Purpose
To describe a new modified technique for the treatment of ROP using the RetCam 3 digital imaging system - Camera-Assisted Laser photocoagulation and Cryotherapy of the Retina (CALCR)
Methods
From Nov 2011 to Oct 2013, 91 infants were diagnosed with ROP at the University Hospital Ostrava. The average postconceptional age (PCA) at the time of diagnosis was 35th week of PCA (median: 34th, SD +/- 2.22, range 30th-40th); the average birth weight was 1070g (median: 990g, SD +/- 357.53, range 460-2645g). All the ophthalmological interventions were performed in artificial mydriasis (phenylephrine hydrochloride 2.5% eye drops + tropicamide 0.5% eye drops) and using an eyelid retractor (K1-5401/K1-5677, Katena Products Inc, Denville, NJ, USA). According to the results and recommendations of the ETROP study, the avascular part of the retina of newborns with high-risk prethreshold ROP was treated with a trans-scleral diode laser (IQ 810, Iridex, Mountain View, CA, USA) or with cryotherapy (Cryomatic Cryo, Keeler Instruments Inc, Broomall, PA, USA) within 48-72 hours of the diagnosis being made. The intervention was performed under general anaesthesia under the direct visual control of the digital imaging system RetCam 3 (Clarity Medical Systems Inc, Pleasanton, CA, USA).
Results
The CALCR technique was used in all 12 infants (24 eyes) diagnosed with high-risk prethreshold ROP. The average age of these infants at the time of the intervention was 38th week of PCA (median: 37.5th, SD +/- 3.24, range 34th-44th); the average birth weight was 818g (median: 860g, SD +/- 198.35, range 550-1250g). None of the infants had any complications during the CALCR procedure. In contrast to the traditional technique, CALCR offers many benefits: the image of the retina is real, magnified and not inverted, it shows details of the retina in a high-resolution, three-dimensional view, photo and video documentation is available. Therefore, the preoperative, peroperative and postoperative condition of the retina can be precisely evaluated and compared on a fully standardized basis.
Conclusions
CALCR is a safe and effective treatment technique. This procedure introduces greater accuracy when targeting the avascular part of retina, enables greater visualisation and treatment control and reduces the risk of unintended damage to surrounding healthy retinal tissue.