively undetected retinal holes were identified in 7 of the 51 eyes and additional retinal holes were found in 21. The mean follow-up was 14 months for Group I and 11.5 months for Group II. The retina was successfully reattached with a single operation in 22 of 24 eyes (92%) in Group I. One eye had a recurrence of RD due to an unsuccessfully treated preexisting retinal tear. Proliferative vitreoretinopathy (PVR) was observed in one case with recurrence of RD. In both cases, a second operation achieved retinal reattachment. In Group II, the retinas were attached with a single operation and visual acuity improved by an average of four or more lines in 62.5% of the vitrectomy-buckling group and in 55.5% of the vitrectomy group. The most frequent complication was a transient hypertony, in 21 cases. CONCLUSIONS: Surgical treatment of pseudophakic RD, combining vitrectomy and scleral buckling or vitrectomy alone, achieves very good anatomic and functional results. The advantages include more efficient detection of the peripheral detachment causing retinal lesions, and a lower redetachment rate than after extraocular surgery only.

Adult↗

PubMed2006

Lens-sparing vitrectomy for stage 4 and stage 5 retinopathy of prematurity.

PURPOSE: To describe the results of lens-sparing vitrectomy for the correction of retinal detachment associated with retinopathy of prematurity (ROP) and its associated complications. METHODS: Seventeen patients who underwent a lens-sparing vitrectomy for stage 4 and stage 5 ROP with plus disease at Seoul National University Children' s Hospital between 1999 and 2003 were enrolled in this study. The patients who had bilateral retinal detachment of ROP underwent a lens-sparing vitrectomy in one eye and a scleral buckling surgery or lensectomy-vitrectomy in the other eye. The patients who had a retinal detachment in one eye and a regressed ROP in the other eye underwent unilateral lens-sparing vitrectomies. A review of their preoperative clinical findings (including the status of retinal detachment and plus disease), post-operative results, and any complications encountered was performed. RESULTS: In 17 patients, the postoperative success rate of lens-sparing vitrectomy was 58.8%. However, lens-sparing vitrectomy as a treatment for stage 5 ROP (25.0%) produced more negative post-operative results than it did when used to treat either those for stage 4a (75,0%) or 4b (66.7%) ROP. Among the 10 eyes in which the retina was attached, form vision was shown in six eyes, light could be followed by three eyes, and no light perception was present in one eye. Intra- and post-operative complications included retinal break formation, cataracts, vitreous hemorrhages, and glaucoma in patients with stages 4b and stage 5 ROP. CONCLUSIONS: Lens-sparing vitrectomy resulted in encouraging surgical outcomes in the correction of retinal detachment of ROP, especially in stage 4 patients. Therefore, a lens-sparing vitrectomy for stage 4 ROP patient may be beneficial, although it is still associated with some intra- and post-operative complications.

Child, Preschool↗

PubMedDate not supplied

Iris neovascularization after vitrectomy combined with phacoemulsification and intraocular lens implantation for proliferative diabetic retinopathy.

PURPOSE: To analyze the incidence of iris neovascularization after vitrectomy combined with phacoemulsification and intraocular lens (IOL) implantation using a small incision in the treatment of proliferative diabetic retinopathy (PDR). PATIENTS AND METHODS: We studied a consecutive series of 46 eyes in which vitrectomy combined with phacoemulsification and IOL implantation had been performed, and compared the surgical results with a prior series of 40 eyes in which vitrectomy alone had been performed. RESULTS: Postoperative iris and angle neovascularization was found in 6 eyes (15%) treated by vitrectomy alone, but in only 1 eye (2%) treated by combined vitrectomy (P<0.05). Final visual acuity improved by two or more lines in 23 eyes (57%) in the vitrectomy alone group, and in 35 eyes (76%) in the combined vitrectomy group. CONCLUSIONS: The incidence of postoperative rubeosis iridis was significantly lower, and the visual results were satisfactory with vitrectomy combined with phacoemulsification and IOL implantation for PDR. These findings suggest that combined vitrectomy for PDR is a useful surgical procedure.

Adult↗

PubMed1991

[Extracapsular cataract extraction and implantation in the capsular sac during vitrectomy in diabetics].

