Oculopharyngeal muscular dystrophy: What's new?

Ocular manifestations and outcomes of OPMD- a report from the national IsrOPMD registry

PURPOSE

This study aims to describe the ocular manifestations, treatment, and prognosis of OPMD patients registered in the national Israel OPMD(IsrOPMD) registry.

METHODS

Data was prospectively collected from patients referred to the IsrOPMD registry from January 2022 to March 2023. This included patient demographics, medical and ocular history, eye exams, eyelid evaluations, visual field exams, and orthoptic evaluations.

RESULTS

30 patients (15 males, mean age 53 years) were treated in the ocular OPMD clinic, predominantly of Bukhari descent (86.6%). The mean visual acuity was 0.06 logMAR. Twenty-one patients (70%) had eye movement problem, mostly in horizontal gaze. 6(20%) patients' complaint about diplopia. Ptosis surgery was performed in 21(70%) patients, with 17(56.7%) patients underwent frontalis sling surgery and 4(13.3%) patients undergoing levator advancement. The mean Margin reflex distance (MRD1) improved post-surgery (2.28 mm vs. 1.58 mm), but 11(36.6%) patients required more than one ptosis surgery.

CONCLUSIONS

The study contributes valuable insights into the ocular aspects of OPMD. It reveals that OPMD patients often experience a range of ocular symptoms, such as ptosis, abnormalities in eye movements, strabismus, and potentially diplopia, which can significantly impact their quality of life. The findings underscore the importance of regular ophthalmological follow-up for these patients to address these symptoms effectively. The study is significant in contributing to the limited but growing knowledge about the ocular manifestations of OPMD and the management of these symptoms to improve the quality of life for patients suffering from this condition.

Oculopharyngeal Muscular Dystrophy Ptosis, Mueller's Muscle Involvement, and a Review of Management Over 34 Years

PURPOSE

To review the management of the ptosis associated with oculopharyngeal muscular dystrophy (OPMD) from one author's experience over 34 years, demonstrate Mueller's muscle involvement in this disease, and how this impacts the preferred choice of surgery.

METHODS

Retrospective, nonrandomized comparative case series. Forty patients with OPMD who underwent primary bilateral ptosis surgery through an anterior eyelid incision and had their Mueller's muscle biopsied (one side) and sent for histopathologic analysis were selected for chart review. The main outcome measure was the presence or absence of dystrophic changes in the biopsied Mueller's muscle.

RESULTS

In 29/40 biopsies (72.5%), there were dystrophic changes and fatty infiltration of Mueller's muscle identified histopathologically.

CONCLUSIONS

Mueller's muscle is involved in the dystrophic process more often than expected contributing to ptosis in the OPMD syndrome. A combined Mueller's-aponeurotic advancement is more effective at elevating the eyelid than simply advancing the aponeurosis when Mueller's is fatty infiltrated at the time of external levator advancement surgery in our experience. Management strategies for ptosis surgery in OPMD are reviewed. The age of onset, levator muscle function, previous ptosis repair, how debilitated the patient is with their disease process systemically, as well as the presence of other eye problems (e.g., dry eye, prior glaucoma filtering procedures, history of corneal surgery, laser refractive procedure) are important clinical considerations in patients with OPMD.

Comparison of Two Polypropylene Frontalis Suspension Techniques in 92 Patients With Oculopharyngeal Muscular Dystrophy

PURPOSE

To compare the functional outcome of the polypropylene trapezoid frontalis suspension with the polypropylene modified Crawford frontalis suspension in a large cohort of patients with oculopharyngeal muscular dystrophy.

METHODS

Retrospective, nonrandomized comparative case series. Patients with oculopharyngeal muscular dystrophy who underwent bilateral polypropylene frontalis suspension were selected for chart review. Main outcome measures were margin reflex distance, duration of surgery, and ptosis recurrence.

RESULTS

Ninety-two patients qualified for chart review; 39 patients underwent the trapezoid sling and 53 patients the modified Crawford sling. There was no difference in preoperative margin reflex distance or levator function between the 2 surgical groups. Postoperative improvement in margin reflex distance was 2.95 ± 1.56 mm in the trapezoid group compared with 2.85 ± 1.65 mm in the modified Crawford group (p = 0.67). Duration of surgery was 40.49 ± 13.33 minutes in the trapezoid group compared with 53.77 ± 16.04 minutes in the modified Crawford group (p < 0.001). Five percent of eyes in the trapezoid group had ptosis recurrence compared with 13% of eyes in the modified Crawford group (p = 0.07).

CONCLUSION

Both polypropylene frontalis suspension techniques generated an equivalent increase in margin reflex distance. However, the trapezoid frontalis suspension required less operative time and trended toward a lower rate of ptosis recurrence.

