Implants, femto-cataract surgery and intracameral prophylaxis

October 8, 2013

Review of the fourth day of ESCRS 2013.

Corneal inlay provides safe and effective presbyopia treatment

The KAMRA Corneal Inlay (ACI7000PDT; AcuFocus Inc.; Irvine, California, USA), implanted in pockets created by a femtosecond laser, seems to provide an effective and safe treatment for the correction of emmetropic presbyopes after 36 months, Dr Orang Seyeddain (University Eye Clinic, Paracelsus Medical University, Salzburg, Austria) and colleagues have reported.
The team were discussing the 3-year postoperative safety and efficacy outcomes of monocular implantation from the prospective, interventional case series they have been conducting, in which naturally emmetropic presbyopes (n=24) with uncorrected distance visual acuity (UDVA) of at least 20/20 in both eyes and without any additional ocular pathology underwent corneal inlay implantation in the non-dominant eye. Throughout the follow-up period, visual acuity values were measured with the Optec 6500 Vision Tester (Stereo Optical Company; Chicago, Illinois, USA).
At 36 months, mean UDVA was 20/20 (95% confidence interval [CI]: 20/20) and 20/16 (95% CI: 20/16) for the implanted eye and binocularly, respectively; mean binocular intermediate and near visual acuity were 20/20 (95% CI: 20/20) and 20/25 (95% CI: 20/25–20/20), respectively, with 17/24 (71%) reading at ≥20/25 at 36 months.
"Throughout the 36 months, no patient had any detectable central visual field defect, no inlay had to be explanted and no inflammatory reactions were observed. Endothelial cell count and central corneal thickness remained stable within the follow-up period," explained Dr Seyeddain. "Therefore we are able to conclude that the KAMRA inlay seems to provide an effective and safe treatment for the correction of emmetropic presbyopes up to 36 months."

AP, UST and EPT shorter in femtosecond laser cataract surgery

"Average ultrasound power (AP), ultrasound time (UST) and effective phacoemulsification time (EPT) are significantly shorter in patients treated with the VICTUS femtosecond laser (Technolas Perfect Vision; Munich, Germany) than in patients receiving conventional lens surgery; however, among patients treated with femtosecond, these parameters are significantly higher in eyes without translenticular hydrodissection (TLH)," announced Mr Sheraz Daya (Centre for Sight, East Grinstead, UK) this afternoon.
Mr Daya, who had performed the UK’s first Victus cataract surgery in April 2012, compared the first consecutive 108 cases of lensectomy (cataract and refractive lens exchange) surgery using the Victus femtosecond laser – with (n=81) or without (n=27) TLH, which was developed to assist lens mobilization and lens dismantling – to perform capsulotomy and lens fragmentation to 107 consecutive conventional immediately prior to adoption of the technology.
The AP was 7.30±2.56% and 5.32±2.48% for conventional surgery versus Victus (p=0.000); UST was 9.89±5.32 seconds and 8.58±4.66 seconds for conventional and Victus, respectively (p=0.044), and EPT was 0.93±1.00 seconds with conventional surgery versus 0.57±0.51 seconds for Victus femtosecond (p=0.002). In the Victus group, for those with versus without TLH, AP was 5.78±2.23% versus 5.16±2.56% (p= 0.046), UST was 10.95±4.66 seconds versus 7.78±4.41 seconds (p=0.046), and EPT was 0.72±0.26 seconds versus 0.52±0.53 seconds (p=0.002).

Intracameral cefuroxime reduces the incidence of endophthalmitis

Intracameral cefuroxime reduces the incidence of endophthalmitis in cataract surgery and has a high clinical and economic impact on its prevention, Dr Carmen García-Sáenz (Hospital Universitario Fundación Alcorcón, Madrid, Spain) told the conference this afternoon.
Dr García-Sáenz and colleagues had conducted a ‘quasi-experimental study’ with before and after analysis of consecutive patients (n=19463) undergoing cataract surgery from January 1999 to December 2012; beginning in October 2005, patients were administered intracameral cefuroxime as prophylaxis for endophthalmitis. The team studied the cumulative incidence of endophthalmitis before (n=6595) and after (n=12868) the introduction of intracameral cefuroxime and compared it to the annual incidence adjusting to a Poisson distribution, leading to a relative risk (RR) assessment of the effectiveness of the prophylaxis.
Over the course of the study period, there were 44 cases of endophthalmitis - 39 before the introduction of intracameral cefuroxime and 5 after - with positive microbiological cultures obtained in 29 patients (66%), resulting in an overall cumulative incidence of 0.23 cases per 100 patients. The RR was 0.06 (p"Because the cost of a dose of cefuroxime was €1 and the cost of a single case of endophthalmitis was €1358, the potential cost saving with cefuroxime was €1177 for every patient treated, which means that there were significant economic as well as clinical benefits associated with the use of intracameral cefuroxime as prophylaxis against endophthalmitis in cataract surgery," said Dr García-Sáenz.

'Champagne' bubbles are an indication of micro-perforation during ICR implantation

Small 'Champagne' bubbles in the femto tunnel could be a previously undescribed pathogenomic sign of micro-perforations caused by the insertion of Intracorneal Rings (ICRs) for keratoconus, Doctors Solange and Guillaume Leroux les Jardins (Boulevard Raspail, Paris, France and Hôpital Hôtel-Dieu, Paris, France) proposed this evening.
The doctors made the announcement while discussing a retrospective study they had conducted, in which 4 micro-perforations occurred during 87 ICR implantations in eyes with grades 3 and 4 keratoconus. Most of the complications arose during the shaping of the femto tunnel, before the insertion of 5 mm Optical Zone ICRs.
The first micro-perforation was diagnosed during the insertion of the ICR because a seidel occurred; in the second case, small Champagne-like bubbles were visible during the shaping of the femto tunnel and a seidel subsequently occurred during implantation. In the remaining two cases, similar small bubbles were visible during the shaping of the femto tunnel and so corneal OCT was performed: in both cases the OCT showed posterior corneal micro-perforations, and therefore no ICRs were inserted in these eyes. Although a localized hydrops occurred in one eye, this resolved rapidly; no corneal transplantations were required, and 3 eyes subsequently underwent successful ICR implantation: 6 months after the initial procedure was attempted, a larger femto tunnel was created and 6 mm Optical Zone ICRs were inserted near the site of the micro-perforation.
The researchers concluded that the bubbles that had been evident in these eyes are a pathogenomic indication of micro-perforation during this procedure; if these bubbles are present, the diagnosis of micro-perforation can be confirmed through use of OCT. Once the diagnosis has been confirmed, the implantation of ICRs should be postponed for 6 months to avoid further complications.