Optometry case study: Dangers of ignoring the far periphery

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Figure 2. LE, showing large temporal mass

By Dr Steven Lam, Specsavers Sunbury, VIC

History

Px: 60-year-old male
Reason for visit: Significantly progressing blur of LE vision over the last two weeks
GH: Nil – last GP visit one year ago
POH: Nil – last eye examination unknown
FOH: Nil

Clinical Assessment

Screening tests
Ocular motility: Full
Pupils: PERRLA DCN followed
Cover test: Orthophoric
Confrontation:
RE: Full
LE: Nasal hemianopia
Red cap test: RE: 10/10    LE: 7/10
Unaided VA: RE: 6/9    LE: 6/12 (eccentric fixation)
Refraction: RE: Plano/-0.75 x 105 = 6/6    LE: Unable to refract

Slit lamp examination
Anterior segment: Normal OU
Posterior segment: Large temporal mass on LE as seen on slit lamp examination and digital retinal photographs (Figures 1 and 2)

Diagnosis & Management

Differential diagnosis:

  • Retinal detachment or tears
  • Posterior vitreous detachment
  • Branch retinal vein / artery occlusion
  • Optic nerve compression
  • Uveal melanoma

Management: Urgent, on-the-day referral to the local hospital’s emergency department to initiate assessment and systemic work up for diagnosis and management

Diagnosis: Uveal melanoma (specifically, choroidal melanoma)

Discussion

Uveal melanoma is a serious, life-threatening intraocular malignancy that accounts for 5% of all melanomas. It can be classified by anatomical locations, which include the commonly benign iris melanomas, and the malignant ciliary body and choroidal melanomas.

Patients may present with gradual vision loss, metamorphopsia, visual field loss and photopsia. Many may also be asymptomatic if the lesion does not impede the macula. Retinal signs of early malignant lesions include a solitary elevated domed shape mass which may be pigmented or amelanotic, lipofuscin in the RPE overlying the lesion, choroidal folds and a ‘collar stud’ appearance of mass if the tumour has penetrated through Bruch’s membrane.

The condition is diagnosed clinically by slit lamp biomicroscopy (fundus examination) and ultrasonography. When the origin of the melanoma is unknown, genetic testing with tissue biopsy using techniques such as trans-scleral and trans-vitreal aspiration with a fine 25-gauge needle can be performed.

Management of uveal melanomas range from conservative therapies such as laser photocoagulation, radiotherapy, transpupillary thermotherapy and photodynamic therapy, to the more invasive surgical procedures such as trans-scleral choroidectomy, enucleation (removing the globe only), evisceration (removing the inner contents of the eye and leaving the globe), and exenteration (removing all contents of the orbit).

Survival rates of patients with melanomas vary depending on time of diagnosis and treatment. Some studies show that the five-year survival rates for patients assigned with enucleation alone was 57% and 62% for patients assigned to pre-enucleation radiation. Ten-year survival rates was 39% for both methods of management.

Outcome

The patient was diagnosed with a choroidal melanoma that was 16mm horizontally and 20mm in depth in the far temporal retina with no systemic metastasis. He was placed on the waiting list for a LE enucleation. It was noted that early liver metastasis is unknown due to limitations of current diagnostic technology.

This case highlights the dangers of uveal melanomas and emphasises the importance of comprehensive retinal examinations on all patients.


REFERENCES

  • Sodhi A, Gutkind S. Molecular Genetic of Choroidal Melanoma. Ryan’s Retina. 6th ed. USA: Elsevier; 2018
  • Damato B, Stewart J, Afshar A, Groenewald C, Foulds W. Surgical resection of the Choroidal Melanoma. Ryan’s Retina. 6th ed. USA: Elsevier; 2018
  • Hawkins B, Schachat A. Collaborative Ocular Melanoma Study. Ryan’s Retina. 6th ed. USA: Elsevier; 2018
  • Herwig M, Grossniklaus H. Pathology of Choroidal Melanoma. Ryan’s Retina. 6th ed. USA: Elsevier; 2018
  • Kanski J, Bowling B, Nischal K, Pearson A. Clinical Ophthalmology: A Systemic Approach. 7th ed. United Kingdom: Elsevier; 2011
  • Shields C, Shields J. Overview of management of Posterior Uveal Melanoma. Ryan’s Retina. 6th ed. USA: Elsevier; 2018
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