Evaluation of optical coherence tomography (OCT) changes following transretinal tumour biopsy for choroidal melanoma.

AIM

This study uses OCT imaging to examine morphological changes at the chorioretinal interface of the choroidal melanoma biopsy site over time.

SETTING

Liverpool Ocular Oncology Centre (LOOC), St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, United Kingdom.

METHODOLOGY

Retrospective analysis of all patients who underwent 25G vitrector-assisted transretinal biopsy for choroidal melanoma between 1st Jan 2017 and 31st Dec 2019. The biopsy procedure does not involve full vitrectomy, treatment of the retinal hole or tamponade. Patients routinely undergo OCT imaging over the tumour site at each follow up. Cases required a minimum of a baseline OCT and two consecutive post-operative OCT scans of adequate quality, overlying the biopsy site. All images were reviewed and graded by an ophthalmic specialist.

RESULTS

Fifty-one patients met the criteria for inclusion. OCT analysis identified 2 characteristic morphologies following transretinal biopsy -a choroidal plugging of biopsy site (47.0%), or a flat retinal hole (53.0%). Choroidal plugging morphologies tend to remain unchanged over time, whereas flat holes demonstrate greater variability and would more commonly seal over with atrophic retina (Fisher Exact Value = <0.01). 60.8% demonstrated vitreous plugging of the biopsy site.

CONCLUSION

OCT analysis has identified key morphological changes following transretinal choroidal melanoma biopsy. The morphologies identified may provide dynamic protective effects against vitreous flow into the subretinal space, accounting for low rates of retinal detachment despite the presence of an untreated iatrogenic retinal hole following transretinal biopsy.