Spontaneous resolution of a unilateral cataract in an adult A case report

Rationale: Cataracts are a disease that is usually caused by aging and involve the irreversible degeneration of the lens material. On the other hand, transient cataracts have also been reported, mainly due to systemic hyperglycemia, which often occurs bilaterally. However, reports of the spontaneous regression of unilaterally occurring cataracts in patients with normal blood glucose levels are rare. Here, we report a rare case of spontaneous regression of unilateral posterior subcapsular cataracts in an adult with normal blood glucose levels. Patient concerns: A 42-year-old woman presented with distorted vision in her right eye. The patient was taking medication for diabetes, and her blood sugar level was well-controlled. Diagnosis: Upon examination, her uncorrected visual acuity and best-corrected visual acuity were 20/70 in her right eye. Slit lamp microscopy revealed fine, feathery, and streak-like posterior subcapsular opacities. Color fundus photography revealed a starshaped shadow due to the cataract, and no diabetic retinopathy was observed. Her two hour postprandial glucose level was 115 mg/dL. The patient was diagnosed with posterior subcapsular cataracts, and cataract surgery was planned. The patient was scheduled to visit the clinic again after seven days. Interventions: Close observation for one week without any intervention. Outcomes: After one week, most of the posterior subcapsular opacities disappeared, and the uncorrected visual acuity and bestcorrected visual acuity in the right eye improved to 20/40 and 20/30, respectively. Lessons: This case report demonstrates that unilateral posterior subcapsular cataracts may spontaneously regress in patients with normal blood glucose levels. Therefore, it is important to check whether cataracts improve spontaneously through short-term close follow-up before planning cataract surgery to avoid unnecessary surgery.