Removal of the lens is often performed during pars plana vitrectomy for complications of proliferative diabetic retinopathy, but correction of aphakia often remains unsatisfactory. Some authors have reported posterior chamber intraocular lens implantation during pars plana vitrectomy in diabetic patients who presented with coexisting cataract and vitreoretinal complications from proliferative diabetic retinopathy. Some patients were operated by pars plana lensectomy and vitrectomy followed by posterior chamber intraocular lens implantation in the ciliary sulcus, others by extracapsular extraction, posterior chamber intraocular lens implantation in the ciliary sulcus, and pars plana vitrectomy. Other authors have described phacoemulsification through the limbus, pars plana vitrectomy and implantation in the capsular bag in one operation in various indications, including complications of proliferative diabetic retinopathy. We inserted a posterior chamber intraocular lens into the capsular bag in 18 eyes of 16 patients with complications of proliferative diabetic retinopathy after extracapsular cataract extraction and pars plana vitrectomy in a single session. A standard extracapsular cataract extraction was performed before pars plana vitrectomy. Sufficient anterior capsule was left in place in order to facilitate implantation in the capsular bag after pars plana vitrectomy. The anterior chamber was filled with sodium hyaluronate in order to maintain anterior chamber depth, corneal clarity, and good mydriasis during the continuation of the procedure. A standard three port pars plana vitrectomy was performed in all cases. After closure of superior sclerotomies, superior corneal incision was partially reopened, an intraocular lens specifically designed for the capsular bag with an optic size of 7 mm was inserted, and the corneal incision was closed with interrupted 10/0 sutures.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1996

Pars plana vitrectomy in the management of phakic and pseudophakic malignant glaucoma.

OBJECTIVE: To determine the indications for and outcome of pars plana vitrectomy in the management of phakic and pseudophakic malignant glaucoma. DESIGN: Retrospective review. SETTING: Tertiary referral ophthalmic hospital. PATIENTS: Twenty-two patients (24 eyes) who underwent pars plana vitrectomy in the management of malignant glaucoma. RESULTS: Fourteen eyes were phakic and 10 were pseudophakic at the initial vitrectomy. The primary indication for vitrectomy was failure of other therapies. In phakic eyes, the initial vitrectomy was successful in terminating malignant glaucoma without further surgery in 7 (100%) of 7 eyes that underwent lensectomy and in 5 (71%) of 7 eyes that not did not undergo lensectomy. The primary indication for lensectomy was corneal edema caused by lens-corneal touch. In pseudophakic eyes, the initial vitrectomy was successful in 9 (90%) of 10 eyes. Removal of the intraocular lens was performed in 1 eye. Perioperative complications included transient serous choroidal detachment in 2 eyes, transient exudative retinal detachment in 1 eye, and suprachoroidal hemorrhage in 1 eye. CONCLUSIONS: Pars plana vitrectomy is effective in treating phakic and pseudophakic malignant glaucoma. Success is contingent on establishing a pathway for aqueous flow into the anterior chamber, which usually is accompanied by intraoperative deepening of the anterior chamber. In phakic eyes, lensectomy may be considered for marked corneal edema, for dense cataract, or when the anterior chamber will not deepen during vitrectomy.

Adult↗

PubMed2001

Vitrectomy results in diabetic macular oedema without evident vitreomacular traction.

