Eye Abnormalities Detectable in Exam May Help to Diagnose Alport Syndrome, Study Says
A thorough eye examination can help to diagnose Alport syndrome even in the absence of obvious kidney symptoms, a case report suggests.
“Alport syndrome with bilateral simultaneous anterior and posterior lenticonus with severe temporal macular thinning” was published in the journal BMJ Case Reports.
Alport syndrome is typically a disease that affects the kidneys; however, manifestations that affect the eye have also been reported. This case report details two patients who were diagnosed with Alport syndrome after they were hospitalized due to vision problems.
The first patient (male, 19 years old) had a five-year history of difficulty seeing and hearing. An eye exam revealed several abnormalities, most notably bilateral anterior and posterior lenticonus. Lenticonus is a cone-like abnormality that can form on the lens of the eye; “bilateral anterior” refers to it affecting both eyes (bilateral), and the location on the lens (anterior/posterior).
The presence of bilateral anterior lenticonus was particularly noteworthy because over 90% of reported cases of bilateral anterior lenticonus occur in people with Alport syndrome.
“Bilateral anterior lenticonus is hence virtually pathognomic of AS [Alport syndrome], wherein it is absent at birth and usually occurs in second to third decade of life,” the researchers wrote. (Pathognomic refers to a symptom that is so characteristic of a particular disease that it can be used to make a diagnosis.)
Although the teenager had no complaints kidney-related problems, further investigation revealed unusually high amounts of protein, as well as the presence of blood cells, in the patient’s urine, which suggests kidney disease.
The second patient (male, 24 years old) had a similar story: hospitalized with difficulty seeing and hearing, subsequently found to have bilateral anterior and posterior lenticonus, and, upon further investigation, signs of kidney disease.
Both were diagnosed with Alport syndrome and began treatment with angiotensin converting enzyme (ACE) inhibitors to limit damage to the kidneys. As of the publication of the case report, both patients’ eyes and kidneys have been stable.
This case report serves as an illustration of how changes in the eye can be used to diagnose Alport syndrome. Although its researchers noted that “AS presenting with visual symptoms before the onset of renal failure and renal complaints is very uncommon … the presence of lenticonus and retinal changes can be useful in predicting early onset renal failure,” they concluded.