For corneal transplants Best anterior-segment imaging

There is a wide range of anterior-segment (AS) imaging technologies on the market today. Some AS imaging devices are better than others in anterior-segement surgeries, and surgeons must decide which options are best suited for their practices. 

This article was reviewed by Dipika V. Patel, MRCOphth, PhD

Corneal Requirements for Lasik Surgery

A wide range of anterior-segment (AS) imaging technologies are available, but not all of these are of practical benefit for AS surgeons. Some are more useful for diagnosing, managing, and assessing the prognoses of patients undergoing keratoplasty, Dipika V. Patel, MRCOpht, PhD, pointed out.

Dr. Patel is a professor of ophthalmology, University of Auckland, Auckland, New Zealand.

Preoperative assessment

Ultrasound biomicroscopy (UBM) provides a view of the AS that can be obscured by corneal opacities on slit lamp examination. The surgeon can have a robust view of the anterior chamber depth, angle, lens and anterior capsule, membranes, adhesions, and vitreous in the anterior chamber using UBM, she commented.

The disadvantage of UBM is that the patient must be supine and water immersion is usually needed (although recent models overcome these issues), both of which require patient cooperation or use of general anesthesia.

“Having the knowledge of the status of the eye behind an opaque cornea aids in planning the surgery as well as discussing the prognosis with the patient,” Dr. Patel emphasized. 

Related: Novel imaging technology provides volumetric visualization for cataract and cornea surgeons  

AS optical coherence tomography (AS-OCT), which is a non-contact technology performed with the patient sitting, allows the surgeon to assess the depth of corneal pathology. 

With the information provided by this imaging, the surgeon can select the most appropriate surgical intervention, Dr. Patel noted. She then described a case of stromal haze that developed following implantation of a Kamra inlay (SightLife Surgical) that ultimately was removed. 

At the slit-lamp, the depth of the haze could not be clearly ascertained. OCT demonstrated that the haze was maximal at the interface, including the location of the inlay, and extended both anteriorly and posteriorly to the deep stroma.

The disadvantages of AS-OCT include poor visualization of both the ciliary body and through corneal opacities.

Related: Yet another new revolution in ocular surface imaging 

In vivo confocal microscopy (IVCM) is useful preoperatively for looking at and differentiating among the endothelial diseases, such as bullous keratopathy, Fuchs’ endothelial dystrophy, or ICE syndrome. 

Intraoperative observation

Real-time, high-quality images are now accessible using intraoperative OCT with microscope-integrated OCT devices. 

Dr. Patl noted that the images may be viewed through the surgeon’s microscope on a heads-up display or an external screen.

“The availability of these images affects decision-making intraoperatively and is thought to reduce the length of the surgery,” she explained.

This technology can be applied to deep anterior lamellar keratoplasty (DALK) to evaluate the depth of the needle and dissection, the plane of big-bubble dissection, the residual stromal thickness, and to detect any microperforations. 

In Descemet’s stripping automated endothelial keratoplasty (DSAEK) and Descemet’s membrane endothelial keratoplasty (DMEK), intraoperative OCT can evaluate graft-host apposition, assess the interface fluid, check the graft orientation in DMEK, and facilitate faster positioning of the graft with less manipulation.

The usefulness of intraoperative OCT technology also was evaluated in a prospective multi-surgeon study that included 244 cases of AS surgery. 

The results indicated that the technology influenced surgical decision-making in 43.4% of cases; 78.3% of surgeons preferred real-time to static image acquisition; and 63.1% of surgeons preferred viewing the images on the external screen.

The limitations of intraoperative OCT include limited details visible on the heads-up display, light scattering and shadowing from surgical instruments, and cost.

Postoperative examination

AS-OCT facilitates assessment of grafts in DSAEK and DMEK for thickness, centration, and detachment. This technology influences management considerations such as graft reshaping and repositioning and rebubbling.

“This technology is particularly valuable in cases with an edematous cornea when the view at the slit-lamp is poor,” Dr. Patel pointed out.

Related: DMEK vs. DSAEK: Debate goes on 

AS-OCT technology allows the surgeon to assess the graft-host junction after penetrating keratoplasty, in which graft-host malpositioning occurs commonly and is associated with high levels of astigmatism. 

Dr. Patel described the case of a patient in whom the vision decreased a few years after deep anterior lamellar keratoplasty due to recurrent granular dystrophy at the interface.

AS-OCT is also useful for evaluating the extent of epithelial ingrowth, albeit rare, following lamellar endothelial keratoplasty. 

The technology is also used to monitor patients over time.

IVCM has proven useful to confirm cases of epithelial ingrowth. Dr. Patel described an interesting case in which the IVCM images showed epithelial cells with fibrotic areas in the stroma, where epithelium should not be present, Dr. Patel explained.

IVCM and specular microscopy are both useful technologies that can be used to determine the prognosis as well as the potential for late endothelial graft failure. 

Related: Budding technology could be an OCT analysis game-changer 

Two long-term studies investigating graft failure after full-thickness or endothelial transplants both found that preoperative donor endothelial density is not predictive of failure, but rather, low endothelial cell density (<1,200 cells/mm2) 6 months postoperatively is associated with late endothelial graft failure.

For physicians, AS-OCT is opening new doors to ensure the fast and efficient diagnosis and treatment of patients. 

This, according to Dr. Patel, can lead to better outcomes for their vision. 

