Research Digest

Smoking and lens density.

Ophthalmologists in Turkey recently showed that smoking had a significant relationship with increased lens density. The study group submitted 60 men and women who had smoked 10 cigarettes per day for at least two years, as well as 60 age- and sex-matched controls, to lens densitometry examinations, dividing the lens into anterior, nuclear and posterior sections.

While the mean ages of the two groups were nearly identical, the mean lens density values for all three regions were greater in the smoking group than in the control group. However, only the difference in thickness for the anterior region was statistically significant.

The authors believe that their study demonstrates that smoking might contribute to the development of anterior cortical and subcapsular cataract development in young adults.

Autologous serum drops for dry eye disease (DED).

Ophthalmologists at the Kellogg Eye Center of the University of Michigan Medical Center in Ann Arbor recently tested an eyedrop consisting of 50% autologous serum, finding that the medication was safe and effective.

To test this serum eyedrop, the authors conducted a retrospective cohort study involving 123 eyes belonging to 63 patients with DED. The patients’ charts were reviewed for ocular surface evaluations, including Schirmer testing, fluorescein staining and Ocular Surface Disease Index (OSDI).

The findings revealed that fluorescein staining improved at six months and one year, and Schirmer test results improved at one and two years. In addition, the OSDI decreased at six months and one year. All improvements were statistically significant.

While acknowledging the limitations of a retrospective study, the authors suggest that 50% autologous serum eyedrops could offer an alternative for patients with DED, particularly those with recalcitrant disease.

Corneal dystrophy and genetics.

Scientists from Italy and Poland undertook a genetic study to determine the role of specific mutations in Polish patients with macular corneal dystrophy.

In 24 patients from Poland with diagnoses of macular corneal dystrophy, the authors performed slit-lamp examinations, confocal microscopy, and time- and spectral-domain OCT examinations. All the patients also were submitted to genetic studies to identify mutations in the carbohydrate sulfotransferase 6 (CHST6) gene.

The OCT and microscopic examinations revealed diffuse, reflective corneal deposits extending from the Bowman layer to Descemet’s membrane, showing phenotypic homogeneity. The results of the genetic analysis showed five different mutations in the CHST6 gene, demonstrating genotypic heterogeneity.

This study is significant because it is the first to report the identification of mutations in the CHST6 gene in patients with this type of corneal dystrophy. Nevertheless, the authors concede that not all of the cases of dystrophy they found could be explained solely by these mutations.

DARPin data.

The results have been published from the European phase 1/2 study of Allergan’s (Irvine, Calif.) MP0112, a designed ankyrin repeat protein (DARPin), in the treatment of wet AMD.

Thirty-two patients with wet AMD received a single intravitreal injection of MP0112, with the doses escalating from 0.04 to 3.6 mg. Safety, efficacy, pharmacokinetics and dose response were monitored for 16 weeks.

The maximum tolerated dose of MP0112 was 1.0 mg, due to a case of endophthalmitis occurring in the 2.0-mg cohort. Thirteen of the 32 patients experienced adverse events, 11 of which consisted of ocular inflammation, including seven mild and four moderate cases.

Nevertheless, VA scores remained stable or improved, and retinal thickness and leakage on fluorescein angiography both decreased with treatment. Patients receiving lower doses required rescue therapy in 40% of cases.

The authors believe that their data show a dose-dependent response for MP0112. They indicate that further trials will ensue with a newly purified product, likely in response to the single endophthalmitis case in the trial.

Treatment for birdshot retinochoroidopathy.

A small but long-term study has shown that fluocinolone acetonide intravitreal implants (Retisert, Bausch + Lomb, Rochester, N.Y.) help control the inflammation caused by birdshot retinochoroidopathy.

At baseline, 54.5% of the 11 patients had intraocular inflammation before surgery. After six months, 9.9% showed signs of inflammation; after three years, none had intraocular inflammation, according to the study authors. Active vasculitis also was gone at three years; at baseline, the percentage was 36.3%.

Importantly, at baseline, 54.5% of patients were taking immunomodulatory agents. By year 3, the percentage was 14.28%. However, all patients developed cataracts and more than half experienced increases in IOP.

I-CAN data.

Eyedrops consisting of aganirsen, an antisense oligonucleotide, demonstrated the ability to inhibit corneal neovascularization in patients with keratitis, according to the Europe-based Inhibition of CorneAl Neovascularization (I-CAN) study data published recently.

In this phase 3 study, 69 patients were treated with either aganirsen or placebo twice per day for 90 days. Follow-up continued for another 90 days. At 90 days, aganirsen significantly decreased the relative area of corneal neovascularization by 26.20%, with the effects persisting at 180 days.

Moreover, aganirsen reduced the need for corneal grafts; in addition, the oligonucleotide demonstrated the ability to lower the risk of graft rejection in patients with viral or traumatic keratitis. Side effects were actually less common in the aganirsen group. Investigators plan additional follow-up of the patients to confirm the findings over a longer term.

Macular dysfunction.

Diabetic patients who had no signs of diabetic macular edema still had central foveal thickness that, compared to healthy controls, was increased, according to Italian researchers.

The researchers tested 36 patients with type 1 and type 2 diabetes and with nonproliferative diabetic retinopathy and 28 healthy controls, using microperimetry and spectral-domain OCT, besides a complete eye examination. The mean central foveal thickness was 234.5±13.7 µm and 256.3±12.7 µm for patients with type 1 and type 2 diabetes, respectively; the researchers said difference in the central foveal thickness was statistically significant when compared with the control groups (P=.04 and P=.01, respectively).

As for mean retinal sensitivity, the researchers found that the type 1 and type 2 patients had, respectively, 18.9±0.5 dB and 17.7±0.4 dB, which they reported was statistically significant different as compared with the control groups (P<.0001 and P<.0001, respectively).