Patients with proliferative diabetic retinopathy (PDR) may delay follow-up with their ophthalmologist due to the myriad comorbidities that accompany diabetes. A new study takes this into account but confirms that a delay in panretinal photocoagulation (PRP) treatment beyond 31 days is associated with worse visual outcomes than those treated earlier. This is consistent with the American Academy of Ophthalmology’s (AAO) recommendation that patients with PRP within 1 month of diagnosis. Researchers further suggest that a hospital admission can delay laser therapy more than socio-economic factors and laboratory values, such as for hemoglobin A1c.
“When comparing patients with or without selected medical comorbidities, there was a significant increase in time-to-treat if patients had an inpatient admission during the period between diagnosis and PRP treatment,” the researchers wrote. “On average, if the patient was admitted for hospitalization, they experienced an average delay of 51.4 days before receiving PRP treatment (with 86.5 ± 50.2 days, without 35.1 ± 35.1 days, P <0.001). For other comorbidities, there was no significant difference in time-to-treat.”
The retrospective clinical study at Cole Eye Institute, Cleveland Clinic, in Ohio examined 259 eyes of 259 patients 18 years of age and older with proliferative diabetic retinopathy who were treated with PRP. Patients were diagnosed and treated from January 2015–August 2019. Visual acuity (VA) was measured at the time of diagnosis, or baseline, and at 1, 3, 6, 12, 18, and 24 months after treatment. Study subjects were grouped into sets: those receiving PRP on the day of diagnosis, within 1 day to 14 days, 15 day to 31 days, or more than 31 days.
Investigators found a significant difference in VA between patients treated the same day of diagnosis with those who received PRP more than 31 days following diagnosis. “At 24 months, visual acuities for these groups were 71.2 ±2 0.0 letters (20/40) vs 55.3 ±2 5.8 letters (20/80), respectively. (P =0.03),” the investigators wrote.
Previous studies compared barriers to follow-up care with factors such as comorbidities, insurance status, income, and age. However, the new study also takes into account the parameter of hospital admission for any cause, and this “provides a potential explanation as to why the results of this study differ and why certain factors, such as age, had been unreliable predictors for delayed PRP treatment in the past.”
Factors such as BMI, or lab values for HbA1c, BUN, and serum creatinine had no significant association between the delays in patients presenting for follow-up. Median household income, distance from the treatment site, and type of insurance plan also did not significantly delay treatment.
Although no significant difference in VA was found between subjects receiving PRP the same day, within 2 weeks, or within 31 days, “the significantly higher VA outcomes of those treated on the day of diagnosis compared with all other patients at 18 and 24 months post-treatment may indicate that the optimal treatment approach is PRP on the day of diagnosis, if possible.”
Ohlhausen M, Payne C, Greenlee T, Chen AX, Conti T, Singh RP. Impact and characterization of delayed panretinal photocoagulation in proliferative diabetic retinopathy., Am J Ophthalmol. Published online October 19, 2020. doi: 10.1016/j.ajo.2020.09.051