“UBM, AS-OCT, intraoperative OCT, IVCM, and specular microscopy are useful for establishing a diagnosis, directing the management and assessing the prognoses of these patients,” Dr. Patel concluded.

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FOR CORNEAL TRANSPLANTS FINEST ANTERIOR-SEGMENT IMAGING

Image result for exclusive pic of corneal transplant


There is a vast array of anterior-segment (AS) imaging technologies on the marketplace today. Some AS imaging tools are far better than others in anterior-segment surgical procedures, as well as specialists should choose which alternatives are best matched for their methods.


A variety of anterior-segment (AS) imaging innovations are offered, yet not all of these are of useful or of advantage for AS doctors. Some are more useful for identifying, managing, and also assessing the diagnoses of clients undergoing keratoplasty, 

Preoperative evaluation
Ultrasound bio microscopy (UBM) gives a sight of the AS that can be covered by corneal opacities on slit light evaluation. The doctor can have a robust sight of the former chamber depth, angle, lens and anterior capsule, membranes, attachments, and also vitreous in the anterior chamber utilizing UBM.

The drawback of UBM is that the individual has to be supine and water immersion is generally needed (although recent designs get rid of these issues), both of which require teamwork or use of basic anaesthetics.

“Having the understanding of the status of the eye behind an opaque cornea help in intending the surgery in addition to talking about the prognosis with the patient,” ophthalmologists stressed.

AS optical coherence tomography (AS-OCT), which is a non-contact innovation executed with the person resting, permits the specialist to examine the depth of corneal pathology.
With the info given by this imaging, the doctor can pick one of the most proper medical interventions.  According to doctors, a case of stromal haze that established complying with implantation of a Kamra inlay (SightLife Surgical), that eventually was gotten rid of.

At the slit-lamp, the depth of the haze might not be plainly ascertained. OCT demonstrated that the haze was maximal at the interface, consisting of the location of the inlay, and extended both anteriorly as well as posteriorly to the deep stroma.

The downsides of AS-OCT include bad visualization of both the ciliary body as well as via corneal opacities.

In vivo confocal microscopy (IVCM), the test works preoperatively for seeing and distinguishing amongst the endothelial illnesses, among them bullous keratopathy, Fuchs’ endothelial dystrophy, or ICE disorder.

Intraoperative monitoring
Real-time, top notch pictures are currently obtainable using intraoperative OCT with microscope-integrated OCT tools.

These images might be seen with the surgeon’s microscopic lenses on a heads-up display screen or an outside screen.

“The availability of these images influences decision-making intraoperatively and is believed to lower the length of the surgery,” the eye doctor explained. This innovation can be related to deep anterior lamellar keratoplasty (DALK) to evaluate the depth of the needle and also breakdown, the plane of big-bubble breakdown, the recurring stromal thickness, and to spot any kind of micro perforations.

In Descemet’s removing computerized endothelial keratoplasty (DSAEK) and also Descemet’s membrane endothelial keratoplasty (DMEK), intraoperative OCT can evaluate graft-host consistency, examine the interface fluid, examine the graft orientation in DMEK, as well as promote faster positioning of the graft with much less adjustment.

The effectiveness of intraoperative OCT technology additionally was assessed in a potential multi-surgeon study that included 244 cases of AS surgical procedure. The outcomes showed that the modern technology affected surgical decision-making in 43.4% of instances; 78.3% of specialists favoured real-time to fixed picture procurement; and 63.1% of doctors chosen
were seeing the photos on the outside display.

The limitations of intraoperative OCT consist of restricted details visible on the heads-up display screen, light scattering and also shadowing from medical tools, as well as price.
Postoperative examination

AS-OCT assists in analysis of grafts in DSAEK and DMEK for thickness, centration, and detachment. This innovation affects management considerations such as graft improving and repositioning and redubbing.

As per the doctor’s observation “This modern technology is particularly useful in cases with an oedematous cornea when the sight at the slit-lamp is poor.”
AS-OCT modern technology enables the doctor to analyse the graft-host junction after penetrating keratoplasty, in which graft-host mispositioning happens generally as well as is related to high degrees of astigmatism.


Actually, the situation of an individual in whom the vision decreased a couple of years after deep anterior lamellar keratoplasty as a result of recurring granular dystrophy at the interface.

AS-OCT is additionally valuable for examining the extent of epithelial in-growth, albeit unusual, following lamellar endothelial keratoplasty.

The innovation is likewise used to keep an eye on individuals gradually.

IVCM has proved valuable to validate cases of epithelial ingrowth. In fact, in an intriguing situation, the IVCM photos showed epithelial cells with fibrotic locations in the stroma, where epithelium should not be present.

IVCM as well as specular microscopy are both beneficial innovations that can be made use of to identify the prognosis as well as the potential for late endothelial graft failing.

While checking out 2 last studies graft failing after full-thickness or endothelial transplants both discovered that preoperative contributor endothelial density is not anticipating of failing, however instead, reduced endothelial cell thickness (<1,200 cells/mm2), 6 months postoperatively is related to late endothelial graft failing.

For doctors, AS-OCT is opening brand-new doors to guarantee the rapid and reliable diagnosis and also treatment of patients.This, can lead to better end results for patient’s vision. UBM, AS-OCT, intraoperative OCT, IVCM, as well as specular microscopy serve their purpose for developing a medical diagnosis, guiding the monitoring and assessing the prognoses of these people.

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