Muscle weakness and speech in oculopharyngeal muscular dystrophy

PURPOSE

We documented speech and voice characteristics associated with oculopharyngeal muscular dystrophy (OPMD). Although it is a rare disease, OPMD offers the opportunity to study the impact of myopathic weakness on speech production in the absence of neurologic deficits in a relatively homogeneous group of speakers.

METHODS

Twelve individuals with OPMD and 12 healthy age-matched controls underwent comprehensive assessment of the speech mechanism including spirometry (respiratory support), nasometry (resonance balance), phonatory measures (pitch, loudness, and quality), articulatory measures (diadochokinetic rates, segment duration measures, spectral moments, and vowel space), tongue-to-palate strength measures during maximal isometric and speechlike tasks, quality-of-life questionnaire, and perceptual speech ratings by listeners.

RESULTS

Individuals with OPMD had substantially reduced tongue strength compared to the controls. However, little impact on speech and voice measures or on speech intelligibility was observed except for slower diadochokinetic rates.

CONCLUSIONS

Despite having less than half the maximal tongue strength of healthy controls, the individuals with OPMD exhibited minimal speech deficits. The threshold of weakness required for noticeable speech impairment may not have been reached by this group of adults with OPMD.

The man who could not see what he could not eat

A 55-year-old Hispanic man born in New Mexico presented with progressively worsening bilateral upper eyelid ptosis and dysphagia. External levator advancement 5 years before did not improve his ptosis. A thorough systemic workup for myasthenia gravis was negative, but electromyography suggested a myopathic process. Molecular genetic testing was positive for oculopharyngeal muscular dystrophy.

Postoperative complications in patients with oculopharyngeal muscular dystrophy: a retrospective study

PURPOSE

Oculopharyngeal muscular dystrophy (OPMD) is a genetic disease with autosomal dominant transmission particularly common in Quebec where its prevalence is about 1:1000. The main features are bilateral ptosis of the eyelids and dysphagia. These symptoms are frequently treated surgically by levator palpebrae resection (LPR) and cricopharyngeal myotomy (CPM). The objectives of this retrospective chart review were to describe the postoperative complications in OPMD patients undergoing LPR or CPM and to determine their incidence.

METHODS

Medical records of all OPMD patients who had either LPR or CPM between 1997 and 2002 were reviewed. The following complications were collected: death, pneumonia, aspiration pneumonitis, airway obstruction, reintubation, and severe coughing and choking caused by profuse secretions.

RESULTS

One hundred and fourteen surgeries on 92 OPMD patients were studied. Fifty-nine were LPR under general anesthesia (LPR-GA) and 22 were LPR under local anesthesia (LPR-LA). Thirty-three surgeries were CPM, all under general anesthesia. There was no death or reintubation. Patients who had LPR-LA had shorter postanesthesia care unit (P<0.001) and ambulatory surgery unit (P<0.001) stays than those who had LPR-GA. Complications were more frequent after CPM than LPR-GA (P<0.001).

CONCLUSION

The complication rate after LPR was low. Both local and general anesthesia are safe alternatives in OPMD patients operated for LPR. Patients having CPM presented more respiratory complications than those having LPR.

Oculopharyngeal muscular dystrophy: a late-onset polyalanine disease

Oculopharyngeal muscular dystrophy (OPMD) is a muscle disease of late onset associated with progressive ptosis of the eyelids, dysphagia, and unique tubulofilamentous intranuclear inclusions (INIs). OPMD is usually transmitted as an autosomal dominant trait (OMIM 164300). A rarer allelic autosomal recessive form has also been observed (OMIM 257950). Both forms are caused by short (GCG)8-13 expansions in the polyadenylate-binding protein nuclear 1 gene (PABPN1) located on chromosome 14q11.1. The mutations cause the lengthening of an N-terminal polyalanine domain. Both slippage and unequal recombination have been proposed as the mutation mechanisms. The size of the mutation has not yet been conclusively shown to inversely correlate with the severity of the phenotype. Mutated PABPN1 proteins have been shown to be constituents of the INIs. The INIs also contain ubiquitin, proteasome subunits, HSP 40, HSP 70, SKIP, and abundant poly(A)-mRNA. The exact mechanism responsible for polyalanine toxicity in OPMD is unknown. Various intranuclear inclusion dependent and independent mechanisms have been proposed based on the major known function of PABPN1 in polyadenylation of mRNA and its shuttling from the nucleus to the cytoplasm. OPMD is one of the few triplet-repeat diseases for which the function of the mutated gene is known. Because of the increasing number of diseases caused by polyalanine expansions and the pathological overlap with CAG/polyglutamine diseases, what pathological insight is gained by the study of OPMD could lead to a better understanding of a much larger group of developmental and degenerative diseases.