CAKE 03 ConferenceHighlights ASCRS AnteriorSegment HIRES IMAGE

A Lowdown on the Latest in Anterior Segment ‘Trends’

Held in May in California, USA, this year’s combined annual meetings of the American Society of Cataract and Refractive Surgery and the American Society of Ophthalmic Administrators (ASCRS-ASOA) organized by ASCRS, proved to be yet another success. Anterior segment surgeons, practice management staff, and ophthalmic technicians and nurses convened in San Diego for one of the industry’s biggest events. 

In case you missed the important details, we’ve compiled five highlights of the latest in anterior segment news below.

Going beyond the fovea with EyeMax Mono in dry AMD 

“EyeMax Mono offers a potential step change in the management of patients with dry age-related macular degeneration (AMD) who undergo cataract surgery.” 

Studies have shown that cataract surgery in patients with dry AMD has the potential to improve visual acuity without increasing the risk of progression to exudative AMD. As patients experience progressive loss of visual function in the fovea, their phakic refractive lens (PRL) may shift to the peripheral macula.

At ASCRS 2019, Dr. Andreas Borkenstein, a private practitioner from Privatklinik der Kreuzschwestern Graz, Austria, provided further insight in his presentation titled, “A new class of intraocular lens designed specifically for patients with center-involving macular disorders”. 

Dr. Borkenstein noted that currently available surgically implanted intraocular lenses (IOLs) used in patients with AMD include standard monofocal IOLs, prism IOLs and telescopic IOLs. However, these lenses have a range of limitations when implanted into patients with dry AMD. In particular, standard monofocal IOLs offer limited functional benefits 

to patients with dry AMD, as they are designed to focus light onto the fovea the area of greatest functional loss with this disease.

EyeMax Mono (LEH Pharma, London, UK), a new type of IOL designed specifically for patients with center-involving macular disorders, shows promise. 

Dr. Borkenstein described his experience with EyeMax Mono, a single-piece, soft, hydrophobic, acrylic IOL. “It is designed to increase breadth of focus and reduce blur, thereby improving image quality across all areas of the macula lens optics, it’s wavefront-optimized to provide an enhanced quality of image to an area extending up to 10 degrees from the foveal center,” he shared.

He added that the goal of this IOL is to supply the highest quality image to PRLs and other functioning areas of the retina that a patient with dry AMD becomes dependent on as macular disease progresses. “Laboratory simulations have showed that EyeMax Mono delivers superior image quality compared with standard monofocal IOLs at up to 10 degrees of eccentricity,” he noted.

Dr. Borkenstein presented a case of an 83-year-old Caucasian female with poor contrast sensitivity and color perception, and increasing glare during the preceding year. Examination revealed progressive cortical cataract (C5) stable, dry AMD, best corrected distant visual acuity (BCDVA) of 0.2, and best corrected near visual acuity (BCNVA) of 0.05. The patient underwent standard phacoemulsification cataract surgery with a small incision, with capsular bag implantation of EyeMax Mono. The surgery was completed with no complications, and the patient’s visual acuity progressively improved after EyeMax Mono implantation. 

“The patient’s visual acuity stabilized after three months, consistent with a neuro-adaptive component that may occur with this IOL. Therefore, no vision rehabilitation training was required,” explained Dr. Borkenstein. “The observed improvements in visual acuity are consistent with previously published results. EyeMax Mono offers a potential step change in the management of patients with dry AMD who undergo cataract surgery,” he concluded.

Does cap thickness determine patient outcomes with SMILE?

“SMILE procedures with 120µm and 140µm cap thicknesses provide excellent and predictable outcomes for the correction of refractive errors.”

Small incision lenticule extraction (SMILE) is an all-in-one femtosecond laser refractive surgery which has been widely used for the correction of myopia or myopic astigmatism worldwide.

At ASCRS, Dr. Ikhyun Jun and colleagues from the Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea, presented a paper where they evaluated clinical outcomes and biomedical changes in patients after SMILE based on two different cap thicknesses of 120μm and 140μm.

“SMILE may preserve corneal biomechanics better than LASIK. This is because the tensile strength of the cornea gradually decreases from anterior to posterior, thus, creating a deeper refractive lenticule which has been considered to result in a stronger cornea by preserving more of the anterior lamellae of the cornea,” explained Dr. Jun. 

He clarified further: “On the contrary, leaving a sufficient residual stromal bed has been known to be important in preventing iatrogenic corneal ectasia, hence creating a thin cap may be effective and desirable because the amount of spherical equivalent correction increases with increasing cap thickness.”

