This article is more than 5 years old. Information may no longer be current.
Postop corneal swelling an indicator of endothelial damage after phaco
A study suggests that the localization of endothelial cell loss is directly linked to the area in which the swelling ocurred.
Click Here to Manage Email Alerts
The degree of corneal swelling after phacoemulsification can be a harbinger for the degree of permanent endothelial cell loss months later, according to researchers in Sweden.
In a study published in the June issue of the American Journal of Ophthalmology, Anders Behndig, MD, PhD, and colleagues at Umeå University Hospital in Umeå, Sweden, analyzed 30 patients scheduled for routine phacoemulsification to determine if corneal swelling could be a predictor for endothelial cell loss.
“Whether postoperative corneal swelling after phacoemulsification surgery correlates to corneal endothelial cell loss has been a matter of debate for several years,” the study authors said.
The study
The researchers selected 30 patients from a series of 41 based on the increase in central corneal thickness on the first postoperative day. Patients ranged in age from 57 to 88 years old. The patients included were the first 10 cases with an increase of less than 5%, the first 10 with a 6% to 20% increase and the first 10 with an increase of 20% or more.
The researchers performed ultrasonic pachymetry and specular microscopic endothelial photography of the central and nasal portions of the cornea, as well as Orbscan II slit-scan tomography preoperatively and at day 1 postop.
The same measurements were repeated after 1, 2 and 3 months to judge the corneal endothelial cell loss and the increase in pachymetry.
Degree of cataract, visual acuity, phacoemulsification time and energy, total surgical time and the amount of infusion fluid used were also noted.
The central corneal swelling on day 1 postop was strongly correlated with the central corneal endothelial cell loss at 3 months (P < .001), the study authors reported.
“In this series of uneventful phacoemulsification cases selected to contain large variations in the corneal swelling at the first postoperative day, a clear correlation was found between the early postoperative swelling and the endothelial cell loss at 3 months,” the researchers said.
Measuring differences in pachymetry on the first postop day was a good way to assess the effects of phacoemulsification on the corneal endothelium, they said.
Central vs. nasal thickness
According to the study, the increase in corneal thickness on day 1 was more pronounced centrally (15.2%) than nasally (11.2%). This also held true for endothelial cell loss at 3 months.
The researchers said that central and peripheral cell losses were only moderately correlated, and that in the central cornea the cell loss in relation to the edema was larger than in the nasal cornea.
The nasal endothelial cell loss at 3 months correlated more strongly with the nasal increase in corneal thickness on day 1 than to the central increase in corneal thickness.
“This may indicate a correlation between the local swelling and the local cell loss within the same cornea, meaning that a central spot of corneal edema is likely to be associated with a smaller overall cell loss than a generalized edema,” they said.
Dr. Behndig and his colleagues noted that this was just a hypothesis and that further investigation is necessary.
They also noted that the endothelial cell loss seemed to taper off by the 3-month mark and that most cell loss occurred after the first month.
The researchers said that previous studies of the relationship between corneal swelling and endothelial cell loss did not make as strong a case for the relationship between the two because of the narrow scope of patients included in those studies.
“It could be that in other studies … patients with very dense nuclei, high levels of ultrasonic energy and a severe postoperative corneal edema comprise a small part of the total material, making this relationship less evident,” they said.
The researchers suggested that the primary aim of future refinements to phacoemulsification techniques should be to minimize early postop corneal swelling.
For Your Information:Reference:
- Anders Behndig, MD, PhD, can be reached at Department of Clinical Sciences/Ophthalmology, Umeå University Hospital, Umeå, SE-901 85 Sweden; 46-90-785-24-23; fax: 46-90-13-34-99; e-mail: anders.behndig@ophthal.umu.se.
- Lundberg B, Jonsson M, et al. Postoperative corneal swelling correlates strongly to corneal endothelial loss after phacoemulsification cataract surgery. Am J Ophthalmol. 2005;139:1035-1041.
- Jared Schultz is an OSN Staff Writer who covers all aspects of ophthalmology. He focuses geographically on Europe and the Asia-Pacific region.