Cutting Edge Glaucoma - Issue 2

CHILDHOOD GLAUCOMA SURGERY IN DEVELOPING COUNTRIES • 17  Khalil and Abdelhakim concluded that both primary trabeculotomy and CTT with MMC had similar outcomes, which could mean that trabeculotomy could be resorted to first [51]. The argument in favor of primary CTT in some ethnic populations is the higher incidence of successful IOP control with a single operative procedure, as has been reported from India and the Middle East (Fig. 2) [42, 49, 52]. In the largest Indian series of 624 eyes of 360 consecutive Indian children with PCG undergoing CTT without MMC, IOP control was achieved in 85% of children after 1 year, reducing to 58% after 6 years. Forty-two percent of patients achieved vision of ≥20/60 [52]. Furthermore, primary CTT is a promising surgical technique for the management of differ- ent forms of childhood glaucoma in the developing world. Although CCT offers the advantage of the dual mechanism of IOP control (trabeculotomy- trabeculectomy) and good long-term results have been reported by authors from India and various other parts of the developing world, there is always a search for the best surgical tech- nique that should be employed in the given patient. Recently 360° trabeculotomy has emerged as an attractive choice that can be performed with a blunted 6/0 Prolene suture or with the help of an illuminated microcatheter. Shi et al . retrospectively studied 43 consecutive cases of Chinese eyes with childhood glaucoma undergoing trabeculotomy performed using either an illuminated microcatheter or a rigid probe trabeculotome [53]. They found microcatheter-assisted circum- ferential trabeculotomy to be significantly more effective at 1 year and as safe as traditional tra- beculotomy with a rigid probe. Similarly, Shakrawal et al . from India performed a randomized clinical trial and concluded that in PCG, illuminated microcatheter-assisted circumferential tra- beculotomy performed better than conventional partial trabeculotomy at 1-year follow-up and resulted in significantly lower IOP measurements [54]. However, a steep learning curve and the 165 with probability of success falling from 83% at 6 months to 44% at 1 year, possibly due to severe disease at presentation, ra ial influences, and no use of antiscarring agent [ 44 ]. Elder reported poor long-term success (IOP ≤ 21 mmHg and no medication) in Palestinian Arab children with PCG undergoing goniotomy and trabeculotomy as compared to pri- mary trabeculectomy without antiscarring agents [ 45 ]. In a subsequent study by the same author comparing retr spective t abeculectomy data to prospectively collected CTT dat , bot without antiscarring agents, the cumulative chance of suc- cess for CTT was 93.5% compared to trabeculec- tomy, which was 72% after a 24-month follow-up [ 46 ]. For a similar follow-up in the same popula- tion, trabeculotomy had only a 51% cumulative chance of success. Mullaney et al. reported that CTT was superior to trabeculotomy or trabeculec- tomy alone; however, they did use MMC [ 47 ]. Whether p imary CTT is superior to trabecu- lotomy or trabeculectomy alone is a subject of considerable debate. In a small series of seven Arab Bedouin infants, Biender and Rothkoff found no difference between trabeculotomy and CTT in patients with PCG [ 48 ]. Dietlein et al. investigated retrospectively the outcome of tra- beculotomy, trabeculectomy, and combined pro- cedure as initial surgical treatment in PCG [ 49 ]. Although the c bine procedure seemed to have favorable outcome, the advantage of this procedure over trabeculotomy or trabeculectomy was not significant after 2 years when assessed by life table analysis. The authors concluded that the prognosis of primary ab externo glaucoma surgery in PCG seemed to be governed more by the individual course and severity of the disease than by mod ficati n of surgic l tech iques. In a retr spective, comparative study, Lawrence and Netland concluded that trabeculectomy and CTT with MMC were equally effective at lowering average IOP in children [ 50 ]. However, CTT was associated with greater long-term success. In a prospective comparative study conducted in Egypt, Khalil and Abdelhakim concluded that both primary trabeculotomy and CTT with MMC had si ilar outcomes, which could mean that ra- beculotomy could be resort d to first [ 51 ]. The argument in favor of primary CTT in some ethnic populations is the higher incidence of successful IOP control with a single operative procedure, as has been reported from India and the Middle East (Fig 11.2 ) [ 42 , 49 , 52 ]. In the largest Indian series of 624 eyes of 360 consecu- a b c d Fig. 11.2 ( a ) Preoperative appearance of the left eye in a 3-month-old child with primary congenital glaucoma who presented with acute corneal hydrops. ( b ) Two-week post- operative appearance of the left eye showing dramatic improvement of corneal edema. ( c ) Six-month postopera- tive appearance showing normal corneal clarity of the left eye. ( d ) Photomicrograph of the left cornea showing Haab striae ( arrows ) 11 Childhood Glaucoma Surgery in Developing Countries i . 2: ( a ) Preoperative appear nce of th l ft eye in a 3- onth-old child with pri ary congenital glaucoma who presented with acute corneal hydrops. ( b ) T o-week postoperative appearance of the left eye showing dramatic improvement of corneal edema. ( c ) Six-month postoperative appearance showing normal corneal clarity of the left eye. ( d ) Photomicrograph of the left cornea showing Haab striae ( arrows ) .