Light-adjustable IOL improves refractive cataract surgery outcomes

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Posted on 30th March 2011 by Pacific ClearVision Institute in Cataracts |General

Implantation of an innovative light-adjustable intraocular lens (IOL) during cataract surgery can improve refractive outcomes, reducing the need for glasses after surgery, according to a new study.

Researchers in Germany evaluated the implantation and post-surgical adjustment of an investigational light-adjustable IOL for the correction of residual refractive errors after cataract surgery in patients with myopia prior to cataract removal. A total of 21 eyes were included in the study.

The light-adjustable IOL is implanted like any other intraocular lens used in cataract surgery, but unlike other IOLs, the power of the lens can be adjusted non-invasively several days after surgery by exposing it to a special UV-light source.

The adjustment process is customized for each patient to correct residual nearsightedness, farsightedness or astigmatism, and this correction is then “locked in” by the process. This ability to fine-tune the power of light-adjustable IOLs makes the lenses well suited for patients who want clear vision without glasses after refractive cataract surgery.

Twelve months after surgery and post-surgical adjustment of the light-adjustable IOLs, 20 eyes (96 percent) were within 0.50 diopter (D) of the intended refractive outcome and 17 eyes (81 percent) were within 0.25 D.

The refractive outcomes were also very stable after the power adjustment and lock-in procedure: In all but one eye, the change in mean refractive spherical equivalent (MRSE) was less than 0.25 D between one month after lock-in and the final follow-up visit one year after surgery.

The study authors concluded that the light-adjustable IOL used in this study effectively corrected up to 2.00 D of residual refractive error after cataract surgery, producing a significant improvement in post-operative uncorrected visual acuity.

Furthermore, the final refractive results of the light-adjustable IOL after power adjustment and lock-in were stable for a period of one year after surgery.

UV exposure in light-adjustable IOL process causes no harm to cornea, study finds

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Posted on 30th March 2011 by Pacific ClearVision Institute in Cataracts |General

Light-adjustable IOLs are an innovative type of refractive intraocular lens designed for implantation in the eye during cataract surgery or refractive lens exchange (RLE) surgery to improve vision.

The advantage of light-adjustable intraocular lenses over other refractive IOLs is that the power of these lenses can be adjusted several days after surgery by a simple and non-invasive process that involves exposing the lens and eye to a special light source that emits ultraviolet (UV) light.

The light-adjustment process is customized for each patient, and is designed to correct residual nearsightedness, farsightedness and/or astigmatism, and then “lock in” this correction to reduce the need for glasses after refractive cataract surgery or RLE.

Since this power adjustment process involves exposing the eye and the implanted IOL to UV radiation, researchers in Mexico recently conducted a study to evaluate the safety of the process. In particular, the study was designed to evaluate the effect of the UV-induced power adjustment and lock-in procedures on the inner layer of cells in the cornea (endothelium), which controls the fluid balance and clarity of the front surface of the eye.

A total of 10 patients were enrolled in the study and underwent modern small-incision phacoemulsification cataract surgery with implantation of a Calhoun Light Adjustable Lens (Calhoun Vision, Pasadena, Calif.).

Measured outcomes of the study included endothelial cell density (ECD) and variation in endothelial cell size after the surgery and UV-induced IOL power adjustment process, compared with pre-operative measures. Two IOL power adjustments and lock-in procedures were performed on each treated eye two to four weeks after surgery.

At six months after surgery and adjustment procedures, eyes that underwent the light-adjustable IOL procedure showed an endothelial cell loss of 9.1 percent, compared with pre-operative measurements. This degree of endothelial cell loss is comparable to cell loss after cataract surgery with implantation of conventional refractive IOLs.

No other significant changes to the corneal endothelium were found.

The study authors concluded that endothelial cell loss six months after implantation of the Calhoun Light Adjustable Lens correlates well with previous reports of changes to the corneal endothelium after cataract surgery with implantation of a standard (non-adjustable) IOL.

UV exposure to the eye during the power adjustment and lock-in procedures did not appear to add to the endothelial damage caused by conventional cataract surgery, they said.

Small pupil size may limit gains from aspheric premium IOLs, surgeon says

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Posted on 30th March 2011 by Pacific ClearVision Institute in Cataracts |General

Patients with small pupils who undergo cataract surgery may perceive less benefit from implantation of aspheric intraocular lenses (IOLs) compared with patients with larger pupils, according to U.K. cataract surgeon David Spalton, FRCS, FRCP, FRCOphth.

