– Savini G, Hoffer KJ, Schiano-Lomoriello D. Agreement between lens thickness measurements by ultrasound immersion and optical biometry. J Cataract Refract Surg 2018;44:1463-1468.– Savini G, Negishi K, Hoffer KJ, Schiano-Lomoriello D. Refractive outcomes of intraocular lens power calculation using different corneal power measurements with a new optical biometer. J Cataract Refract Surg 2018;44:701-708.– Savini G, Hoffer KJ, Shammas HJ, Aramberri J, Huang J, Barboni P. Accuracy of a new swept-source optical coherence tomography biometer for IOL power calculation and comparison to IOLMaster. J Refract Surg 2017;33:690-695.– Hoffer KJ, Savini G. IOL power calculation in short and long eyes. Asia Pacifc J Ophthalmol 2017;6:330-331.– Hoffer KJ, Shammas HJ, Savini G, Huang J. Multicenter study of optical low-coherence interferometry and partial-coherence inteferometry optical biometers with patients from the United States and China. J Cataract Refract Surg 2016;42:62-67.– Savini G, Hoffer KJ, Lombardo M, Serrao S, Schiano-Lomoriello D, Ducoli P. Influence of the effective lens position, as predicted by axial length and keratometry, on the near add power of multifocal intraocular lenses. J Cataract Refract Surg 2016;42:44-49.– Savini G, Barboni P, Carbonelli M, Ducoli P, Hoffer KJ. Intraocular lens power calculation after myopic excimer laser surgery: selecting the best method using clinically available data. J Cataract Refract Surg 2015;41:1880-1888.– Hoffer KJ, Aramberri J, Haigis W, Olsen T, Savini G, Shammas HJ, Bentow S. Protocols for studies of intraocular lens formula accuracy. Am J Ophthalmol 2015;160:403-405.– Savini G, Hoffer KJ, Barboni P. Influence of corneal asphericity on the refractive outcome of intraocular lens implantation in cataract surgery. J Cataract Refract Surg 2014;41:785-789.– Savini G, Naeser K. An analysis of the factors influencing the residual refractive astigmatism after cataract surgery with toric intraocular lenses. Invest Ophthalmol Vis Science 2015;56:827-835.– Savini G, Barboni P, Ducoli P, Borrelli E, Hoffer KJ. Influence of intraocular lens haptic design on refractive error. J Cataract Refract Surg 2014;40:1473-1478.– Savini G, Bedei A, Barboni P, Ducoli P, Hoffer KJ. Intraocular lens power calculation by ray-tracing after myopic excimer laser surgery. Am J Ophthalmol 2014;157:150-153.– Savini G, Hoffer KJ, Carbonelli M, Ducoli P, Barboni P. Influence of axial length and corneal power on the astigmatic power of toric intraocular lenses. J Cataract Refract Surg 2013;39:1900-1903.– Savini G, Barboni P, Carbonelli M, Hoffer KJ. Comparison of methods to measure corneal power for intraocular lens power calculation using a rotating Scheimpflug camera. J Cataract Refract Surg 2013;39:598-604.– Savini G, Barboni P, Carbonelli M, Hoffer KJ. Accuracy of corneal power measurements by a new Scheimpflug camera combined with Placido-disk corneal topography for intraocular lens power calculation in unoperated eyes. Journal of Cataract and Refractive Surgery 2012;38:787-792.– Savini G, Barboni P, Carbonelli M, Hoffer KJ. Accuracy of a dual Scheimpflug analyzer and a corneal topography system for intraocular lens power calculation in unoperated eyes. J Cataract Refract Surg 2011;37:72-76.

Dal febbraio 2014 lo Studio Oculistico d’Azeglio è dotato anche di un secondo biometro ottico, il Tomey OA-2000. Tomey, azienda giapponese che da numerosi anni costruisce strumenti oftalmici, ha infatti scelto il nostro studio per introdurre sul mercato europeo e sviluppare questo strumento.

LEDStrip lights

Dal dicembre 2013 grazie alla collaborazione con Topcon è disponibile anche un biometro ottico, l’Aladdin (foto a sinistra). Questo, invece di utilizzare gli ultrasuoni, misura la lunghezza dell’occhio per mezzo della luce. Aladdin è inoltre dotato di un topografo corneale, che permette una valutazione accurata della superfice e della curvatura corneale.

The LED lighting is taking the world by storm and there is no denying that it will be the standard for years to come. The technology is still improving and it is now being used in different applications. These include the following:

The LED lenses come in various shapes and sizes. They can come in square, hexagonal, or round shapes. They are commonly made out of plastic and silicone in order to give them flexibility but still be rigid enough to stay in shape.

When talking about luminous flux, you will be focusing on a lens’ optical efficiency. For lenses made with high-quality materials, they can reach efficiency ratings of 90% or higher. While this looks like a good way to measure how “good” a specific lens is, it still won’t give us the big picture. There are still a lot of factors to consider such as Full-Width Half Maximum FWHM angle and the candela-per-lumen (cd/lm) figure. With all these factors considered, designers can come up with more realistic assessments of lighting effects and “how good they are” in terms of distribution and intensity.

