A girl with Hermansky-Pudlak syndrome

Eye movement abnormalities in hermansky-pudlak syndrome

BACKGROUND

Hermansky-Pudlak Syndrome (HPS) is a type of oculocutaneous albinism associated with a bleeding diathesis and pulmonary fibrosis. Although it is known that patients with HPS exhibit nystagmus, the nature of these abnormal eye movements has not been studied.

METHODS

Twenty-seven patients with HPS, diagnosed by platelet morphology and genetic analysis, underwent a systemic evaluation and complete eye examination. Twenty-five had eye movement recordings using magnetic search coil, infrared, or video oculography.

RESULTS

All patients had iris transillumination, foveal hypoplasia, and variable hypopigmentation in skin and eyes. All had bleeding tendencies, and 2 reported excessive bleeding during strabismus surgery. Nine patients had pulmonary fibrosis. Visual acuities ranged from 20/20- to 20/320. Twenty patients had strabismus despite 6 having strabismus surgery previously. Ocular oscillations consistent with congenital nystagmus (CN) were clinically evident in 24 of 27 patients, and half showed periodic alternating nystagmus. In 3 patients without CN, eye movement recordings revealed minimal end-gaze nystagmus, square-wave jerks, drift during fixation and saccades, and low-gain pursuit. These patients had melanin in the posterior pole and better visual acuities than the others (P = 0.002).

CONCLUSIONS

Most patients with HPS have CN, and many have periodic alternating nystagmus. Some have subtle eye movement abnormalities without clinically evident nystagmus, which can obscure the diagnosis, especially if hypopigmentation is mild. Absence of clinical nystagmus in a child with HPS suggests good vision. Patients with albinism, especially before surgery, should be evaluated for HPS to prevent life-threatening complications.

Ocular findings in the Hermansky-Pudlak syndrome

BACKGROUND

The Hermansky-Pudlak syndrome (HPS) is defined by the autosomal recessively inherited triad of tyrosinase-positive oculocutaneous albinism, bleeding diathesis and accumulation of ceroid in tissues. Late complications include: interstitial pulmonary fibrosis; inflammatory bowel disease; and renal failure.

PATIENTS AND METHODS

We undertook a non-concurrent prospective study of 55 Puerto Rican patients with HPS (age range 1 to 54 yrs; mean = 19.7 yrs). These patients had a comprehensive ocular examination and a systemic evaluation for HPS.

RESULTS

Visual acuities ranged from 20/50 to 5/200. All patients had nystagmus. Forty-three patients had strabismus; esotropia was found in 24 patients; exotropia in 18 patients; and one patient had hypertropia. Posterior embryotoxon occurred in 15 patients and Axenfeld anomaly in 4 patients. Iris pigmentation varied from minimal to almost completely normal. Three patients had cataract formation. The retina was typically albinotic with macular hypoplasia. All patients had cutaneous albinism, bleeding diathesis and various systemic manifestations as part of HPS.

CONCLUSION

Ocular findings in HPS include reduced visual acuity; congenital nystagmus, strabismus and cataract. Diagnosis of the syndrome ought to be made preoperatively to help minimize the potential complications associated with bleeding diathesis at the time of extraocular muscle and intraocular surgery in patients with HPS.