A single sclerotomy vitreous biopsy technique in endophthalmitis

Pars plana vitrectomy in uveitis in the era of microincision vitreous surgery

Pars plana vitrectomy (PPV) in uveitis is indicated for various diagnostic and therapeutic indications. With the advent of microincision vitreous surgery (MIVS), the use of PPV in uveitis has increased with a wider spectrum of indications due to shorter surgical time, less patient discomfort, less conjunctival scarring, and a decreased rate of complications as compared to standard 20G vitrectomy. Because of faster post-operative recovery in terms of visual improvement and reduction of inflammation, and reduced duration of systemic corticosteroids, MIVS has gained popularity in uveitis as an adjunctive therapy to the standard of care medical therapy. The safety and efficacy of MIVS is related to the emerging vitrectomy techniques with better and newer cutters, illuminating probes, and accessory instruments. Because of the instrumentation and fluidics of MIVS, PPV is emerging as a safe and useful alternative for diagnostic challenges in uveitis, aiding in earlier diagnosis and better outcome of inflammatory disease, even in the presence of severe and active inflammation, which was once considered a relative contraindication for performing vitreous surgery. However, for surgical interventions for therapeutic indications and complications of uveitis, it is advisable to achieve an optimum control of inflammation for best results. The increasing reports of the use of MIVS in uveitis have led to its wider acceptance among clinicians practicing uveitis.

Intraocular biopsy in uveitis

An intraocular biopsy is performed for diagnostic, prognostic and investigational purposes. Biopsies help to confirm or exclude malignancies and differentiate inflammatory from infectious processes. Histopathological analysis is the final verdict in unresponsive uveitis, atypical inflammation, metastases and masquerade syndromes. Advances and refinement of techniques in cytopathology, immunohistochemistry, microbiological and molecular biologic study offer much more than just diagnosis. They provide prognosis based on cell characteristics and are helpful in planning treatment and intervention. Many biopsy procedures have evolved to provide more safety and minimise complications thus improving the quality of specimens or samples available for analysis. The type of biopsy and technique adopted varies based on the clinical suspicion, size and location of lesions. In uveitis, a working diagnosis of intraocular inflammation is made on clinical examination and laboratory investigations and ancillary tests. Malignancy and uveitis is interlinked and masquerade syndromes are among the commonest indications for biopsy and analysis of specimen. The various types of intraocular biopsies include aqueous tap, fine needle aspiration biopsy, vitreous biopsy, iris and ciliary body, and retinochoroidal biopsy. They will be reviewed in this article with respect to current perspective

One-port vs. three-port diagnostic vitrectomy for posterior segment diseases of unknown origin

PURPOSE

To compare the safety and the effectiveness of one-port vs. three-port diagnostic vitrectomy in undiagnosed cases of posterior segment inflammation.

METHODS

We retrospectively collected data from 80 consecutive diagnostic vitrectomies performed using a one-port (n = 40) or a three-port approach (n = 40). Cases of suspected postoperative endophthalmitis were not included in the study. Several variables were compared among groups, including length of surgery, postoperative best-corrected visual acuity (BCVA), diagnostic success and surgical complications.

RESULTS

The mean duration of surgery was shorter in the one-port group when compared to the three-port group (15 ± 8 min vs. 49 ± 30; p = 0.0001). The patients were observed for a mean follow-up of 19 months (range 1-84). In the one-port group, the mean BCVA improved from 1.31 ± 0.96 to 0.57 ± 0.59 logarithm of minimum resolution (LogMAR) (p = 0.0009). In the three-port group, BCVA improved from 0.98 ± 0.76 to 0.51 ± 0.76 LogMAR (p = 0.0005). The difference in mean postoperative BCVA between groups was not significative at the last follow-up. One-port vitrectomy yields to a final diagnosis in 80% of the cases, and three-port vitrectomy in 48%. Most of the one-port vitrectomies were carried out under topical anesthesia. After surgery, in both groups three eyes developed a retinal detachment.

CONCLUSIONS

In this pilot study, the one-port diagnostic vitrectomy has proven to be as effective and safe as the three-port approach, allowing a reduction in surgical times. One-port diagnostic vitrectomy might be considered as the first option for those cases where more complex surgical procedures are not needed.

Biopsy pathology in uveitis

Uveitis is fraught with speculations and suppositions with regard to its etiology, progress and prognosis. In several clinical scenarios what may be perceived as due to a systemic infection may actually not be so and the underlying etiology may be an autoimmune process. Investigations in uveitis are sometimes the key in identification and management. Invasive techniques could be of immense value in narrowing down the etiology and help in identifying the cause. This article updates one on the invasive techniques used in biopsy such as anterior chamber paracentesis, vitreous tap and diagnostic vitrectomy, iris and ciliary body biopsy, choroidal and retinochoroidal biopsy and fine needle aspiration biopsy (FNAB). In populations where certain infections are endemic, the clinical scenario does not always respect a known presentation and the use of biopsy is resorted to as a sure way of confirming the etiology. Biopsies have a role in diagnosis of several inflammatory and infectious conditions in the eye and are pivotal in diagnosis in several dilemmas such as intraocular tumors and in inflammations. Appropriate and timely use of biopsy in uveitis could enhance the diagnosis and provide insight into the etiology, thus enabling precise management.

Performing vitreous biopsy by perfluorocarbon-perfused vitrectomy

PURPOSE

To evaluate the safety and efficacy of perfluorocarbon-perfused vitrectomy (PCPV) as a novel technique in obtaining a large undiluted vitreous biopsy.

DESIGN

Cross-sectional interventional study.

METHODS

Patients with undiagnosed posterior uveitis scheduled for vitreous biopsy underwent PCPV. A syringe containing 5 ml of perfluorocarbon liquid (PCL) was connected to the infusion line. Aspiration of the central and superior vitreous was initiated with simultaneous infusion of the PCL.

RESULTS

Twenty eyes of 20 patients were included in this study. The mean +/- SD amount of PCL used in each eye was 4.50 +/- 0.69 ml. The volume of vitreous sample obtained in each eye was 2.25 +/- 0.413 ml. No complications occurred.

CONCLUSIONS

PCPV is a safe and effective method for obtaining large undiluted vitreous biopsy.