VITRECTOMY-ASSISTED BIOPSY FOR MOLECULAR PROGNOSTICATION OF CHOROIDAL MELANOMA 2 MM OR LESS IN THICKNESS WITH A 27-GAUGE CUTTER

Incisional choroidal surgery

The choroid is a thin layer of highly vascular uveal tissue enclosed externally by sclera and internally by neurosensory retinal tissue. The choroid is a "middle layer" ocular tissue with anatomically challenging surgical access. The primary functional role of the choroid is to provide rapid, oxygenated, and nutrient-rich blood flow to both the highly metabolic retinal pigment epithelium and outer retina (i.e. photoreceptors) while simultaneously removing waste products. Historically, incisional choroidal surgery (ICS) has involved tumor biopsy or excision, removal of choroidal neovascular complex or autologous choroidal translocations; however, ICS also holds unique potential for novel and innovative approaches to address macular pathology. Using large-animal surgical studies, researchers have explored ICS with the objective of finding safer and more effective techniques to reduce surgical risks such as bleeding, tissue contraction, and scar tissue formation. We explore the relevant anatomy and embryology, existing surgical techniques, discuss the implications for retinal drug delivery, define ICS guiding principles, and offer a rationale for implementation of ICS into a vitreoretinal surgical practice. We also identify other future challenges and anticipate future innovations that will advance ICS.

Choroidal biopsies; a review and optimised approach

The majority of choroidal tumours are diagnosed accurately with clinical examination and the additional data obtained from non-invasive imaging techniques. Choroidal biopsies may be undertaken for diagnostic clarity in cases such as small melanocytic or indeterminate lesions, identifying the primary tumour in the case of choroidal metastases or the subclassification of rarer conditions such as uveal lymphoma. There is however an increasing use of biopsy techniques for prognostication in uveal melanoma. This review explores the main indications and surgical techniques for tumour acquisition, and the optimised approach utilised by the current authors to improve successful yield for histological and genetic analysis.

Presumed incipient choroidal melanoma: proposed diagnostic criteria and management

AIMS

To propose diagnostic criteria for a presumed incipient choroidal melanoma based on tumour growth rate and tumour doubling time (TDT) and to describe management of such tumours with transpupillary thermotherapy (TTT).

METHODS

Retrospective interventional case series of nine consecutive presumed incipient uveal melanomas diagnosed and treated with TTT in 2010-2017. Growth rate in mm/year and per cent/year in largest basal diameter (LBD) and TDT were compared with published data for uveal melanomas and growing naevi that did not transform to melanoma under long-term follow-up.

RESULTS

The median LBD and thickness were 1.6 mm (range 0.9-2.3) and 0.20 mm (range 0.15-0.29), respectively. The median age was 57 years (range 47-78). Seven tumours were classified as de novo melanomas and two as transformed naevi. The median time from first observation to diagnosis was 3.3 years (range 2.2-7.3), LBD growth rate 0.25 mm/year (range 0.11-0.72) and 34 per cent/year (range 10-1437), and TDT 609 days (range 97-1612). The estimates matched those reported for uveal melanoma (median TDT 521 days, 90th percentile 2192) and exceeded those for growing naevi (median growth rate 0.04 mm/year, 90th percentile 0.12; 1.1 per cent/year, 90th percentile 2.6). The predicted median age at de novo appearance was 51 years (range 32-63). No tumour grew after TTT during a median follow-up of 2.1 years (range 0.6-8.7).

CONCLUSIONS

In this series, relative growth rate and TDT best qualified as diagnostic criteria for an incipient choroidal melanoma. Too small for brachytherapy, they could be managed with TTT.

Intraoperative choroidal detachment during small-gauge vitrectomy: analysis of causes, anatomic, and visual outcomes

INTRODUCTION

To investigate the incidence and causes of intraoperative choroidal detachment (CD) during small-gauge vitrectomy, as well as the anatomic and visual outcomes.

METHODS

We retrospectively reviewed the medical records of 1026 consecutive patients who underwent small-gauge vitrectomy from June 2017 to December 2018 at Zhongshan Ophthalmic Centre, Guangzhou, China. Data on the presence, location, and extent of intraoperative CD and its relationship to the infusion cannula were collected. Patient demographic characteristics and postoperative anatomic and visual outcomes were also assessed.

