Introduction:
Hereditary macular dystrophies constitute a group of rare disorders whose exact prevalence is unknown. They include Doyne honeycomb retinal dystrophy (DHRD), inherited in an autosomal dominant manner and associated with a missense mutation in the EFEMP1 gene (2p16.1), which encodes a fibulin-like extracellular matrix protein containing an epidermal growth factor. Radially arranged, laminar, round drusen appear in childhood, whereas visual disturbances manifest only in the 4th and 5th decades of life.

Case reports:
Two 72-year old female patients, who are twins, presented to the Outpatient Ophthalmology Clinic due to visual disturbances. Visual acuity (VA) was 0.04 in the right eye (RE) and 0.08 in the left eye (LE) in patient A, and 0.06 in RE and 0.2 in LE in patient B. Intraocular pressure (IOP) measured 18 mmHg in RE and 17 mmHg in LE in patient A, and 17 mmHg in RE and 11 mmHg in LE in patient B. The patients were qualified for further diagnostic evaluation of both eyes.

Results:
OCT examination revealed confluent drusen and atrophy of the retinal pigment epithelium and photoreceptors in both patients. In patient A, an atrophic macular hole was additionally identified. The ganglion cell complex (GCC) measured an average of 120 μm in the RE and 120 μm in the LE in patient A, and 112 μm in RE and 113 μm in LE in patient B.

Conclusions:
Patients with suspected DHRD require regular ophthalmological follow-up to monitor disease progression, correct refractive errors, and assess the degree of lens opacity.