SCLEROTOMY LEAKAGE IN TRANSCONJUNCTIVAL SMALL-GAUGE PARS PLANA VITRECTOMY: Effect of Removing the Cannula Over the Light Pipe.

PURPOSE: To determine the effect of cannula removal over the light pipe on the incidence of sclerotomy leakage and to evaluate other factors that may influence the incidence of sclerotomy leaks and hypotony on conclusion of small-gauge transconjunctival pars plana vitrectomy. METHODS: Retrospective, interventional clinical study of consecutive patients who underwent small-gauge transconjunctival pars plana vitrectomy at a single academic center. Eyes were divided into a group in which cannulae were removed over the light pipe (Group L) and a group in which cannulae were simply pulled out (Group N). The primary comparison was the comparison in requirement for suturing of sclerotomies between Groups L and N. RESULTS: Forty-eight eyes of 48 patients were included in the study (Group L: 21 eyes; Group N: 27 eyes). In Group L, 14/42 (33%) superior sclerotomies required suturing compared with 7/54 (13%) sclerotomies in Group N (P = 0.024). Superior sclerotomy leaks were also more common in Group L (28/42, 67%) compared with Group N (23/54, 43%, P = 0.024). Similarly, more eyes had hypotony after cannula removal in Group L (11/21; 52%) compared with Group N (5/27; 19%, P = 0.03). There were no differences in any of these measures when comparing fluid-filled to air- or gas-filled eyes. CONCLUSION: Removing the cannula over the light pipe results in a greater frequency of leaking, including leaking that results in hypotony or that requires suturing. The technique of cannula removal affects the risk of leakage and the risk of requiring suturing of a sclerotomy.

Intraoperative breakage of a disposable 23-gauge trocar tip.

PURPOSE: To report breakage of the tip of a 23-gauge trocar system during pars plana vitrectomy. METHODS: Retrospective single case report. RESULTS: A 56-year-old man was undergoing pars plana vitrectomy for vitreous hemorrhage using a 23-gauge 1-step trocar/cannula entry system. After placement of the first cannula and upon withdrawing the trocar from the sclera, we noted that the tip had broken. We switched to another brand and completed the surgery without complication. Inspection of the fundus and plain radiography showed no intraocular foreign body, and the patient had an uncomplicated recovery. CONCLUSION: Vitreoretinal surgeons should be aware of the possibility of intraoperative breakage of the 23-gauge trocar tip after creation of the scleral tunnel.

Emerging pharmacotherapies for diabetic macular edema.

Diabetic macular edema (DME) remains an important cause of visual loss in patients with diabetes mellitus. Although photocoagulation and intensive control of systemic metabolic factors have been reported to achieve improved outcomes in large randomized clinical trials (RCTs), some patients with DME continue to lose vision despite treatment. Pharmacotherapies for DME include locally and systemically administered agents. We review several agents that have been studied for the treatment of DME.

Management of ruptured retinal arterial macroaneurysm with intravitreal bevacizumab.

The authors report the management of a ruptured retinal arterial macroaneurysm and associated hemorrhages with intravitreal injections of bevacizumab. A 79-year-old woman presented with a history of systemic arterial hypertension and a ruptured retinal arterial macroaneurysm with pre-retinal, intraretinal, and subretinal hemorrhages extending into the macula. Visual acuity at presentation was 20/400. The patient was treated with two intravitreal injections of bevacizumab at 4-week intervals. Steady clearing of the pre-retinal, intraretinal, and subretinal hemorrhages was observed with restoration of final visual acuity to 20/20 in the 12 months after the initial presentation. It appears that the novel application of intravitreal bevacizumab may be used in the treatment of ruptured retinal arterial macroaneurysm.

Methicillin-resistant Staphylococcus epidermidis isolation from the vitrectomy specimen four hours after initial treatment with vancomycin and ceftazidime.

A patient presented with acute-onset, postoperative endophthalmitis and visual acuity of light perception. Because of a time delay in arranging a pars plana vitrectomy (PPV), the patient was treated with a prompt vitreous tap for culture an injection of vancomycin and ceftazidime. Four hours later, the PPV was performed and additional antibiotics were injected. The cultures from both the initial needle tap and the subsequent PPV isolated methicillin-resistant Staphylococcus epidermidis sensitive to vancomycin, but resistant to fourth-generation fluoroquinolones. The patient eventually recovered a visual acuity of 20/80 before developing retinal detachment. This case illustrates the time lag necessary to sterilize the vitreous cavity, and suggests a possible two-step staged treatment strategy for situations in which access to PPV equipment and support staff may be limited.