Aspheric IOLs are premium refractive IOLs designed to reduce spherical aberration, a specific type of higher-order aberration of the eye that causes glare and halos around lights.

According to Dr. Spalton, a recent study conducted at St. Thomas’ Hospital in London shows the aberration-correcting effect of aspheric IOLs is clinically insignificant in most older cataract patients due to age-related small pupil size.

The study compared outcomes after cataract surgery in both high- and low-light conditions, and found no significant difference in most measures of visual performance between aspheric and conventional (spherical) IOLs.

“Only contrast sensitivity in mesopic (low-light) conditions was better (with aspheric IOLs), but the advantage was related to larger pupil size, which we won’t find in our average cataract patients,” Dr. Spalton said.

When patients in the study (who received an aspheric IOL in one eye and a spherical IOL in the other after cataract removal in both eyes) were asked about the quality of vision in each eye, most patients could not discern a difference between IOLs, according to Dr. Spalton.

In 70-year-old patients with an average pupil diameter of 4 millimeters, the effect of correcting spherical aberration on visual performance is relatively small, he said.

Dr. Spalton conceded that there is little downside risk to the use of aspheric IOLs in cataract surgery, and that they might provide some gain in visual performance compared with conventional spherical IOLs when implanted in eyes of younger patients with larger pupils.

“There may also be some benefits in asphericity with diffractive multifocal IOLs in reducing halos and glare,” he said.

Dr. Spalton presented his findings at the winter meeting of the European Society of Cataract and Refractive Surgeons held recently in Istanbul, Turkey.

Smoking may increase risk of haze after PRK, study says

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Posted on 30th March 2011 by Pacific ClearVision Institute in General |LASIK

Smoking appears to be a risk factor for corneal haze in patients undergoing laser vision correction surgery to treat -5.0 diopters (D) or more of myopia, according to a recent study.

The research was headed by J. Richard Townley, MD, who was clinical director of ophthalmology services at Lackland Air Force Base (San Antonio, Texas) at the time of the study and is now affiliated with Massachusetts Eye & Ear Infirmary in Boston.

Dr. Townley and colleagues conducted a retrospective review of medical charts of more than 25,000 patients who underwent laser vision correction, with the objective of determining the percentage of these patients who developed corneal haze in association with smoking.

A total of 157 patients developed post-operative haze that was graded more than “mild.” Among them, 127 had been treated with PRK, 32 had undergone LASEK, and one patient had undergone LASIK.

The amount of treatment ranged from 3.9 D of farsightedness to -8.0 D of nearsightedness.

The researchers found that smokers undergoing laser vision surgery for the correction of -5.0 D of myopia or more were significantly more likely to develop corneal haze than non-smokers or smokers undergoing laser surgery to correct lesser amounts of refractive error.

Based on the results of the study, Dr. Townley recommended that refractive surgery candidates should be encouraged to stop smoking. Longer use of topical steroid medications after laser eye surgery also might lower the risk of corneal haze among smokers, he said.

Dr. Townley cautioned that because the rate of corneal haze in this study population was so low, a large multi-center prospective study would be helpful to reach definitive conclusions about the risk of corneal haze after refractive surgery associated with smoking.

Thyroid Hormone Controls the Eye‘s Visual Pigments Throughout Life

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Posted on 30th March 2011 by Pacific ClearVision Institute in General |Retina

What part does the thyroid gland have in vision? Thyroid hormone is crucially involved in controlling which visual pigment is produced in the cones. Previously, it was assumed that the colour sensitivity of the cones is fixed in the adult retina. Researchers at the Max Planck Institute for Brain Research in Frankfurt/M., together with colleagues at the University of Frankfurt and universities in Vienna, have now been able to show that in mature cones of mice and rats the production of visual pigment is regulated by thyroid hormone. It is assumed that this mechanism exists in all mammals, including humans. If so, the adult-onset of thyroid hormone deficiency would affect colour vision.

Thyroid hormone has a crucial role during development of the body and also of the nervous system. Children born with a thyroid hormone deficiency have serious defects of physiological and mental development, hence newborns are routinely checked for thyroid hormone deficiency, and hormone substitution therapy is given when indicated.

