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3 Ultra Thin Descemet’s Stripping Automated Endothelial Keratoplasty

3 Ultra Thin Descemet’s Stripping Automated Endothelial Keratoplasty

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202



D.K. Dhaliwal and A.M. Kouchouk



complication – 0.4 % of all cases occurred in the second year of the study).

Perforation of tissue requiring the tissue to be discarded occurred in 2.1 % of

cases, a rate significantly lower than that seen with DMEK donor preparation.

Complete graft detachment was seen in 3.9 % of cases and was always managed

successfully with a maximum of two re-injections of air, while peripheral detachments (0.7 %) were left untreated with no negative sequelae. Postoperative graft

dislocation was significantly lower than that reported with DMEK by Price et al.

(63 %). Graft failure rates with UT DSAEK are similar to DSAEK. Immunologic

rejection with UT DSAEK (2.5 %) occurs at a similar rate to DMEK, and occurs

less frequently than has been reported with DSAEK (9 %) [23, 24].



12.4



Pre-Descemet’s Endothelial Keratoplasty



A mean graft thickness at day 1 of 37.3+/-3.5 microns and 30.3 +/- 2.6 microns at day

90 with a statistically significant decrease in graft thickness over time. A statistically

significant increase in visual acuity from pre-operatively to post-operatively with a

final corrected distance visual acuity of 0.61 +/-0.2 was seen [25].



12.5



Conclusion



In conclusion, there is mounting evidence that thinner GT such as with DMEK and

UT DSAEK may provide improved and more rapid visual outcomes compared with

DSAEK. Both of these techniques are still relatively new, and do not have the years

of optimization and innovation from surgeons worldwide as seen with

DSAEK. Hopefully, as we continue to refine endothelial keratoplasty techniques,

and gain more prospective case series data for these new techniques, we can provide

improved and more rapid visual improvement for our patients.



References

1. Anshu A, Price MO, Tan DT, Price Jr FW. Endothelial keratoplasty: a revolution in evolution.

Surv Ophthalmol. 2012;57(3):236–52.

2. Neff KD, Biber JM, Holland EJ. Comparison of central corneal graft thickness to visual acuity

outcomes in endothelial keratoplasty. Cornea. 2011;30(4):388–91.

3. Patel SV, Baratz KH, Hodge DO, Maguire LJ, McLaren JW. The effect of corneal light

scatter on vision after Descemet stripping with endothelial keratoplasty. Arch Ophthalmol.

2009;127(2):153–60.

4. Dupps Jr WJ, Qian Y, Meisler DM. Multivariate model of refractive shift in Descemet-stripping

automated endothelial keratoplasty. J Cataract Refract Surg. 2008;34(4):578–84.



12 Graft Thickness and Its Relationship to Visual Outcome in Endothelial Keratoplasty



203



5. Busin M, Albé E. Does thickness matter: ultrathin Descemet stripping automated endothelial

keratoplasty. Curr Opin Ophthalmol. 2014;25(4):312–8.

6. Busin M, Madi S, Santorum P, Scorcia V, Beltz J. Ultrathin Descemet’s stripping automated

endothelial keratoplasty with the microkeratome double-pass technique: two-year outcomes.

Ophthalmology. 2013;120(6):1186–94.

7. Terry MA, Straiko MD, Goshe JM, Li JY, Davis-Boozer D. Descemet’s stripping automated

endothelial keratoplasty: the tenuous relationship between donor thickness and postoperative

vision. Ophthalmology. 2012;119(10):1988–96.

8. Daoud YJ, Munro AD, Delmonte DD, Stinnett S, Kim T, Carlson AN, Afshari NA. Effect of

cornea donor graft thickness on the outcome of Descemet stripping automated endothelial

keratoplasty surgery. Am J Ophthalmol. 2013;156(5):860–6.e1.

9. Shinton AJ, Tsatsos M, Konstantopoulos A, Goverdhan S, Elsahn AF, Anderson DF, Hossain

P. Impact of graft thickness on visual acuity after Descemet’s stripping endothelial keratoplasty. Br J Ophthalmol. 2012;96(2):246–9.