PURPOSE: To determine the effectiveness of vitrectomy in eyes with diabetic macular oedema without evident traction from a thickened vitreous membrane. METHODS: Twenty-one consecutive eyes from 19 patients with diabetic macular oedema that had undergone vitrectomy were analysed retrospectively. All eyes had an attached posterior hyaloid membrane in the macular region, but without thickening and without evident traction on the macula. A standard pars plana vitrectomy with the creation of a posterior vitreous detachment was performed. RESULTS: Median duration of macular oedema at the time of vitrectomy was approximately 11.0 months (range 2-36 months). The median preoperative best-corrected visual acuity of 0.08 (range hand motions/0.003 to 0.4), improved by 5 lines to a median final postoperative best-corrected visual acuity of 0.25 (range 0.025-0.5) (P = 0.001). Seven eyes without preoperative macular photocoagulation had a median visual acuity improvement of 77%, range 32-400%, while 12 eyes with preoperative macular laser treatment had a median visual acuity improvement of 14.8%, range 0-66.1% (P = 0.02, CI 95%, after multivariate regression analysis). In all 21 eyes, macular oedema was no longer visible on microscopic examination after a median period of 3.0 months (range 1-9 months) after vitrectomy. CONCLUSIONS: In eyes with diabetic macular oedema without evident macular traction from a thickened vitreous membrane, vitrectomy resulted in the resolution of macular oedema, with an improvement in visual acuity in the majority of cases. Eyes without preoperative macular photocoagulation had a significantly higher percentage visual improvement than eyes without preoperative macular laser treatment. A randomised controlled prospective trial of primary vitrectomy versus macular photocoagulation is needed to determine the role of vitrectomy as treatment modality for diabetic macular oedema.

Adult↗

PubMed2005

Vitrectomy surgery increases oxygen exposure to the lens: a possible mechanism for nuclear cataract formation.

PURPOSE: To report vitreous oxygen tension before, immediately after, and at longer times after vitrectomy. DESIGN: A prospective, interventional consecutive case series. METHODS: Oxygen was measured using an optical oxygen sensor in patients undergoing vitrectomy. Intraoperatively, oxygen measurements were taken before and after vitrectomy in two intraocular locations: adjacent to the lens and in the mid-vitreous. RESULTS: Sixty-nine eyes underwent oxygen tension measurements at the time of vitrectomy. In baseline eyes, oxygen tension in the vitreous was low, measuring 8.7 +/- 0.6 mm Hg adjacent to the lens and 7.1 +/- 0.5 mm Hg in the mid-vitreous. The difference between the two locations was statistically significant (P < .003), indicating that vitreous gel maintains an intraocular oxygen gradient. Immediately after vitrectomy, oxygen tension in the fluid-filled eye was higher, measuring 69.6 +/-4.8 mm Hg adjacent to the lens and 75.6 +/- 4.1 mm Hg in the mid-vitreous. There was no statistically significant oxygen gradient between the two locations. The difference in oxygen tension pre- and postvitrectomy is highly statistically significant (P < .0001 lens, P < .0001 mid-vitreous). In eyes with a history of vitrectomy and previous removal of the vitreous gel, the intraocular oxygen tension was significantly higher than in eyes with a formed vitreous gel undergoing a first vitrectomy (P < .02 lens, P < .003 mid-vitreous). CONCLUSION: Vitrectomy surgery significantly increases intraocular oxygen tension during and for prolonged periods after surgery. This exposes the crystalline lens to abnormally high oxygen and may lead to nuclear cataract formation.

Aged↗

PubMed2004

Oxygen tension in the rabbit lens and vitreous before and after vitrectomy.

Oxygen is believed to be one of the potential causative agents for the development of nuclear cataract following vitrectomy. The aim of this study was to determine the partial pressure of oxygen (pO2) in different compartments of the rabbit eye, and to describe the changes following vitrectomy. Twenty-six rabbits (3.5-5.3 kg) were anesthetized and oxygen tension was probed using a fiber-optic oxygen sensor system (optode). A micromanipulator was employed to ascertain the exact position of the probe within the eye. Measurements were taken pre- and post-vitrectomy at several defined positions within the vitreous, the lens and the anterior chamber. Follow-up measurements were performed 2 and 8 weeks after vitrectomy. The contralateral eye served as a control. Measurements in the normal rabbit eye showed that oxygen tension in the globe is asymmetrical with the lowest pO2 in the nucleus of the lens (10.4 mmHg+/-3.0). The region of the lens near the posterior capsule has an oxygen tension close to the values of the vitreous directly behind the posterior capsule (12.4 mmHg+/-3.1). The highest pO2 within the posterior compartment of the eye was measured close to the retinal surface (40-l60 mmHg) depending on neighboring large vessels. The tension drops off rapidly to 20 mmHg some 0.5 mm from the retina. From that position to the posterior surface of the lens there is a shallow gradient of decreasing pO2. Immediately following vitrectomy the pO2 in the BSS replacement varied from ca. 90-140 mmHg, and decreased over approximately 30 min. to levels that were 2-3 times that of normal vitreous. Two weeks after vitrectomy the pO2 values in the lens were 2-3 times as high as in the control eye (p < 0.05). In addition there is no longer a gradient in the vitreous cavity, except close to the retina. Eight weeks after vitrectomy, pO2 levels in the lens were decreased but still remained higher than in the normal eye (13.83 mmHg+/-0.02). The pO2 gradient in the vitreous was not detectable anymore. Overall the results provide evidence that oxygen levels in the lens increase significantly after vitrectomy in rabbits. If this occurs in humans it may contribute to cataract formation following surgery.