RESULTS

A total of six cases were found to have intraoperative CD, including two with serous CD, three with limited haemorrhagic CD, and one with CD caused by inadvertent perfusion of gas during air/fluid exchange. Retraction of the infusion cannula and acute ocular hypotony were found to be the main causes of intraoperative CD in five out of the six cases. The best-corrected visual acuity of all cases significantly improved after the surgery.

CONCLUSION

The incidence of intraoperative CD during small-gauge vitrectomy is low; the predominant causes are retraction of the infusion cannula and acute ocular hypotony. Immediate awareness and timely closure of the incision may contribute to a better surgical prognosis.

Surgical Approach in Intraocular Tumors

Surgery in intraocular tumors is done for excision/biopsy and the management of complications secondary to the treatment of these tumors. Excision/biopsy of intraocular tumors can be done via fine-needle aspiration biopsy (FNAB), transretinal biopsy (TRB), partial lamellar sclerouvectomy (PLSU), and endoresection. FNAB, TRB, and PLSU can be used in tumors that cannot be diagnosed by clinical examination and other ancillary testing methods. PLSU is employed in tumors involving the iridociliary region and choroid anterior to the equator. Excisional PLSU is performed for iridociliary and ciliary body tumors with less than 3 clock hours of iris and ciliary body involvement and choroidal tumors with a base diameter less than 15 mm. However, for biopsy, PLSU can be employed with any size tumor. Endoresection is a procedure whereby the intraocular tumor is excised using vitrectomy techniques. The rationale for performing endoresection is based on the fact that irradiated uveal melanomas may cause complications such as exudation, neovascular glaucoma, and intraocular pigment and tumor dissemination (toxic tumor syndrome), and removing the dead tumor tissue may contribute to better visual outcome. Endoresection is recommended 1-2 weeks after external radiotherapy. Pars plana vitrectomy is also used in the management of complications including vitreous hemorrhage, retinal detachment, and epiretinal membrane that can occur after treatment of posterior segment tumors using radiotherapy and transpupillary thermotherapy. It is important to make sure the intraocular tumor has been eradicated before embarking on such treatment.

Biopsy for molecular risk stratification in uveal melanoma: Yields and molecular characteristics in 119 patients

BACKGROUND

Prognostic cytological and molecular features of uveal melanoma have been well researched and are essential in management. Samples can be obtained in vivo through fine needle aspirate biopsy, vitrector cutter, forceps or post-enucleation for off-site testing. This study aims to examine cytological and chromosome microarray yields of these samples.

METHODS

A retrospective cohort analysis of 119 uveal melanoma biopsies submitted to our laboratory. Samples included those taken in vivo (n = 57) and post-enucleation (n = 62). Patient and tumour features were collected including age, sex, primary tumour location, basal diameter and tumour height. Prognostic outcomes measured include cell morphology, chromosomal status and immunohistochemistry.

RESULTS

Post-enucleation biopsies accounted for just over half of our samples (52%). Post-enucleation samples had a more successful genetic yield than in vivo biopsies (77% vs. 50%, p = 0.04) though there was no difference for cytological yields. There was no difference in cytological or microarray yields between instruments. The vitrector biopsy group had the smallest tumour thickness (5 mm vs. 10 mm [fine-needle aspirate biopsy], p = 0.003). There was a strong correlation between monosomy 3, BAP1 aberrancy and epithelioid cell type in post-enucleation samples (Tb  = 0.742, p = 0.005). However, epithelioid morphology was not associated with either monosomy 3 (p = 0.07) or BAP1 aberrancy (p = 0.24) for in vivo biopsies.

CONCLUSIONS

All three biopsy instruments provide similar cytological yields as post-enucleation sampling, although post-enucleation samples had a more successful chromosome microarray yield. Epithelioid cytomorphology alone is insufficient for prognostication in in vivo biopsies, immunohistochemistry would be a useful surrogate test.