10. Van Cleynenbreugel H, Remeijer L, Hillenaar T. Descemet stripping automated endothelial

keratoplasty: effect of intraoperative lenticule thickness on visual outcome and endothelial cell

density. Cornea. 2011;30(11):1195–200.

11. Woodward MA, Raoof-Daneshvar D, Mian S, Shtein RM. Relationship of visual acuity

and lamellar thickness in Descemet stripping automated endothelial keratoplasty. Cornea.

2013;32(5):e69–73.

12. Phillips PM, Phillips LJ, Maloney CM. Preoperative graft thickness measurements do not

influence final BSCVA or speed of vision recovery after Descemet stripping automated endothelial keratoplasty. Cornea. 2013;32(11):1423–7.

13. Melles GR, Lander F, Rietveld FJ. Transplantation of Descemet’s membrane carrying viable

endothelium through a small scleral incision. Cornea. 2002;21(4):415–8.

14. Price MO, Giebel AW, Fairchild KM, Price Jr FW. Descemet’s membrane endothelial keratoplasty: prospective multicenter study of visual and refractive outcomes and endothelial survival. Ophthalmology. 2009;116(12):2361–8.

15. Anshu A, Price MO, Price Jr FW. Risk of corneal transplant rejection significantly reduced

with Descemet’s membrane endothelial keratoplasty. Ophthalmology. 2012;119(3):536–40.

16. Guerra FP, Anshu A, Price MO, Giebel AW, Price FW. Descemet’s membrane endothelial

keratoplasty: prospective study of 1-year visual outcomes, graft survival, and endothelial cell

loss. Ophthalmology. 2011;118(12):2368–73.

17. Dapena I, Ham L, Melles GR. Endothelial keratoplasty: DSEK/DSAEK or DMEK--the thinner the better? Curr Opin Ophthalmol. 2009;20(4):299–307.

18. Ham L, Balachandran C, Verschoor CA, van der Wees J, Melles GJ. Visual rehabilitation rate

after isolated Descemet membrane transplantation: Descemet membrane endothelial keratoplasty. Arch Ophthalmol. 2009;127(3):252–5.

19. Terry MA, Shamie N, Chen ES, Phillips PM, Hoar KL, Friend DJ. Precut tissue for Descemet’s

stripping automated endothelial keratoplasty: vision, astigmatism, and endothelial survival.

Ophthalmology. 2009;116(2):248–56.

20. Jun B, Kuo AN, Afshari NA, Carlson AN, Kim T. Refractive change after Descemet stripping

automated endothelial keratoplasty surgery and its correlation with graft thickness and diameter. Cornea. 2009;28(1):19–23.

21. Price MO, Baig KM, Brubaker JW, Price Jr FW. Randomized, prospective comparison of

precut vs surgeon-dissected grafts for Descemet stripping automated endothelial keratoplasty.

Am J Ophthalmol. 2008;146(1):36–41.

22. Yoo SH, Kymionis GD, Deobhakta AA, Ide T, Manns F, Culbertson WW, O’Brien TP,

Alfonso EC. One-year results and anterior segment optical coherence tomography findings of

Descemet stripping automated endothelial keratoplasty combined with phacoemulsification.

Arch Ophthalmol. 2008;126(8):1052–5.

23. Price MO, Fairchild KM, Price DA, Price Jr FW. Descemet’s stripping endothelial keratoplasty

five-year graft survival and endothelial cell loss. Ophthalmology. 2011;118(4):725–9.



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24. Price MO, Gorovoy M, Price Jr FW, Benetz BA, Menegay HJ, Lass JH. Descemet’s stripping

automated endothelial keratoplasty: three-year graft and endothelial cell survival compared

with penetrating keratoplasty. Ophthalmology. 2013;120(2):246–51.

25. Kumar DA, Dua HS, Agarwal A, Jacob S. Postoperative spectral-domain optical coherence

tomography evaluation of pre-Descemet endothelial keratoplasty grafts. J Cataract Refract

Surg. 2015 Jul;41(7):1535–6.