We won’t get too technical here but think of it this way. If you wanted to showcase the garden landscaping you have at home, would you want the light to just be thrown all over the place or focused on the parts that can really call the attention of the viewers?

LED lighting fixtures use at least one type of secondary optic to alter the beam of light coming from the LED source. There are two kinds of secondary LED optics: Lenses and Reflectors. Here is a quick rundown of each kind.

Un caso a parte è rappresentato dal calcolo della curvatura corneale negli occhi precedentemente operati di chirurgia refrattiva con laser ad eccimeri. In tale evenienza sono necessari calcoli più complessi, per i quali lo Studio Oculistico d’Azeglio è diventato un punto di riferimento a livello internazionale grazie alla pubblicazione di numerosi lavori scientifici sull’argomento ed allo sviluppo di uno specifico foglio di calcolo, l’Hoffer/Savini LASIK IOL Power Tool (clicca qui per andare al sito dello IOL Power Club e scaricare il file).

Another type of secondary LED optic is called reflectors. Reflectors work almost the same as lenses although the difference is that reflectors don’t have as much control as lenses. They are, however, a much cheaper solution compared to lenses.

It’s easy to assume that creating reflectors and lenses for LED’s are quite easy given that manufacturers have been doing this for years. However, one must understand that LEDs emit light differently from older, more traditional forms of lighting. For example, incandescent lights illuminate 360 degrees. LEDs, on the other hand, only illuminate 180 degrees (also called directional lighting). Due to the basic design of an LED, it can only emit light at a maximum angle of 180 degrees.

Let’s play a little game here, what goes into your mind when people say LED optics? Do you imagine this highly complex dome lens that helps in focusing or spreading the light? Well, technically you are right. However, that’s going a bit too far. In order to better understand LED optics, let us try to take a step back first.

Amministrazione: amministrazione@studiodazeglio.it Pec: amministrazione@pec.studiodazeglio.it Segreteria: info@studiodazeglio.it Dott. Piero Barboni: p.barboni@studiodazeglio.it Dott. Giacomo Savini: g.savini@studiodazeglio.it

There is no single metric that can fully describe the optical performance of a given lens. To specify an optimal lens for a given application, lighting designers need to understand several parameters and the relationships between them.

Designing LED lighting implements has one specific goal – to illuminate a specific area in the best way possible. That’s why engineers are finding ways of not only creating diodes that emit more light but also optical systems that can magnify it. While there are a lot of considerations such as spread, light intensity, cost, size, and complexity, frontrunners in the industry of LED lighting are still finding ways to make the technology better. This is so we can have the best lighting possible for all our needs.

Gli eccellenti risultati ottenuti nel corso degli anni sono stati pubblicati (caso unico in Italia) sulle più importante riviste scientifica del settore, quali Ophthalmology, il Journal of Cataract and Refractive Surgery, Investigative Ophthalmology and Visual Science, e l’American Journal of Ophtalmology:

While the main purpose of the secondary optic is to collimate the beam of light, it’s not the only purpose it has. Secondary optics are also used to ensure color uniformity and even light distribution within the targeted area. Depending on the optic and lens you use, you will get varying results.

LEDLens

The technology behind LED lighting is impressive as it is. However, LED lighting is more than just a revolutionary means of lighting that saves energy. You need to consider a lot of things including lenses and reflectors. These two magnify (both literally and figuratively) the importance of LED lighting in our daily lives. As a matter of fact, since time immemorial, optics have played a major role in how we have harnessed and used the power of light.

It will be hard to describe how good a specific type of lens performs. As a matter of fact, there’s no single metric for it. However, experts still find a way to quantify the performance of optics using several parameters and how they relate to each other.

Carclooptics

Most reflectors are made out of plastic and they often have metal coatings. To achieve varying effects, reflectors often come smooth or multi-faceted inside and have different shapes. For further customization, reflectors often contain sub-lens to diffuse or control the light a bit more.

To further understand how a secondary optic or lens can collimate a beam, let’s introduce a few terms. Now, understand that there are things such as viewing angle or full width half maximum (FWHM). What you only need to remember is that FWHM is the angular width of the beam when the intensity at the edge is half the intensity from that of the center of the beam. While this is the easiest way to classify optics, this still omits the major differences presented by different optical platforms (usually by different sized diodes). Basically, optics may have identical viewing angles but still different in intensity and quality due to the emitter’s optical design.

