Two groups of international researchers recently published studies that may help cataract surgeons minimize com-plications.

A group composed of researchers from the New Zealand National Eye Center at the University of Auckland and the Greenlane Clinical Centre at the Auckland District Health Board say that cataract surgeons may be able to take certain measures preop to help minimize the recurrence of herpes zoster-related ocular disease.

In what the researchers deem the largest study to date examining the outcomes of cataract surgery in eyes with a history of herpes zoster keratitis and uveitis, the researchers retrospectively studied 57 cases (57 eyes of 57 patients) in which patients with herpes zoster-related keratitis and/or uveitis had cataract surgery in the affected eye.¹ Patients were included if they had clinical presentation of HZO with keratitis or anterior uveitis, or if they had anterior uveitis consistent with a viral picture that was confirmed to be varicella zoster virus on aqueous humor tap.

The median age at the time of HZO diagnosis was 71.4 years (range: 65.9 to 76.8), and 34 patients (59.6 percent) were men. Nine patients were immunosuppressed at the time of presentation, including two with Crohn’s disease, one with rheumatoid arthritis, two with chronic lymphocytic leukemia, two on low-dose prednisone for polymyalgia rheumatica and two with a solid organ transplant. No patients were HIV-positive. 

At presentation, the researchers say that 55 patients (96.5 percent) had a typical clinical presentation of HZO, with unilateral rash. Fifty-four patients were taking antivirals, and 48 of them (88.9 percent) received seven to 10 days of oral antiviral therapy. The median corrected distance visual acuity at presentation was 20/30 (range: 20/25 to 20/60). Thirty-seven patients (64.9 percent) had corneal disease at presentation, with pseudodendrites in 21 cases (36.8 percent) and disciform keratitis in 19 (33.3 percent). Forty-eight patients (84.2 percent) had anterior uveitis at presentaton. 

In terms of herpes recurrence preop, 38 patients (66.7 percent) had recurrent disease, with 28 (49.1 percent) having recurrent corneal disease and 25 having recurrent uveitis. The patients had a median of two recurrences before surgery, and the median time from the last recurrence to surgery was 1.2 years (range: 0.7 to 2.4 years). Twenty-two patients (38.6 percent) had surgery less than a year after their most recent flare-up, and three (5.3 percent) had surgery fewer than three months after the last recurrence. 

After the group’s cataract surgeries, the HZO recurred in 23 patients (40.4 percent), with recurrences in the first two years postop being the most common. Three patients developed band keratopathy after repeated inflammation, and one had a neurotrophic keratitis with a persistent epithelial defect. There was a severe recurrence of herpes keratitis with corneal melt in the eye of a Crohn’s-disease patient which ultimately required evisceration.

The study’s corresponding author, Rachael L. Niederer, MB ChB, PhD, FRANZCO, of the Department of Ophthalmology at Greenlane Clinical Centre, says a couple things stood out to her from the study’s findings. “Cataract surgery in subjects with previous HZO is complicated by corneal scars (43.9 percent), atrophic floppy iris (5.3 percent) and posterior synechiae (8.8 percent),” she says. “I was surprised that despite this more complex surgery, the early postoperative complications were low, with few subjects experiencing cystoid macular edema or prolonged postoperative inflammation. What really stood out from the study, was the very high rate of recurrence of zoster keratitis and/or uveitis over the first year following surgery, often with a reduction in vision to below preoperative levels.” Seven patients (12.3 percent) saw a decline in their 12-month CDVA compared to their preop level. A poor visual outcome was more common in patients with a central scar, and complications during the surgery didn’t correlate with decreased acuity afterward. 

At this point, the researchers can’t say for sure what it is about phaco that triggers a higher rate of HZO recurrence. “An increase in recurrence of herpes zoster and herpes simplex has been noticed by a few researchers following other surgery,” Dr. Niederer says. “The mechanisms are unclear, but could include local trauma, release of sequestered virus, or the stress of the surgery. Herpes simplex virus has previously been isolated from the lens in a patient with previous acute retinal necrosis, so it seems plausible that sequestered virus may exist in patients with herpes zoster. We have a further study under way to examine this link in more detail. There was no difference in the rate of recurrence following complicated cataract surgery (p=0.727).”

Dr. Niederer says surgeons can take steps to possibly decrease the risk of a postop flare-up. “Normally in subjects with uveitis, we advocate three months of disease quiescence prior to considering cataract surgery,” she says. “However, in the current study, the highest rates of recurrence of herpes zoster eye disease were seen in those with less than one year of quiescence. We therefore recommend a longer period of quiescence (ideally one year) where possible in those with herpes zoster. The role of antivirals in decreasing disease recurrence in zoster is currently unknown and we are eagerly awaiting the results of the Zoster Eye Disease Study (ZEDS) to provide more guidance on this. In our personal practice, we use three months of antiviral prophylaxis, starting on the day of surgery, for those with simple previous herpes zoster eye involvement, and one year of antiviral prophylaxis for those with recurrent episodes of inflammation.” 

Researchers in New Delhi, India, say that the timing of cataract surgery appears to be a key factor for patients with chorioretinal coloboma. 

In the largest case series of cataract surgery in patients with chorioretinal coloboma, the researchers reviewed the medical records of patients with chorioretinal coloboma who had cataract surgery between January 2016 and May 2018.² The study comprised 39 eyes of 38 patients. There were 14 women and 24 men, with a mean age of 36.74 ±15.24.

