Ophthalmology's data science initiative yields important clinical post-surgery insights

The IRIS Registry is used by more than 10,000 physicians to benchmark quality of care. Only in its second year of operation, the ophthalmology database is one of the fastest growing medical specialty registries in the world. It is also a model other medical specialties are beginning to emulate. The IRIS registry currently houses data on 17.6 million patients and 60 million patient visits.

As a result, it is already yielding important insights about patient outcomes. It is also identifying key opportunities for improvements in patient care. Most recently, the IRIS Registry has uncovered new information about endophthalmitis, a very rare complication of cataract surgery and intravitreal injections for wet age-related macular degeneration.

Analysis of IRIS Registry data shows no significant difference in endophthalmitis rates between the three most commonly used anti-VEGF treatments for wet AMD.

According to data in the IRIS Registry, there is no statistically significant difference between endophthalmitis rates for injections of compounded anti-VEGF drugs used 'off label' for wet age-related macular degeneration and those manufactured specifically for that purpose. Wet AMD is the most severe form of the disease that is the leading cause of blindness among older Americans. The difference in infection rates, highest to lowest, was 0.01 percent. The following were the findings in more detail based on data collected in the IRIS Registry on 1,084,306 injections provided to 174,891 unique patients from 2013 to 2014:

• Avastin (Bevacizumab): 95,651 unique patients received 490,799 injections of this treatment. There were 391 cases of endophthalmitis at 30 days, for an endophthalmitis rate of .08 percent.
• Eylea (Aflibercept): 34,372 unique patients received 298,482 injections of this treatment. There were 202 cases of endophthalmitis at 30 days, for an endophthalmitis rate of .068 percent.
• Lucentis (Ranibizumab): 44,868 unique patients received 295,025 injections of this treatment. There were 212 cases of endophthalmitis at 30 days, for an endophthalmitis rate of .072 percent.

The growing collective experience of ophthalmologists indicates that all three drugs are safe and effective treatments for wet AMD. However, to use Avastin for ocular injections, it must first be repackaged into smaller doses -- a process that in some compounded and repackaged drugs has been associated with increased risk of infection. However, this association of increased risk is not evident when applied to anti-VEGF treatments for wet AMD.

"This data disproves previous assertions made in reference to federal compounding legislation that no compounded product should ever be injected into the eye because of an elevated risk of infection," said George A. Williams, M.D., the Academy's Secretary for Federal Affairs and Chair of the Department of Ophthalmology at Oakland University's William Beaumont Hospital. "It could be instrumental in future discussions surrounding federal drug quality and security guidelines that could complicate patient access to compounded Avastin."

Analysis of IRIS Registry data shows that endophthalmitis rates appear to be slightly higher in eyes that had cataract surgery combined with anterior vitrectomy.

Analysis of IRIS Registry and Medicare data shows that endophthalmitis tends to be higher in eyes that had cataract surgery combined with anterior vitrectomy. This is a procedure that is often used to disentangle the vitreous the clear jelly-like substance that fills the eye from an intraocular lens or other structures.

Anne L. Coleman, M.D., Ph.D., an ophthalmology researcher and professor at UCLA, will reference these learnings during the conference's Jackson Memorial Lecture, the premier scientific lectureship in ophthalmology. Her findings were based on a review of published studies, analysis of public-use Medicare claims files from 2010 to 2013 and analysis of IRIS Registry data from 2013 to 2014.

In the Medicare database, Dr. Coleman found the overall rate of endophthalmitis after cataract surgery was 0.14% in 216,703 individuals. In the IRIS Registry, this rate was 0.08% among 511,182 individuals. Endophthalmitis rates appeared to be slightly higher in eyes with combined cataract surgery and anterior vitrectomy, although only 0.08% of eyes had this combined procedure. As the findings verge on being statistically significant, further research is required to confirm the observation.

Dr. Coleman pointed out that a potential next step could be to consider the use of prophylactic antibiotics when anterior vitrectomy is combined with cataract surgery. The data in the IRIS Registry could make such an investigation or clinical trial possible. The full lecture is published online in the American Journal of Ophthalmology.

"While common eye procedures such as cataract surgery are extremely effective, successful and with very little risk of complication, ophthalmologists will always aim to find ways to lessen these risks no matter how small," said Dr. Coleman. "Since these complications are so rare, previously tracking and studying the occurrence and potential contributing factors was challenging. The IRIS Registry makes this easier."