A retrospective, noncomparative case series documented a new and simple technique of glaucoma tube extension that may have several advantages over previously described techniques. The study looked at three patients (one adult and two pediatric cases) with glaucoma tube retraction managed by the “tube-in-tube” technique. The follow-up duration ranged from one month to three years.

Here’s a description of the technique, which uses minimal dissection: The anterior portion of the drainage tube is surgically exposed. The tube is then flushed with balanced salt solution. A new tube segment is obtained from either a glaucoma drainage device or a tube extender. Forceps are then inserted into one end of the tube with the tip closed. The tip is then opened to stretch the tube, creating adequate opening for a second tube insertion. To help withdraw the forceps, a non-toothed forceps may be required to maintain the two-tube segment fixation. The joined tube is stretched to check strength and flushed to ensure patency and a watertight interface. Depending on the surgical exposure and mobility of the pre-existing tube, either the original can be inserted into a stretched second tube or vice versa. The extended tube is then inserted into the anterior chamber using a 25-ga. tract to minimize leakage. Either an anterior chamber maintainer or viscoelastic is used to prevent intraoperative hypotony. The authors say that, depending on the state of the patient’s pre-existing scleral graft, the surgeon can place a new graft, but this is usually not required. The surgeon then closes Tenon’s and conjunctiva.

The surgeons say they noted adequate tube position and length in in all cases throughout the follow-up period. There was no tube migration. The intraocular pressures were significantly reduced and maintained in all cases, with no visual loss.

The study’s authors say that this new “tube-in-tube” glaucoma drainage-device tube extension technique explored in their report is safe and simple to perform and may yield advantages over previously reported techniques. It can be used in both the adult and pediatric glaucoma populations and isn’t limited to one type of drainage implant.

J Glaucoma 2017;26:93-95
Chiang M, Camuglia J, Khaw P.

Graft Detachment after Endothelial Keratoplasty
In a retrospective institutional cohort study, researchers from Forli, Italy, sought to identify risk factors associated with postoperative graft detachment after Descemet’s stripping automated endothelial keratoplasty.

The study group included consecutive eyes that underwent primary DSAEK between January 2005 and October 2015 at Villa Serena-Villa Igea private hospitals. The control group included all eyes that underwent primary DSAEK during the same time period and did not go on to develop graft detachment. The main outcome was whether or not postoperative graft detachment occurred.

The main indications for surgery were Fuchs’ endothelial dystrophy (525/1,212, 41 percent), pseudophakic bullous keratopathy (422/1,212, 35 percent) and a failed penetrating keratoplasty graft (190/1,212, 16 percent). Postoperative graft detachment occurred in 45 of 1,212 eyes (3.7 percent). Medically treated glaucoma, previous trabeculectomy, previous aqueous shunt procedure and failed PK were all associated with an increased risk of graft detachment in univariate analysis. No particular lens status at the time of graft implantation was significantly associated with graft detachment. The investigators conclude that previous penetrating keratoplasty and trabeculectomy are independent risk factors for postoperative graft detachment in primary DSAEK.

Cornea 2017;36:265-268
Nahum Y, Leon P, Mimouni M, Busin M.

Medicare Payments for Female vs. Male Ophthalmologists
Because of the growing number of women in ophthalmology, researchers conducted a retrospective review of the CMS database to look at the clinical activity of, and payments made to female ophthalmologists. The study specifically examined whether charges, as reflected in reimbursements from the Centers for Medicare & Medicaid Services to ophthalmologists, differ by sex and how any disparity relates to differences in clinical activity.

The study looked at the CMS database for payments to ophthalmologists from January 1, 2012 through December 31, 2013. After exclusion of J and Q codes, the total payments to and the number of charges by individual ophthalmologists were analyzed. The mean values were compared using a single-sample t-test, and the medians were compared by the nonparametric Wilcoxon rank sum test.

The study included 16,111 ophthalmologists (3,078 women, 19.1 percent; and 13,033 men, 80.9 percent) in 2012 and 16,179 ophthalmologists (3,206 women, 19.8 percent; and 12,973 men, 80.2 percent) in 2013. In 2012, the average female ophthalmologist collected $0.58 (95% CI, $0.53-$0.62; p<0.001) for every dollar collected by a male ophthalmologist; comparing the medians, women collected $0.56 (95% CI, $0.50-$0.61; p<0.001) for every dollar earned by men. Mean and median collections were similar in 2013 (p<0.001). The mean payment per charge was the same for men and women: $66 in 2012 and $64 in 2013. There was a strong association between collections and work products, with female ophthalmologists submitting fewer charges to Medicare in 2012 (median, 1,120 charges; difference -935; 95% CI, -1,024 to -846; p<0.001) and in 2013 (median, 1,141 charges; difference -937; 95% CI, -1,026 to -848; p<0.001) than male ophthalmologists. However, when corrected by comparing men and women with similar clinical activity, remuneration was still lower for women. In both years, women were underrepresented among ophthalmologists with the highest collections.

The authors conclude that remuneration from the CMS was disparate between male and female ophthalmologists in 2012 and 2013 primarily because of the submission of fewer charges by women. Further studies are necessary to explore root causes for this difference, with equity in opportunity and parity in clinical activity standing to benefit the specialty, the researchers say.

JAMA Ophthalmol 2017:135:205-213
Reddy A, Bounds G, Bakri S, Gordon L, et al.