Cornea in acromegalic patients as a possible target of growth hormone action

BACKGROUND

GH exerts its effects on many organs and the eye also seems to be a target site, although few authors have investigated the corneal thickness in patients with acromegaly.

AIM

To perform a detailed ophthalmological evaluation in acromegalic patients, in relation to disease activity.

MATERIAL AND METHODS

Twenty-eight acromegalic patients (11 males, 17 females) and 22 voluntary healthy subjects underwent complete metabolic and ophthalmological evaluation, including retinal thickness (RT), central corneal thickness (CCT), and intraocular pressure values (IOP).

RESULTS

Significantly greater CCT values were found in all acromegalic patients in comparison with controls (567 vs 528.5 μm; p<0.001), without concomitant greater corrected IOP. No difference was found for RT. Analyzing these data according to disease activity, uncontrolled patients showed greater CCT values (573.5 vs 559 μm; p=0.002) and corrected IOP (17.4 vs 16 mmHg; p=0.001) than the controlled ones. CCT also correlated with basal and nadir GH after oral glucose load levels, IGF-I levels, and duration of active disease.

CONCLUSIONS

Acromegaly is characterized by greater CCT values, supporting the hypothesis that GH excess may have stimulatory effects on the cornea as well as on other target organs. Higher GH levels, disease control status and duration of active disease seem to be the main causes of increased corneal thickness. We suggest a careful and detailed corneal evaluation in acromegalic patients to prevent the potential risk of increased IOP, in addition to the already-known complications.

Tonometers and infectious risk: myth or reality? Efficacy of different disinfection regimens on tonometer tips

PURPOSE

To evaluate the adequacy of common disinfection regimens for disposable tonometer tips and assess if disinfection of reusable prisms or the use of disposable tips is preferable.

METHODS

We used disposable tonometer tips, using the same material and tip diameter of standard Goldmann tonometer prism. Strains of Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilisand Candida albicanswere tested according to the European standard guidelines for disinfectants test. Antimicrobial effectiveness of the following disinfection practices has been assessed: dry wipe, Minuten wipes (Alpro), soaking in 3% hydrogen peroxide, 0.5% benzalkonium chloride, and 0.5% Pantasept for 1, 5, and 15 min. All tests have been performed three times and all conditions tested in duplicate.

RESULTS

Dry wiping and 1 min soak in 3% hydrogen peroxide were ineffective on all microrganisms. Minuten wipes, 1 min soak in 0.5% benzalkonium chloride or 3% hydrogen peroxide were ineffective on B. subtilis. 0.5% Pantasept soak was effective in 1 min for all microrganisms tested, whereas 3% hydrogen peroxide and 0.5% benzalkonium chloride soaks were effective when performed for at least 5 min. B. subtiliswas the most resistant organism to disinfectant regimes at 1 min time.

CONCLUSIONS

Results of our study demonstrate a relative disinfection efficacy for the different evaluated regimens, provided that correct exposure times are adopted for the chosen disinfectants, a condition difficult to ensure in a busy clinic setting. We conclude that disposable prism tonometry provides a safe alternative to Goldmann tonometry.

Temporal versus superior approach phacoemulsification: short-term postoperative astigmatism

PURPOSE

To compare short-term clinical, postoperative astigmatism, and uncorrected visual acuity results 2 months after no-stitch phacoemulsification using a temporal clear corneal approach and poly(methyl methacrylate) (PMMA) intraocular lens (IOL) implantation through a 5.2 mm incision with those after no-stitch superior corneoscleral phacoemulsification.

SETTING

University Eye Clinic of Palermo, Italy.

METHODS

This prospective clinical trial comprised 80 patients with senile cataract who were randomly assigned to have phacoemulsification using a temporal approach or a superior approach. Surgically induced astigmatism (SIA) was calculated using Naeser's polar value method for determining with-the-rule (WTR) or against-the-rule (ATR) change.

RESULTS

There was a highly significant between-group difference in SIA at each examination (P < .001; t-test) because of positive (WTR) SIA in the temporal approach group and negative (ATR) SIA in the superior approach group. No other significant differences between groups were found (P < .05, t-test). More patients in the temporal group had an uncorrected visual acuity of 20/25 or better 2 weeks postoperatively, although the difference between groups was not statistically significant (P = .562; chi-square).

CONCLUSION

Phacoemulsification using a no-stitch, temporal, 5.2 mm clear corneal incision produced results comparable to those using a corneoscleral superior approach. A longer study of a larger series should be done to confirm the findings.