We thank the authors for bringing out important issues related to the use of enoxaparin (low-molecular-weight heparin) in the intraocular irrigating solution during pediatric cataract surgery. We used a dose that was reported to be safe and effective in pediatric eyes undergoing cataract surgery for ethical reasons. A total hyphema has been reported in a patient who was administered systemic enoxaparin after eye surgery. Hyphema also was reported after the intraocular use of heparin sodium during a pediatric secondary intraocular lens (IOL) implantation. We acknowledge that future studies should address higher doses and the dose-effect relationship for different age groups.
The authors note that because the inflammatory response is so variable in the pediatric population, it is questionable to use a particular strength of enoxaparin for all children. We wonder how precisely to customize the strength of enoxaparin for an individual child when the inflammatory response is so variable. In addition, randomization in this study would have taken care of assigning both known and unknown variables equally in both groups.
As for the postoperative topical steroid regimen, in our vast clinical experience, we have found that topical prednisolone acetate applied 6 times daily in the early postoperative period suffices as a routine. Therefore, we chose to adhere to the same regimen for this study. The study protocol calls for a postoperative regimen for infant aphakia in which topical prednisolone acetate 1% is instilled at least 4 times daily for 1 month after cataract surgery, even when only infants between 1 and 7 months were enrolled. From a clinical care point of view, we believe that the postoperative steroid used in our study was adequate. From a research perspective, it is important to note that a standardized postoperative regimen was used for both groups. A higher dose in the enoxaparin group would have required increasing the dose in the control group also. This may not necessarily have helped the objective of the study, because a higher anti-inflammatory response might have been observed in both the groups.
The authors propose that IOL deposits may be a result of inadequate steroid use. We propose an alternative hypothesis. Careful evaluation would have identified IOL deposits more often than would have been observed just using torch light examination. We performed postoperative assessment using slit-lamp microscopy in the clinic or in the operating room, using the slit-lamp attachment of the operating microscope. A specular reflex was obtained on slit-lamp biomicroscopy using a wide slit, high magnification, and maximum illumination. It is easier to obtain and observe deposits using specular reflex in eyes with an AcrySof IOL (Alcon Laboratories, Fort Worth, Texas, USA) because of its high refractive index.
Once again, we thank the authors for discussing important issues related to the use of enoxaparin in pediatric cataract surgery.