Literature Roundup
Literature Roundup
23-Gauge Transconjunctival Pars Plana Vitrectomy for Removal of Retained Lens Fragments.
Baker PS, Spirn MJ, Chiang A, et al.
Am J Ophthalmol. 2011;152(4):624-627.
Small-gauge vitrectomy has supplanted 20-gauge surgery for a growing number of indications due to improved patient comfort, reduced operative time, improved pressure maintenance, and an increased ability to manipulate tissue with a smaller-gauge vitrector that has a more distally placed cutter. However, retained lens material has typically been managed with 20-gauge vitrectomy that allows use of ultrasonic fragmentation.
This retrospective study reports on the utility of 23-gauge pars plana vitrectomy (PPV) for removal of retained lens fragments and outlines which cases are more likely to require use of a 20-gauge fragmatome.
Twenty eyes in 20 consecutive patients had 23-gauge PPV for retained lens fragments after complicated cataract surgery. One sclerotomy was enlarged to allow 20-gauge fragmentation of remaining lens material if required. Twelve patients (60%) were managed with 23-gauge PPV alone, while 8 patients (40%) required 20-gauge fragmentation.
The cases successfully managed with 23-gauge instrumentation had a smaller amount of retained lens fragments (median 10% of total lens size, range 0% to 75%) compared to the 20-gauge cases (median 90%, range 10% to 100%). If retained lens material was less than 50% of total lens size, 23-gauge surgery was successful 83% of the time. If more than 50% of the lens was retained, 75% required conversion to the 20-gauge fragmatome. There was no significant difference in complication rates.
Application to Practice
Twenty-three-gaugevitrectomy is feasible for management of retained lens material after complicated cataract surgery. Eyes with more than 50% of the lens retained are more likely to require conversion of one port to use the 20-gauge fragmatome. The surgeon should ensure that adequate infusion pressure is maintained if the fragmatome is used in order to prevent hypotony. This approach can offer the advantages of improved patient comfort and potentially reduced surgical time associated with small-gauge vitrectomy.
Evaluation of the United States Public Health Service Guidelines for Discontinuation of Anticytomegalovirus Therapy After Immune Recovery in Patients With Cytomegalovirus Retinitis.
Holbrook JT, Colvin R, van Natta ML, Thorne JE, Bardsley M, Jabs DA. Studies of Ocular Complications of AIDS (SOCA) Research Group.
Am J Ophthalmol. 2011;152(4):628-637.e1.
Cytomegalovirus (CMV) retinitis is a late-stage opportunistic infection typically occurring in the setting of severe immunodeficiency secondary to AIDS. CMV retinitis used to develop in 30% of patients with AIDS and was associated with poor survival. Ongoing treatment for the retinitis was required. The advent of highly active anti-retroviral treatment (HAART therapy) allowed immune recovery and much-improved survival.
Case series were described where immune recovery allowed discontinuation of anti-CMV therapy without recurrence of the retinitis. The United States Public Health Service (USPHS) developed guidelines for discontinuing CMV therapy in this setting.
This study compared the outcome of 2 groups of patients with CMV retinitis enrolled in the Longitudinal Study of Ocular Complications of AIDS. All patients had CMV retinitis and CD4+ T-cell counts of 50 cells/μL or fewer, were treated with anti-CMV and HAART therapy, and demonstrated sustained immune recovery (2 consecutive CD4+ T-cell counts of 100 cells/μL or more at least 6 months apart) and inactive retinitis. One group of 37 patients discontinued anti-CMV therapy, while the second group of 34 patients continued anti-CMV therapy. The groups were compared with respect to survival, visual acuity, and CMV retinitis activity.
There were no statistical differences in any of the clinical outcomes (death, retinitis progress, visual acuity, or incidence of bilateral retinitis) over a median of 5-year follow-up. Patients in the continued anti-CMV therapy group tended to be older (44 vs 40 years; P = .09), have bilateral retinitis (53% vs 32%; P = .10), and have lower CD4+ T-cell counts (148 vs 207 cells/μL; P < .001). Both groups lost visual acuity during follow-up, on average 1.2 letters per year (P < .01), primarily due to cataract or other factors unrelated to retinitis progression.
Application to Practice
This study is the first to compare similar groups of patients with immune recovery and quiescent retinitis who continued or stopped anti-CMV therapy. Discontinuation of anti-CMV therapy after immune recovery did not increase the risk of poor outcomes. The results support the current guidelines for discontinuation of anti-CMV therapy after achieving sustained immune recovery.
