All About Cataracts

Though people who are highly nearsighted have a greater risk of a developing a detached retina than the general population, cataract surgery doesn’t add to that risk.

That’s the finding of a large-scale study presented at the World Ophthalmology Congress held last month in Berlin.

Irmingard Neuhann, MD, who practices at Tuebingen University Eye Hospital in Germany, reported the results of a retrospective study of 1,519 consecutive patients with high myopia that underwent modern phacoemulsification cataract surgery. The surgery was performed on a total of 2,356 eyes that had an axial length greater than 27 millimeters.

Axial length is the distance between the front surface of the eye (cornea) and the back of the eye (retina), usually measured in millimeters (mm).

A normal adult eye typically has an axial length of approximately 24 mm. Eyes with axial length greater than 24 mm usually are nearsighted, and each additional millimeter corresponds to approximately -2.50 diopter (D) of myopia. Therefore, an axial length greater than 27 mm typically corresponds to myopia of -7.50 D or more.

The incidence of retinal detachment following cataract surgery among the eyes in the study was approximately 2 percent, according to Dr. Neuhann. The patients were followed for a period of 2 years.

Though this rate is higher than the rate of detached retina among the general population, no large study has ever demonstrated that this rate is different than that of spontaneous retinal detachment in nearsighted individuals with eyes of comparable axial length, she said.

High myopia associated with increased axial length of the eye is believed to be a risk factor for retinal detachment because, as the eye elongates during development, the peripheral retina becomes thinner and more fragile in these longer-than-normal eyes.

[Resource: Cataract surgery not a risk factor for retinal detachment in highly myopic eyes, study says. Published online June 8, 2010 on Ocular Surgery News website.]

Eye safety is essential to protect your eye as it heals after cataract surgery. Typically, your cataract surgeon will give you a large pair of sunglasses after your cataract operation to reduce your sensitivity to light and shield your eye so you don’t inadvertently rub or bump your eye as it is healing.

Clifford W. Brooks III, MD, warns, however, that post-cataract surgery sunglasses are not true safety glasses and should not be worn in high risk situations that warrant a higher degree of eye protection. Dr. Brooks is an ophthalmologist at Wilford Hall Medical Center, Lackland Air Force Base, Texas.

In this month’s issue of Journal of Cataract & Refractive Surgery, Dr. Brooks and colleagues report the case of a male cataract surgery patient who ruptured his eyeball 3 months after surgery in a fall while playing tennis. The patient was wearing the protective sunglasses given to him after cataract surgery, and damage to the sunglasses during the fall is the suspected cause of the severe eye injury.

Dr. Brooks and his colleagues warned that the large sunglasses given to patients after cataract surgery are not designed for activities that pose a risk of significant impact or injury to the eye.

The authors also said patients should be counseled to use protective sports eyewear or other safety eyewear specifically designed and approved for the sport or activity they participate in.

SOURCE:  Globe rupture with post cataract-surgery safety sunglasses. Journal of Cataract & Refractive Surgery. July 2010.

Statin medications — such as Zocor, Lipitor, Lescol, Pravachol and Crestor — used to lower cholesterol and prevent cardiovascular disease may have a side effect of increasing the risk of cataracts.

That’s the finding of a large study of adult men and women published recently in British Medical Journal. Researchers studied more than 2 million patients at 368 general practices in England and Wales. All patients were between the ages of 30 and 84, and 225,922 (10.7 percent) were new users of statins.

The objective of the study was to quantify unintended effects of the use of statin medications, according to type, dose and duration of use.

The researchers found that each statin studied was associated with an increased risk of cataract in both men and women (apart from Leschol in men due to the small number of men in the study taking this medication).

The mean increased risk of cataract formation ranged from from 25 percent to 56 percent among male and female patients being treated with Zocor, Lipitor, Pravachol and Crestor.

A direct comparison test showed no significant difference between the effects of individual statins in men or in women, and there was no evidence of greater risk of cataract with higher doses compared with lower doses.

Risk of cataract was significantly increased within one year of starting statin treatment, persisted during treatment, and returned to normal within the first year after stopping treatment.

The results of this study suggest patients taken statins should be proactively monitored for cataract formation with routine eye exams by an optometrist or ophthalmologist.

The outcomes of this study contradict results of a previous Israeli study that found statins may reduce cataract risk among men and women age 45 to 54.

SOURCE:  Unintended effects of statins in men and women in England and Wales: population based cohort study using the QResearch database. British Medical Journal (BMJ). May 20, 2010.

Use of sun-sensitizing medications appears to interact with exposure to the sun’s UV rays and the two factors combine to significantly increase the risk of developing cataracts.

That’s the finding of a long-term retrospective study conducted by researchers at the University of Wisconsin School of Medicine and Public Health.

The researchers examined the relationship between the use of sun-sensitizing medications — including commonly prescribed anti-depressant, antibiotic and anti-inflammatory medicines — and the occurrence of age-related cataract among a population of more than 2,000 Wisconsin residents over a 15-year period.

Sun exposure was estimated from the residential history of adults in the community of Beaver Dam, Wisconsin. Medication history was reported at each examination, and cataract presence was determined by photographs of the lens inside the eye.

When considered separately, sun exposure and the use of sun-sensitizing medications did not appear to increase the risk of cataracts, compared with an age- and sex-matched control population. However, the combination of increased sun exposure and the use of sun-sensitizing medications resulted in a statistically significant increase in the risk of a specific type of age-related cataract called a cortical cataract.

Use of hats with brims or use of sunglasses for at least half the time spent outdoors did not appear to decrease the added risk of cataracts among the study group.

(The study authors noted, however, that data regarding use of hats and sunglasses were obtained from only about half of the study population, and that they could not assess the effect of this association on the entire population.)

The researchers said additional study of other populations is needed to confirm the finding of the study, and that if the finding is confirmed, it may have important implications for future medication use.

SOURCE:  Selected sun-sensitizing medications and incident cataract. Archives of Ophthalmology. Published online June 14, 2010.