Animals↗

PubMed2003

Retinal detachment rate after vitrectomy for retained lens material after phacoemulsification.

PURPOSE: To report the rate of retinal detachment after vitrectomy for retained intravitreal lens material after phacoemulsification using specific vitrectomy techniques designed to minimize retinal detachment. DESIGN: Consecutive, interventional case series. METHODS: Retrospective chart review of 100 consecutive eyes (one surgeon) of 100 patients undergoing vitrectomy for retained lens material after phacoemulsification and followed up for 3 months or longer unless an outcome event had occurred. Vitrectomy techniques employed to minimize the frequency of retinal detachment included inducing posterior vitreous detachment with maximal vitreous removal before phacofragmentation to avoid vitreous trauma, lens fragment debulking before fragmentation, use of low energy with high aspiration during removal of retained lens material, and intraoperative indirect ophthalmoscopic evaluation of the retinal periphery with scleral indentation to diagnose and treat intraoperative retinal breaks. The main outcome measures included prevalence of coexisting retinal detachment in eyes with retained lens material, incidence of retinal detachment or retinal breaks after vitrectomy for removal of retained lens material, and final visual acuity. RESULTS: The prevalence of previtrectomy retinal detachment was 4%; the incidence of postvitrectomy retinal detachment was 4%; the final visual acuity was 20/40 or better in 53%. One patient had a retinal break recognized during vitrectomy and was treated with retinocryopexy, but postoperative retinal detachment developed from a separate break. Three others were treated during vitrectomy for retinal breaks (including two with known preexisting breaks) and did not have any retinal detachment. Poor previtrectomy visual acuity (hand motions) was a risk factor for postvitrectomy retinal detachment. CONCLUSIONS: The rate of retinal detachment reported after vitrectomy for retained lens material after phacoemulsification can be minimized to approximately the rate expected with cataract extraction complicated by vitreous loss by employing standard surgical techniques. Higher risk eyes may benefit from more frequent postvitrectomy examinations.

Aged↗

PubMed1995

Evaluation of vitrectomy machines as a source of false-positive culture contamination in endophthalmitis.

PURPOSE: We sought to determine whether a venturi-aspiration vitrectomy machine could contaminate a vitrectomy culture. METHODS: Ninety vitrectomies were simulated in a hospital operating room and were cultured with standard techniques. An additional 90 control specimens were cultured in the exact same manner, but the vitrectomy machine was not used. Instead, the control specimens were placed directly into a sterile vitrectomy cassette. Contamination rates in the two groups were compared. RESULTS: Contamination occurred in four of 90 vitrectomy-simulation cultures and in three of 90 control cultures. This difference in contamination rate was not statistically significant. CONCLUSIONS: Although the result of a culture of the vitrectomy effluent can be false-positive, the source of contamination is not likely to be the vitrectomy machine.

Bacteria↗

PubMed2002

A new 25-gauge instrument system for transconjunctival sutureless vitrectomy surgery.

