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December 2002
IN THIS ISSUE

Transcleral drugs overcome usual delivery limitations
Wavefront rated in 'top five' innovations of last 25 years
Ultrasound tool 'crystal ball' for anterior surgeons
Task force develops classification system for retinopathy screening
Cool laser blasts way to micro-incision cataract surgery
Anterior chamber maintainer adequate for micro surgery
Artemis 2 provides 'unprecedented' diagnostic readings
Laser biometry more reliable with experts and novices
In search of objective accommodation evaluation
Cataract surgery more than meets front of the eye
Combined surgery safe for PEX patients
Deferring PI in filtering surgery does not increase risks
Early glaucoma intervention delays progression
Oxygen may be the culprit in nuclear cataract
New IOL accommodates cataract patients
Trainee surgeons hold didactic wisdom
Antiviral treatment best defence for ocular herpes
Sutureless surgery advances with help of corneal glue
New weapons in the fight against corneal infection
New weapons in the fight against corneal infection
Intravitreal triamcinolone could reduce need for PDT re-treatment in eyes with exudative AMD
Ultra-thin lens reveals mystery accommodation
Two IOL styles prove to be equally accommodating in comparative trial
New drug improves diabetic retinopathy therapy
Good long-term results with combination surgery
Treating ocular cancer with designer molecules
Clear lens extraction prompts vitreoretinal concern
Roots of Fuchs' dystrophy may be found in mitochondrial genes
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Two IOL styles prove to be equally accommodating in comparative trial

By Roibeard O'hÉineacháin

NICE - The HumanOptics and CrystaLens IOLs appear to perform equally well in what may be the first direct comparison of accommodative lenses, according to a Swiss ophthalmologist.

Thirty-two eyes of cataract patients underwent phacoemulsification and implantation of the HumanOptics Accommodative® 1CU or the AT-45 CrystaLens™.
The accommodative amplitude was almost identical with the two lenses after three to six months follow-up, Filippo Simona MD said.

The 14 eyes implanted with the CrystaLens achieved 1.33 D of accommodation while the 18 eyes implanted with HumanOptics IOL achieved 1.36 D of accommodation.
Visual acuity improved in all patients with values between 20/50 and 20/16. Overall the amplitude of accommodation ranged from 0.5 to 1.75 D. Near visual acuity with distance correction ranged from J10 (0.2) to J1 (0.8).

Eyes implanted with the CrystaLens had a mean distance UCVA of 0.84 and a mean distance BCVA of 0.94. The mean near UCVA was 0.36 and best corrected near visual acuity was 0.32.

Eyes with the HumanOptics lens had a mean distance UCVA of 0.80 and a mean distance BCVA of 1.01. The mean near UCVA for the group was 0.48 and 0.34 with distance correction.

Spherical equivalent (SE) was -0.25 D for the CrystaLens and -0.59 D for the HumanOptics IOL, Dr Simona noted.
"The HumanOptics eyes tended to be a little bit more myopic and therefore had better unaided near visual acuity. We have since increased the A constant from 119 to 118.5," he added.

Prior to carrying out the implantation procedures, Dr Simona and his associates measured anterior chamber depth and axial length using immersion biometry and the IOL master machine.

Surgery was uncomplicated in all patients with successful in-the-bag implantation and good centration of the IOLs.

Dr Simona noted that patients with both lenses appeared to learn to achieve better accommodation as time went on. Their findings also suggested that the physiology of accommodation still holds some mystery.

"In theory the greater the power of the IOL the less it must move to achieve the same accommodation, but in reality we didn't find this strong relationship.
"For example, while we have one patient with an IOL of 16 D power who has an accommodation of 1.75 D, another patient with an IOL of 23 D has the same 1.75 D of accommodation," he said.

Dr Simona noted that the unanswered questions with the two lenses include their long-term efficacy and the degree of ametropia in which they will be useful.
"Our results show that at three months the two types of IOL are mathematically identical and the mean accommodative power was
1.35 D. Further studies are needed to assess the long-term stability of this pseudoaccommodation," Dr Simona added.

Both the CrystaLens and the HumanOptics 1CU operate mechanically. The IOLs have hinged haptics that create accommodation by moving the lens in response to the ciliary muscles.

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