Diffractive multifocal intraocular lenses effectively improve functional capacity for distance and near and provide good quality of vision due to significantly reduced spherical aberration, say Italian researchers.
Twenty-eight patients were randomized to two groups. Group 1 (six men, eight women, mean age, 60.86) received the Tecnis ZM900. Group 2 (five men, nine women, mean age 60.79) received the AcrySof ReSTOR. All were followed for six months. The main outcome measures were spherical equivalent cycloplegic subjective refraction, uncorrected distance visual acuity and best-corrected distance visual acuity, both at high and low contrast, best-corrected near VA, and near addition and defocus curve.
There was no statistically significant difference between the two groups in high or low contrast UCVA or BCVA for distance. The distance corrected near VA was 1.86 ±1.66 in Group 1 and 1.93 ±1.12 in Group 2. The depth of focus was 4.5 D in both groups. The root mean square of total aberration and of spherical and coma aberrations were significantly lower in Group 1 than in Group 2. A higher percentage of patients with Tecnis showed a more severe grade of anterior fibrosis. The lower incidence of capsule fibrosis of the ReSTOR confirms the better biocompatibility of the AcrySof material compared to silicone. Posterior opacification was minimal and not significantly different between the two groups.
Among other limits, a monolateral IOL was implanted in all cases, so the study provides no information about binocular viewing conditions with MIOLs. All patients had a total ocular aberrometric evaluation, preventing distinction between internal aberration associated mainly with the IOL and the external aberration related mainly to the cornea. The researchers call for further studies to better understand the possible effect of capsule fibrosis on IOL centration, particularly for aspheric and apodized IOLs.
(J Cataract Refract Surg 2007;33:1559-1564)
Moorfields IOL Study Group
Facial Nerve Paralysis Linked to Entropion
Researchers in
The retrospective review of five pediatric cases of paralytic entropion looked at etiologic diagnosis, nature of craniofacial anomalies, ophthalmic examination findings, description of surgery (if any) and length of follow-up. All patients had facial nerve palsy (unilateral or bilateral), and entropion on the side of facial palsy. All five patients presented with epiphora and punctate keratopathy. Following surgical correction of the entropion, all ocular symptoms resolved.
The researchers identified several factors that may help to explain the occurrence of entropion in the setting of pediatric facial nerve paralysis. Skin and facial soft tissues in youth are firmer and have greater resiliency. Also, ligamentous attachments in children are less elongated and more taut. Sheer facial volume is less, decreasing the contribution of gravitational effects. Last, younger patients with facial paralysis often show lesser signs of facial droop.
Ophthalmologists and pediatricians should consider this association in the evaluation of children with craniofacial abnormalities and facial nerve paralysis.
(Ophthal Plast Reconstr Surg 2007;23:126-129)
Myopia Reduced After Orthokeratology
Myopia reduction resulting from rapid central corneal flattening and improvement of uncorrected VA occurred after orthokeratology, say researchers in
In this prospective, nonrandomized cohort study, 14 myopic patients (26 eyes) underwent an orthokeratology fitting test with the BE contact lens. BSCVA, uncorrected VA, cycloplegic refraction, biomicroscopy, corneal topography, optical pachymetry and aberrometry were performed at baseline, and one and eight nights after ortho-k.
The mean SE changed from -2.24 ±0.98 D at baseline to 0.15 ±0.76 D after the eight nights of lens wear (p=0.001). All patients had an UCVA of 20/30, 69.2 percent of which saw with 20/20 or better. Changes in central corneal pachymetry were not observed. Temporal corneal thickness increased significantly from night one, with no difference between nights one and eight (p>0.001). A significant increase of HO RMS values was observed from baseline (0.42 ±0.16 µm), night one (0.81 ±0.24 µm) and night eight (1.04 ±0.24 µm). Increases in coma and spherical aberration were observed.
The researchers stress the importance of excellent centration during orthokeratology fitting to avoid inducing HOAs, such as coma; inducing little to no asymmetrical aberrations will maintain visual quality. Only high-contrast VA was measured, because the researchers had no knowledge prior to the study of whether there was a correlation between the induced HOAs resulting from orthokeratology and uncorrected visual function.
(Am J Ophthalmol 2007;144:378-386)
Stillitano IG, Chalita MR, Schor P, Maidana E, Lui MM, Lipener C, Hofling-Lima AL.
Claims Databases Reliable for Compliance Estimates
According to researchers in
For the study, telephone surveys, a claims database analysis and a chart review were conducted. From 10,260 persons who were recently prescribed a prostaglandin eye drop for open-angle glaucoma, a sample of 300 charts was selected for detailed abstraction. A database review was conducted of pharmacy refill, diagnostic testing and visit information, with chart review of a sample of patients from the database and interviews with an overlapping sample of patients and physicians. Main outcome measures included individual patient medication possession ratio (MPR), an index estimating the proportion of time that patients have the prescribed drug available for use, frequency of examination findings present in charts and associations between MPR and physician adherence to a preferred practice pattern (PPP).
Chart data confirm that the claims database accurately identified the specific glaucoma eyedrop prescribed, but often identified long-term OAG patients as being new to treatment. Physicians frequently used billing codes for OAG in patients with normal field tests. Physicians varied dramatically in their adherence to the PPP, performing IOP measurements, disc evaluations and imaging, and visual field tests on 90 percent of OAG patients, but carrying out gonioscopy, central corneal thickness measurement and setting of target IOP on half of patients.
The researchers hope further developments of metrics for physician adherence can be validated as related to patient behavior and outcome using a larger sample size.
(Ophthalmology 2007;114:1599-1606)
Quigley HA, Friedman DS, Hahn SR.