OBJECTIVES: To introduce and evaluate the infusion and aspiration rates and operative times of the 25-gauge transconjunctival sutureless vitrectomy system (TSV) DESIGN: In vitro experimental and comparative interventional study. PARTICIPANTS AND CONTROLS: Twenty eyes of 20 patients underwent a variety of vitreoretinal procedures using the 25-gauge TSV, including idiopathic epiretinal membrane (n = 10), macular hole (n = 4), rhegmatogenous retinal detachment (n = 3), branch retinal vein occlusion (n = 2), diabetic vitreous hemorrhage (n = 1), and 20 cases similar in diagnosis and severity were matched to provide comparison between duration of individual portions of the surgical procedures with the existing 20-gauge vitrectomy system. METHODS: Description of the 25-gauge TSV is provided; infusion and aspiration rates of the 25-gauge and standard 20-gauge vitrectomy system were measured in vitro using balanced saline solution and porcine vitreous for several levels of aspirating power and bottle height, and operating times of individual portions of surgical procedures were measured for the 25-gauge and 20-gauge vitrectomy system. MAIN OUTCOME MEASURES: Infusion, aspiration rates, and operative times of the 20-gauge and 25-gauge vitrectomy system. RESULTS: Infusion and aspiration rates of the 25-gauge TSV system were reduced by an average of 6.9 and 6.6 times, respectively, compared with the 20-gauge system when balanced saline solution was used. The average flow rate of the Storz 25-gauge cutter (at 500 mmHg, 1500 cuts per minute [cpm]) was 40% greater than that of the 20-gauge pneumatic cutter (at 250 mmHg, 750 cpm) but about 2.3 times less than the 20-gauge high-speed cutter (at 250 mmHg, 1500 cpm). Mean total operative time was significantly greater for the 20-gauge high-speed cutter (26 minutes, 7 seconds) than for the 25-gauge vitrectomy system (17 minutes, 17 seconds) (P = 0.011). CONCLUSIONS: Although the infusion and aspiration rates of the 25-gauge instruments are lower than those for the 20-gauge high-speed vitrectomy system, the use of 25-gauge TVS may effectively reduce operative times of select cases that do not require the full capability of conventional vitrectomy.

Diabetes Complications↗

PubMed1993

Perioperative choroidal hemorrhage at pars plana vitrectomy. A case-control study.

PURPOSE: Risk factors for choroidal hemorrhage during pars plana vitrectomy surgery are currently not well defined. The authors analyzed potential risk factors for perioperative choroidal hemorrhage at pars plana vitrectomy in a case-control study. METHODS: Of 683 consecutive vitrectomy procedures, 13 cases of choroidal hemorrhage were identified in the operative or immediate postoperative period. Fifty vitrectomy controls from the same period were randomly selected and were compared with the hemorrhage cases by univariate analysis with respect to various potential risk factors. RESULTS: The incidence of choroidal hemorrhage associated with vitrectomy was 1.9%. Statistically significant risks (P < or = 0.05) included: greater age (mean, 70.9 versus 52.1 years); elevated preoperative pressure (19.9 versus 13.0 mmHg); preoperative diagnosis of rhegmatogenous retinal detachment (relative risk, 8.1); aphakic or pseudophakic status (relative risk, 5.2); and scleral buckle procedure at vitrectomy (relative risk, 12.0). Eyes with previous ocular trauma and previous vitrectomy had a reduced risk of choroidal hemorrhage. The incidence of severe visual loss (final visual acuity < 5/200) did not differ significantly from controls. CONCLUSIONS: Significant risk factors for choroidal hemorrhage are identified in this study which may help to identify patients at increased risk for this complication. Good visual outcome is possible after choroidal hemorrhage at vitrectomy (69% with visual acuity > 5/200).

Aged↗

PubMed1995

Vitrectomy for ciliary block (malignant) glaucoma.