Studies in mice have shown that thyroid hormone also plays an important role in the development of the eye and particularly the cone visual cells. In the retina of the eye, the cones are the visual cells responsible for colour vision. Most mammals have two spectral cone types containing either of two visual pigments (opsins), one sensitive to shortwave light (UV/blue opsin), the other to middle-to-longwave light (green opsin). Cones express a thyroid hormone receptor. Its activation by the hormone suppresses the synthesis of UV/blue opsin and activates the production of green opsin.

Until now, the control of opsin production by thyroid hormone was considered a developmental phenomenon. Experts assumed that in mature cones the developmentally established ‘opsin program’ is fixed and needs no further regulation. This perception is now challenged by a study carried out by lead authors Martin Glösmann and Anika Glaschke in Leo Peichl’s team at the Max Planck Institute for Brain Research, Frankfurt, and their colleagues at the universities of Frankfurt and Vienna. The study shows that opsin production in mature cones continues to depend on the thyroid hormone level.

The researchers had started with an analysis of thyroid hormone involvement in the early postnatal development of mouse cones. “Then we wanted to know how long the time window for the hormone effect was, at what point the hormone’s influence on opsin production stopped,” says Anika Glaschke. “To our surprise we did not find such an endpoint, even several weeks after birth there was a hormone effect.” So the team analysed the cones in adult mice and rats that had been rendered hypothyroid for several weeks. In these mice all cones switched to the production of UV/blue opsin and reduced green opsin production. After termination of the treatment, hormone levels returned to normal and the cones reverted to the production of their ‘regular’ opsin — one cone type to green opsin, the other to UV/blue opsin. The researchers conclude that the spectral cone types, which are defined by the opsin they express, are dynamically and reversibly controlled by thyroid hormone throughout life.

“In addition to their importance for basic retinal research, our findings may also have clinical relevance,” says Martin Glösmann, who currently examines the genetic foundations of the process at the University of Veterinary Medicine, Vienna. “If this mechanism also acts in human cones, the adult-onset of thyroid hormone deficiency — e.g. as a consequence of dietary iodine deficiency or removal of the thyroid — would also affect the cone opsins and colour vision.” There are no such reports in the clinical literature, presumably because the general symptoms of thyroid hormone deficiency are so severe that therapy is initiated before the cone opsin shifts would show up.

Flipping a Switch on Neuron Activity

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Posted on 30th March 2011 by Pacific ClearVision Institute in General |Retina

All our daily activities, from driving to work to solving a crossword puzzle, depend on signals carried along the body’s vast network of neurons. Propagation of these signals is, in turn, dependent on myriad small molecules within nerve cells — receptors, ion channels, and transmitters — turning on and off in complex cascades. Until recently, the study of these molecules in real time has not been possible, but researchers at the University of California at Berkeley and the University of Munich have attached light-sensing modules to neuronal molecules, resulting in molecules that can be turned on and off with simple flashes of light.

“We get millisecond accuracy,” says Joshua Levitz, a graduate student at Berkeley and first author of the study. According to Levitz, the “biggest advantage is that we can probe specific receptors in living organisms.” Previous methods using pharmacological agents were much less specific, affecting every receptor in every cell. Now, investigators can select individual cells for activation by focusing light. And by attaching light-sensing modules to one class of molecules at a time, they can parse the contributions of individual classes to neuronal behavior.

Levitz will be presenting a system in which G-protein-coupled receptors, molecules that play key roles in transmitting signals within cells, can be selectively activated. He is planning to use the system to study the hippocampus, a region of the brain where memories are formed, stored and maintained. There may be clinical utility to the system as well, he points out. G-protein-coupled receptors are also critical for vision in the retina, and light-sensing versions could potentially be introduced into people with damaged retinas in order to restore sight.

The research was funded by the Nanomedicine Development Center at the National Institutes of Health.

New Microscope Decodes Complex Eye Circuitry

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Posted on 30th March 2011 by Pacific ClearVision Institute in General |Retina

The properties of optical stimuli need to be conveyed from the eye to the brain. To do this efficiently, the relevant information is extracted by pre-processing in the eye. For example, some of the so-called retinal ganglion cells, which transmit visual information to the brain via the optic nerve, only react to light stimuli moving in a particular direction. This direction selectivity is generated by inhibitory interneurons that influence the activity of the ganglion cells through their synapses.

Using a novel microscopy method developed at the Institute, scientists from the Max Planck Institute for Medical Research in Heidelberg have now discovered that the distribution of the synapses between ganglion cells and interneurons follows highly specific rules. Only those dendrites that extend from the cell body of the amacrine cell in a direction opposite to the preferred direction of the ganglion cell connect with the ganglion cell.

