Lowering IOP, latest survey results and improving sleep

Sep 10, 2012

Sundays free paper sessions covered lowering IOP in POAG, how sleep is affected by IOL selection, an angle-supported phakic IOL for high myopia and the latest results of the ASCRS/ESCRS foldable IOL survey.

Angle-supported phakic IOL is successful


An angle-supported phakic IOL demonstrate good visual acuity and stable refractive outcomes for high myopia, according to Dr Schmickler's lecture in the Phakic IOLs session.
Dr Schmickler presented the paper "Visual and refractive outcomes five years after implantation of an angle-supported phakic lens in a European clinical trial". She explained the study was a "prospective, multicentre and a 5-year clinical trial, there was an unilateral implantation of the AcrySof CACHET Phakic Lens. All the subjects with an average preoperative spherical equivalent of -10.38±2.43 D were included."
The outcome measures included uncorrected visual acuity (UCVA), corrected visual acuity (CVA), and manifest refraction spherical equivalent (MRSE).
At the five-year follow-up 75.5% of subjects achieved a UCVA of 20/25 or better and 93.4% achieved a UCVA of 20/40 or better. All subjects presented with a CVA of 20/32 and MRSE was -0.30±0.67 D.
Dr Schmickler said, "Five years after implantation of the AcrySof CACHET Phakic Lens patients demonstrated good visual acuity, stable refractive outcomes and good predictability of refraction."

iStent lowers IOP in POAG


The iStent lowers IOP and reduces the need for ocular hypotensive treatment in open-angle or pseudoexfoliation (PEX) glaucoma, revealed Dr Neuhann on the second day of the ESCRS.
The paper, "24-month results with iStent implantation during small incision cataract surgery", was part of the Paediatric Cataract Surgery lecture on Wednesday. Dr Neuhann and the team included 56 eyes with primary open-angle glaucoma (POAG) and PEX.
Each patient experienced iStent impantation into the Schlemm's canal through the temporal, limbal incision. Of the eyes studied, all but one required topical anti-hypotensive medication.
Preoperative the mean IOP was 23.4 mmHg and was reduced to 15.6 mmHg on the first postoperative day. This then changed to 17.2 mmHg at 24 months. There were no intraoperative or postoperative complications reported with conventional glaucoma surgeries.
Dr Neuhann approved the use of the iStent as a "safe and effective treatment in patients with ocular hypertension, open-angle or PEX glaucoma . The implantation of the iStent significantly reduces the number of hypotensive medications required for ocular hypertension."

UVB IOL improves sleep quality


Ultra-violet blocking (UVB) IOLs improve subjective sleep quality, compared to a blue-filtering (BF) IOL, claimed Dr G. Ratnarajan, also speaking at the Best of the Best free paper session.
Dr Ratnarajan presented the findings of the paper "The impact of an ultra-violet blocking or a blue-filtering intraocular lens on sleep quality pre and post cataract surgery". The survey information was completed for 520 patients with a UVB IOL and 271 patients fitted with a BF IOL. The study included pre-op information and the Pittsburgh Sleep Quality Index (PSQI) information.
The PSQI was completed preoperatively and 1, 6 and 12 months postoperatively. BCVA was recorded as good if it was 6/7.5 or better and poor if it was worse than 6/9.
Sleep quality, latency, duration, efficiency, level of disturbance, day-time dysfunction and sleep medication were self-assessed by the patient and scored between 0 and 3, with 3 being the worst score. The scores are added up out of a possible total of 21 and a score of more than 5 indicates a poor night of sleep.
The mean preoperative total score for the UVB IOL patients was 6.31 and postoperatively it was 5.85. For the BF IOL the mean preoperative and postoperative total scores were both 6.20.
An improvement in sleep scores was seen in the UVB IOL group in a sub-analysis based on preoperative BCVA. The scores improved from 5.94 to 5.49 in the good visual acuity (VA) group and from 6.79 to 6.28 in the poor VA group. The BF IOL group sleep scores changed from 6.53 to 6.72 in the good VA group and 6.14 to 6.10 in the poor VA group.
This demonstrates that subjective sleep quality improves in poor VA groups, regardless of the lens used. However, UVB IOLs tend to get a significantly higher quality of sleep compared to those who wore BF IOLs.

Latest survey results: multifocal IOL explantation increased


The latest results of a survey have shown that multifocal IOL explantation has increased over the past year.
Dr Mamalis presented the results of the "ASCRS/ESCRS survey on foldable IOLs requiring explantation or secondary intervention 2011 update" at the Best of the Best free paper session. .
The survey was given to all ASCRS/ESCRS members to complete throughout 2011. Surgeons answered one form for each foldable IOL they explanted. Patient's signs, symptoms and complications were recorded, along with postoperative results.
Dislocation or decentration was the most common complication linked to the one-piece silicone IOLs. It was also seen as the most common reason for the removal of three-piece silicone and one-piece acrylic lenses.
The most common reason for the explantation of multifocal IOLs was glare and optical aberrations, whereas hydrophilic acrylic IOLs were removed due to calcification or opacification.
Dr Mamalis commented, "Dislocation and decentration was overall the most common reason for IOL explantation. This was followed by glare and optical aberrations and incorrect IOL power. These complications have changed little over the last five years."
"There were an increasing number of explanted multifocal IOL in the survey and most were removed due to glare and optical aberrations . This trend reflects the increasing popularity of multifocal IOLs. Hydrophilic acrylic (hydrogel) IOLs were explanted less frequently and this likely represents the decrease in secondary calcification noted in these lenses with improvements in the hydrogel materials."
Complications associated with foldable IOLs can be avoided with meticulous surgical technique, including an intact CCC with capsular bag fixation of the IOL, accurate IOL measurements, and proper patient selection and pre-op counselling."

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