Patients presenting with stage IV uveal melanoma: Lessons learned

Challenges persist in identifying patients with stage IV uveal melanoma. While clinical, histopathologic, and genetic features of the primary tumor have been shown to provide prognostic value for assessing metastatic risk, biopsy-related genetic analyses are expensive and not universally available. Therefore, this review will focus on clinical characteristics. Initial staging and follow-up screening protocols have evolved for patients with uveal melanoma. The Collaborative Ocular Melanoma Study (COMS) required a physical examination, chest X-ray, and hematologic survey (primarily liver function tests). Though these studies were found to have a high specificity, COMS investigators typically found late-stage metastases. More recently, protocols have concentrated on liver imaging (abdominal ultrasound, computed tomography, and magnetic resonance imaging). Though hepatic radiographic imaging has been found more likely to reveal earlier metastatic uveal melanoma, by definition it cannot detect most extrahepatic and multiorgan metastases. An international multicenter registry study recently focused on patients who were diagnosed with stage IV uveal melanoma simultaneously with their primary intraocular melanoma. Therein, utilizing center-specific diagnostic methods, stage IV was found to occur in about 2% of patients. However, subgroup analysis found that a disproportionate number of multi-organ metastases were discovered when whole-body positron emission tomography/computed tomography was used for staging. Herein, we review the literature on patients who present with stage IV uveal melanoma, how they were detected, and their outcomes.

Small Choroidal Melanoma: Correlation between Clinical Characteristics and Metastatic Potential

IMPORTANCE

Diagnosis of small choroidal melanoma is based upon clinical features and presence of factors predictive of local malignant growth. Prognostic biopsy quantifies risk of metastasis.

OBJECTIVE

The aim of this study is to explore relationship between clinical characteristics and metastatic potential of a small choroidal melanoma.

DESIGN

Retrospective review of 53 patients with small choroidal melanoma treated in a tertiary oncology clinic. Patients were derived from 3 cohorts, with pathologic confirmation, with growth confirmation, and those treated only on clinical basis. Based upon prognostic biopsy outcomes, each case was classified into low or high metastatic potential groups. Distribution of clinical characteristics such as age, laterality, symptoms, tumor dimensions, tumor distance from optic nerve and fovea, presence of surface orange pigment, drusen, retinal pigment epithelial atrophy, and subretinal fluid was analyzed between metastatic groups.

MAIN OUTCOME MEASURES

Distribution of clinical characteristics between low or high metastatic potential groups was analyzed.

RESULTS

A total of 53 patients [mean age, 61 years (range, 27-81 years); 32 (60%) men and 21 (40%) women] were classified into pathology confirmed group (n = 13), growth confirmed group (n = 26), and with clinical group (n = 14). Prognostic biopsy in the growth, pathology, and clinical groups revealed low metastatic potential in 23, 10, and 11 patients, respectively, and high metastatic potential in 3 patients in each group. Distribution of clinical characteristics between low or high metastatic potential groups was not statistically significantly different.

CONCLUSION

Clinical characteristics do not identify metastatic potential of a small choroidal melanoma.

Vitrectomy-Assisted Biopsy: An in vitro Study on the Impact of Cut Rate and Probe Size

Purpose

The aim of this study was to optimize the technique of performing vitrectomy-assisted biopsy of intraocular tumors by comparing the cytohistological findings in specimens obtained with different vitrectomy probes and cut rates.

Methods

Vitrectomy-assisted biopsies were taken from a fresh porcine liver. For each sampling, the vacuum level was 300 mm Hg. The following parameters were compared; cut rate (60, 600 and 6,000 cuts per minute [cpm]), probe type (standard and two-dimensional cutting [TDC]), and probe diameter (23-gauge and 25-gauge). The specimens were assessed by automated whole-slide imaging analysis and conventional light microscopy.

Results

Seventy-two biopsies were analyzed for the number of hepatocytes, total area of tissue fragments, and total stained area of each microscope slide. For all probe types, these parameters were significantly and positively correlated with the cut rate. TDC probes led to significantly higher scores than those of standard probes, independent of the cut rate. There were no significant differences in results when using 23-gauge or 25-gauge standard probes. Light microscopic examination demonstrated well-preserved cells sufficient for cytohistological analyses in all investigated cases.

Conclusions

The higher the cut rate, the larger is the amount of aspirated cellular material. There were no significant differences between 23-gauge and 25-gauge biopsies. Cut rates up to 6,000 cpm did not adversely affect the cytohistological features of the samples.

Transretinal biopsy via 23-gauge pars plana vitrectomy for retinal and choroidal tumors: cytopathological results, surgical complications, and patient outcomes

PURPOSE

To evaluate the cytopathological results, surgical complications, and patient outcomes after transretinal biopsy (TRB) for diagnosis of retinal/choroidal tumors METHODS: Records of 40 cases who underwent TRB via 23-gauge (23 G) pars plana vitrectomy between March 2011 and March 2020 were reviewed.