Con il termine di biometria intendiamo la misurazione di alcuni parametri oculari (in particolar modo curvatura corneale e lunghezza assiale) che permettono di calcolare il potere diottrico delle lenti intraoculari prima dell’intervento di cataratta. La lente artificiale che viene inserita al posto del cristallino opacizzato ha un proprio potere diottrico, in maniera simile alle lenti degli occhiali o alle lenti a contatto. Il chirurgo deve pertanto calcolarne il potere più appropriato per ogni paziente, in modo da ridurre al massimo l’uso degli occhiali dopo l’intervento. Questi calcoli vengono effettuati sulla base di due misurazioni, che nel loro insieme sono chiamate biometria: la curvatura corneale e la lunghezza assiale dell’occhio. La curvatura della cornea è misurata con un topografo corneale, strumento in grado di ricostruire la forma della cornea generando delle mappe corneali. I medici dello Studio Oculistico d’Azeglio dispongono di uno dei topografi più sofisticati, il Keratron della Optikon 2000 (foto a destra). Inoltre il potere corneale viene misurato attraverso due Scheimpflug cameras, il Sirius ed il Pentacam, strumenti indispensabili per calcolare l’astigmatismo corneale totale, ovvero l’astigmatismo della superficie corneale anteriore e posteriore. L’importanza di tale misurazione è cresciuta nel corso degli anni, dal momento che il miglioramento delle tecnologie e delle nostre conoscenze ha portato ad un utilizzo sempre maggiore delle cosiddette lenti toriche per la correzione anche di astigmatismi di bassa entità. I chirurghi dello Studio Oculistico d’Azeglio oggi mirano alla correzione di tutti gli astigmatismi superiori alle 0.5 diottrie.

Corso avanzato di biometria Gennaio 2019: leggi di piùCorso avanzato di biometria Gennaio 2018: leggi di piùCorso avanzato di biometria Febbraio 2017: leggi di piùCorso avanzato di biometria Gennaio 2016: leggi di piùCorso avanzato di biometria Dicembre 2014: leggi di piùCorso avanzato di biometria Dicembre 2013:leggi di più

LEDlight strip 24V

La lunghezza assiale dell’occhio viene misurata per mezzo di uno strumento (il biometro) dotato di una sonda ad ultrasuoni. Lo Studio Oculistico d’Azeglio è dotato di un biometro ad ultrasuoni, l’OcuScan dell’Alcon (foto a destra). Tutte le misurazioni sono effettuate con la tecnica ad immersione, che non prevede il contatto diretto della sonda ad ultrasuoni con la superficie dell’occhio.

Note that on all the applications mentioned above they all need one thing – focus lighting. With just the primary optic and the diode, LED lights simply cannot perform for such purposes. Without secondary optics, LED lights won’t be able to deliver enough intensity to the target surface.

Linear lens

LEDiL

( This article shared from our official website https://www.anethic.com/optics-in-led-lighting-for-dummies/, more articles please read our blog page)

Due to the versatility of lenses, they can be used with single or multiple LEDs. As such, they are often the choice for LED modules or strips. With the right type of lenses, they can come up with various effects. This is all thanks to the precise control one can get from using a lens. Add the fact that a lens can give LED bulbs a certain aesthetic and you have one complete package.

Look for any basic LED light near you. Assuming you turned it off. you can see a small protective dome over the diode. That is what we call the primary optic. Its purpose is to protect the diode and to help shape the “output”. However, the primary optic can’t really focus the light and the end result is still pretty broad and may not be used for most applications. For starters, it lacks intensity over the distance which makes it useless for lighting large rooms. This is where the secondary optics (lenses, reflectors, TIR optics, etc.) come in. The job of the secondary optics is to collect all that light and magnify its intensity towards the target.

Let’s consider a lens with perfect symmetry that delivers the maximum intensity of light at its center. Find the angle where the intensity of illumination is at 50% from the maximum value and you will get the FWHM. The FWHM can give us a good idea of how narrow the beam is. So this does not get too confusing, some suppliers provide the angle wherein the intensity is at 10% of the maximum. This is so designers and light engineers can have a good idea of how much light strays from the main beam. By comparing the difference in intensity between the FWHM and 10% angle, we can easily see how concentrated and narrow the produced beam of light.

Dal febbraio 2016 al gennaio 2018 abbiamo aggiunto un terzo biometro ottico, il Galilei G6 della Ziemer, il primo biometro che contiene al proprio interno una Scheimpflug camera, mentre ad aprile 2017 abbiamo ricevuto il quarto biometro ottico, il Pentacam AXL della Oculus.

L’esperienza acquisita negli anni, la costante ricerca a livello scientifico e la possibilità di avere a disposizione gli strumenti più sofisticati garantiscono i migliori risultati per i nostri pazienti e fanno dello Studio Oculistico d’Azeglio un punto di riferimento nazionale ed internazionale per i chirurghi della cataratta che si occupano di biometria, come dimostrato dai corsi tenuti dal 2013 ad oggi.

Secondary optics work in such a way that they offer a controlled beam of light that you can point at a certain spot to get the full intensity. In a way, secondary optics are used to collimate the light rays. Collimated rays of light contain parallel rays and therefore do not spread as much. While physics will tell us that there is no way to line up the lights in a perfect parallel due to diffraction and limitations of the emitter, our eyes can barely see the difference.

a fianco dello studio è presente un parcheggio a pagamento che può rilasciare il permesso di ingresso nel centro di Bologna a chi non ne è in possesso.