Type 2 big bubble deep anterior lamellar keratoplasty-serial anterior segment optical coherence tomography documentation showing resolution of bubble in the postoperative period.

A 26-year-old female underwent big bubble (BB) deep anterior lamellar keratoplasty (DALK) in the left eye for advanced keratoconus. During the procedure, a Type 2 bubble (T2B) with a clear margin and extending to periphery was noticed [Fig. 1]. As manipulating T2B carries a high risk of rupture of Descemet's membrane (DM), it was left in situ. An anterior chamber paracentesis was done. The procedure was completed by manual layer by layer dissection to get close to DM [Fig. 2]. Donor tissue was secured with interrupted 10-0 nylon sutures. Postoperative anterior segment optical coherence tomography (AS-OCT) scans were taken to document the absorption of T2B [Figs. 3–5]. The bubble got completely absorbed at the end of the first week. At the last follow-up of 4 months, the patient had an uncorrected visual acuity of 6/36 with a clear graft.

Figure 1

Intraoperative Type 2 bubble (arrow)

Figure 2

Dissection completed by manual layer by layer method

Figure 3

Postoperative day 1 anterior segment optical coherence tomography image with bubble in situ (arrow)

Figure 5

Postoperative day 7 anterior segment optical coherence tomography image showing complete resolution of Type 2 bubble with clear graft

Postoperative day 3 anterior segment optical coherence tomography image showing partial resolution of Type 2 bubble (arrow)

Discussion

Perforation of DM during BB DALK remains a common complication necessitating the conversion to penetrating keratoplasty (PKP). The rate of perforation reported ranged from 5% to 19% with conversion to PKP in 0% to 12% of eyes.[123] Types of BB (Type 1 and Type 2) formed during BB DALK can be differentiated based on their clinical appearance.[4] T2B is larger with a thinner wall and usually bursts on minimal pressure during cutting the stroma or even during suturing. In one case series, 12 out of the 14 eyes (86%) with T2B during DALK were converted to PKP because of large perforations.[5] Till now no definitive strategy has been recommended for the management of the T2B. Leaving the T2B in situ and completing DALK with manual layer by layer dissection of corneal stroma can be a safe option. The bubble seems to absorb within a week.

Conclusion

To the best of our knowledge, this is the first reported serial AS-OCT documentation showing absorption of T2B in the postoperative period.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.