The impact of cataract surgery by phacoemulsification on eyes previously treated by laser photocoagulation for diabetic retinopathy

Poster Details

First Author: M.Ilavska SLOVAKIA

Co Author(s):                  

Abstract Details

Purpose:

The aim of the study was to evaluate the evolution of diabetic retinopathy (DR) after cataract surgery in eyes previously treated by photocoagulation (LK) for DR. The compensation of glycaemia (glycosylated haemoglobin HbA1c) and prevalence of attendant disease (hypertension, ischemic heart disease and alteration of lipid metabolisms) were evaluated. The impact of the amount of LK and interval LK – cataract surgery on the visual outcome of cataract surgery was evaluated

Setting:

40 eyes (40 patients) were evaluated. 10 (25%) eyes with DR without laser photocoagulation (LK). 30 (75%) eyes was previously treated by LK. The two criterions for evaluation of stabilisation were used – the best corrected visual acuity (BCVA) and the necessities the additional laser photocoagulation.

Methods:

The ophthalmologic examination (BCVA, intraocular pressure and biomicroscopic investigation of anterior segment and the retina) was done before surgery. Fluorescein angiography with use 10% natrium fluorescein intravenously was done 5 days before surgery. The Blood level of HBA1c was obtained at the day of cataract surgery. Information about general health status was collected from internal preoperative examination (hypertension, coronar ischemic disease (CID), and the alteration of metabolisms of lipids (AML). The cataract surgery was performed by phacoemulsification with implantation intraocular lens. BCVA and complete ophthalmologic examination, same as before surgery, was investigated at the 1th day after surgery, 5th week, 3th, 6th month after cataract surgery. The fluorescein angiography was made 5 weeks after cataract surgery again. The two criterions were used for assessment the stabilisation of diabetic retinopathy in this study: 1. The BCVA – - stabilisation -the change of BCVA ± 1 line of Snellen“s optotyps - worsening or improving - BCVA - the change more than 2 lines of Sellen’s optotyps 2. The photocoagulation - stabilisation - without additional LK after cataract surgery - worsening - additional LK guided by FAG Statistical analysis ANOVA – statistical analysis of variation and t-test for comparison of conformity for two middle values were used in this study.

Results:

100% of eyes without LK and 86.7% eyes with LK had BCVA improved at the first day after surgery. 31(77.5%) of eyes had the BCVA 0.5 or better. The mean level of HbA1c in group without LK was 7.09±1.21%; in the group after LK it was 7.361±1.635%. The mean level HbA1c in the group with stabilised BCVA was 7.136±0.462 % and duration of DM was 18.6±2.929 years. HbA1c in the group of deteriorated eyes was 7.857±2.231% and the duration of DM was 21.0±8.543 years. HbA1c in the group of stabilised eyes (without LK after surgery) was 6.714±0.994% and duration of DM was 17.857±8.969 years. HbA1c in the group, where additional LK was applied, was 7.558±0.690 % and the duration of DM was 19.538± 3.262 years. The difference in levels of HbA1c was statistically significant (p? 0.1). The incidence of hypertension was 80% of all groups. 62% of patients had ischemic heart disease and 35% of patients had alteration of lipid metabolism. 26 (86.66%) of eyes had the ended laser coagulation before cataract surgery. The number of spots before surgery in eyes with stabilised BCVA was 505.208±503.449, in the group of eyes with deteriorated BCVA it was 929.333±447.979 spots. (p?0.005).

Conclusions:

The results of the study confirm improvement of BCVA after cataract surgery by phacoemulsification for most of the patients (p?0,005). In the group of eyes with LK before cataract surgery was present increasing of hyperfluorescencie after cataract surgery (p? 0.005). The group of eyes with stabilised BCVA and those that needn“t additional LK after cataract surgery have better stabilisation of glycaemia levels and lower frequency of evaluated diseases. The eyes those needed additional laser coagulation was higher prevalence of evaluated disease. The lower number of laser spots was in stabilised eyes (p=0.063).The longer interval between LK and cataract surgery was in group with stabilised BCVA and with necessities of additional LK (p?0.005).The group of eyes with stabilised BCVA and those that needn“t additional LK after cataract surgery have better stabilisation of glycaemia levels and lower frequency of evaluated diseases. The eyes those needed additional laser coagulation was higher prevalence of evaluated disease. The lower number of laser spots was in stabilised eyes (p=0.063).The longer interval between LK and cataract surgery was in group with stabilised BCVA and with necessities of additional LK (p?0.005). FINANCIAL DISCLOSURE?: No