Traditionally, PK has been commonly performed as the definitive treatment of a variety of corneal pathologies, such as bullous keratopathy, keratoconus, corneal degenerations and dystrophies
Nowadays, DALK has become increasingly popular since it provides better graft survival that is especially important for young KC patients. Also, it leaves the healthy endothelium of the recipient cornea intact that eliminates endothelial rejection, prevents postoperative endothelial loss and subsequent graft failure
This study was conducted on 41 eyes of 41 Egyptian patients having advanced keratoconus. 22 eyes peformed PK and 19 performed DALK. All surgeries were carried out between August 2017 and September 2018.
Preoperative evaluation
1. Complete history
2. UCVA & BCVA
3. Slit lamp biomicroscopy
4. SE and astigmatism in diopters.
5. Corneal topography with K readings, Q value and pachymetry
6. Fundus examination
7. Ocular ultrasonography, VEP & ERG.
8. Laboratory studies including fasting blood sugar, complete blood picture, liver and kidney function tests.
- In our study, there was no significant difference between both groups in the mean postoperative BCVA
- Similarly, Panda et al., in 1999, Shimazaki et al, in 2002, Kawashima et al., in 2006, Silva et al., in 2007, Krumeich et al., in 2008, Han et al., in 2009, Borderie et al., in 2012, Huang et al., in 2015, Donoso et al., in 2015 and Koçluk et al., in 2017 compared PK to DALK and they reported that comparison of DALK with PK for the best-spectacle corrected LogMAR visual acuity showed no significant differences
- There was better BCVA in the DALK group in one study (Trimarchi et al., 2001)
- Better BCVA in the PK group in 4 studies (Watson et al., 2004; Funnell et al., 2006; Ardjomand et al., 2007; Bahar et al., 2008).
- Regarding the refractive outcomes, in our study, there was no significant differences of mean K reading between both groups
- These results are similar to the results published by Cheng et al., in 2011 ,Reinhart et al., in 2011 and Sari et al. in 2012
- Regarding the central graft thickness following DALK and PK our study reported that there was no significant difference in the mean graft thickness between both groups
- Similar results were reported by Shimazaki et al., in 2002, Cohen et al. in 2010, Borderie et al., in 2012, Donoso et al., in 2015 and Koçluk et al., in 2017
- Regarding operative and postoperative complications, our work showed comparable results with the previous studies
Keratoconus
Patients and methods
Postoperative:
Results
Exclusion criteria
Inclusion criteria
- Topical antibiotics, steroids, lubricants and antiglaucoma medications
- Successive follow up visits arranged until removal of all stitches
- Complete ophthalmological examination was taken for all cases at 6 month and 12 months
1. Patients having advanced KC
2. Corneas with or without scarring
3. Hard contact lens fitting is impossible
4. Normal fundus
1. Patients with previous ophthalmic surgery.
2. Any concomitant ophthalmic disease eg.: cataract, retinal disorders or glaucoma.
3. Uncooperative patients for measuring the visual acuity and getting reliable corneal topography.
4. Patients who are fit for other modalities of treatment eg.: RGP cl or INTACS
Keratoconus is a corneal ectasia which leads to progressive stromal thinning and protrusion, resulting in irregular astigmatism, visual impairment, and decreased quality of life
During surgery, 6 cases out of 25 cases included in the DALK group had to be converted from DALK to PK due to macroperforation or rupture Descemet’s membrane. These cases were excluded from our study
Complications
Preoperative
Preopertive medications
Informed consent
PKP
Discussion
Complications
Aim of the work
DALK
To compare visual, surgical and topographic outcomes of deep anterior lamellar keratoplasty and penetrating keratoplasty for keratoconus patients.
Introduction
Conclusion
- DALK is a technically more difficult procedure that needs an experienced surgeon, and has a slower learning curve than PK
- However, It provides many advantages:
1. greater incidence of graft survival
2. elimination the risk of endothelial rejection
3. earlier discontinuation of steroids after surgery
4. avoids many of the intraocular complications as
glaucoma and intraocular infections
- There were no significant visual, refractive nor topographic differences between patients undergoing PK and DALK
Recommendations
- We recommend to do DALK in cases of advanced keratoconus with no scars if you have a well equipped operating theater and a trained surgeon to avoid intraocular complications and decrease the risk of endothelial rejection
- In cases of descemet’s membrane scars or intraoperative perforation, we recommend to convert to PK which have comparable results
Comparison between outcomes of deep anterior lamellar keratoplasty and penetrating keratoplasty in corneal disorders
By\ Mohamed Gamal, Msc
Banha University
2019