Randomized Comparison of Systemic Anti-inflammatory Therapy Versus Fluocinolone Acetonide Implant for Intermediate, Posterior, and Panuveitis: The Multicenter Uveitis Steroid Treatment Trial.
The Multicenter Uveitis Steroid Treatment (MUST) Trial Research Group, Writing Committee. Kempen JH, Altaweel MM, Holbrook JT, et al.
Ophthalmol. 2011;118(10):1916-1926.
Intermediate, posterior, and panuveitis are the forms of uveitis most likely to cause vision loss. The mainstay of treatment for chronic vision-threatening uveitis has been systemic steroids, supplemented with immunosuppressive therapy. An alternative approach is surgical placement of an intravitreal steroid implant that releases fluocinolone into the vitreous over 3 years.
This randomized, controlled, parallel superiority trial compared the relative effectiveness of systemic corticosteroids plus immunosuppression (systemic therapy) vs fluocinolone acetonide implant (implant therapy) for noninfectious intermediate, posterior, or panuveitis (uveitis). Two hundred fifty-five patients with active or recently active uveitis (479 eyes) were randomized to systemic or implant therapy at 23 clinical centers. Patients randomized to implant had both eyes implanted if they had bilateral uveitis.
At the primary endpoint of 24 months, the implanted eyes improved by a mean of +6.0 letters and the systemic therapy group improved by +3.2 letters (P = 0.16). There was an improvement in vision-related quality of life of +11.4 and +6.8 units (P = 0.043), and a change in EuroQol-EQ5D health utility of +0.02 and −0.02 (P = 0.060). Uveitis was more effectively controlled with the implant (88%) vs the systemic therapy group (71%)(P=0.001).
Macular edema was common at baseline (41% implant vs 39% systemic), and responded more quickly in the implant group by 6 months (20% with edema in implant group vs 34% systemic), but did not demonstrate a statistically significant difference in response by 24 months (22% vs 30%)(P=0.071).
Implanted eyes had a higher risk of cataract surgery (80%, hazard ratio [HR] = 3.3, P < 0.0001), treatment for elevated intraocular pressure (61%, HR=4.2, P < 0.0001), and glaucoma (17%, HR=4.2, P = 0.0008). Patients assigned to systemic treatment had more prescription-requiring infections (0.60 vs 0.36/person-year, P=0.034), without notable long-term consequences. Other systemic adverse outcomes were unusual in both groups.
Application to Practice
Mean visual acuity improved over 24 months in both groups, with neither approach providing a statistically superior result. The implant was more effective at suppressing uveitis, but was also associated with increased cataract formation and development of glaucoma.
It was important that 2 years of oral steroid and immunosuppressive therapy was not associated with significant adverse systemic effects. The researchers concluded that the specific advantages and disadvantages identified for each treatment should dictate the choice of therapy for each patient based on clinical circumstances.
Same-Day Versus Delayed Vitrectomy with Lensectomy for the Management of Retained Lens Fragments
Colyer MH, Berinstein DM, Khan NJ, et al.
Retina. 2011; 31:1534-1540.
Retained lens fragments after complicated cataract surgery place the patient at risk of developing inflammation, cystoid macular edema, glaucoma, and retinal detachment (RD). Vitrectomy has been shown to reduce the incidence of these comorbidities. This retrospective study evaluated whether performing same-day pars plana vitrectomy (PPV) vs delayed PPV affects visual outcomes and ocular morbidity of patients with retained lens fragments after a complicated cataract surgery.
A total of 172 eyes were reviewed, with 59 eyes undergoing same-day PPV (vitrectomy performed within 12 hours after cataract surgery) and 113 eyes undergoing non-same-day PPV (vitrectomy performed at a mean delay of 15 days after cataract surgery). Seventy-one percent of the same-day group achieved>20/40 visual acuity at 6-month follow-up, vs 65% in the non-same-day group. The difference in these results was not statistically significant. Complication rates were also found to be similar, with 29% occurring in the same-day group and 34% occurring in the non-same-day group.
Application to Practice
Visual outcomes and complication rates of patients undergoing same-day vs non-same-day vitrectomy for retained lens after complicated cataract surgery were not statistically different. The authors suggest that same-day vitrectomy is a reasonable treatment alternative. The decision to perform same-day vitrectomy vs non-same-day vitrectomy is multifactorial; consideration should be given to media clarity, degree of ocular inflammation, and proximity of the patient to facilities and/or a vitreoretinal specialist.