STUDY DESIGN

Retrospective.

RESULTS

Twenty-six (65.0%) cases were women and 14 (35.0%) were men. The mean age at diagnosis was 57.2 (range: 18-83) years. The mean tumor base diameter was 12.0×9.8 mm and the mean tumor thickness was 4.9 mm. According to cytopathological examination, 29 (72.5%) cases had choroidal melanoma, 2 (5.0%) had non-small cell lung cancer metastasis, 1 (2.5%) had adenoma of retinal pigment epithelium, 1 (2.5%) had small cell lung cancer metastasis, 1 (2.5%) had invasive breast cancer metastasis, 1 (2.5%) had retinal astrocytic hamartoma, and 1 (2.5%) had pseudoneoplastic gliosis. Cytopathological examination of 4 (10.0%) cases revealed findings consistent with macular and extramacular degeneration. Postoperative complications were mild vitreous hemorrhage in 16 (40.0%) cases, gradually worsening cataract in 4 (11.8%), retinal detachment in 1 (2.5%), hyphema in 1 (2.5%), glaucoma in 1 (2.5%), and macular hole in 1 (2.5%). During the mean 11.1 (range: 1-55) months follow-up, 1 (3.4%) patient with choroidal melanoma developed liver metastasis. All patients were alive at the end of follow-up.

CONCLUSIONS

TRB using 23 G pars plana vitrectomy can be used to make the cytopathologic diagnosis of retinal/choroidal tumors whenever the clinical diagnosis is not certain or in cases with known diagnosis to obtain information on cell type/cytogenetics. In our series, the most common diagnosis after cytopathologic examination was choroidal melanoma.

Uveal Melanoma Biopsy: A Review

Intraocular tumor diagnosis is based on clinical findings supported by additional imaging tools, such as ultrasound, optical coherence tomography and angiographic techniques, usually without the need for invasive procedures or tissue sampling. Despite improvements in the local treatment of uveal melanoma (UM), the prevention and treatment of the metastatic disease remain unsolved, and nearly 50% of patients develop liver metastasis. The current model suggests that tumor cells have already spread by the time of diagnosis, remaining dormant until there are favorable conditions. Tumor sampling procedures at the time of primary tumor diagnosis/treatment are therefore now commonly performed, usually not to confirm the diagnosis of UM, but to obtain a tissue sample for prognostication, to assess patient's specific metastatic risk. Moreover, several studies are ongoing to identify genes specific to UM tumorigenesis, leading to several potential targeted therapeutic strategies. Genetic information can also influence the surveillance timing and metastatic screening type of patients affected by UM. In spite of the widespread use of biopsies in general surgical practice, in ophthalmic oncology the indications and contraindications for tumor biopsy continue to be under debate. The purpose of this review paper is to critically evaluate the role of uveal melanoma biopsy in ophthalmic oncology.

The Small Fatal Choroidal Melanoma Study. A Survey by the European Ophthalmic Oncology Group

PURPOSE

To determine the size at which choroidal melanomas can metastasize and to report the characteristics of small fatal choroidal melanomas (SFCM).

DESIGN

Retrospective case series.

METHODS

Ten ocular oncology services submitted 45 patients with a choroidal melanoma 3 mm or less in thickness and 9 mm or less in largest basal diameter (LBD), when treated, who developed metastases.

RESULTS

Median tumor thickness was 2.4 mm (range, 1.0-3.0 mm) and LBD 7.3 mm (range, 3.0-9.0 mm). Of 14 (31%) tumors that were first observed, 12 grew a median of 0.5 mm (range, 0.1-1.2 mm) in thickness and 1.0 mm (range, 0-3.0 mm) in LBD within a median of 7 months; 3 were initially smaller than 3 mm in LBD. Number of risk factors for growth and metastasis was 0 for 4% of the tumors; 60% were over 2 mm in thickness, 63% had subretinal fluid, 84% caused symptoms, 57% had orange pigment, and 92% were within 3 mm of the disc. Local recurrence occurred in 8 of 31 eyes (26%) treated conservatively. Median metastasis-free survival was 4.5 years (range, 0.8-15.7 years). Kaplan-Meier estimate of metastasis developing was 15% (95% confidence interval [CI], 7-26), 51% (95% CI, 36-64) and 85% (95% CI, 71-92) by 2, 5, and 10 years, respectively. By the time of analysis, 37 patients had died of metastasis after a median of 7 months.