Chapter 13



Targeting Emmetropia in Endothelial

Keratoplasty

Arun C. Gulani



Contents

13.1

13.2

13.3

13.4

13.5

13.6



Introduction

DSEK

DSAEK

DMEK

PDEK

Gulani Refractive Descemet’s Endothelial Keratoplasty

(REFDEK) Classification

13.6.1 Preoperative

13.6.2 Intraoperative

13.6.3 Postoperative

13.7 My Personal Techniques

13.7.1 Minimal DSAEK Surgery: Gulani Key Hole Transplant (REFDEK)

References



13.1



205

207

209

209

211

212

212

212

213

215

215

216



Introduction



It is my unwavering desire and goal in every eye surgery to achieve a higher level of

vision outcome or at least not to decrease the vision potential from the preoperative

status no matter how difficult the condition or complexity of the case maybe.

With this mindset, I approach every surgery including corneal transplant surgery

as an opportunity to either improve or retain the vision while fixing the mechanical



Electronic supplementary material The online version of this chapter (doi:10.1007/978-81322-2821-9_13) contains supplementary material, which is available to authorized users.

A.C. Gulani, MD, MS

Chief Surgeon and Founding Director, Gulani Vision Institute,

8075 Gate Parkway (W) Suite 102& 103, Jacksonville, FL 32216, USA

e-mail: gulanivision@gulani.com

© Springer India 2016

S. Jacob (ed.), Mastering Endothelial Keratoplasty,

DOI 10.1007/978-81-322-2821-9_13



205



206



A.C. Gulani



problem of the cornea keeping the five principles of Corneoplastique™ in my mind

like filters, i.e., elegant, least interventional, brief, topical, and most visually

promising. These principles allow me to break down the complexity of any presenting corneal case and also unfold a logical plan in rehabilitating vision in each and

every case.

To begin this journey of raising the bar on endothelial keratoplasty to aim for

refractive outcomes while dealing with surgical complexities of each situation, let

us first understand the cornea and the various variants of endothelial keratoplasty.

The cornea is one of the many components of the eye, but has one of the most

important roles in vision. The cornea serves as a protective barrier for the eye; however, it has a bigger role in optics. It acts as a refractive component in combination

with the anterior chamber and lens to focus incoming light onto the retina, creating

a clear image of the outside world [1]. The cornea accounts for about two-thirds of

the eye’s total optical power, the lens being the last third [2]. The light entering the

eye is bent toward the midline; however, the focus is fixed, as the cornea cannot

change shapes. The light is then fine-tuned by the lens, as it changes shape, to produce a focused, crisp image onto the retina. Once an image is formed on the retina,

the signal is transmitted through the optic nerve to the brain; the brain then translates the signal into an image.

The cornea has a refractive index of about 1.36, equivalent to about 40 diopters

[3]. This refractive index is the sum of the five layers of the cornea (and now a

recently discovered sixth layer—Dua’s layer): corneal epithelium, Bowman’s layer,

stroma, Descemet’s membrane, corneal endothelium, from anterior to posterior

[1–4].

The cornea must remain clear and stable in order to provide good vision. Variation

in opacity or corneal thickness may be a result from disease, trauma, or age. If one

of these factors affects the cornea’s structure, it will subsequently disrupt the function, resulting in disrupted or damaged vision. Changes in the thickness of the cornea results in something called a refractive error. Diseases, such as Fuchs’ dystrophy

and bullous keratopathy, affect the function of the innermost layer of the cornea,

endothelium. When disease such as Fuchs’ dystrophy affects the cornea, the corneal

endothelial cells dysfunction, causing the cornea to swell and consequently blurred

vision [1, 5]. Damage to the inner layer of the cornea, endothelium, is the most common cause of decreased vision and a cloudy cornea [1]. The endothelium is responsible for maintaining the water content of the cornea by pumping water out of the

cornea, keeping it thin and clear [5]. Such diseases damage the layer’s ability to

maintain proper water levels and cause the cornea to swell; consequently, causes

poor vision. When this layer dysfunctions, medications or surgical interventions

may be required.

New surgical techniques and medical technologies are concurrently being developed and modified to match the continuous evolution of medicine (Fig. 13.1).

