Our Summary

This study looked at the largest group of patients to date with a genetic disorder called Hurler syndrome and other similar conditions (all under the umbrella term of mucopolysaccharidosis or MPS I), who had undergone cornea transplants due to a symptom of the condition - cloudy corneas.

The researchers examined 15 corneas from 9 patients who had this surgery between May 2011 and October 2020. They looked at clinical data and also examined the removed corneas under a microscope, using different types of stains to highlight the areas of interest.

They found that all of the corneas had mucopolysaccharides (a type of large molecule) deposited in them, which could be seen when stained and viewed under a microscope. All the corneas also had changes in a part of the cornea called Bowman’s layer, and most had abnormalities in the epithelium, which is the outermost layer of cells covering the cornea.

These findings suggest that a type of cornea transplant called deep anterior lamellar keratoplasty is a successful treatment for the cloudy corneas seen in MPS I. The changes seen in the removed corneas could potentially provide clues to pathologists that the patient may have a lysosomal storage disorder, a group of rare metabolic disorders that includes MPS I. These are subtle changes but important for diagnosis and treatment.

FAQs

  1. What is the primary treatment for corneal clouding in patients with Hurler syndrome and other variants of mucopolysaccharidosis (MPS) I?
  2. What are the common histopathologic and histochemical characteristics of explanted corneas from patients with MPS I?
  3. How are mucopolysaccharide depositions in the corneas of patients with MPS I detected and highlighted?

Doctor’s Tip

A doctor might tell a patient undergoing a corneal transplant for corneal clouding related to MPS I or other lysosomal storage disorders to be aware that the excised corneas may show characteristic changes such as alterations in Bowman’s layer, epithelial abnormalities, and mucopolysaccharide deposition. It is important for the patient to follow up with their healthcare provider regularly to monitor for any signs of recurrence or complications related to their underlying condition.

Suitable For

Patients with Hurler syndrome and other variants of mucopolysaccharidosis (MPS) I are typically recommended corneal transplant to treat corneal clouding associated with the condition. This study showed that corneas from patients with MPS I spectrum disease undergoing corneal transplantation had mucopolysaccharide deposition, alterations in Bowman’s layer, and epithelial abnormalities. Deep anterior lamellar keratoplasty was successful in treating the corneal clouding in these patients. The histopathologic and histochemical characteristics of these corneas can help pathologists identify underlying lysosomal storage disorders in patients with corneal clouding.

Timeline

Before Corneal Transplant:

  1. Patient experiences symptoms of corneal clouding, such as blurry vision and sensitivity to light.
  2. Patient undergoes a thorough eye examination to determine the extent of corneal damage and the need for a corneal transplant.
  3. Patient is evaluated for any underlying conditions, such as mucopolysaccharidosis (MPS) I, which may be causing the corneal clouding.
  4. Surgical team plans for the corneal transplant procedure, taking into consideration the patient’s overall health and any potential risks.

After Corneal Transplant:

  1. Patient undergoes deep anterior lamellar keratoplasty to replace the cloudy cornea with a clear donor cornea.
  2. Pathologist examines the excised cornea and identifies mucopolysaccharide deposition, alterations in Bowman’s layer, and epithelial abnormalities.
  3. Patient undergoes postoperative care and monitoring to ensure proper healing and visual recovery.
  4. Patient experiences improved vision and relief from symptoms of corneal clouding.
  5. Long-term follow-up is conducted to monitor the success of the corneal transplant and any potential complications related to the underlying condition, such as MPS I.

What to Ask Your Doctor

  1. What is the underlying cause of my corneal clouding that necessitates a corneal transplant?
  2. What type of corneal transplant procedure will be performed for my condition?
  3. What are the potential risks and complications associated with the corneal transplant surgery?
  4. What is the expected recovery process and timeline following the corneal transplant surgery?
  5. Will I need to take any specific medications or follow any special post-operative care instructions after the surgery?
  6. How will the success of the corneal transplant be monitored in the long term?
  7. Are there any potential long-term effects or considerations I should be aware of following the corneal transplant surgery?
  8. How frequently will I need to follow up with my ophthalmologist after the corneal transplant?
  9. Are there any specific lifestyle changes or precautions I should take to protect my new cornea?
  10. Are there any alternative treatments or therapies that may be beneficial for my condition in addition to or instead of a corneal transplant?

Reference

Authors: Williams IM, Pineda R, Neerukonda VK, Stagner AM. Journal: Am J Ophthalmol. 2021 Nov;231:39-47. doi: 10.1016/j.ajo.2021.05.014. Epub 2021 May 26. PMID: 34048802