The sensory cells in the retina of the mammalian eye convert light stimuli into electrical signals and transmit them via downstream interneurons to the retinal ganglion cells which, in turn, forward them to the brain. The interneurons are connected to each other in such a way that the individual ganglion cells receive visual information from a circular area of the visual field known as the receptive field. Some ganglion cells are only activated, for example, when light falls on the centre of their receptive fields and the edge remains dark (ON cells). The opposite is the case for other ganglion cells (OFF cells). And there are also ganglion cells that are activated by light that sweeps across their receptive fields in a particular direction; motion in the opposite (null-) direction inhibits activation.

Starburst amacrine cells, which modulate the activity of the ganglion cells through inhibitory synaptic connections, play an important role in this direction selectivity. The same research group at the Max Planck Institute in Heidelberg demonstrated a number of years ago that starburst amacrine cells are activated by moving stimuli. Each branch in the circular dendrite tree reacts preferentially to stimuli that move away from the cell body; movements in the opposite direction, towards the cell body, inhibit its activity. In the central area around the cell body dendrites function only as receivers of synaptic signals, while the dendrites on the periphery act as transmitters as well — and, therefore, double as axons. Whether these dendrites cause the direction selectivity in the ganglion cells or whether the ganglion cells “compute” it using other signals was unclear up to now.

Max Planck researchers Kevin Briggman, Moritz Helmstaedter and Winfried Denk have now discovered that, although the cells themselves are symmetrical, the synapses between retinal ganglion cells and starburst amacrine cells are distributed asymmetrically: seen from the ganglion cell, the starburst cell dendrites connected with it run in the direction opposite to the preferred direction of motion. “Ganglion cells prefer amacrine-cell dendrites that run along the null-direction,” says Winfried Denk.

According to previous studies by Winfried Denk and his research group, the electrical characteristics of the dendrites, which emerge starlike from the cell bodies of amacrine cells, play a crucial role here. The further they are located from the centre of the cell toward the edge, the easier they are to excite; therefore, stimuli are transmitted preferentially in this direction. This mechanism does not require but is helped by inhibitory influences between neighbouring amacrine cells, known as lateral inhibition. “A ganglion cell can thus differentiate between movements from different directions simply by making connections with certain starburst amacrine cell dendrites — namely those that prevent activation of the ganglion cell in null-direction through their inhibitory synapses. These are precisely the amacrine cell dendrites that run along this direction,” explains Winfried Denk.

Functional and structural analysis

This discovery was made possible by combining two different microscopy methods. The scientists succeeded, first, in determining the preferred motion direction of the ganglion cells using a two-photon fluorescence microscope. A calcium-sensitive fluorescent dye indicated in response to which stimuli calcium flows into the cells — a process that signals electrical activity in cells.

They then measured the exact trajectory of all of the dendrites of these ganglion cells and those of connected amacrine cells with the help of a new electron microscopy method known as serial block face electron microscopy. This process enabled them to produce a volumetric image by repeatedly scanning the surface of a tissue sample using the electron beam of a scanning electron microscope. A thin “slice” is shaved off the sample surface after each scan is complete, using an extremely sharp diamond knife. These slices are thinner than 25 nanometers, just about one thousandth of the thickness of a human hair.

The high three-dimensional resolution of this method enabled the scientists to trace the fine, densely packed branched dendrites of retinal neurons and clearly identify the synapses between them. The complete automation of the imaging process enables them to record data sets with thousands and even tens of thousands of sections “while on holiday or attending a conference,” says Winfried Denk. “For the first time, minute cell structures can now be viewed at a high resolution in larger chunks of tissue. This procedure will also play an indispensable role in the clarification of the circuit patterns of all regions of the nervous system in the future.”

New Mathematical Model of Information Processing in the Brain Accurately Predicts Some of the Peculiarities of Human Vision

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Posted on 30th March 2011 by Pacific ClearVision Institute in General |Retina

The human retina — the part of the eye that converts incoming light into electrochemical signals — has about 100 million light-sensitive cells. So retinal images contain a huge amount of data. High-level visual-processing tasks — like object recognition, gauging size and distance, or calculating the trajectory of a moving object — couldn’t possibly preserve all that data: The brain just doesn’t have enough neurons. So vision scientists have long assumed that the brain must somehow summarize the content of retinal images, reducing their informational load before passing them on to higher-order processes.