Resolution of Pigmented Keratic Precipitates Following Treatment of Pseudophakic Endophthalmitis Caused by Propionibacterium Acnes.

Propionibacterium acnes is a well-recognized cause of chronic postoperative endophthalmitis after cataract surgery. The subtle clinical signs of this infection and its initial favorable response to topical steroids may lead to delayed diagnosis and treatment. Two patients with culture proven P. acnes endophthalmitis after cataract surgery that presented with prominent pigmented keratic precipitates (KPs) and low-grade iritis in the involved eye were managed. Both cases had initial treatment with diagnostic pars plana vitrectomy (PPV) with intraocular antibiotic (IOAB) injection. Secondary treatment for recurrence was required in both patients. The KPs and iritis resolved after removal of intraocular lens (IOL) and capsular bag.

Management of ruptured retinal arterial macroaneurysm with intravitreal bevacizumab.

The authors report the management of a ruptured retinal arterial macroaneurysm and associated hemorrhages with intravitreal injections of bevacizumab. A 79-year-old woman presented with a history of systemic arterial hypertension and a ruptured retinal arterial macroaneurysm with pre-retinal, intraretinal, and subretinal hemorrhages extending into the macula. Visual acuity at presentation was 20/400. The patient was treated with two intravitreal injections of bevacizumab at 4-week intervals. Steady clearing of the pre-retinal, intraretinal, and subretinal hemorrhages was observed with restoration of final visual acuity to 20/20 in the 12 months after the initial presentation. It appears that the novel application of intravitreal bevacizumab may be used in the treatment of ruptured retinal arterial macroaneurysm.

Lack of toxicity of stainless steel retinal tacks during 21 years of follow-up.

Retinal tacks were historically used in the repair of complex retinal detachment associated with giant retinal tear. The authors describe a patient with retinal detachment associated with giant retinal tear who was treated successfully with pars plana vitrectomy, use of stainless steel retinal tacks, endolaser photocoagulation, and gas-fluid exchange. Twenty-one years after treatment, the retina has remained attached, the tacks are in place, and best-corrected visual acuity is 20/30 in the operated eye. Although retinal tacks are no longer used, this case report suggests that intraocular stainless steel may cause minimal or no retinal toxicity during long-term follow-up.

Prediction of postoperative astigmatism in cataract surgery.

BACKGROUND: The purpose of this study was to predict postoperative astigmatism using refraction, keratometry, and other preoperative information after phacoemulsification with posterior chamber intraocular lens (IOL) implantation. METHODS: A retrospective study was conducted of 176 eyes of 161 patients undergoing phacoemulsification for visually significant cataract with capsular bag or sulcus IOL fixation at the Hunter Holmes McGuire Veterans Administration Medical Center, Richmond, Va. Eyes with complications and final-corrected visual acuity of less than 20/60 were excluded. Keratometric and refractive astigmatism were described by Jackson cross-cylinder with-the-rule (J0) and oblique (J45) components. Preoperative predictors of postoperative refractive J0 and J45 were determined by univariate and multivariate regression analysis. RESULTS: The final multivariate model to predict postoperative with-the-rule astigmatism was J0Postoperative = 0.24 x J0Preoperative 0.46 x J0Keratometric (-0.08 )(coefficient of determination [r2] = 0.51, all p < 0.001). The multivariate model based on expected predictors of oblique astigmatism was J45Postoperative = 0.10 x J45Preoperative + 0.23 x J45Keratometric + 0.01, (r2 = 0.05, p = 0.09 for J45Preoperative and 0.03 for J45Keratometric). Temporal clear cornea (as opposed to superior scleral tunnel) incisions, and use of sutures in scleral tunnel incisions, were not predictive of postoperative astigmatism. INTERPRETATION: Postoperative astigmatism can be estimated from preoperative astigmatism using the following weighted average: two-thirds keratometric and one-third refractive astigmatism. Preoperative refraction may predict postoperative astigmatism independent of keratometry because keratometry reflects only the paracentral anterior (not posterior) corneal curvature.