Causes of subnormal vision in patients following cataract surgery at a tertiary hospital in Kashmir

Abstract

Cataract surgery is aimed at restoring sight to near normal vision. This study, conducted at the Department of Ophthalmology, Government Medical College, Srinagar, is an attempt to determine the causes of subnormal vision in patients following cataract surgery at a tertiary hospital in Kashmir. One hundred patients who underwent cataract surgery with an unaided visual acuity of <6/9 at 16 weeks postoperatively were included in the study. Postoperative follow-up examinations were conducted until the 16th week. Intraoperative and postoperative complications were recorded to determine the cause of subnormal vision. Of 100 patients, 40 underwent extracapsular cataract extraction (ECCE), 30 underwent small incision cataract surgery (SICS) and 30 underwent phacoemulsification. Seventy-five percent of the patients who underwent ECCE had postoperative astigmatism with a mean astigmatism of 2.2 ± 0.81 diopters at 16 weeks, with the majority having with-the-rule astigmatism. In the SICS group, 17 (56.6 %) patients had a mean postoperative astigmatism of 0.75 ± 0.40 diopters, with the majority (82.3 %) having against-the-rule (ATR) astigmatism. In the phacoemulsification group, 13 (43.3 %) of the patients had a mean postoperative astigmatism of 0.48 ± 0.23 diopters with the majority having ATR astigmatism. Other causes of subnormal vision were pseudophakic ametropia, posterior capsular opacity and intraoperative complications like posterior capsular rent and vitreous loss. Postoperative astigmatism was the major cause of subnormal vision with greater astigmatism seen in the ECCE group. Therefore, procedures like smaller incision sutureless surgery and careful biometry are advocated to improve visual outcome and patient satisfaction.

Post operative visual outcomes after cataract surgery in a teaching hospital

“…Andleeb Ahangar, Aalia Rasool Sufi et al from Kashmir (2014) reported in their SICS group that 17 (56.6 %) patients had a mean postoperative astigmatism of 0.75 ± 0.40 diopters, with the majority having against-therule (ATR) astigmatism. 20 In patients not improving with spectacle correction, posterior capsular opacity (PCO) was found in 08% of our cases. Due to the affordability of patients, we used only non square edge IOLs in all our selected cases and hence this higher percentage.…”

Complications of manual small-incision cataract surgery

“…A large DD would require unscrolling followed by descemetopexy using 20% sulfur hexafluoride, 14% perfluoropropane, or suturing. [ 29 ] The reported rates of DD in MSICS vary from 0%,[ 30 ] 0.009% (3/31674),[ 7 ] 0.4% (4/1087),[ 31 ] 1.16% (8/689),[ 32 ] to 1.34% (7/522). [ 8 ]…”

“…Higher rates of iridodialysis were seen in MSICS in comparison to PE. [ 7 30 ] The reported rates of iridodialysis in MSICS are nil,[ 8 ] 0.03% (10/31674),[ 7 ] 0.5% (5/1087),[ 31 ] 0.73% (5/689),[ 32 ] and 6.6% (2/30). [ 30 ]…”

“…PCR commonly occurs during cortical clean-up, accidental pull on the anterior capsular tag, or capsular polishing. [ 30 36 ] In brunescent and black cataracts, the creation of a large capsulorhexis allowed minimum manipulation of the nucleus and brought down the PCR rates to 1.96% (2/102). [ 37 ]…”

“…In the comparison of PCR rates between PE and MSICS, variability in data was observed. The reported PCR rates of PE vs. MSICS being 3.5% (7/199) vs. 6%(12/201),[ 39 ] 4.3% (18/417) vs. 6.5% (29/445),[ 32 ] 13% (4/30) vs. 6.6% (2/30),[ 30 ] 0.5% (159/31674) vs. 0.65% (126/19337),[ 7 ] and 4.3% (22/507) vs. 6.9% (36/522). [ 8 ]…”