BACKGROUND: Ciliary block (malignant) glaucoma is a rare surgical complication occurring in patients with pre-existing glaucoma. Misdirected aqueous fluid causes forward movement of the lens/iris diaphragm, shallowing the central and peripheral anterior chamber. Although most patients with ciliary block respond to medical or laser therapy, those with refractory glaucoma often require pars plana vitrectomy to normalize aqueous flow. METHODS: The medical records of 21 consecutive patients with refractory ciliary block glaucoma treated by pars plana vitrectomy were reviewed retrospectively to determine the efficacy of this procedure in alleviating ciliary block. Data were collected regarding anatomic characteristics of the eye, history of glaucoma, prior ocular surgery, and outcome after vitrectomy. RESULTS: Pre-existing glaucoma and recent intraocular surgery were noted in all patients with ciliary block glaucoma. Of 21 eyes, 8 (38%) had undergone multiple prior intraocular surgeries. The initial pars plana vitrectomy was successful in alleviating ciliary block in 14 (70%) of 20 eyes. Of those six eyes that failed to improve after initial vitrectomy, five (83%) were phakic. Additional vitrectomy surgery to relieve ciliary block was required in three (60%) of five phakic patients who failed initial vitrectomy. Complications during the treatment of ciliary block included cataract formation, retinal detachment, bleb failure, and serous choroidal detachment. CONCLUSIONS: Pars plana vitrectomy is a useful adjunct to therapy for ciliary block glaucoma when medical and laser treatment fail to alleviate the process. Surgically removing the anterior hyaloid to re-establish normal aqueous flow constitutes the primary goal of surgery. In some cases, surgery is compromised by poor visualization of the anterior hyaloid, avoiding glaucoma filtration sites, and guarding against damage to the crystalline lens.

Anterior Chamber↗

PubMed1996

Outcomes of vitrectomy for retained lens fragments.

PURPOSE: Retained lens fragments after cataract surgery is an infrequent, but potentially serious surgical complication. The aim of this study is to evaluate outcomes after vitrectomy has been performed for removal of retained lens material. METHODS: A retrospective review was conducted to evaluate all cases of pars plana vitrectomy for removal of retained lens fragments performed at Wills Eye Hospital from April 1991 through August 1994. RESULTS: A total of 121 eyes of 121 patients underwent pars plana vitrectomy with removal of retained lens material over the 3 1/2-year period. Visual acuity on presentation was 20/200 or worse in 95 eyes (79 percent). Visual acuity after vitrectomy was 20/40 or better in 82 eyes (68 percent). The postoperative visual acuity was 20/50 to 20/400 in 21 eyes (17 percent), and counting fingers or worse in 18 eyes (15 percent). Nineteen eyes (16 percent) had retinal detachment (RD), 8 were noted at the time of vitrectomy and 11 occurred after vitrectomy. Of the 19 eyes with RD, visual acuity was 20/200 or worse in 12 (63 percent) and counting fingers or worse in 6 (32 percent) at the time of last follow-up. The use of posterior segment phacofragmentation was associated with higher rate of RD, but the difference did not reach statistical significance. Major causes of poor final visual outcome included RD (6 eyes), cystoid macular edema (4 eyes), and glaucoma (2 eyes). CONCLUSION: The timing of vitrectomy did not have a statistically significant impact on visual outcome. Neither the type of intraocular lens nor the timing of lens implantation significantly altered the final visual acuity. Most eyes with retained lens fragments do well after vitrectomy, with the majority recovering good vision. However, the risk of RD is increased, and visual outcome may be adversely affected if RD occurs.

Adult↗

PubMed1996

Miyake analysis of anterior vitrectomy techniques.

PURPOSE: To study the efficacy and safety of anterior vitrectomy with the Miyake system. SETTING: Miyake Laboratory, IOLAB, Claremont, California. METHODS: Four pig eyes and three human eyes were transected equatorially. The anterior segments were glued to a glass slide and placed on a stage for anterior and posterior videography. Phacoemulsification was performed, and the posterior capsule was intentionally ruptured. Three different vitrectomy techniques were studied: anterior vitrectomy with coaxial infusion sleeve, anterior vitrectomy with separate limbal infusion, and pars plana vitrectomy with limbal infusion. RESULTS: All techniques showed that vitreous could be safely and effectively removed without undue stress on the retina whenever the vitrectomy instrument was held directly beneath the iris and not placed peripherally to the iris root. Only the pars plana site allowed access to the entire posterior aspect of the iris for removal of vitreous gel. CONCLUSION: Anterior vitrectomy can be performed safely and effectively with any of the three approaches studied. The pars plana technique permitted removal of gel beneath the superior iris. This has important clinical implications because iridovitreous adhesions tend to form superiorly after limbal vitrectomy.

Animals↗