At the Society of Photo-Optical Instrumentation Engineers’ Human Vision and Electronic Imaging conference on Jan. 27, Ruth Rosenholtz, a principal research scientist in the Department of Brain and Cognitive Sciences, presented a new mathematical model of how the brain does that summarizing. The model accurately predicts the visual system’s failure on certain types of image-processing tasks, a good indication that it captures some aspect of human cognition.

Most models of human object recognition assume that the first thing the brain does with a retinal image is identify edges — boundaries between regions with different light-reflective properties — and sort them according to alignment: horizontal, vertical and diagonal. Then, the story goes, the brain starts assembling these features into primitive shapes, registering, for instance, that in some part of the visual field, a horizontal feature appears above a vertical feature, or two diagonals cross each other. From these primitive shapes, it builds up more complex shapes — four L’s with different orientations, for instance, would make a square — and so on, until it’s constructed shapes that it can identify as features of known objects.

While this might be a good model of what happens at the center of the visual field, Rosenholtz argues, it’s probably less applicable to the periphery, where human object discrimination is notoriously weak. In a series of papers in the last few years, Rosenholtz has proposed that cognitive scientists instead think of the brain as collecting statistics on the features in different patches of the visual field.

Patchy impressions

On Rosenholtz’s model, the patches described by the statistics get larger the farther they are from the center. This corresponds with a loss of information, in the same sense that, say, the average income for a city is less informative than the average income for every household in the city. At the center of the visual field, the patches might be so small that the statistics amount to the same thing as descriptions of individual features: A 100-percent concentration of horizontal features could indicate a single horizontal feature. So Rosenholtz’s model would converge with the standard model.

But at the edges of the visual field, the models come apart. A large patch whose statistics are, say, 50 percent horizontal features and 50 percent vertical could contain an array of a dozen plus signs, or an assortment of vertical and horizontal lines, or a grid of boxes.

In fact, Rosenholtz’s model includes statistics on much more than just orientation of features: There are also measures of things like feature size, brightness and color, and averages of other features — about 1,000 numbers in all. But in computer simulations, storing even 1,000 statistics for every patch of the visual field requires only one-90th as many virtual neurons as storing visual features themselves, suggesting that statistical summary could be the type of space-saving technique the brain would want to exploit.

Rosenholtz’s model grew out of her investigation of a phenomenon called visual crowding. If you were to concentrate your gaze on a point at the center of a mostly blank sheet of paper, you might be able to identify a solitary A at the left edge of the page. But you would fail to identify an identical A at the right edge, the same distance from the center, if instead of standing on its own it were in the center of the word “BOARD.”

Rosenholtz’s approach explains this disparity: The statistics of the lone A are specific enough to A’s that the brain can infer the letter’s shape; but the statistics of the corresponding patch on the other side of the visual field also factor in the features of the B, O, R and D, resulting in aggregate values that don’t identify any of the letters clearly.

Road test

Rosenholtz’s group has also conducted a series of experiments with human subjects designed to test the validity of the model. Subjects might, for instance, be asked to search for a target object — like the letter O — amid a sea of “distractors” — say, a jumble of other letters. A patch of the visual field that contains 11 Q’s and one O would have very similar statistics to one that contains a dozen Q’s. But it would have much different statistics than a patch that contained a dozen plus signs. In experiments, the degree of difference between the statistics of different patches is an extremely good predictor of how quickly subjects can find a target object: It’s much easier to find an O among plus signs than it is to find it amid Q’s.

Rosenholtz, who has a joint appointment to the Computer Science and Artificial Intelligence Laboratory, is also interested in the implications of her work for data visualization, an active research area in its own right. For instance, designing subway maps with an eye to maximizing the differences between the summary statistics of different regions could make them easier for rushing commuters to take in at a glance.

In vision science, “there’s long been this notion that somehow what the periphery is for is texture,” says Denis Pelli, a professor of psychology and neural science at New York University. Rosenholtz’s work, he says, “is turning it into real calculations rather than just a side comment.” Pelli points out that the brain probably doesn’t track exactly the 1,000-odd statistics that Rosenholtz has used, and indeed, Rosenholtz says that she simply adopted a group of statistics commonly used to describe visual data in computer vision research. But Pelli also adds that visual experiments like the ones that Rosenholtz is performing are the right way to narrow down the list to “the ones that really matter.”

