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Big Bubble Technique in Anterior Lamellar Keratoplasty
letters Big Bubble Technique in Anterior Lamellar Keratoplasty
W
e admire the effort of Anwar and Teichmann in their recent paper on a new technique to bare Descemet’s membrane in anterior lamellar keratoplasty.1 The technique facilitates separation of the corneal layers and will no doubt enable smoother and easier lamellar separation in places in which corneal surgeons do not have access to sophisticated tools such as microkeratomes and lasers. Although lamellar keratoplasty was introduced to the field of corneal surgery 150 years ago, it has not been used by everyone for various reasons. Besides its time-consuming nature, suboptimal visual outcome from interface opacity is blamed for its decreasing popularity. As irregular lamellar separation is a major factors in interface opacification, efforts have been made to achieve a smooth and regular recipient bed. This is greatly facilitated by lamellar separation. In 1974, Anwar tried to modify the technique of dissection. Further studies appeared subsequently. These include air dissection by Archila3 and Price,4 viscodissection by Manche and coauthors5 and Melles and coauthors,6 and hydrodissection by Amayem and Anwar.7 In 2000, we compared air, viscoelastic, and hydrodissection for the same and found that the lamellar hydration technique offered better results in surgical speed without untoward effects.8 Being pioneers in the field of lamellar dissection, we could compare the hydrotechnique with the “big bubble” technique. To conclude, we believe the technique has a good future as far as complications are concerned but it appears to be a time-consuming proposition. We therefore would like to know about its indications, the time required to complete the procedure, and the visual outcome in a randomized prospective study. Finally, we would like to express our sincere gratitude to the authors for bringing this neglected but important issue to the notice of ophthalmologists and suggesting a new technique. ANITA PANDA, MD, NAMS, FICS, MRC(OPHTH) MAYANK S. PANGTEY, MD PARUL SONY, MD SUDERSHAN KHOKHAR, MD New Delhi, India © 2002 ASCRS and ESCRS Published by Elsevier Science Inc.
References 1. Anwar M, Teichmann KD. Big bubble technique to bare Descement’s membrane in anterior lamellar keratoplasty. J Cataract Refract Surg 2002; 28:398 –403 2. Anwar M. Technique in lamellar keratoplasty. Trans Ophthalmol Soc UK 1974; 94:163–171 3. Archila EA. Deep lamellar keratoplasty dissection of the host tissue with intrastromal air injection. Cornea 1984; 3:217–218 4. Price FW Jr. Air lamellar keratoplasty. Refract Corneal Surg 1989; 5:240 –243 5. Manche EE, Holland GN, Maloney RK. Deep lamellar keratoplasty using viscoelastic dissection. Arch Ophthalmol 1999; 117:1561–1565 6. Melles GRJ, Remeijer L, Geerards AJM, Beekhuis WH. A quick surgical technique for deep anterior lamellar keratoplasty using viscodissection. Cornea 2000; 19:427–432 7. Amayem AF, Anwar M. Fluid lamellar keratoplasty in keratoconus. Ophthalmology 2000; 107:76 –79 8. Panda A, Singh R. Intralamellar dissection techniques in lamellar keratoplasty. Cornea 2000; 19:22–25
Reply: We welcome the letter by Panda and coauthors regarding different methods of achieving a smooth lamellar bed. The smoothest stromal lamellar bed can probably be achieved with a microkeratome or a femtosecond laser. Descemet’s membrane (DM), however, provides an extremely smooth bed when all the stroma has been removed. If this is followed by inserting and suturing a full-thickness corneal donor button (donor endothelium and Descemet’s peeled off without disturbing the stromal fiber architecture), there is no stroma-to-stroma interface. At present, Descemet’s membrane can only be laid bare by manual techniques; although the excimer laser could conceivably also perform this task, the risk of damaging the endothelium is too high. Conventional air dissection results in myriad tiny air bubbles between the stromal layers and frequently also between DM and deep stroma. The aim of our method is to achieve complete separation of DM from the deepest stroma, over the whole of the central cornea, by means of a relatively large amount of air in the shape of a single big bubble. In his only successful case of DM-baring (1 of 10 attempted cases), Price1 mentioned a “pocket of air” between DM and the posterior stroma—probably the first description of what we have named a “big bubble.” Morris and coauthors2 also noticed air cleavage in this plane. However, none of these authors developed a technique for achieving the explosive detachment of DM from posterior stroma consistently. We have several years’ experience with hydrodissection (hydrodelamination) as described by Sugita and Kondo,3 and we still use this valuable technique, as we have reported.4 Hydrodissection remains an important technique and should
