Endocapsular artificial iris implantation for iris defects: Reducing symptoms, restoring visual function and improving cosmesis

Cysts and tumours of the iris: Diagnostic tools and key management considerations-A review

The iris is a unique structure, with exquisite variations in colour and form. Pathological changes, specifically including iris cysts and tumours are relatively uncommon, difficult to diagnose, and yet potentially blinding or life-threatening. Based on a comprehensive literature review, with highly illustrated key case examples, this report aims to guide the clinician in filtering the differential diagnoses of iris cysts and tumours. Evaluation is in the context of key diagnostic clinical tools and management considerations. Diagnostic imaging techniques include serial anterior segment photography, ultrasound, anterior segment optical coherence tomography, and iris fluorescein angiography, however, the roles of computerised topography and magnetic resonance imaging are also considered in this review. Management includes categorisation in terms of solid iris tumours (melanocytic vs. non-melanocytic), or iris cysts (primary vs. secondary) that may be usefully differentiated by clinical assessment, avoiding more invasive interventions. Cystic lesions are generally benign, although implantation cysts in particular cause significant complications and surgical challenges. Most solid tumours are melanocytic and also typically benign. However, in larger lesions, rapid growth, symptoms and complications more likely indicate malignancy, requiring further investigation.

An optimized 3T MRI scan protocol to assess iris melanoma with subsequent histopathological verification - A prospective study

INTRODUCTION

Magnetic resonance imaging (MRI) has demonstrated high levels of tissue contrast, accuracy and reproducibility in evaluating posterior uveal melanoma. Owing to smaller size, the role of MRI in detecting and characterising iris melanoma has not yet been explored.

AIMS

To develop a protocol to image iris melanoma and describe the MRI characteristics of histopathological-confirmed iris melanoma.

MATERIALS AND METHODS

An optimised MRI protocol, using a 3T MRI scanner and a 32-channel head coil, was developed to image iris tumours. A prospective, single-centre, 12-month study was conducted on all patients with lesions suspicious for iris melanoma. All patients were offered an MRI scan in addition to the standardised clinical procedures. Image quality comparison was made with existing clinical investigations. Iris melanoma characteristics on MRI are described.

RESULTS

A successful optimised MRI scan protocol was developed that was able to detect and characterise iris melanoma. One normal participant and five patients with subsequent histopathological-confirmed iris melanoma (n = 6) were recruited. Four patients completed the full MRI sequence. All iris melanoma were detected on at least one T1- or T2-weighted images. When compared to the vitreous, all iris melanomas demonstrated hyper-intensity on T1-weighted images and hypo-intensity on T2-weighted images. On T1-mapping, T1-values of iris melanoma demonstrated an inverse relationship with the degree of tumour pigmentation.

CONCLUSIONS

This study highlights an optimised, easily reproducible MRI scan protocol to image iris melanoma. Numerous MR imaging characteristics of iris melanoma are reported for the first time and a potential non-invasive tumour biomarker is described.

Microscopic analysis of preinsertion cutting modalities on custom, flexible iris prostheses

PURPOSE

To determine the induced edge effects of different clinically used device postmanufacture modification styles and modalities on custom iris implants.

SETTINGS

An academically affiliated multispecialty private practice group and an academic medical center.

DESIGN

Laboratory study.

METHODS

Sample custom iris prostheses were cut using patterns, blades, and surgical instruments described in the literature. The cut edges were evaluated with slitlamp microscopy, light microscopy, and scanning electron microscopy.

RESULTS

Disposable blades yielded smoother cuts than scissors. Trephine blade brand significantly affected the cut surface smoothness of the silicone matrix. Meshwork-embedded prostheses had some irregular sharp edges where the mesh fibers were cut with all modalities, although these were worse with scissors and one tested trephine brand compared with the other. Pseudoiridectomies and scissor cuts created sharp points and corners in the device periphery.

CONCLUSIONS

Postmanufacture modifications of iris implants should be minimized. The cut margins of the fiber-free implants have fewer sharp edges and may be preferable for sulcus placement. In-the-bag device placement may mitigate clinical impact of sharp edges and corners. These practices may help to minimize inflammatory sequelae postimplantation.