CONCLUSIONS

Choroidal melanomas less than 3.0 mm in LBD are highly unlikely to metastasize. Risk factors of an SFCM are similar to those for all choroidal melanomas of similar size.

Surgical outcomes of 27-gauge and 25-gauge vitrectomy day surgery for proliferative diabetic retinopathy

PURPOSE

To compare postoperative outcomes of 27-gauge (G) and 25-G vitrectomy conducted as day surgery for proliferative diabetic retinopathy (PDR).

METHODS

One hundred eighty-five consecutive PDR patients (185 eyes) who underwent primary vitrectomy (27-G in 64 eyes, 25-G in 121 eyes) were analyzed.

RESULTS

The 27-G and 25-G groups did not differ significantly in preoperative Early Treatment Diabetic Retinopathy Study (ETDRS) score, age, or preoperative intraocular pressure. The proportions of simultaneous cataract surgery (27-G vs. 25-G: 59.4% vs. 62.4%) and air-filled eyes (76.6% vs. 85.1%) were not significantly different between two groups. Both groups showed significant improvement in ETDRS score at postoperative 1, 3, and 6 months (all, P < 0.0001). Mean gain in ETDRS score from baseline was apparently better in 27-G group than in 25-G group at 1, 3, and 6 months, but there were no significant differences (1 month: 20.3 vs. 13.1 letters, P = 0.0703; 3 months: 22.9 vs. 17.5 letters, P = 0.1561; 6 months: 24.3 vs. 19.3 letters, P = 0.3313). Operation time was apparently longer for 27-G vitrectomy, but there was no significant difference (54.0 vs. 51.1 min, P = 0.3676). The same was observed for postoperative intraocular pressure at postoperative day 1 (19.7 vs. 18.1 mmHg, P = 0.1353). Incidence of postoperative retinal detachment (1.6% vs. 0.8%) and reoperation due to vitreous hemorrhage (6.3% vs. 6.6%) was not different between two groups.

CONCLUSIONS

The 27G system is as safe and as useful as the 25G system when used for PDR and can be expected to achieve earlier recovery of postoperative visual acuity.

Outcomes of 27-Gauge Vitrectomy-Assisted Choroidal and Subretinal Biopsy

BACKGROUND AND OBJECTIVE

To report the initial experience of 27-gauge vitrectomy-assisted choroidal and subretinal biopsy PATIENTS AND METHODS: Retrospective, interventional case series. Eighteen eyes of 18 patients undergoing 27-gauge vitrectomy-assisted choroidal (n = 16) or subretinal biopsy (n = 2). Clinical and lesion characteristics, cytopathology, histology, gene expression profiling (GEP), visual acuity (VA), complications including vitreous hemorrhage (VH), development of rhegmatogenous retinal detachment (RD), and need for additional surgeries were analyzed.

RESULTS

Indications were choroidal melanoma (n = 10), indeterminate choroidal (n = 5), and subretinal lesions (n = 3). Mean lesion height was 3.33 mm ± 1.55 mm (range: 0.80 mm to 6.75 mm) and largest diameter was 8.63 mm ± 4.14 mm (range: 3 mm to 15.5 mm). Mean number of intralesional biopsy passes required was 1.76 ± 0.83 (range: one to four). During a mean follow-up of 7.4 months ± 2.7 months (range: 4 months to 14 months), VA was unchanged (0.5 logMAR ± 0.6 logMAR vs. 0.7 logMAR ± 0.84 logMAR; P = .07). Pathologic diagnosis was obtained in 16 of 18 eyes (88.9%), and GEP data were collected for all 11 choroidal melanomas. Post-biopsy VH occurred in 13 of 18 eyes (72.2%) and was severe enough to require a concurrent limited vitrectomy in six eyes (33.3%). These eyes had a greater lesion height compared to eyes not requiring a vitrectomy (4.08 mm ± 1.68 mm vs. 2.76 mm ± 1.43 mm; P = .04). A rhegmatogenous RD requiring repeat surgery developed in two of 18 eyes (11.1%).

CONCLUSION

The authors concluded that 27-gauge vitrectomy-assisted choroidal and subretinal biopsy established a diagnosis in 88.9% of eyes in lesions 0.8 mm or larger. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:406-415.].