Advanced Macular Degeneration Is Associated With an Increased Risk of Bleeding Stroke, Study Finds

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Posted on 3rd March 2011 by Pacific ClearVision Institute in General |Retina

Older people with late-stage, age-related macular degeneration (AMD) appear to be at increased risk of brain hemorrhage (bleeding stroke), but not stroke caused by brain infarction (blood clot), according to research presented at the American Stroke Association’s International Stroke Conference 2011.

“Other studies have found there are more strokes in older individuals with late AMD, but ours is the first to look at the specific types of strokes,” said Renske G. Wieberdink, M.D., study researcher and epidemiologist at Erasmus Medical Center in Rotterdam, the Netherlands. “We found the association is with brain hemorrhage, but not brain infarction.”

AMD is degeneration of the macula, which is the part of the retina responsible for the sharp, central vision needed to read or drive. Because the macula primarily is affected in AMD, central vision loss may occur. Age-related macular degeneration usually produces a slow, painless loss of vision. Early signs of vision loss from AMD include shadowy areas in your central vision or unusually fuzzy or distorted vision.

Because the number of brain hemorrhages observed in the study was small, the findings will need to be corroborated in a larger group, Wieberdink said.

“These findings should be considered preliminary,” she said. “Patients and physicians must be very careful not to over-interpret them. We don’t know why there are more brain hemorrhages in these patients or what the relationship with AMD might be. This does not mean that all patients with late-stage AMD will develop brain hemorrhage.”

Beginning in 1990, the Rotterdam Study is a prospective, population-based cohort investigation into factors that determine the occurrence of cardiovascular, neurological, ophthalmological, endocrinological and psychiatric diseases in older people.

The researchers tallied stroke incidence among 6,207 participants 55 years and older. All of the participants were stroke-free at the study’s outset. AMD was assessed during scheduled eye examinations, and participants with the condition were divided into five different stages of AMD, and whether their condition was wet AMD or dry AMD. Participants were tracked for an average of 13 years. Of the 726 persons who suffered a stroke in that time, 397 were brain infarctions, 59 were brain hemorrhages and the stroke type was not available for 270.

Late AMD (stage 4) was associated with a 56 percent increased risk of any type of stroke. Late AMD, both the dry and the wet form, was strongly associated with more than six times the risk of brain hemorrhage, but not with brain infarction. Early AMD (stages 1-3) did not increase the risk of any stroke. Associations were adjusted for possible confounders, such as diabetes, blood pressure, anti-hypertensive medications, smoking status, body mass index, alcohol use and C-reactive protein levels.

“We cannot yet say if there is a common causal pathway or mechanism of action yet — this association needs to be further investigated,” Wieberdink said. “But I don’t think it is a causal relationship. It seems more likely that late AMD and brain hemorrhage both result from some as yet unknown common mechanism.”

If the findings are replicated, it may be possible to develop some stratification of risk among such patients, Wieberdink said.

Removal of Hard Cataract No More a Challenging Task

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Posted on 3rd March 2011 by Pacific ClearVision Institute in Cataracts |General

During a live surgical workshop on ‘Phacoemulsification and Lasik’, ophthalmologists of AIIMS, Dr. J.S.Titiyal and Dr. Rajesh Sinha have demonstrated that removal of tough, dense and hard cataracts are no more a challenging task for the eye surgeons. This surgery which was performed with the help of Ozil Torsional Phaco has no repulsion of lens matter. This improves the lens removal efficiency. “There is more effective phacoemulsification, better fluidicas and increased safety in the technique. Cataract surgery can be performed by 2.2 mm incision by Ozil Torsional machine, which is smaller than previous techniques of 2.8 mm incision,” said Dr Titiyal.

To correct refractive errors Dr. Sinha also performed Lasik surgery on a few patients. “Refractive error is a very common problem. We need to wear spectacle or contact lens to correct this. However, this error can be corrected permanently by very precise and accurate Excimer Laser. This procedure called Lasik takes five to seven minutes per eye. The person can go back to work the next day,” said Dr Sinha. Dr. Titiyal and Dr. Sinha also spoke about new intraocular lenses, latest in phaco technology and the most acceptable modality of correcting refractive error by lasik.

The workshop was organized by Divyadrishti Eye Center. Chief consultant of the center Dr. Subhash Prasad also demonstrated lasik surgery on a patient. Dr. Prasad added, “This workshop has definitely enriched the ophthalmologists of the state with new technologies and techniques in cataract and refractive surgery, which will now be applied to patients here also.” Over 100 ophthalmologists attended the workshop.

Source – Medindia