Today, many eye surgeons around the world are choosing endothelial keratoplasty

(EK) over penetrating keratoplasty (PK) to treat corneal endothelial diseases. Severe



13



Targeting Emmetropia in Endothelial Keratoplasty



207



Techniques and Technology

Dry Eye



Target



Punctal Plugs



Monofocal



Thermal pulsation



Monovision



PRK/ASA



Toric



LASIK



Multifocal



Ocular Surface



Pterygium removal



Accomodative



Phakic Implants



ICL Anterior – VERISYS]



Lasik Vision Surgery



ICL Posterior – VISIAN

ALK



Cornea



INTACS

Collagen cross linking

DSAEK

PKP

Cataract Surgery



Monofocal

Toric



Fig. 13.1 The Gulani 3T system which helps understand and select the right technique, technology, and vision target for each patient



cases of corneal diseases were commonly treated with PK, a form of transplant that

involved a full thickness cornea, but as medicine advanced, alternative surgical

techniques, such as DSEK/DSAEK, DMEK, and now, PDEK, have been the preferred treatment method [6] (Fig. 13.2a–h).

Descemet’s stripping endothelial keratoplasty (DSEK) and Descemet’s stripping

automated endothelial keratoplasty (DSAEK) have become a promising treatment

method for advanced corneal disorders [6, 7]. These transplant surgeries have

proven to reduce the postoperative recovery period, lessen graft complications and

rejections, and provide better postoperative visual acuity and corneal function.



13.2



DSEK



DSEK is one of the modalities of EK that is performed by eye surgeons all over the

world. DSEK is the preferred choice of surgery because it is fairly easy to perform

and provides promising outcomes. This surgery involves the removal of a small



208



A.C. Gulani



a



b



c



d



e



f



g



h



Fig. 13.2 (a) The PBK cornea; (b) paracentesis made at 11 and 1 o’clock; (c) single instrument

inserted for scoring seen here; (d) same instrument peels and rolls the Descemet’s membrane out

through paracentesis (as seen in the image); (e) checking complete 8.5 mm removal of Descemets

by unfolding on top of cornea; (f) inserting donor cornea; (g) air bubble to inflate AC; (h) air

bubble decreased with BSS exchange and suture less incision covered by conjunctiva



13



Targeting Emmetropia in Endothelial Keratoplasty



209



Fig. 13.3 A case of DSAEK surgery was referred with anterior corneal irregularity and scarring.

Amniotic membrane resurfacing following lamellar keratectomy resulted in a clear cornea



portion of the posterior corneal stroma, the dysfunctional corneal endothelial layer,

as well as the basement membrane, Descemet’s membrane, which the endothelial

cells are attached to [6, 7].



13.3



DSAEK



DSAEK is practically similar to DSEK, except for the use of a machine to automatically address the cornea. DSEK and DSAEK involve a thicker corneal transplant

compared to the ones used during Descemet’s membrane endothelial keratoplasty

(DMEK) [6] (Figs. 13.3 and 13.4).



13.4



DMEK



Many technical modifications and improvements are flourishing DMEK’s emergence as DSEK/DSAEK’s contender. DMEK is currently in the works of becoming

the favored corneal endothelial transplant technique. DMEK, contrary to DSEK/

DSAEK, only strips the Descemet’s membrane (DM) with the endothelial cells

resulting in the need for a thinner and more fragile donor graft [3]. One of the drawbacks eye surgeons found in DMEK was the handling and insertion of the delicate

donor graft. Because the graft is so thin and frail, surgeons must handle it with caution in order to keep from damaging the endothelium cells. Compared to DSEK/

DSAEK, inserting the donor graft into the eye is found to be challenging because of

the delicacy of the graft [6, 8]. Surgeons must be able to unroll the donor graft once

inside the chamber of the eye, determine which side contains the DM and endothelium cells, and perfectly position the graft so that it is centered in the eye without

any wrinkles [6, 8]. The visual outcomes and anatomical restoration are anecdotally

superior though with this technique (Fig. 13.5).