W
e admire the effort of Anwar and Teichmann in their recent paper on a new technique to bare Descemet’s membrane in anterior lamellar keratoplasty.1 The technique facilitates separation of the corneal layers and will no doubt enable smoother and easier lamellar separation in places in which corneal surgeons do not have access to sophisticated tools such as microkeratomes and lasers. Although lamellar keratoplasty was introduced to the field of corneal surgery 150 years ago, it has not been used by everyone for various reasons. Besides its time-consuming nature, suboptimal visual outcome from interface opacity is blamed for its decreasing popularity. As irregular lamellar separation is a major factors in interface opacification, efforts have been made to achieve a smooth and regular recipient bed. This is greatly facilitated by lamellar separation. In 1974, Anwar tried to modify the technique of dissection. Further studies appeared subsequently. These include air dissection by Archila3 and Price,4 viscodissection by Manche and coauthors5 and Melles and coauthors,6 and hydrodissection by Amayem and Anwar.7 In 2000, we compared air, viscoelastic, and hydrodissection for the same and found that the lamellar hydration technique offered better results in surgical speed without untoward effects.8 Being pioneers in the field of lamellar dissection, we could compare the hydrotechnique with the “big bubble” technique. To conclude, we believe the technique has a good future as far as complications are concerned but it appears to be a time-consuming proposition. We therefore would like to know about its indications, the time required to complete the procedure, and the visual outcome in a randomized prospective study. Finally, we would like to express our sincere gratitude to the authors for bringing this neglected but important issue to the notice of ophthalmologists and suggesting a new technique. ANITA PANDA, MD, NAMS, FICS, MRC(OPHTH) MAYANK S. PANGTEY, MD PARUL SONY, MD SUDERSHAN KHOKHAR, MD New Delhi, India © 2002 ASCRS and ESCRS Published by Elsevier Science Inc.
References 1. Anwar M, Teichmann KD. Big bubble technique to bare Descement’s membrane in anterior lamellar keratoplasty. J Cataract Refract Surg 2002; 28:398 –403 2. Anwar M. Technique in lamellar keratoplasty. Trans Ophthalmol Soc UK 1974; 94:163–171 3. Archila EA. Deep lamellar keratoplasty dissection of the host tissue with intrastromal air injection. Cornea 1984; 3:217–218 4. Price FW Jr. Air lamellar keratoplasty. Refract Corneal Surg 1989; 5:240 –243 5. Manche EE, Holland GN, Maloney RK. Deep lamellar keratoplasty using viscoelastic dissection. Arch Ophthalmol 1999; 117:1561–1565 6. Melles GRJ, Remeijer L, Geerards AJM, Beekhuis WH. A quick surgical technique for deep anterior lamellar keratoplasty using viscodissection. Cornea 2000; 19:427–432 7. Amayem AF, Anwar M. Fluid lamellar keratoplasty in keratoconus. Ophthalmology 2000; 107:76 –79 8. Panda A, Singh R. Intralamellar dissection techniques in lamellar keratoplasty. Cornea 2000; 19:22–25
Reply: We welcome the letter by Panda and coauthors regarding different methods of achieving a smooth lamellar bed. The smoothest stromal lamellar bed can probably be achieved with a microkeratome or a femtosecond laser. Descemet’s membrane (DM), however, provides an extremely smooth bed when all the stroma has been removed. If this is followed by inserting and suturing a full-thickness corneal donor button (donor endothelium and Descemet’s peeled off without disturbing the stromal fiber architecture), there is no stroma-to-stroma interface. At present, Descemet’s membrane can only be laid bare by manual techniques; although the excimer laser could conceivably also perform this task, the risk of damaging the endothelium is too high. Conventional air dissection results in myriad tiny air bubbles between the stromal layers and frequently also between DM and deep stroma. The aim of our method is to achieve complete separation of DM from the deepest stroma, over the whole of the central cornea, by means of a relatively large amount of air in the shape of a single big bubble. In his only successful case of DM-baring (1 of 10 attempted cases), Price1 mentioned a “pocket of air” between DM and the posterior stroma—probably the first description of what we have named a “big bubble.” Morris and coauthors2 also noticed air cleavage in this plane. However, none of these authors developed a technique for achieving the explosive detachment of DM from posterior stroma consistently. We have several years’ experience with hydrodissection (hydrodelamination) as described by Sugita and Kondo,3 and we still use this valuable technique, as we have reported.4 Hydrodissection remains an important technique and should