Outcomes and Risk Factors Associated with Endophthalmitis after Intravitreal Injection of Anti-Vascular Endothelial Growth Factor Agents
Shah CP, Garg SJ, Vander JF, Brown GC, Kaiser RS, Haller JA; for the Post-Injection Endophthalmitis (PIE) Study Team.
Ophthalmol. 2011;118:2028-2034.
The role of intravitreal injections of anti-VEGF treatments continues to expand. One of the most feared complications of this treatment is endophthalmitis. Given the severity of vision loss that can occur secondary to endophthalmitis, and the dissimilarity among techniques when administering intravitreal injections, it is important to evaluate visual outcomes and modifiable risk factors.
This case series and retrospective case-control study reports visual outcomes in postinjection endophthalmitis and attempts to identify modifiable risk factors to prevent postinjection endophthalmitis. Twenty-three cases of presumed infectious endophthalmitis were identified from a total of 27,736 consecutive intravitreal anti-VEGF injections administered over 17 months.
Seventy-eight percent returned to baseline vision between 3 months to 6 months. There was no significant difference in the visual recovery rate between the culture-positive cases (71% by 6 months) and culture-negative cases (81% by 6 months). The authors noted all cases of presumed infectious endophthalmitis had pain, decreased visual acuity, and vitritis, and believe these signs and symptoms could not be used to distinguish culture-positive cases from culture-negative cases.
This study reported no modifiable risk factors for postinjection endophthalmitis, including the use of a bladed lid speculum, conjunctival displacement with a sterile cotton-tip applicator, superior vs inferior hemisphere of injection, and the use of bevacizumab vs ranibizumab.
Application to Practice
This study reports that the rates of postinjection endophthalmitis remain low, and the potential for visual recovery is good, with most eyes returning to baseline visual acuity. The authors recommend a high index of suspicion and a low threshold for tap and injection, given that both culture-positive and culture-negative cases presented with similar signs and symptoms.
The authors also emphasize the importance of sterilizing the ocular surface with povidone-iodine, as it remains the only proven act to prevent infection. Physicians and patients also should avoid talking, coughing, and sneezing during anti-VEGF injection administration to prevent contamination with oral flora.
Morphologic Differences in Epiretinal Membranes on Ocular Coherence Tomography as a Predictive Factor for Surgical Outcome.
Kinoshita T, Kovacs KD, Wagley S, Arroyo JG.
Retina. 2011;31(8):1692-1698. doi:10.1097/IAE.0b013e31820f49d0.
While vitrectomy with membrane peeling can improve vision in most cases, some cases simply do not improve. This retrospective study evaluated whether morphologic differences seen on the preoperative optical coherence tomography (OCT) correlates with postoperative functional and morphologic outcomes to help understand why some cases do not improve with membrane-peeling surgery.
Using preoperative time-domain OCTs, 75 eyes were classified into 4 categories based on their macular contour and grouped as follows:
- Diffuse (DIF) type
- Cystoid macular edema (CME) type
- Pseudolamellar hole (PLH) type
- Vitreomacular traction (VMT) type
Preoperative visual acuity was best in the PLH type, followed by the DIF, CME, and VMT types, in that order. Average preoperative central retinal thickness (CRT) decreased in the following order: VMT-, CME-, DIF-, and PLH-type membranes. Surgical procedure for the PLH type resulted in compromised visual outcomes.
Visual improvement was best in the VMT type, followed by the CME, DIF, and PLH types in that order, which is consistent with that of mean CRT reduction. The DIF and CME types demonstrated favorable surgical results in visual improvement, CRT reduction, and the rate of reoperation.
Applications to Practice
Morphological categorization of preoperative macular contour may be a predictive factor for surgical outcomes. Further investigation in the detailed morphologic differences among the 4 types of ERM cases using spectral domain OCT imaging needs to be conducted with larger sample sizes. This may help the vitreoretinal surgeon in identifying the appropriate epiretinal membranes that may benefit the most from surgery.
Questions? Comments? Contact Dr. Tewari at asheeshtewari@yahoo.com or Dr. Altaweel at mmaltaweel@wisc.edu.
Financial disclosures
Dr. Reinauer – None; Dr. Tewari – None; Dr. Altaweel – REGENERON: Grant Support; GSK: Consultant Advisor; NIH: Grant Support; Pfizer: Grant Support.