Preop, the mean best-corrected vision of the group was 1.83 logMAR (slightly worse than 20/800). Coloboma involving the macula was present in 46.5 percent of the cases. The cataracts were grade 2 in five cases (12.8 percent), grade 3 in seven (17.9 percent) and grade 4 in 17 cases (43.6 percent). 

Other morphologies in the study included six cortical cataracts, two total cataracts, one posterior subcapsular cataract and one congenital nuclear cataract. 

For the procedure itself, surgeons performed phaco in 22 eyes (56 percent), lens aspiration in five cases (12.8 percent), extracap in five cases, intracap in four eyes (10.3 percent), small-incision cataract surgery in two cases (6.7 percent) and pars plana lensectomy in one case (2.6 percent). 

Immediately postop, eyes with increased intraocular pressure were managed with glaucoma drops. Eleven cases had corneal edema, which resolved with conservative therapy in nine cases; the remaining two needed endothelial keratoplasty. At one year, data was available for 13 cases (14 eyes). The mean vision at that time was 1.51 ±0.58 logMAR (slightly better than 20/800).

Looking at the study’s results in relation to similar studies, the authors say that the patient age at the time of surgery likely dictates the type of surgery that’s performed. In one study composed of relatively young patients (mean age: 27.7), phaco was performed in all cases. In this study and another in which patients were older (mean age: 37.6), some cases required ECCE, ICCE or lensectomy through the pars plana, which might invite complications that wouldn’t be as likely to occur with phaco. The researchers also point out that the outcomes of surgery in younger patients were better; specifically the proportion of uneventful surgeries, IOL implantation rate and the rate of posterior capsule rupture were all better in the series with younger patients.

Praful Maharana, MD, one of the study’s authors, says some other factors may have impacted the suboptimal outcomes. “The macular involvement rate was significantly more in our series (45.2 percent),” he notes. “In fact, there was a marked difference in the baseline visual acuity of our cases compared to other studies reporting cataract surgery outcome in chorioretinal coloboma. This could have resulted in the suboptimal outcome. The second major cause could be the associated amblyopia. “Most of the cases of CRC have had some refractive error since the early part of their lives,” Dr. Maharana continues. “Due to poor access to health care or lack of knowledge on the part of the primary care physician, refractive error, especially irregular astigmatism, often goes uncorrected. This could lead to amblyopia and subsequent poor outcomes following cataract surgery.”

Dr. Maharana says the main thing he learned from the study was regarding surgical timing. “One should not delay cataract surgery in patients with chorioretinal coloboma,” he says. “In our area, the greatest difficulty in decision making is the unpredictable follow-up pattern of the patient after the surgery. Hence, most surgeons avoid cataract surgery while the patient has some reasonable vision. However, the result of our study suggests that the surgery should be done early.

“The standard practice of being prepared with capsular supporting devices such as CTR/Cionni, using capsulorhexis forceps for CCC, low and slow phacoemulsification, use of viscodispersive viscoelastics, and performing pupilloplasty at the end of surgery should be kept in mind. Careful follow-up is essential as the complication rate is high and the majority of patients requires laser delimitation in the postoperative period.”  

 

^{1. Lu L, McGhee C, Sims J, Niederer R. High rate of recurrence of herpes zoster-related ocular disease after phacoemulsification cataract surgery. J Cataract Refract Surg 2019;45:810-815.}

^{2. Sahay P, Maharana P, Mandal S, et al. Cataract surgery outcomes in eyes with chorioretinal coloboma. J Cataract Refract Surg 2019;45:630-638.}

 

Keratoconus’ Genetic Connection

New data adds some weight to the theory that keratoconus is driven, in part, by genetics. Researchers recently evaluated the tomographic and refractive characteristics of siblings of pediatric patients with keratoconus or the children of adults with keratoconus and found that the prevalence of keratoconus was high, warranting screening in this high-risk group.¹

This cross-sectional study evaluated 183 pediatric first-degree relatives of patients with keratoconus and included both eyes of all participants between the ages of six and 18. The participants underwent manifest refraction, slit-lamp exams and Scheimpflug tomography—the latter of which was evaluated by two masked cornea and refractive surgeons.

The researchers found the tomography data showed 17.5 percent participants had keratoconus, while 19.1 percent were labeled as having keratoconus by objective analysis. The team found that 11.5 percent to 15.5 percent of patients with keratoconus were younger than 11, with steepest anterior curvature and thinnest pachymetry values of 44.8 ±6.5D and 515.9 ±39.2 µm. The 18 percent between the ages of 12 and 15 with keratoconus had values of 47.34 ±3.4D and 496.1 ±37.9 µm, while the 25.5 percent of keratoconus patients between 16 and 18 had 49.7 ±6.1 D and 486.0 ±66.5 µm. They add that 37.5 percent of keratoconus patients were unilateral as evaluated by tomography alone.  

 

^{1. Awwad ST, Yehia M, Mehanna CJ, et al. Tomographic and refractive characteristics of pdiatric first-degree relatives of keratoconus patients. Am J Ophthalmol. June 10, 2019. [Epub ahead of print].}

 

AbbVie to Acquire Allergan

AbbVie and Allergan announced that the companies have entered into a definitive transaction agreement under which AbbVie will acquire Allergan in a cash and stock transaction for a transaction equity value of approximately $63 billion, based on the closing price of AbbVie’s common stock of $78.45 on June 24, 2019. In the official announcement of the acquisition, AbbVie describes the deal as, a “transformational transaction for both companies” that “achieves unique and complementary strategic objectives.”  REVIEW