Dr. Jun and colleagues collaborated with surgeons from the London Vision Clinic and Ohio State University to conduct a prospective, comparative case series of 150 eyes of 150 patients who underwent SMILE procedures with a cap thickness of either 120μm (91 eyes) or 140μm (59 eyes). They found no significant differences at baseline between the two patient groups, who were all between 20- and 45-years-old, with myopia of < 8.0D and corrected distance visual acuity of ≥ 0.8. The study team excluded patients with keratoconus, cataract, glaucoma, retinal disorders, previous history of ocular surgery or severe ocular surface disease.

Post-operative visual refractive outcomes were similar between the two groups,” shared Dr. Jun. “Furthermore, there were no significant differences between pre- and postoperative higher order aberrations between the two groups.” However, he observed that “because the thick cap group needs a thicker lenticule to correct the same spherical equivalent, weakening of corneal biomechanics was less in the thin cap group”.

Dr. Jun and colleagues concluded: “SMILE procedures with 120μm and 140μm cap thicknesses provide excellent and predictable outcomes for the correction of refractive errors.”

Halting keratoconus in its tracks: The role of femto-assisted crosslinking

“Crosslinking of posterior corneal stroma deeper than 250 microns could be better achieved with femto laser-assisted CXL than conventional procedures.”

Corneal crosslinking (CXL) is a minimally invasive outpatient procedure designed to treat progressive keratoconus. It strengthens and stabilizes the cornea by creating new links between collagen fibers within the cornea.

In a study presented at ASCRS, Dr. Lional Raj and colleagues from the Dr. Agarwal’s Eye Hospital, Tirunelveli, India, sought to compare femto-assisted crosslinking with the conventional procedure. The investigators designed a phase 1 prospective, non-randomized clinical trial which compared the two treatment options and explored the significance of the concept that deeper stromal crosslinking is more efficacious on inhibiting the progression of keratoconus.

According to Dr. Raj, 21 patients were enrolled into the conventional treatment group and 25 patients into the femto-assisted CXL group. Study eligibility was defined by age between 15 and 30 years, history of progressive keratoconus with the thinnest pachymetry >400μm, and endothelial cell density of >2000 cells/mm2.

In the femtosecond CXL group, a stromal bed (140 to 160 microns deep, 8.5mm to 9.0mm diameter) with two incisions 180 degrees apart was fashioned with femto lasers into which isotonic riboflavin 0.1% w/v was infused every five minutes, in addition to transepithelial application every two minutes for 25 minutes, followed by UV irradiance for 30 minutes. Finally, the bed was washed with balanced salt solution at the end of the procedure. An epi-off procedure with Dresden protocol of 3 mW/cm2 was utilized in the conventional treatment group.

The study showed that uncorrected visual activity (UCVA) was improved by 2 lines and 1 line in femto-CXL and conventional-CXL groups, respectively, (p = 0.005). Furthermore, there was no significant intergroup differences in the best corrected visual activity (BCVA) improvement.

The investigators showed that the minimal central pachymetry was maintained in the femto-CXL group and reduced by 25μm (p < 0.05) in the conventional-CXL group. Furthermore, patients in the femto-CXL group showed better retention of corneal thickness (p = 0.01).

The investigators also reported that crosslinking flattened corneas in both the femto-CXL treatment group and the conventional treatment group. “Astigmatism was reduced in the femto-CXL group by 0.22D and increased by 0.27D in the conventional-CXL group, while no endothelial changes were noted in either treatment groups,” highlighted Dr. Raj.

In conclusion, Dr Raj noted: “Crosslinking of posterior corneal stroma deeper than 250 microns could be better achieved with femto laser-assisted CXL than conventional procedures. Femto laser-assisted CXL leads to an effective stabilization of keratoconus 

in terms of preventing steepening and further thinning of cornea, as a proof of ‘deeper the better’ concept.” He further stated that “femto-assisted crosslinked corneas clinically remained stable with no progression after two years”.

Editor’s Note: ASCRS-ASOA 2019 was held in San Diego, California, USA, from May 3 to 7, 2019. Reporting for this story also took place at ASCRS-ASOA 2019.

CAKE Magazine Issue 03: The ebook version (The 'Haute Couture' Issue, ESCRS 2019 Edition)

CAKE (Cataract – Anterior Segment – Kudos – Enlightenment) is The World’s Second Funky Ophthalmology Magazine, and Asia-Pacific’s Most Delicious Magazine on the Anterior Segment. CAKE Magazine is published by Media MICE Pte Ltd (Singapore).

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