At Press Time

IFIS Awareness Improved Outcomes

After April 2005 warning, surgeons could combat IFIS.

■ A study of a large number of cataract surgery patients who had their procedures at the Veterans Affairs New York Harbor Healthcare System between 2000 and 2010 included two large cohorts of patients. One group took alpha receptor agonists (such as Flomax) — and then had their surgery — prior to the identification of intraoperative floppy iris syndrome (IFIS) in mid-2005. Another large cohort took alpha receptor agonists but had their procedure after warnings about IFIS were widely disseminated.

The study sought to determine if outcomes for these resident-performed procedures improved once the surgeons were aware of the link between alpha receptor agonists and IFIS.

Researchers from the VA Medical Center and Columbia University found that being able to identify those patients who had taken alpha receptor agonists prior to surgery and being aware of the potential for IFIS did improve overall outcomes. The results showed that vitreous loss was 11.6% in the cohort operated on prior to May 1, 2005, and only 3.5% in the group operated on after May 1, 2005. The probability of achieving a BCVA of 20/40 or better in the postoperative period was 82.7% (178/215) in the earlier group vs. 88.1% (201/228) in the later group.

The researchers concluded “we believe that the improved outcomes are a result of heightened awareness of intraoperative floppy iris syndrome, implementation of IFIS prophylaxis techniques including preoperative atropine, intracameral epinephrine, the use of iris stabilization devices (such as iris hooks and Malyugin rings) and improved phacoemulsification techniques. The description of IFIS and implementation of prophylactic measures have resulted in improved outcomes in resident performed phacoemulsification in patients exposed to alpha receptor blockers.”

IFIS is characterized by iris billowing, prolapse to phaco and side port incisions, and progressive miosis during phaco.

IFIS was first identified by the highly respected cataract surgeons Drs. David F. Chang and John Campbell in an article published in the Journal of Cataract and Refractive Surgery in April 2005.

The “Myth” of Thin DSAEK Grafts

Thicker grafts produced similar visual outcomes.

■ A large study led by the highly respected corneal transplant pioneer Mark A. Terry, MD, of the Devers Eye Institute, Portland, Ore., goes a long way to debunk the somewhat widespread belief that “thin” and “ultra-thin” DSAEK grafts produce superior visual outcomes.

The researchers' goal in conducting the study of 356 eyes was to determine if preoperative graft thickness influences visual results after DSAEK. This was the largest study of this issue ever reported and was presented at the recent ARVO meeting.

The researchers compiled data on DSAEK patients with Fuchs' dystrophy and no ocular comorbidities that would limit visual acuity, (retinal pathology, advanced glaucoma, epithelial irregularities, capsule opacities). Correlation analysis of preoperative graft thickness — measured by OCT — and BCVA at six months was performed. The thickness of the transplanted donor tissue was also considered as a proportion of the total thickness of the donor cornea, and this “percent thickness” was also analyzed for correlation with six-month BCVA. In addition, BCVA from grafts thicker than 130 microns were compared to BCVA from grafts thinner than 130 microns.

Overall graft thickness ranged between 80 to 200 microns. Mean BCVA at six months postop was 20/28 (Range: 20/16 to 20/60). There was no significant correlation between graft thickness and postop visual acuity in the thickness range between 100 and 200 microns. Grafts thicker than 130 um (n=314) yielded mean BCVA of 20/28, with 21% 20/20 or better. Grafts thinner than 130 um (n=42) yielded mean BCVA of 20/26 with 24% 20/20 or better. There was no significant difference in mean vision or in percent with 20/20 or better between groups.

The researchers concluded that “excellent vision can be obtained with grafts 200 microns and thinner and no correlation can be found between preoperative graft thickness and visual results.” They also noted that “special requests from eye banks for thin or ultra-thin tissue may not be justified.”

Causes of DSAEK Failures

Patient age may play a role.

■ Researchers at the Kellogg Eye Center at the University of Michigan sought to determine whether pre-cut donor corneal tissue characteristics have an effect on DSAEK dislocation rates. Their findings were presented at the recent ARVO meeting.

Pre- and postoperative data were obtained retrospectively on consecutive DSAEK procedures performed from 2007 to 2011 by six surgeons at one institution using eye bank pre-cut donor corneas. Data collected included: time of death to tissue processing (D-to-P), time of tissue processing to surgery (P-to-S), preoperative endothelial cell density (ECD), change in pre- versus postcut endothelial cell density and preoperative graft thickness. The primary outcome measure was graft dislocation.

The researchers reported that 355 patients underwent DSAEK; 57% were women and 43% men. Indications for surgery were Fuchs' dystrophy(81%), pseudophakic bullous keratopathy (16%) or other diagnoses (3%). There were 64 dislocation events(18%).

The mean D-to-P, mean P-to-S, mean preoperative ECD, mean change in pre- to post-cut ECD, and mean preoperative graft thickness were not significantly different between the two groups. The only variable that was statistically significantly different between the two groups was recipient age; mean age 70.2 in the no-dislocation group and 73.6 in the dislocation group. The patients' gender, preoperative diagnosis, and visually limiting ocular comorbidities were not associated with the occurrence of dislocation. Graft dislocation did not impact the patients' logMAR visual acuity at 1 year or at the last visit.

The researchers concluded that “pre-cut donor cornea tissue characteristics did not have a significant effect on dislocation rates after DSAEK. Older recipients were more likely to experience graft dislocation.” The likelihood of dislocation may be more affected by differences in recipient characteristics or surgical technique, rather than donor corneal tissue characteristics.

Problems in Aniridic Eyes

Survey reveals multiple issues.

■ A survey conducted by ophthalmologists at the University of Virginia and presented at the recent ARVO meeting sought to determine the extent of corneal problems in aniridic eyes and how they were treated. Aniridia is a panocular disorder that can manifest with multiple problems, including glaucoma, foveal and optic nerve hypoplasia, visual disturbance and aniridia-associated keratopathy.

This study was a retrospective review of survey data collected in the Aniridia Foundation International registry. Subjects were asked about corneal pannus or scarring, age of onset, corneal surgical intervention, cataract and dry eyes. The cumulative proportion of subjects with corneal disease and cataract versus time was determined.

One hundred and three subjects responded to the survey. Of these, 43.7% had corneal pannus or scarring, while 45% did not and others were unsure. Of those with scarring, the average age at diagnosis was 20 years old, with a standard deviation of 12.2 years. Of the total of 103 individuals, 15.5% and 12.9% had keratolimbal allograft (KLAL) and penetrating keratoplasty (PK), respectively. Of those who received both PK and KLAL, 1.9% had PK prior to KLAL, and 6.8% reported PK after KLAL. Of the total subjects, 63.3% reported cataracts with an average age of 9.4 years at time of diagnosis. Dry eyes were reported in 56 of 102 (55%) subjects.

The researchers concluded that corneal disease is common in aniridia, with an average onset in young adulthood. Subjects with aniridia also had high prevalence of cataract and dry eyes.