210



A.C. Gulani



Fig. 13.4 A case of bubble trouble. This patient rubbed his eye and next day postop we found the

bubble in the interface between the recipient and donor cornea. The air bubble was manipulated

with a 26-gauge needle and found its position back under the donor cornea to allow the graft to

appose to the recipient



Fig. 13.5 A case of

DMEK with lens implant;

straight to emmetropia



13



Targeting Emmetropia in Endothelial Keratoplasty



211



Fig. 13.6 The PDEK

bubble (Courtesy,

Dr. Soosan Jacob,

Dr. Agarwal’s Eye

Hospital, Chennai, India)



13.5



PDEK



In recent times, Dr. Harminder Singh Dua made a contributing discovering of a

previously undetected layer of the cornea [9, 10]. This thin, yet tough layer was later

named after the discoverer as Dua’s layer. Dua’s layer lies between the corneal

stroma and Descemet’s membrane. The tough characteristic of Dua’s layer is due to

the fibrous tissue that makes up this layer. Because the layer is tougher, it is easier

to manipulate and reduces the chances of collateral damage to the cornea. The discovery of this new corneal layer has led to the innovation of a new endothelial keratoplasty technique, pre-Descemet’s membrane endothelial keratoplasty (PDEK) by

Agarwal et al. [9, 10]. Unlike DMEK, which uses a thin, fragile donor graft, PDEK

utilizes an extra layer, Dua’s layer, in the graft, which permits surgeons more freedom with handling and inserting the graft in the eye without struggle. Also, the

donor graft used for PDEK can be obtained from donors of any age, preferably

younger donors. Earlier corneal grafts were obtained from donors aged 50 and over

[9, 10]. The tougher Dua’s layer also aids the surgeon to perform the EK with more

liberty and ease, compared to other modalities of EK. PDEK procedure is similar to

DSEK and DMEK with slight variations to accommodate for the extra layer being

removed and replaced (Fig. 13.6).

With the surgical evolutionary escalation of the abovementioned modalities, endothelial keratoplasty has achieved a paradigm shift in corneal transplant surgery wherein

most of the Corneoplastique™ principles [11–13] are already being followed.

Add to this an unrelenting mindset of concluding with improved vision using

refractive surgery principles and the bar is now raised from the surgical evolution of

endothelial keratoplasty to heightened visual outcomes.

The entire thought process of raising the bar on endothelial keratoplasty to a

refractive outcome should be initiated and sustained at all levels of preoperative

planning, surgery, and follow-up.



212



13.6

13.6.1



A.C. Gulani



Gulani Refractive Descemet’s Endothelial Keratoplasty

(REFDEK) Classification

Preoperative



In patients with Fuchs’ dystrophy, I suggest earlier cataract surgery in order to

remove a softer lens (hence less phaco energy which good damage the already compromised endothelium). This could allow us to nearly neglect the existence of associated Fuchs’ dystrophy and plan for emmetropia by additionally providing premium

lens implant options which may not be the case with more advanced Fuchs’ dystrophy in the late future.



13.6.2



Intraoperative



Though endothelial keratoplasty is already an advancement on penetrating keratoplasty, we can further refine and elevate this surgery to being refractively neutral or

even corrective using well planned steps during surgery itself.

A. The main incision could be made posterior to the limbus or a frown scleral incision that not only is self-sealing but also astigmatic ally neutral.

B. Minimal manipulation of tissues with good alignment and intrinsic care to prevent wrinkles in the donor cornea or edge discrepancy between donor

recipients.

C. The drainage incisions made on the recipient cornea anteriorly could be performed on the steep axis (as predetermined by preoperative topography and

refraction) acting like mini limbal relaxing incisions to not only help drain the

fluid between the donor and recipient graft interface but also correct coexistent

astigmatism.

D. If the patient is pseudophakic, maintain the stability of the anterior chamber and

prevent dislodgment or decentration of the lens implant and also check to make

sure it is still in the capsular bag nicely secure to prevent any refractive shift.

E. Do remember the Barraquerine principle of lamellar corneal surgery wherein

the addition of donor graft will move a refractive status to a relatively hyperopic

direction (this principal is also important when doing a combined case to make

sure to plan for a matching myopic outcome to compensate for this hyperopic

directive).

F. Intraocular lens implants including premium lens implants like toric lenses can

be confidently chosen once sufficient confidence is achieved with consistent

refractive outcomes of your own endothelial keratoplasty techniques.

G. Avoid sutures if you can (and thus avoid adding astigmatism) and hydrate to

close all incisions which were minimal to begin with. This can further be facilitated with recently approved wound sealants like ReSure®.

H. Facilitate rapid epithelial healing to determine refractive status (Figs. 13.7 and

13.8).



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