Influence of phacoemulsification and intraocular lens implantation on the course of diabetic retinopathy.

PURPOSE: To study the effect of phacoemulsification and posterior chamber intraocular lens implantation on the course of diabetic retinopathy using the nonoperated fellow eye as a control. SETTING: Departments of Ophthalmology, Diabetes Center, Tokyo Women's Medical University, and University of Tokyo School of Medicine, Tokyo, Japan. METHODS: One eye of 66 diabetic patients who preoperatively had a similar stage of retinopathy in both eyes or no retinopathy bilaterally had cataract surgery. The course of diabetic retinopathy was followed for 1 year postoperatively. Patients were placed into 1 of 2 groups: Group A, progression of retinopathy in the operated eye was attributable to the surgical invasion (i.e., there was progression of retinopathy only in the operated eye or more progression in the operated eye than in the nonoperated fellow eye); Group B, no deterioration of retinopathy bilaterally, comparable level of deterioration in both eyes, or greater progression in the nonoperated eye than in the operated eye. RESULTS: Surgery resulted in retinopathy progression in 16 patients (24.2%, Group A): 13 with unilateral deterioration and 3 with greater progression in the operated than in the nonoperated fellow eye. Of the remaining 50 patients (75.8%, Group B), 39 presented no significant progression in either eye, 8 had bilaterally comparable progression, and 3 showed progression in the nonoperated fellow eye only. Retinopathy worsened in the operated eye in 24 cases (36.3%); of these, changes in 16 patients were attributed to surgical influence. There was no significant difference between Groups A and B in age, diabetes mellitus duration, diabetes treatment method, and preoperative and postoperative hemoglobin A1c levels. The distribution of preoperative retinopathy stage significantly differed between groups, with more patients without retinopathy in Group A and more patients with advanced retinopathy in Group B. CONCLUSION: Factors such as age, diabetes mellitus duration, diabetes treatment method, and hemoglobin A1c level did not affect the progression of retinopathy; however, preoperative status of retinopathy may influence the susceptibility of the retinopathy to surgical invasion. A considerable proportion of eyes with aggravation of retinopathy would reflect the natural course of the disease, systemic factors, or both rather than the influence of cataract surgery.     

Comparison of the repair of potentially lethal damage after low- and high-LET radiation exposure,assessed from the kinetics and fidelity of chromosome rejoining in normal human fibroblasts

Potentially lethal damage (PLD) and its repair (PLDR) were studied in confluent human fibroblasts by analyzing the kinetics of chromosome break rejoining after X-ray or heavy-ion exposures. Cells were either held in the non-cycling G₀ phase of the cell cycle for 12 h, or forced to proliferate immediately after irradiation. Fusion premature chromosome condensation (PCC) was combined with fluorescence in situ hybridization (FISH) to study chromosomal aberrations in interphase. The culture condition had no impact on the rejoining kinetics of PCC breaks during the 12 h after X-ray or heavy-ion irradiation. However, 12 h after X-ray and silicon irradiation, cycling cells had more chromosome exchanges than non-cycling cells. After 6 Gy X-rays, the yield of exchanges in cycling cells was 2.8 times higher than that in non-cycling cells, and after 2 Gy of 55 keV/μm silicon ions the yield of exchanges in cycling cells was twice that of non-cycling cells. In contrast, after exposure to 2 Gy 200-keV/μm or 440-keV/μm iron ions the yield of exchanges was similar in non-cycling and cycling cells. Since the majority of repair in G₀/G₁ occurs via the non-homologous end joining process (NHEJ), increased PLDR in X-ray and silicon-ion irradiated cells may result from improved cell cycle-specific rejoining fidelity through the NHEJ pathway, which is not the case in high-LET iron-ion irradiated cells.     

Brain abscess secondary to the middle ear cholesteatoma: a report of two cases

We experienced two cases of brain abscess secondary to middle ear cholesteatoma. One, a 61-year-old woman, presented with left otalgia, appetite loss and nausea. The computed tomography obtained on admission revealed a middle ear cholesteatoma. The magnetic resonance image showed the presence of a brain abscess in the cerebellum. The brain abscess was drained and the cholesteatoma was removed using the canal down procedure under general anesthesia. Part of the cholesteatoma invaded the posterior cranial fossa was could not be removed from the otological surgical field. The patient has been under observation as an outpatient for 6 months already and no abnormal signs have been detected.

The other patient, a 55-year-old man, was admitted to our hospital for a detailed examination because he had right otalgia and progressive headache. The examination of spinal fluid obtained by lumbar puncture showed marked elevation of the white blood cells count. Computed tomography revealed a middle ear cholesteatoma. The magnetic resonance image obtained on admission showed an area of low-intensity encapsulated by an area of high-intensity in the right temporal lobe. The abscess was drained and the cholesteatoma was removed using the canal down procedure under general anesthesia. The patient has been under observation for 1 year already and has presented no signs of recurrence.