Optometry case study: Retinitis pigmentosa with macular complications

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Figure 1. RE

By Catrina Roberts, Specsavers Morayfield, QLD

History

Px: 22-year-old Caucasian male
Reason for visit: New retail team member at Specsavers having an eye exam to experience the full customer journey. Reported poor peripheral vision and struggled with night-time exercises involving the use of night-vision goggles when previously in the army.
GH:
 No issues
POH: First eye exam
FOH: No relevant issues

Clinical Assessment

Refraction:
Unaided VA: RE: 6/7.5    LE: 6/6-2
Subjective refraction:
RE: +0.25/-0.75×175    6/7.5+2    LE: +0.50/-0.50×10    6/6+2

Fundus examination:
RE (Figure 1):

  • Healthy optic nerve
  • Epiretinal membrane (ERM), fluid at macula
  • Slightly attenuated arterioles
  • Extensive peripheral bone spicule pigmentation

LE (Figure 2):

  • Healthy optic nerve
  • ERM with possible macula hole
  • Slightly attenuated arterioles
  • Extensive peripheral bone spicule pigmentation

OCT imaging of the optic nerve showed pronounced macular oedema in the RE and a lamellar hole in the LE (Figure 3).

Figure 3. Macula OCT images

Ocular motility: Full and smooth
Pupils: PERRLA, no RAPD

Central visual field testing was undertaken on the same day with the aim of confirming a diagnosis of retinitis pigmentosa and assessing central vision with respect to fitness to drive (Figures 4 and 5).

Diagnosis

Differential diagnosis:

  • Retinitis pigmentosa
  • Bilateral ERM with macular oedema

Management

Due to strong suspicion of retinitis pigmentosa (RP) with macular involvement, an urgent ophthalmic referral to a retinal specialist was arranged. A discussion was also carried out with the patient about fitness to drive and the possible implications of restricted peripheral vision upon holding an unconditional licence. The patient decided not to drive again until after discussing the situation further with the ophthalmologist and getting a definitive answer regarding his suitability to hold a licence.

Upon seeing the specialist, a diagnosis of RP was confirmed. The ophthalmologist also felt that there was bilateral vitreous debris indicative of previous inflammation. This could have led to the development of the ERMs and the macular oedema. Traction from the ERM was also causing a partial thickness macular hole in the LE, but as this was not near the photoreceptor layer, the specialist decided to manage this conservatively with close observation.

The patient was started on topical anti-inflammatories to try to clear the macular fluid away, although it is possible that some of this was secondary to potential spaces caused by fluid in the ERM.

Electrodiagnostic testing (including a wide-field multifocal electroretinogram) was arranged, as well as Esterman visual field testing. As the patient achieved a satisfactory result on the Esterman, he was able to keep his licence but will most likely need some restrictions applied for night-time driving in the future.

Discussion

RP is a genetic eye condition that causes photoreceptor cells in the retina to degenerate slowly and progressively. There are many different subtypes and the severity is variable. Inflammation is common in RP and is associated with younger patient age.1

Macular involvement is often seen with RP and can include cystoid macular oedema, vitreomacular traction, ERM and macular holes. OCT screening has increased the rate of detection of these complications and has been shown to be more effective than either slit-lamp examination or fluorescein angiography with respect to detecting macular involvement in RP.3,4

OCT is an excellent tool for monitoring oedema and in this case was invaluable for getting a clear picture of what sort of macular changes were involved. It has allowed the oedema to be monitored objectively during the course of topical anti-inflammatory treatment to measure the reduction in fluid.


REFERENCES

  1. Yoshida N, Ikeda Y, Notomi S, Ishikawa K, Murakami Y, Hisatomi T, Enaida H, Ishibashi T. Clinical Evidence of Sustained Chronic Inflammatory Reaction in Retinitis Pigmentosa. Ophthalmology 2013; 120: 100-105.
  2. Apushkin MA, Fishman GA, Janowicz MJ. Monitoring cystoid macular edema by optical coherence tomography in patients with retinitis pigmentosa. Ophthalmology 2004; 111: 1899-1904.
  3. Hagiwara A, Yamamoto S, Ogata K, Sugawara T, Hiramatsu A, Shibata M, Mitamura Y. Macular abnormalities in patients with retinitis pigmentosa: prevalence on OCT examination and outcomes of vitreoretinal surgery. Acta Ophthalmologica 2011; 89: e122-e125.
  4. Hajali M, Fishman GA, Anderson RJ. The prevalence of cystoid macular oedema in retinitis pigmentosa patients determined by optical coherence tomography. British Journal of Ophthalmology 2008; 92: 1065-1068.
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